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Dustin

Orpheus Silex - worthwhile project?

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The Orpheus T/T without the arm bracket and mushroom,is the first manufactured series under that product name and is not the later 'Silex' model.Indeed it was the fact that the motion of the t/t assembly relative to an arm fitted to a common mounting board caused problems that led to the arrangement that was patented.I would think someone has added a Decal label to the chassis and since Hi Fi Exchange basically work on a commision/consignment basis I would be a little suspicious of the original seller.

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Hello all, whilst I'm not exactly new here I admit that I've been a minimalist poster.

I picked up an Orpheus Silex some time ago at the local auction (Hobart) and have been trying to squeeze it into my main system. ATM it's housed in a full size 21"' x 18" x 30" with matching speakers (which I won't be using) and until I can build a new plinth like that Thomas Schick one (:P) it will have to stay in isolation.

It came with Decca ffss tonearm and 2 early ffss carts and tonearm rest and lift, all in superb condition and I have to say that it's the most detailed sound I've heard in any TT. To be fair, all my other TTs are MOTL at best.

As I said, all in superb condition EXCEPT the foam/leather? suspension and the belt looks to be developing a slightly weak spot which I may cut and superglue.

It runs very quiet but is a little slow to come to speed and as someone else mentioned once it's there it's fine. I'll definately be following this thread in the hope that I can learn a bit more about this "under the radar" TT.

Cheers

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A bit of progress . .

Suspension systems:

Finally finished refurbishing the various suspension systems today. There are separate systems for the motor, motor mounting bracket, and the spider that supports the platter. There are ten bushes in all and these were made from the various Sorbothane stock I bought recently.

Quite a lot of the time was taken making the various sized hole punches (cutters) to be able to cut the Sorbothane sheet. These were used like scone cutters to fashion the various grommets. Sorbothane is a bit weird to work with . . a bit like trying to drill bluetak . . you can't. But in the end it seems to have worked quite well and does appear to absorb vibrations. I'll have to wait till there's a tonearm installed to be any more positive than that. If anything appears to be too stiff (or too soft), it can be modified easily enough.

Platter Spindle:

Measuring inside diameters can be a bit tricky and I wanted to get an idea of the play in the platter spindle so I machined up a dummy spindle shaft. It was made 2 thou oversize and it wouldn't go in the bearings. I figure that's enough to declare the spindle bearings OK. If 2 thou is OK for Garrard, it'll be OK for this one too.

Motor:

Took the motor apart to inspect and found the bearings to be quite good. No apparent wear on the shaft and there was lubricant still visible on the thrust ball, so I gave it a few drops of oil, blew out the dust and reassembled.

I then installed the motor into it's mounting bracket and then that, to the TT base, temporarily connected the wiring and fired it up. Brilliant . . the motor is essentially silent.

Next up is figuring out the absent spring that engages the idler wheel. I've no idea how strong (or weak) it's supposed to be . . nor exactly where it goes. :cool:

Ahhhh well . .

Edited by Dustin
speeling

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Sounds like a lot of (frustrating) fun Dustin. Great write up thus far and congrats on the progress!

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Hello VanArn,

It sounds like you're familiar with the history of the Orpheus TT's. Would you care to elaborate, please?

Hello all, whilst I'm not exactly new here I admit that I've been a minimalist poster.

I picked up an Orpheus Silex some time ago at the local auction (Hobart) and have been trying to squeeze it into my main system. ATM it's housed in a full size 21"' x 18" x 30" with matching speakers (which I won't be using) and until I can build a new plinth like that Thomas Schick one (:cool:) it will have to stay in isolation.

Hello sashmo,

Looks like you have good find there. Being a minimalist poster is absolutely fine . . but we still need pics! :cool:

Sounds like a lot of (frustrating) fun Dustin.

Thanks Bear . . yes it is a bit of a challenge trying to figure it all out. Luckily these old TT's are pretty lo-tech and quite doable from a DIY perspective (I hope).

Cheers,

Gavin

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How perceptive of you Dustin; where were you when I was studying form on cup day? 'Once upon a time'...,I worked for the Australiawide distributor of the Orpheus product.Manufacture of the turntable was by a husband and wife team by the name of Morgan. Something of the order of only 20 units per week could be assembled as all casting and machining were carried out on the premises. Demand always exceeded supply as the Silex was considered to be a superior turntable in its day. It was the first turntable to use an isolated, rigid sub chassis to directly link the arm and platter together so that unwanted microscopic movements caused by vibration and bearing polish were kept in phase and therefore at a minimum.There was another distinct advantage as the adjustable arm bracket and different arm adaptors (mushrooms) allowed easy installation of the popular pickup arms then available.Other makers often gave no thought to how and where the arm should be placed on the deck plate or plinth.This often gave poor results as the indicated position often was in a spot prone to vibration from the bearing and motor.The same distributor acted for Commonwealth Electronics (until 'Philips' took on that agency )E.M.T.and Thorens.Incidentally,while I reminisce , the last version of the Silex used a 2 pole motor,which was shielded to reduce hum.This was done I believe to cut costs and speed up production as by the late 60's and early 70's imports from overseas made things difficult.

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Hello VanArn,

I knew you'd know something . . :cool:

Cup day? . . I was of course studiously cutting biscuit shapes out of gooey rubber instead of trying to make sense of rubbery figures provided by bookmakers. I expect there's a moral in there somewhere but I'm damned if I can find it.

Seriously though, thanks for the interesting background info. I'll bet that was a time and a half to be in the turntable business.

This turntable should be up there with the Hills hoist and the Victa mower.

So where did this square version fit in to the scheme of things?

http://cgi.ebay.com.au/Orpheus-Silex-turntable-rare-square-version_W0QQitemZ130341948310QQihZ003QQcategoryZ14998QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Incidentally, please feel free to comment if I'm getting some of this refurbishment wrong.

Cheers,

Gavin

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It is a model prior to the cut down top chassis models (and before my experience maintaining them).Obviously with a one piece cast metal plate if you made a mistake in fitting an arm or wanted to changeover one you end up with a headache.It also would have been prone to damage if mishandled.The Silex model evolved from lessons learnt through experience.All is not lost;it would be worthwhile to purchase it for spare parts.

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The Orpheus T/T without the arm bracket and mushroom,is the first manufactured series under that product name and is not the later 'Silex' model.Indeed it was the fact that the motion of the t/t assembly relative to an arm fitted to a common mounting board caused problems that led to the arrangement that was patented.I would think someone has added a Decal label to the chassis and since Hi Fi Exchange basically work on a commision/consignment basis I would be a little suspicious of the original seller.

Right so not only is it not the model advertized that I received from Hifi Exchange, but it is not even an Orpheus Silex.

I now wish I had sent the machine back to them.

I have received no message from John of Hifi exchange.

This is a completely unacceptable way of doing business.

Thanks anyway for the information.

