95 replies to this topic

[turntable]

I have experience with isolating equipment from both structural and acoustic excitation.

so you keep telling us. Yet with zero specifics on anything historical to do with turntables, or even room acoustics.

As Tax said, do not post if you have nothing to say.

Edited by turntable, 25 March 2012 - 08:25 PM.

[GFuNK]

Not doubting your experience with isolation from structural and acoustic excitation. Not doubting that the theory and your learning exists either. But am experienced enough to know that no two differing pieces of equipment react the same. I also teach theoretical concepts in a University environment and see that sometimes the theory doesn't mimic operational parameters in my paid day job which is aligned with the theory.

My concern is all encompassing theoretic or generic posts (not yours in particular) which become acrimonious, that seem to be on the increase on this forum lately.

Of course nothing beats experience, but theoretical concepts are developed to support real world observations...

Turntable, of course I'm not going to give you specific advice because I do not know your exact situation...

I think there is a much larger problem with people chosing "solutions" which are not consistent with either theoretical or practical consideration of the physics.

[handysteel]

Looks like the digital boys are at it again…..They must be bored with their digital world.

[Dr Good Vibe]

Quite true, the Omnigon is for you. would work well with the Atlas. It has a total of 5 MC inputs and 1 phono and 5 line inputs. You could get rid of the input switcher.

What a beauty. here is a pic

Where do you order these items Tax

[turntable]

Where do you order these items Tax

From Daniel GV. Same guy that makes the input switcher and uni tractor.

[Dismord]

Very good generic advice on some posts here, for the novice which inadvertantly or by choice seems to lead onto some debate ala the high res debate

Sorry, I don't get the connection.

However it would be beneficial, prudent and appreciated that those who post on some of these topics, especially when it comes to turntables, arms, cartridges, phonostages etc that they have not used or are not intimately familiar with just not post some generic advice.

Fair enough but if it's made clear that a result is only anticipated, not yet experienced, that's not giving advice, it's simply thinking aloud. Is that always such a bad idea? At least if I say something like " I suspect component X used with component Y would be a great way to go" does that not give others an opportunity to respond with something like "No, X is better with low mass cartridges and Y is high mass" and thus preventing someone making an expensive mistake?

I certainly don't try and post on a topic unless it is to share my personal experience. Not what I think it may do, how a cable may sound etc etc. There is no way you can tell until you hear it in a system.

If nuclear physics, or for that matter any other research discipline followed that dictum they wouldn't no where to start looking. What's important is to make it clear when speculation is involved rather than experience.

Some of us here are on first names basis with the manufacturers (if they are still alive and coherent that is) of their/our respective equipment. In some cases we are already pushing the boundries of the equipment beyond what the manufacturer thought possible or wanted us to without buying the uber expensive next model up (if there is one), In some cases our gear is Vintage and those companies do not exist. So guess we have already sucked that egg

Well I too knew manufacturers of components who have gone to the great listening room in the sky just as I know some who are still alive but I don't see what you're trying to say here. I don't see why advice about vintage gear isn't valuable, if that's what you're saying, as such objects of worship as Quad 57's, Garrard TT's etc can still be picked up on the used market.

There is nothing that beats real life experience so let's all live it first and discuss our experience thereafter.

I'm in complete disagreement with this. One of the most valuable resources provided by forums such as this is advice given to those who are yet to suck the egg by those who already have. Or am I misinterpreting something? However, this area is so complex that there are always some combinations that no-one may have yet attempted and these are in themselves worthy of discussion even if no single person's 'life experience' is involved. Or are we forbidden to ever ask 'What if?"

Edited by Dismord, 25 March 2012 - 10:05 PM.

[Dr Good Vibe]

Thanks TT on to it

[wolster]

Very good generic advice on some posts here, for the novice which inadvertantly or by choice seems to lead onto some debate ala the high res debate

However it would be beneficial, prudent and appreciated that those who post on some of these topics, especially when it comes to turntables, arms, cartridges, phonostages etc that they have not used or are not intimately familiar with just not post some generic advice.