Regards

13D3

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A bit of progress . .

Suspension systems:

Finally finished refurbishing the various suspension systems today. There are separate systems for the motor, motor mounting bracket, and the spider that supports the platter. There are ten bushes in all and these were made from the various Sorbothane stock I bought recently.

Quite a lot of the time was taken making the various sized hole punches (cutters) to be able to cut the Sorbothane sheet. These were used like scone cutters to fashion the various grommets. Sorbothane is a bit weird to work with . . a bit like trying to drill bluetak . . you can't. But in the end it seems to have worked quite well and does appear to absorb vibrations. I'll have to wait till there's a tonearm installed to be any more positive than that. If anything appears to be too stiff (or too soft), it can be modified easily enough.

Good work, Gavin.

Perhaps we can have a fair idea of what to expect by reading reports on the effects of materials chosen for turntable mats (albeit to a lesser extent as the bushes are further away from the record cartridge interface.). Mat material does include both rubber, and sorbothane.

As Jonathan Noble points out, each material has its charcateristic sound "print":

http://www.theanalogdept.com/diy%27ing_a_time_machine.htm

"The theory goes that we are listening to a vibration interface which dissipates energy from the stylus into the vinyl, into the mat, into the platter and then in reverse as the vibration bounces back. The astonishing bit is that mats seem to sound exactly the way you might expect them too! A glass mat gives excellent transient attack but can also tend to sound hard, brittle and a bit ‘glassy’ in the highs. Felt is airy and free in the highs but rather grey everywhere else. Spongy rubber (such as sorbothane) has rich colours in the low mids and powerful bass but also tends to be overly warm. Acrylic sounds very clean but possibly a bit anti-septic, possibly even a bit too clean, a bit ‘plastic’. Cork in some ways comes close to felt because it is airy and light but is far less grey through the mid-band and, overall, more natural sounding even if it does lose a bit of transient attack."

Jonathan finally used a composite mat of cork and acrylic. I know the bushes are further way from the record cartridge "interface", but I imagine they are part of the "bounce back" vibration loop. I was thinking about making a composite bush, possibly including some sorbothane or similar, but possibly some cork, wood, acrylic, or even graphite, but simplicity may prevail, and perhaps I too will go for sorbothane, if it works for you.

I think the motor is quite different and the damping should not be heard unless it somehow destabilizes the motor rotation.

Platter Spindle:

Measuring inside diameters can be a bit tricky and I wanted to get an idea of the play in the platter spindle so I machined up a dummy spindle shaft. It was made 2 thou oversize and it wouldn't go in the bearings. I figure that's enough to declare the spindle bearings OK. If 2 thou is OK for Garrard, it'll be OK for this one too.

The platter bearing structure seems closer to the ideal than either that of the Garrard or the Linn, closer to that of the TD124:

BASICBearingTypes-1.jpg

It is probably safe to say that the Orpheus and the TD124 both using ball bearings, should improve on the standard Garrard in that area (indeed Garrard bearing upgrades often introduce a ball-bearing).

The difference is that the TD124 uses a captive ball-bearing, while the Orpheus one is free.

TD 124

lub11.jpg

Orpheus:

OrpheusBearing-1.jpg

I wonder whether it would be possible to improve on this bearing set-up, in a similar way to that proposed for the TD124 by Jec965. He adds a second captive ball-bearing in the thrust-pad, below the captive spindle one:

Ball-on-ballbearing.jpg

As shown here:

BearingThorensJec965-1.jpg

The flat thrust-pad is replaced by a concave one. This upgrade to my Thorens did bring a distinct improvement

The Orpheus, on the other hand, already has a concave thrust pad, that holds the ball bearing, as well as a concave spindle ending, and the ball-bearing is at least twice the size of that of the Thorens.

In my photo, the ball-bearing is resting in the concave spindle end:

DSC01346.jpg

Might it not be possible to introduce a very small ball-bearing (held temporarily with grease), in the mouth of the spindle cavity so that it rests on the larger thrust-pad ball-bearing.

DSC01339.jpg

As shown here:

OrpheusBearingUpgrade-1.jpg

I am wondering whether the concave thrust pad, holding the lower ball-bearing, would be enough to stabilize it, while the concave spindle ending would constrain the movement of smaller upper ball-bearing.

Motor:

Took the motor apart to inspect and found the bearings to be quite good. No apparent wear on the shaft and there was lubricant still visible on the thrust ball, so I gave it a few drops of oil, blew out the dust and reassembled.

I then installed the motor into it's mounting bracket and then that, to the TT base, temporarily connected the wiring and fired it up. Brilliant . . the motor is essentially silent.

Was there anything to watch while doing this, Gavin, or was it completely straightforward?

Was there a ball-bearing involved as on the TD124, or a teflon washer?

I think it is best to isolate the wires where they enter the motor casing, unless mine is different frol yours, it does seem to be razor sharp, at that point.

DSC01388.jpg

I simply isolated the wires as so:

DSC01389.jpg

I don't think this will cause any hindering of the motor movement.

I would also suggest deconnecting the motor wires at the switch and the domino, to avoid breaking the fragile wires.

Regards

Anthony

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A bit of progress . .

Next up is figuring out the absent spring that engages the idler wheel. I've no idea how strong (or weak) it's supposed to be . . nor exactly where it goes. :P

Ahhhh well . .

Here are the idler spring photos, I sent Dustin, and I think it could be useful, for anyone else looking to change the spring, if I add the measures Dustin came up with.

DSC01395.jpg

Detail at one end shwoing holder-clip:

DSC01381.jpg

The spring itself:

DSC01403.jpg

Dustin estimated the spring's spec. would be "5.00 mm (dia of spring section) x 55 mm length x 0.5 mm wire diameter."

However, something close, like 6.350 mm x 82.55 mm x 0.635 mm should also work.

13D3

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You couldn't help yourself at Hifi Exchange.:P

Worthwhile project? Only one way to find out.

For tonearm, with the strong A$ you can consider landing a new 12 inch Jelco 750L for $700 from US (search ebay) and match it with a Denon 103 or 103R. I'm using this combo on my Garrard 301.

For a few hundred dollars more, there's another 12 inch arm with a more vintage look by Thomas Schick. Good for Denon 103R and Ortofon SPU.

Non issue if you decide to do a DIY Schroeder.

This is my Fuch's magnet-bearing arm. It should not be too difficult to make for a competent metal worker.

arm%20detail.jpg

This differs from Schroeder's in that the two magnets (above and below the wand) pull, rather than push. So the wand is not exactly floating on a magnetic push, but torn between two oppositie directions.

The sound can be tweaked, in that you can lower the top strong magnet, so as to bring the lower magnet more or less into play.

The closer the lower magnet to the wand the dryer the sound, or the higher the warmer. I like it as low as possible.

It is not hard to change cartridges, but I do like the convenience of an interchangeable SME type head-shell.