I certainly don't try and post on a topic unless it is to share my personal experience. Not what I think it may do, how a cable may sound etc etc. There is no way you can tell until you hear it in a system.

Some of us here are on first names basis with the manufacturers (if they are still alive and coherent that is) of their/our respective equipment. In some cases we are already pushing the boundries of the equipment beyond what the manufacturer thought possible or wanted us to without buying the uber expensive next model up (if there is one), In some cases our gear is Vintage and those companies do not exist. So guess we have already sucked that egg

There is nothing that beats real life experience so let's all live it first and discuss our experience thereafter.

Not sure I get the gyst of this, Tax. It seems to me that the OP (DGV) asked for opinions on isolation systems for turntables which is pretty well what members have responded to.

[Tax]

Not sure I get the gyst of this, Tax. It seems to me that the OP (DGV) asked for opinions on isolation systems for turntables which is pretty well what members have responded to.

I must be confused because post #29 about some vinyl rip aiding isolation around the turntable doesn't make sense to me.

You?

[loki65]

It's not the ultimate isolation, but what i'm using at the moment. The tray is made from 16mm melamine, and the top from 35mm. Under the top at the moment i have a piece of 8mm styrofoam, have some 6mm sorbothane on the way. Used the melamine for the top as it was free. Only got it under the TT yesterday, there is a noticable difference. The sound seems a little tighter and more focused (for lack of better wording). Will be giving it more of a run over the next week or so while waiting for the sorbothane to arrive. Down the track i may look into getting a top made out of corian or granite.

[Tax]

It's not the ultimate isolation, but what i'm using at the moment. The tray is made from 16mm melamine, and the top from 35mm. Under the top at the moment i have a piece of 8mm styrofoam, have some 6mm sorbothane on the way. Used the melamine for the top as it was free. Only got it under the TT yesterday, there is a noticable difference. The sound seems a little tighter and more focused (for lack of better wording). Will be giving it more of a run over the next week or so while waiting for the sorbothane to arrive. Down the track i may look into getting a top made out of corian or granite.

Follows the form of the TT well :-)

Interested to hear your views once you have tried the soborthane.

BTW: I have also used a cut up yoga mat from Clark Rubber http://www.clarkrubb...u/yoga-mat.html with good effect sitting under a couple of pieces of basalt slabs and my old Well Tempered TT sitting on top of the slab.

[caliburn]

Not sure I get the gyst of this, Tax. It seems to me that the OP (DGV) asked for opinions on isolation systems for turntables which is pretty well what members have responded to.

That is exactly what I believe we were/are trying to do. Share experiences of isolation techniques and where data is available or published by respected manufacturers this should be raised for all to digest.

Turntables come in many shapes and sizes as we all know. Suspended, non-suspended are two broad categories most of us have either direct experience with as owners or have friends with one or the other.

Some of us have audio rooms on upper floors or have to contend with older houses in need of improved floor support. So wall mounts are popular to avoid the problems of footfall bounce. How many of us have to tiptoe around our tables when they are playing to avoid needle jumps?

So the suspended tables get a few points for attempting to address these common domestic installation issues. Some like the SOTA, Avid, Basis or the SME do a pretty amazing job of isolation and do so right out of the box.

For non-suspended tables the floor problem becomes an issue. So the use of slabs of concrete/metal/wood with air bladders in between do provide a relatively low cost way of creating a compliant interface between the table and it's mounting surface.

Rubber inner tubes can be deflated to create a super "spongy" interface (low natural frequency). Occassional pressure adjustments can be an annoyance depending on your point of view. (Cost vs Performance).

Suspended "bungee" or "hockey strap" systems also work a treat but tend not to have a good WAF in the looks department. However they can be made to support a heavy table and can be loaded to have a very low natural frequency (1-2hz) both vertical and horizontal (pendulum). They have limited adjustment via mass loading or subtraction. Again low cost.

Once you start looking at commercial alternatives such as Vibraplanes, Negative Stiffness mechanisms, Active Piezo or Voice coil solutions then you can get access to manufacturers published specifications.