Another alternative to the Jelco or the SME with this facility, could be various 11" broadcast arms, such as the Grace G-660P, the AT 1501, the Denon DA-203, or the shorter AT 12T, which is easier and cheaper to find.

These do not have arm lifts, but it is possible to buy a Jelco arm lift and adapt it for any of these arms. Neither do these arms have bias weights, but if you use an SPU or a Denon 103 at 2.5gm it might not be so necessary.

I am thinking of trying to add one to the Denon DA 203 I bought, but I am not sure whether there could be problems just adding the bias directly to the arm, via a bias weight and SME bias guide.

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Hi guys . . my small update for the week, just so you don't think I've been totally slack.

With the help of 13D3 and his mastery of the micrometer, camera, ruler and e-mail we were able to calculate the rate of the spring that engages the idler wheel with the motor. Armed with that info, I made a trip to good ol' Bunnings to have a look at their stock of springs. While there wasn't an exact match, I got one that was well close enough. In any event, there's provision to adjust the spring pull, so that should be fine.

Got home and eagerly hooked up this spring, remembering that I hadn't previously had the whole unit working . . just the motor on it's own.

I took a guess at the spring position and it worked first time . . woohoo.

During the above spring installation, I deliberately left out the fact that I initially attached the other end of the spring to a motor bolt ('cos it was there) and took a little time to figure out where the vibration was coming from . . ahhh well. :P

The speed adjustment seems to work OK and it's a significantly finer adjustment than I'd expected. I set the speed and let it run for an hour while I had lunch. I was rather expecting some drift as the motor warmed up, but hey presto, it was still running dead right after an hour. Maybe I shouldn't have been surprised . . dunno.

I'll experiment with the spring adjustment to find the sweet spot between too strong and too soft.

After seeing Anthony's pic of his motor wiring . . well that was the last straw for me. Those motor wires are indeed very delicate and while mine don't seem to have chafed, I'm always worried about accidentally yanking one out of the motor. I've now cut the wires and installed a plug to make it a lot more secure and easier to work on . . pic below.

motorplug.jpg

Having some further thoughts about a plinth and I've been trampling around annoying ENIGMA in his Slate Plinth thread.

It occurs to me that given there are only two miniscule bolts with which to secure the Orpheus chassis to any plinth, I may even do away with the chassis altogether and just attach the various parts to a plinth. Thoughts?

Cheers,

Gavin

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Incidentally,while I reminisce , the last version of the Silex used a 2 pole motor,which was shielded to reduce hum.This was done I believe to cut costs and speed up production as by the late 60's and early 70's imports from overseas made things difficult.

Thanks for your expertise, VanArn. I note that Dustin's Orpheus Silex, and my Orpheus (not Silex) seem to have the same motor, so presumably Dustin's motor is before the time of the two pole motor.

The Orpheus:

DSC01320.jpg

The Orpheus Silex

orpheussilexmotor.jpg

Unless the motor was changed on mine.

Another difference apart from missing the bracket stub of the later Silex, is the bolted double platter on the older Orpheus, which seems only to be cast and not milled, and not painted either. Perhaps the Silex also has a double platter, but that might be welded? Although, Dustin did show me a photo of an Orpheus Silex that also seemed to have that bolted double platter (but it was painted).

I had thought that the bronze Orpheus was the older MRK I model, but perhaps it was a deluxe version? I think this may be one, unless the colour is due to the lighting.

album_pic.php?pic_id=4226&full=true

The first one I saw on sale on ebay definitely was a bronze one, and it seemed to have a rectangular motor structure with no casing.

I have linked the photo of the square Orpheus to this page, so that we keep a record of it.Regards

13D3

orphSQ.jpg

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Having some further thoughts about a plinth and I've been trampling around annoying ENIGMA in his Slate Plinth thread.

It occurs to me that given there are only two miniscule bolts with which to secure the Orpheus chassis to any plinth, I may even do away with the chassis altogether and just attach the various parts to a plinth. Thoughts?

Cheers,

Gavin

Glad to see your still working hard at it, Gavin.

I have been giving plinths much thought, but I will add my more general thoughts later, and only describe how my project is changing, here.

I would first like confirmation that the Orpheus was only held by those two bolts. This one does seem to follow your suggested plan:

album_pic.php?pic_id=2941&full=true

I was thinking of passing the suspension bolts (as per TD124), and even possibly the motor bolts through the plinth. I went to great lengths to locate these holes, by using yellow tack. I put patches roughly where the holes would come, and then pressed the Orpheus onto it. These "nipples" correspond to the actual hole positions

DSC01474.jpg?t=1258466365

I am adapting a Garrad 301 plinth for the Orpheus. I was hoping not to cut much away, but to pass the relevant bolts through it.

Originally, I thought I would make the plinth like part of my present tiered Garrard plinth.

prt3_w.jpg

Had there been an arm bracket, that was what I was going to do

Once I realized I might have to put the arm on a solid plinth, I thought I might as well reuse my old 301 plinth.

This was a Martin Bastin maxi-plank solid plinth with long bolts allowing a top plate to be bolted onto the base. This was my imagined TT:

OrpheusRekGray.jpg?t=1258466742

I was considering keeping it that way, as I thought that was what Thomas Schick had used here (although perhaps is is hollow):IMG_4640.jpg

but as soon as I saw the Orpheus, I realized this would not allow me to clean the belt, or oil the engine. It is not possible to remove the platter of an Orpheus from above to get to the motor, as you can with a Thorens or a Garrard. Thus I would have to unbolt all the 15 bolts to have access each time. Furthermore, I don't like massive plinths. I believe they tend to overdamp the sound. That is why I abandonned the maxiplinth in the first place.

I have now decided to create something intermediary between the tiered plinth and the maxi-plinth, with a top plate on brass weight pillars, roughly as shown here:

DSC01373bJPG.jpg?t=1258466532

DSC01374b.jpg?t=1258467618

I think this will allow me to access the motor, and also allow a freer sound.

I might even have both an AC and a DC motor (removed from my Linn), just to be able to compare.

Before, I can progress, I must, however, be sure about this question of how many bolts should be used to hold the Orpheus.

Actually, I thought the two additional bolt holes were for grounding the top chassis.

Regards

Anthony

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Hi Anthony,

On the subject of platter spindle thrust bearings:

The difference is that the TD124 uses a captive ball-bearing, while the Orpheus one is free.

Well, I'd say the TD124 is certainly more recessed into the lower end of the spindle . . and appears to be mounted in a brass bush of sorts.

I'm not sure what's meant to be achieved by this bush because I expect the ball will have more friction where it mates to the spindle and will rotate on it's lower contact point in any case. So, in that context I'd think one design is as free (or not) as the other.

The same thinking applies to that lower thrust pad on the TD124. There seems to be a hole in the middle of the pad but I'm mystified as to why. Given the ball is captured in the spindle, it will centre itself on a lower point in the middle anyway. I can't understand why one would look to interfere with that.

To my mind, the same logic applies to using two balls, one atop the other. Why? . . and more to the point, you introduce unnecessary complications . . the possibility that the top ball will not ride dead centre on the lower one. The spindle shaft has a clearance and there's a propensity to introduce wobble due to the heavy platter . . maybe minute, I grant.

So, could the Orpheus system be improved? Well, I'm coming around to your thinking about a ceramic ball. The only benefit I can see would be the improved roundness. That, together with a Teflon thrust washer might be an improvement, but whether it was audible, I'd be guessing.

The Orpheus, on the other hand, already has a concave thrust pad, that holds the ball bearing, as well as a concave spindle ending

Hmmm . . I don't believe I have a separate concave thrust pad. Am I missing something else? :P

My ball just runs on the machined flat surface of the adjustment bolt.

Was there anything to watch while doing this, Gavin, or was it completely straightforward?

Was there a ball-bearing involved as on the TD124, or a teflon washer?

The motor was very straight forward. Yes, there's a ball thrust for the shaft but I didn't see any Teflon thrust washer but there might have been one. Mine still had some grease in it . . or maybe it was partially dried oil. Given the shaft and bushes were in good condition, I gave it a quick clean and a blow out with the air compressor. From there, it was lubricated with a small dab of moly grease on the ball, engine oil and reassembled.

Cheers, Gavin

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Hi Anthony,

On the subject of platter spindle thrust bearings:

Well, I'd say the TD124 is certainly more recessed into the lower end of the spindle . . and appears to be mounted in a brass bush of sorts.

I'm not sure what's meant to be achieved by this bush because I expect the ball will have more friction where it mates to the spindle and will rotate on it's lower contact point in any case. So, in that context I'd think one design is as free (or not) as the other.

Well, in the case of my one, it was held quite tightly, and did not turn freely, so in fact it was really only turning on the thrust pad. In the upgrade I was told to remove the brass ring, to make it run freer.

It was still held in place by the shape of the spindle recess.

The same thinking applies to that lower thrust pad on the TD124. There seems to be a hole in the middle of the pad but I'm mystified as to why. Given the ball is captured in the spindle, it will centre itself on a lower point in the middle anyway. I can't understand why one would look to interfere with that.
In the original, the ball bearing turns on a flat piece of plastic. In the "upgrade" it turns on a ball bearing, which is also free to turn, but held so it can't escape. I believe this is to lower friction.

Also the ball-bearings are special ceramic. I can't speak of the theory, but only the effect. I know this can be "psychological", but it did seem that the image became clearer, particularly in the central space between the speakers.

To my mind, the same logic applies to using two balls, one atop the other. Why? . . and more to the point, you introduce unnecessary complications . . the possibility that the top ball will not ride dead centre on the lower one. The spindle shaft has a clearance and there's a propensity to introduce wobble due to the heavy platter . . maybe minute, I grant.
Yes, I think this possible, but it does appear to me that my thrust plate is curved and not flat. I haven't unbolted it, just shined a light into it, so that both balls should be held. The weight should prevent movement, but only if the ball-bearings are excessively highly polished (ie ceramic).
So, could the Orpheus system be improved? Well, I'm coming around to your thinking about a ceramic ball. The only benefit I can see would be the improved roundness. That, together with a Teflon thrust washer might be an improvement, but whether it was audible, I'd be guessing.
Only those who have two machines could be fairly sure, if they introduce the change in one and not the other. I imagine Kokomo (analogtube) and others have that possibility, which we don't. I think I heard a definite change in both the Garrard and the Thornens, I think it was for the better, but I agree that auditory memory is very short term.
Hmmm . . I don't believe I have a separate concave thrust pad. Am I missing something else? :P

My ball just runs on the machined flat surface of the adjustment bolt.

I will try to look again, perhaps there is a difference here. In which case the double ball-bearing would not work.
The motor was very straight forward. Yes, there's a ball thrust for the shaft but I didn't see any Teflon thrust washer but there might have been one. Mine still had some grease in it . . or maybe it was partially dried oil. Given the shaft and bushes were in good condition, I gave it a quick clean and a blow out with the air compressor. From there, it was lubricated with a small dab of moly grease on the ball, engine oil and reassembled.
Thanks, I was worried that I might lose the ball-bearing. Now I know there is one I will take care, and also try to use my newly learnt skills for measuring the ball (you taught me), so as to perhaps also use a ceramic ball, here.

Regards

Anthony

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Hmmm . . I don't believe I have a separate concave thrust pad. Am I missing something else? :P

My ball just runs on the machined flat surface of the adjustment bolt.

Well, I looked again and it could be an optical illusion. It looks curved, but that could be due to the milled rings on the thrust plate.

I have not tried unbolting for fear of some difficulty in putting it together again. In that case (if flat), it probably would not be such a good idea to try the ball-on-ball bearing (unless the fit is very tight).

Yes, some upgrades to Linns and Thorens use a teflon thrust plate.

I have one for a Thorens that I didn't use, but unfortunately, it won't fit the Orpheus (too big). I might "borrow" the one in my Linn (too small?).

However, Teflon does not last all that long. A change to a ceramic ball-bearing would be the best bet.

Anthony

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Having some further thoughts about a plinth and I've been trampling around annoying ENIGMA in his Slate Plinth thread.

It occurs to me that given there are only two miniscule bolts with which to secure the Orpheus chassis to any plinth, I may even do away with the chassis altogether and just attach the various parts to a plinth. Thoughts?

Cheers,

Gavin

I have just reread your words, and realize that you are thinking of removing the top chassis, and possibly bolting directly to slate.

That could remove some ringing related to the metal chassis, I dare say.

I had thought of bolting the motor to the lower plinth, rather than to the metal chassis, so as to reduce vibration to the platter. I know that a number of people do that with the Garrard.

I am not sure how much I would gain, as the platter is suspended.

Regards

Anthony

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I've made a small start with this refurbishment and so far . . .

Idler arm assembly:

This was making some rattling noise so I pulled it apart to investigate. I've put a micrometer on the shaft and couldn't determine any wear but there were some witness marks indicating some polishing in the middle section of the shaft. I figured any wear would be at either end of the shaft but it all looked pretty good. Maybe there was some anomaly in the middle of the idler wheel that's left this polishing on the shaft . . dunno.

Just to be sure, I rotated the shaft so as to present the non-polished side of the shaft to the thrust loaded side. I reckon that'll be OK.

The idler wheel is retained on the shaft by an E-clip but I found the clip was rotating with the idler wheel. This is not the usual function of an E-clip as they are intended to fit snugly in the machined groove on the shaft . . and not rotate.

I replaced the E-clip with an R-clip (seen in the pic) for now as I didn't have one the correct size and it fits fine after a little grinding. It doesn't rotate with the idler wheel. If it looks like interfering with belt assembly, I'll find a correct sized E-clip.