As these sources are often focused on the scientific or engineering community you can rely on published specifications to be very accurate. Active systems are proven solutions used in many laboratories around the world. They work well in some pretty impressive sites. So do the Passive alternatives.

So when faced with a choice of isolation solution it would be good to look at the problem at a high level to decide which is best for you.

For example what is the total weight of your turntable?

Compare this to the total weight of your stand that you intend to place the turntable onto.

If you place your isolation system between these two items one should consider if the turntable (i.e a high mass non suspended table) is heavier than the stand it sits on.

Why so?

If for example you use an active correction system and it "pushes and shoves" your table in its correction mode and the stand you have seated the table on is lighter in weight - then the stand will move before the table and there will be an overshoot and lag occuring.

To address this you need to stiffen the stand (preferably infinite stiffness) so that it does not move when the active system is "pushing and shoving" and performing the correction cycle to external vibration.

On wooden floors the stand will rock the floor again leading to lag and overshoot.

So for the active system to be allowed to work at its optimum one should consider a high mass stand well exceeding the weight of the table. That way the isolator will be given the best environment to deliver the published attenuation.

An active system based around a feedback loop can only deal with feedback signals that are so large. When these are exceeded the feedback loop can go into a positive feedback state and ring. This ring is vibration. Active systems typically have a dynamic range (maximum displacement capabilities) on the order of a few thousandths of an inch.

Passive systems such as the MinusK can deal with vibrations that are MUCH larger. This is why they are often chosen for isolating footfall problems on upper floors.

GFunk pointed out springs will exhibit some non-linear behaviour. Have a look inside the mechanism and see if there are springs used. All systems with springs will exhibit some form of non-linear behaviour in action. Even soem Active solutions use springs inside to assist the voice coil actuators support the payload.

For the audiophile to hear these "non-linearities" would be difficult as the isolators bring overwhelming benefits. Yes Active systems will actually be better than no isolation at all. So will Passive systems.

Compare the published isolation specifications, and work out the maximum displacements you will experience on your floor installation. Even concrete floors still transmit vibration - just ask any laser interferometer or LIGO researcher who probably has war stories of truck traffic 2 kilometers away disturbing sensitive observation systems.

So if your budget is able to expand to include commercial isolation solutions for your non-suspended table then the sonic improvements far outweigh the negatives (cost, looks, mounting concerns etc).

Suspended tables using additional suspension systems are a whole nother discussion.

Happy to discuss

[Tax]

I don't see why advice about vintage gear isn't valuable, if that's what you're saying, as such objects of worship as Quad 57's, Garrard TT's etc can still be picked up on the used market.

My intent was to outline that being asked to go and speak to a manufacturer who may no longer exist, is not an option in some cases.

I don't have any issues with vintage. I am using a Vintage analog rig. Production on my TT, tonearms and cartridges stopped 30 years ago.

I'm in complete disagreement with this. One of the most valuable resources provided by forums such as this is advice given to those who are yet to suck the egg by those who already have. Or am I misinterpreting something?

I am in agreement! That is why some of us post on these forums.The intent on this one was to outline that one should suck similar eggs first rather than work off a generic theory.

If a poster makes statement or has an opinion, then I as a reader I expect that he/she would explain these insights in relation to his or her PERSONAL equipment and audio journey.

Happy to comment further if deemed necessary.

[loki65]

Follows the form of the TT well :-)

Interested to hear your views once you have tried the soborthane.

BTW: I have also used a cut up yoga mat from Clark Rubber http://www.clarkrubb...u/yoga-mat.html with good effect sitting under a couple of pieces of basalt slabs and my old Well Tempered TT sitting on top of the slab.

Cheers, may give a piece of yoga mat a go and see how it sounds. Will post when i get the sorbothane and give it a run. Should also add i'm looking into room acoustics, as i guess that plays a part in isolating vibrations too.

[Dr Good Vibe]

Morning Caliburn, very fine points. Did some more tests on the weekend and all that you pointed out is absolutely true will need to have my table weigh in at about 130Kg and of course that cradle.

[wolster]

I must be confused because post #29 about some vinyl rip aiding isolation around the turntable doesn't make sense to me.

You?