I also noted a Teflon washer at the lower end of the shaft and have read somewhere that this should be inspected periodically. I don't have a manual and noted that during normal operation, the idler wheel will tend to climb the conical drive spindle on the motor . . that appears to be normal and as one would expect except that it rattles that bloody E-clip in my case.

I deduced from what appears to be this normal function that the Teflon washer is pointless on the lower end of the shaft and I feel it should be on the top end, so I moved it there. It is now backed up by a ground steel washer for support. The lower point is only contacted when the turntable isn't running anyway, so I've just used a thin brass washer where the Teflon one used to be. Oh, yes . . I also faced off the top of the idler wheel where it contacts the Teflon washer.

I reassembled everything and set the end float of the Idler wheel to 10 thou . . should be OK.

For lubricant, I used an engine assembly lube which contains moly and graphite and is a sort of a thin grease . . or a thick oil, depending on how you look at it. It seems this might be a little too thick but it does run smoothly with no noise now.

The rubber drive 'tyre' seems to be flexible and OK, so I've left it for now.

There was some small black gunky lumpy bits in the drive belt groove and I suspect they were a mixture of rubber, black paint from the platter and who knows what else. They cleaned off easily enough, so I'll consider that part to be OK.

The conical drive spindle appears to have some light wear grooves . . probably from years of spinning vinyl and I considered skimming, say . . 5 thou or so off in order to clean it up. Having had second thoughts, I can't see that it'll actually make a difference and I figure once the correct speed is set . . that's it.

idlerwheel.jpg

idlerwheel.jpg

I'll just add a photo of the parts you can epect to find (as described by Gavin) if you dismantle the idler wheel.

You do not necessarily need to remove the C clip, but you need to unbolt the bearing rod holder, you can observe here:

DSC01362b.jpg?t=1258529697

The teflon washer simply lies on top of the bearing ring. Like Gavin I cleaned the parts, but also polished the shaft with MAAS metal polish.

DSC01369b-1.jpg?t=1258529809

The main problem I had was the irregularity of the Idler wheel rubber, that I smoothed by using rubber restorer. The weel can be turned against a piece of tissue on the edge of a straight kitchen table. The excess rubber comes off.

Anthony

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A bit of progress . .

Motor:

Took the motor apart to inspect and found the bearings to be quite good. No apparent wear on the shaft and there was lubricant still visible on the thrust ball, so I gave it a few drops of oil, blew out the dust and reassembled.

I then installed the motor into it's mounting bracket and then that, to the TT base, temporarily connected the wiring and fired it up. Brilliant . . the motor is essentially silent.

Quote:

Originally Posted by 13D3 viewpost.gif

Was there anything to watch while doing this, Gavin, or was it completely straightforward?

Was there a ball-bearing involved as on the TD124, or a teflon washer?

The motor was very straight forward. Yes, there's a ball thrust for the shaft but I didn't see any Teflon thrust washer but there might have been one. Mine still had some grease in it . . or maybe it was partially dried oil. Given the shaft and bushes were in good condition, I gave it a quick clean and a blow out with the air compressor. From there, it was lubricated with a small dab of moly grease on the ball, engine oil and reassembled.

With Gavin's advice above, I did more or less the same. I unbolted the motor and expected to find a loose ball-bearing on the thrust-pad, but it seems to be captive. At least, I couldn't move it.

DSC01476.jpg?t=1258538227

I put a little microgrease on the ball, and refilled with bearing oil.

DSC01479.jpg?t=1258537619

I ploished the end with MAAs, but didn't take a photo of the result.

It just looks more polished and clean, but the wear point remains.

Probably it should be polished smooth. What do you think, Gavin, is it likely to effect performance?

I could have added a piece of teflon. If the motor remains noisy, perhaps I will.

Anthony

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Having some further thoughts about a plinth and I've been trampling around annoying ENIGMA in his Slate Plinth thread.

It occurs to me that given there are only two miniscule bolts with which to secure the Orpheus chassis to any plinth, I may even do away with the chassis altogether and just attach the various parts to a plinth. Thoughts?

Cheers,

Gavin

I have to come back to this question. It is true that, if the chassis is only bolted with two miniscule bolts on to the subchassis, it is really only the weight of the Orpheus which prevents it from rattling on its plinth.

The Garrard has four solid bolts, at the edges, while the Thorens uses three fairly substantial long bolts.

Is there a good reason for this method of fixing? Perhaps, it makes it far easier to release the turntable from its plinth, if you need to clean the belt or oil the machine. You only have two bolts to release.

The problem with that is that you would have to make the plinth so that it only covers the extreme edge of the player. It also means you couldn't use an arm bracket, or that would prevent you from releasing the TT, unless no arm was attached.

orpheussilexbottom.jpg

So clearly, this can't be the reason for using just two bolts.

If I understand you correctly Gavin you are thinking of bolting the motor and the subchassis directly to a slate plinth. This should kill vibrations dead, and could be worth a try.

I had thought of keeping the subchassis bolted to the chassis, but bolting the motor to my subplinth. Thus there would be no direct contact between platter and motor.

Another possibility has dawned on me, and that is to keep the motor bolted to the chassis, but to bolt the suspended subchassis to the wooden plinth, rather than to the chassis.

Ok there will be some contact between the two, but the vibration paths will not be so direct, through the metal chassis.

The problem could be that the subchassis will not be held quite so firmly, as the wood here would be around 5,5mm.

What are your thoughts? Is what I am saying clear?

I suppose it depends on how close the subchassis needs to be to the chassis. Should it be milimeters below or at least 5mm below?

If it should be very close then of course the wood of the plinth at that point would just be too thin.

Regards

Anthony

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Having some further thoughts about a plinth and I've been trampling around annoying ENIGMA in his Slate Plinth thread.

It occurs to me that given there are only two miniscule bolts with which to secure the Orpheus chassis to any plinth, I may even do away with the chassis altogether and just attach the various parts to a plinth. Thoughts?

Cheers,

Gavin

A plinth for an Orpheus, initial reflections.

The classic Orpheus Silex plinth is more or less like an open thin woooden box, or a light frame holding a thin board on which the Orpheus sits, as this one described here by RustyNuts at

http://www.vinylengine.com/phpBB2/viewtopic.php?t=15527

This light open structure gives complete access to the motor, idler wheel and belt, from below, should there be any need to oil or adjust, without taking the Orpheus out of its plinth.

It was probably considered, at the time, that the rubber bushing suspension would isolate the platter and arm from vibration transmitted by the flimsy resonant structure, whether it is air-born or transmitted from the motor.

However, the question may just not have been a consideration at that time, as powerful unsuspended Garrards (in the early 70s) were also housed in flimsy resonant plinths like that of the SME 2000.

The SME 2000 suspended the top board on springs, in a rather futile attempt to isolate the turntable from accoustic feed back, but the motor was not isolated, as in the Orpheus, and the light box structure just served to amplify motor noise.

Image8-1.png

In the Garrard revival of the 80s, there was a tendancy to go in quite the opposite direction favouring massive plinths to damp the Garrard's motor.

Only Loricraft, kept the idea of the sprung plinth, using half squash balls on the floor of an open wooden box, supporting a fairly sturdy top-plate on which the Garrard could be housed. See this description at TNT Audio:

http://www.tnt-audio.com/sorgenti/loricraft_e.html

The Loricraft could be considered a sort of beefed-up SME 2000. The sides were solid hardwood, and the top plinth fairly massive:

Would this be suitable for an Orpheus? Well, it would be easy to remove the turn table so as to be able to get at the belt and oiling points; but at the same time the Orpheus is already suspended (a double suspended TT might be over-kill), and in any case, the box like structure, (even beefed-up), is likely to amplify motor resonances.

Indeed, Loricraft seems to have followed others in abandonning the box plinth for a tiered structure for their newest 501 plinth (see below).

The argument that the plinth structure does not matter for a suspended belt driven Orpheus, has indeed often been put forward for the TD124, and yet it is now generally held that a "serious" plinth can bring an improvement to the Thorens, and I think this will no doubt be true for the Orpheus.

In England during the 80s, the Martin Bastin maxiplank plinth, was the favoured alternative to the Loricraft, for the Garrard.

history%20part1_w.jpg

It was thought that the massive multi-layered birch-ply plinth would sink or disperse vibrations, and in the 80s that was perhaps the most copied model? While the Shindo cherry wood plinth was the deluxe variant

A cheaper solution was to use a similar sized heavy MDF plinth, but most considered the MDF inferior to the birch-ply plinth, as it not only damped the motor vibration but even much of the sparkle in the music.

Are these heavy maxi-plinths suitable for the Orpheus? I think not, as there will be no easy access to the oiling points on the motor (or to make other adjustments).

Whereas, with the Garrard, you can have access to the motor and wheel drive simply by lifting off the platter, you can't lift off the Orpheus' platter from above; and even if you could it would still be difficult to access the motor or change the belt.

Furthermore, a number of Audiophiles quickly discovered that heavy vibration sinking maxiplanks (if not so bad as MDF ones) were not the ideal solution, even for the Garrard.

See in particular Jonathan Noble's account of testing different thicknesses of maxiplanks at

http://www.theanalogdept.com/diy'ing_a_time_machine.htm

His conclusion was that an overthick maxi-plank can render the sound almost as lifeless as MDF.

Jonathan found the ideal thickness to be about 3,6 cm thick. (of course this might be slightly different with a different machine, but it is a safe starting point for a simple plinth project).

"The final part of the vibration loop is the plinth itself. As already mentioned, I experimented with no less than three or four plinth arrangements and in the end settled for a medium mass birch plywood plinth (36 mm thick)."

http://www.theanalogdept.com/images/spp6_pics/J_Noble/GARRARD.JPG

Now, such a medium thickness maxiplank plinth would be a good starting point for an Orpheus: It is fairly easy to construct. There would be no problem getting at the motor, no resonant chamber, and a lively sound.

I had an opportunity to test Jonathan's idea when I acquired a Thorens TD 124. However, I just happened to have some 100 year old oak-ply panelling taken from the Grand Hotel in Bournemouth. I decided to make a medium thickness plinth, but constraining the glued ply wood within an oak banister surround:

history%20part2_w.jpg

The result was my French "country plinthed TD124 MKII :

thorens_w.jpg

This immediately seemed to improve on all areas, compared to the Garrard in heavy maxiplank plinth (and this structure would no doubt work just as well with an Orpheus).

However, I then returned my attention to the Garrard to see how I could bring this up to a similar (or better) level of performance to that of my TD124.

Around that time, I saw pictures of the beautiful Cain and Cain plinth, in the 6 Moons Garrard project (which could also be an excellent choice for an Orpheus).

http://www.6moons.com/audioreviews/garrard3/garrard.html

However, I thought it might be possible to associate this type of tiered structure with medium thickness maxiplanking.

The result can be seen here:

http://www.theanalogdept.com/anthony_hind.htm

Now on acquiring my Orpheus, which the ebay advert showed to have a complete suspended arm bracket, I thought I would use just part of this type of structure to make the plinth for my Orpheus. I intended to use the principle followed in the first two tiers for my Garrard turntable,

prt3_w.jpg

while mounting the arm to the right hand rear side, as in this plinth belonging to Thomas Schick:

IMG_4640.jpg

I am not sure how Thomas Schick's plinth functions, so I will not take it into account, here.

It strikes me that an open structure (either the one I adopted, or the Cain & Cain) would be better for the Orpheus, both from a practical point of view, and for the sound.

However, partly because my Orpheus was not an Orpheus Silex (and so does not have the arm bracket, nor even the stub and lug on to which to bolt such a bracket), but also because two fully tiered plinths could be a little too much in the same room, and because I did not want to throw away the Maxiplank plinth, I finally came up with this half tiered half maxi-plank idea,

I would use the standard maxiplank base, but with its top raised on brass weights, which I happen to have, and which usually decorate my turntables:

DSC01349.jpg

I would thicken the top plate by adding two thicknesses of Grand Hotel oak panelling (all that remains in my possession). Then I would, of course veneer or stain and polish the top of the lower plinth.

This would give me easy access to the motor, without moving the turntable, and it would also be able to lift up the top plate for changing the belt, for example. It would be possible to fix the motor either to the chassis, as intended by Orpheus, or to fix it to the lower plinth (This was an idea that Haden Boardman of World Audio suggested to me for the Garrard).

It might also be possible to attach the suspended subchassis to the wooden top plinth, rather than to the upper chassis.

Both these points have to be decided, and I may keep to the original design.

I will of course have to cut into both the top and the lower plinth so that they can accept the Orpheus, which is slightly wider than the Garrard, but this should be quite a minor alteration, particularly once the top plinth is raised on pillars.

For others thinking about beginning from scratch, there are a number of plinths that look worthwhile considering for an Orpheus. Some of these seem to have followed the same line of thought that I did on seeing the Caine & Caine plinth. One described by Roger S. Gordon in POSITIVE FEEDBACK ONLINE - ISSUE 25

http://www.positive-feedback.com/Issue25/garrard_401.htm

This looks half way between the Caine and Caine and my plinth, with a hint of Bertoncello (who also influenced my project (see 15gEMT9972007%20GE211001.jpg

Loricraft also seems to have gone along these lines, with their new plinth for the 501:

garrard601025.jpg

http://www.garrard501.com/

Another more sturdy affair, appears, here

http://www.vinylengine.com/phpBB2/viewtopic.php?p=103048

RK014a.jpg

This should also work well with an Orpheus.

There are however other excellent solutions, but not quite so DIY compatible. Tim de Paravacini told me he mounts his Garrards on a heavy metal block, but uses white bathroom vinylic sealant to create a non rattling interface between the turntable and the block.

Early BBC grey Garrards in the 50s, often came on a slate plinth, and this has been reborn in a number of different forms (Slate Audio among many). Slate has a natural leaved structure which kills resonance. However, again, the metal/slate interface could be a problem, and one could expect rattles, unless certain precautions are taken. Certainly, just using the two small bolts of the Orpheus would most probably result in rattling or sizzling (See disussion on the slate thread).

On the other, hand directly bolting the components of the Orpheus to slate (as Gavin seems to be considering), could get round that problem.

Another excellent solution could be a Graphite plinth, as Simone Luchettti was offering for the Thorens. However, I don't know whether he is still doing that.

He is still making "Audio Silente" Graphite mats, which could work well with any turntable.

(I have a graphite mat on my Garrard, and it works well, but it didn't seem to work so well on my Thorens).

A friend of mine has his Garrard on a medium thickness Corian plinth. See this article:

http://www.diyaudio.com/forums/analogue-source/67089-corian-turntable-fun.html

http://www.stereo.net.au/forums/showthread.php?p=288239

I think it could be a fairly cheap and easy solution for an Orpheus (if you can find a cutting shop that will sell you cut-offs).

Regards

Anthony

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Right so not only is it not the model advertized that I received from Hifi Exchange, but it is not even an Orpheus Silex.

I now wish I had sent the machine back to them.

I have received no message from John of Hifi exchange.

This is a completely unacceptable way of doing business.

Hi Anthony,

I reckon just give John a call . . that's likely the best and quickest way to get a resolution.

Alternatively, I could easily fabricate a mounting tag for your spider and you could have it TIG welded by any competent outfit locally. Let me know.

I need to correct myself when I made this comment:

"The same thinking applies to that lower thrust pad on the TD124. There seems to be a hole in the middle of the pad but I'm mystified as to why. Given the ball is captured in the spindle, it will centre itself on a lower point in the middle anyway. I can't understand why one would look to interfere with that."

On reflection, that small hole in the lower thrust pad may just be sufficient to stabilise and maintain the spindle shaft centrally in it's lower bearing. I'll still stick with the rest of my little rant though . . haha.

Yes, some upgrades to Linns and Thorens use a teflon thrust plate.

What about this for an idea then . . pic below:

I didn't do the annotations for this pic but that's supposed to represent a steel shim epoxied to a cork shim.

The Orpheus has a pretty good arrangement with the ball thrust and there'd be room to install something like this underneath. This means that the low friction ball remains and rides on the steel shim . . as per normal. The cork would hopefully dampen some spindle rumble being transmitted to the spider. Beyond that, judicious selection of a suitably viscous lubricant should also contribute to the damping if my rather crude experiments this afternoon are any guide.

. . and it's really really cheap.

corkthrust.png

I ploished the end with MAAs, but didn't take a photo of the result.

It just looks more polished and clean, but the wear point remains.

Probably it should be polished smooth. What do you think, Gavin, is it likely to effect performance?

I could have added a piece of teflon. If the motor remains noisy, perhaps I will.

I wouldn't worry about the wear point . . pretty normal.

I'd be much more concerned if the motor is noisy? . . and I wouldn't think a piece of Teflon would help.

What sort of noise? Is it bearing noise or is the commutator making contact?

The plinth / chassis dilemma; here's a few point thoughts as I see them.

Firstly, I think we probably should only use Garrard plinthing principals as a guide. Garrard owners probably consider a number of different issues that we are less concerned about inherent in the different designs. I imagine a Garrard has a lot of attention paid to their large powerful motor and the vibrations issues accompanying that, for instance.

With a Garrard, it's possible to have a full width massive plinth that effectively encases the platter spindle.

Have a look at ENIGMA's thread on Slate Plinths for an idea of what can be achieved:

http://www.stereo.net.au/forums/showthread.php?t=15795

By contrast, the Orpheus has the arm directly connected to the platter/spindle and independent of everything else. While that may be good from some perspectives, it brings different potential considerations / problems . . like possible spindle rumble. You can't encase the spindle in the plinth and you can't get a full width plinth directly under the platter . . there's no room.

To balance that, the Orpheus has two more motor isolation points than the Garrard. It has a separately damped motor chassis and the belt drive . . and a rather smaller motor.

So as a very general comment, the Orpheus is probably in less 'need' of a massive plinth . . hopefully.

Having said that, I reckon those two piddly chassis mounting bolts are a bit lame in any case.

I guess you could employ the spider mounting bolts to do a double duty, but there isn't much room to do that. What . . maybe 10 mm between spider and the underside of the chassis? With only that much room, the material you're attaching to becomes an issue. Attaching to steel or aluminium would be OK, but I'd worry if it was only wood / ply.

So . . what to do? I reckon there are maybe three options:

1. Attach some decent brackets to the upper chassis, either welded or seriously bonded to enable proper bolting and coupling to the plinth.

2. Delete the upper chassis altogether and provide embedded pick up points on the plinth for the spider, motor chassis and switch etc. I'd agree that deleting the upper chassis either makes or breaks the Orpheus in terms of it's character and aesthetics . . according to taste.

3. If you don't want to ditch the upper chassis, then I guess it'd be possible to just attach it for cosmetic reasons.

Thoughts?

Cheers, Gavin

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Hi Anthony,

I reckon just give John a call . . that's likely the best and quickest way to get a resolution.

Alternatively, I could easily fabricate a mounting tag for your spider and you could have it TIG welded by any competent outfit locally. Let me know.

A phone call to Australia would be alright, if I was sure it would result in a sudden twinge of conscience which John would want to resolve. So far he has sent me two messages in which he said he was ready to send the bracket, but nothing has come of it. I fear a similar outcome from a phone call. If I could go and make a fuss in the shop, it would of course be very different.

Thank you greatly for your kind suggestion, which I may well take up, if it is not too much trouble; although for the moment, I don't have the tonearm: the DA 302 Denon is supposed to be heavy, and I don't know (not having seen one) whether an arm bracket would actually take it.

How strong are they?

VanArn explains clearly why the bracket was introduced:

"The Orpheus T/T without the arm bracket and mushroom,is the first manufactured series under that product name and is not the later 'Silex' model. Indeed it was the fact that the motion of the t/t assembly relative to an arm fitted to a common mounting board caused problems that led to the arrangement that was patented."

But I have two questions in relation to this:

1) Was this solution envisaged because arms and cartridges had become much lighter than previously, and so could easilly be supported by an extension bracket from the Orpheus subchassis, or would this be valid whatever the arm weight?

2) Would the problem be the same if the plinth had been less flimsy than the Orpheus plinth undoubtedly was, at that time?

When I see the Denon arm, I may get a better idea of this, although I still won't get much idea about the strength of the bracket.

I need to correct myself when I made this comment:

"The same thinking applies to that lower thrust pad on the TD124. There seems to be a hole in the middle of the pad but I'm mystified as to why. Given the ball is captured in the spindle, it will centre itself on a lower point in the middle anyway. I can't understand why one would look to interfere with that."

On reflection, that small hole in the lower thrust pad may just be sufficient to stabilise and maintain the spindle shaft centrally in it's lower bearing. I'll still stick with the rest of my little rant though . . haha.

The original bearing has a flat thrust pad. It is the ball-on-ball bearing that has to have a centring device to keep both balls aligned.

It is hard to prove in a mail that this gives an improvement, but it is easy to perceive that it makes a difference. With the ball-on-ball bearing in place the platter goes on turning far longer, implying less resistance.

At first thought, this seems a positive result (less friction), although some may hope that an element of resistance may even out any fluctuations (a little as a fly wheel does, albeit by a different principle). This is said to be what happens with the grease bearing Garrard: the grease offering more resistance than oil, it would even out any small fluctuations, thus improving on the performance of the oil-bearing.

I have not tried this, but I would nevertheless expect the grease-bearing to go on turning less than the oil-bearing would. Thus going against the usual idea of best bearing type.

This however, seems to be the layman's understanding this question:

"Am I correct to assume that friction will be heard as rumble, and therefore the least amount of friction is the goal? I've seen mention of spin down time after shut off being an indicator of the level of friction present. I'm currently getting only 15 seconds, but I recall reading of some folks achieving 2 minutes or more with various upgrades".

"http://www.vinylengine.com/phpBB2/viewtopic.php?t=17490

What about this for an idea then . . pic below:

I didn't do the annotations for this pic but that's supposed to represent a steel shim epoxied to a cork shim.

The Orpheus has a pretty good arrangement with the ball thrust and there'd be room to install something like this underneath. This means that the low friction ball remains and rides on the steel shim . . as per normal. The cork would hopefully dampen some spindle rumble being transmitted to the spider. Beyond that, judicious selection of a suitably viscous lubricant should also contribute to the damping if my rather crude experiments this afternoon are any guide.

. . and it's really really cheap.

corkthrust.png

It might work, and needs to be tested, but I would fear the cork would allow "rocking" or wiggle.

Most upgrades on bearings go for a stronger bearing material, possibly with a higher frequency point of resonance, as with Titanium.

There are complete Titanium bearings made for the TD124 by one Thorens tweaker.

Although, some prefer a material that has a similar resonance to that of musical instruments (bronze, for example).

I wouldn't worry about the wear point . . pretty normal.

I'd be much more concerned if the motor is noisy? . . and I wouldn't think a piece of Teflon would help.

What sort of noise? Is it bearing noise or is the commutator making contact?

Indeed, this thread seems to highlight the weakness of using Teflon that can actually dent, and then increase resistance, so it is not the ideal material:

http://www.vinylengine.com/phpBB2/viewtopic.php?t=20822

The plinth / chassis dilemma; here's a few point thoughts as I see them.

Firstly, I think we probably should only use Garrard plinthing principals as a guide. Garrard owners probably consider a number of different issues that we are less concerned about inherent in the different designs. I imagine a Garrard has a lot of attention paid to their large powerful motor and the vibrations issues accompanying that, for instance.

With a Garrard, it's possible to have a full width massive plinth that effectively encases the platter spindle.

Yes, I was able to completely clamp my Garrard bearing, using Tim de Paravacini's H clamp above:

prt4_w.jpg

and a yellow tack well below, into which was forced the bearing. You can just see that here:

prt3_w.jpg

Evidently, this can not be done with the Orpheus, without losing its suspended subchassis, that should "float" and not be grounded.

Have a look at ENIGMA's thread on Slate Plinths for an idea of what can be achieved:

http://www.stereo.net.au/forums/showthread.php?t=15795

Yes, slate could be an excellent solution (it was used in early BBC Garrard 301s) and it would be possible, as you have suggested to bolt the components directly onto the slate, and either dispense with the chassis, oe use it as a decoration.
By contrast, the Orpheus has the arm directly connected to the platter/spindle and independent of everything else. While that may be good from some perspectives, it brings different potential considerations / problems . . like possible spindle rumble. You can't encase the spindle in the plinth and you can't get a full width plinth directly under the platter . . there's no room.
It might be possible to fix a block of wood to the spider, and then pass a hollow block (or a strong closed hollow pipe) full of yellow tack over the bearing, and bolt that to the block on the spider. I will try to look into this possibility.

If you knock on the spider subchassis or the platter, you will observe that both ring like a bell. I think some damping is called for, although it should be used sparingly to avoid damping the sparkle out of the music.

To balance that, the Orpheus has two more motor isolation points than the Garrard. It has a separately damped motor chassis and the belt drive . . and a rather smaller motor.
Yes, like the TD124, a Braun model, and a Dual.
So as a very general comment, the Orpheus is probably in less 'need' of a massive plinth . . hopefully.
I am sure you are right, and even on the Garrard a massive plinth per se does not actually work well; but work on the TD124 has nevertheless shown that this type of tunrtable can benefit from a serious plinth.

Simone Luchetti had plinths made out of graphite for the TD124, and he claims these gave a noticeable improvement.

Having said that, I reckon those two piddly chassis mounting bolts are a bit lame in any case.

I guess you could employ the spider mounting bolts to do a double duty, but there isn't much room to do that. What . . maybe 10 mm between spider and the underside of the chassis? With only that much room, the material you're attaching to becomes an issue. Attaching to steel or aluminium would be OK, but I'd worry if it was only wood / ply.

Agreed, I am beginning to think I may bolt to the chassis points, but pass it through 6mm of wooden chassis point to help damp the metallic structure. The top plinth of course would be much thicker, a little less than 4cm, which is ideal according to Jonathan Noble's experiments.

I have no idea whether there is an ideal thickness of slate, but I believe I have also seen tiered pillared structures in which the top plinth is around 4cms.

So . . what to do? I reckon there are maybe three options:

1. Attach some decent brackets to the upper chassis, either welded or seriously bonded to enable proper bolting and coupling to the plinth.

2. Delete the upper chassis altogether and provide embedded pick up points on the plinth for the spider, motor chassis and switch etc. I'd agree that deleting the upper chassis either makes or breaks the Orpheus in terms of it's character and aesthetics . . according to taste.

3. If you don't want to ditch the upper chassis, then I guess it'd be possible to just attach it for cosmetic reasons.

Thoughts?

Cheers, Gavin

I agree with all these points. There is probably no one ideal solution, and according to the material used different strategies become possible. As you say, some solutions may not work well with certain materials.

Perhaps, if you use wood, it may be difficult to avoid using the original bolt holes for the subchassis.

Regards

Anthony

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