Me neither. It just seemed to me that the thread was generally on topic apart from the usual odd sidetrack.

[Dismord]

My intent was to outline that being asked to go and speak to a manufacturer who may no longer exist, is not an option in some cases.

Well, unless you're into seances it makes no sense.

I don't have any issues with vintage. I am using a Vintage analog rig. Production on my TT, tonearms and cartridges stopped 30 years ago.

Well ,we have one thing in common. For ancient mono LP's I use a Decca "London' mono cartridge re-built by Garrott Bros. Somehow it doesn't 'hear' recorded rumble that often infests those old mono LP's.

[jaspert]

+1
works a treat...

OTOH putting the TT right next to the subwoofer probably 'livens it up'.... which seems to be a priority for many audiophiles.

Not all audiophile want to liven up the vinyl sound that way....

Having too many turntables in my room means 2 have to be placed next to my 15 inch woofer cabinets unfortunately and i have horrible suspended wooden floor too
so I do get feedback issue from the speakers naturally, one in particular is affected more at moderate volume. I now use 4 Paulstra industrial anti vibration mounts under the turntables which is then placed on a piece of blue stone with 3 adjustable feet to aid with levelling. That stop the feedback issue ( or greatly reduce it ) for not too much money.

Exclusive P3 has little problem with the effective build in suspension and the heavy non suspended Micro Seiki RX 5000 is located at the back of the room and sits on top of a SGR rack with quite a few sorbothane underneath the top shelf. I had been contemplating getting a Minus-K BM-8 for 2 years for the Micro but never got round to it.

[Flamenco_diego]

I use the Gingko Cloud 11. Layers of solid acrylic separated by a layer of sort of squash balls. Marvellous thing.
Quieter backgrounds, more dynamics, better imaging.

Also, i use the Herbies Audio: 'Tenderfeet' . "Just too make sure" ! between the table and the cloud.
- 3 under the motor, (stiff ones) and four under the turntable (soft ones).

All this sits on top of a brass spiked corian 3 layer platform which i mainly use as a levelling system.

Under those threaded spikes i have brass / carbon spke-cup thingies. Herbies Audio.

On the acrylic platter I also use the "Herbies Audio Way Excellent Turntable Matt II". Cleaner highs.

[Tax]

Somehow it doesn't 'hear' recorded rumble that often infests those old mono LP's.

Interestingly I have some Decca and RCA stereo LP's that also have rumble.

Btw: have you shared your system details in the showcase or any other threads? Would love to hear your experiences with various carts. Maybe you could start a thread if you haven't already so we don't digress from the OP's intent in this one.

[Tax]

I use the Gingko Cloud 11. Layers of solid acrylic separated by a layer of sort of squash balls. Marvellous thing.
Quieter backgrounds, more dynamics, better imaging.

Also, i use the Herbies Audio: 'Tenderfeet' . "Just too make sure" ! between the table and the cloud.
- 3 under the motor, (stiff ones) and four under the turntable (soft ones).

All this sits on top of a brass spiked corian 3 layer platform which i mainly use as a levelling system.

Under those threaded spikes i have brass / carbon spke-cup thingies. Herbies Audio.

On the acrylic platter I also use the "Herbies Audio Way Excellent Turntable Matt II". Cleaner highs.

Good stuff Herbies! Works great in some applications.

Can you share what modifications you have done to your Well Tempered TT?

[Lucky Carl]

Caliburn,

Just wanted to thank you for a very informative and well thought out post which summarised the issues surrounding non-suspended tables very well for novice and experienced audio-nutter alike.

Because I am looking at building a new table (wall mounted) for my Gyrodec TT I confess I can't wait for the second instalment covering suspended TT's ;-)

[Arg]

+1 <<responding to GregWormald''s suggestion to put the TT in another room>>
works a treat...
OTOH putting the TT right next to the subwoofer probably 'livens it up'.... which seems to be a priority for many audiophiles.

You two <<Arg and GFuNK>> talk absolute garbage sometimes. adequately isolated turntables have no issues with vibrating air from speakers.

I assume your 'absolute garbage' comment also applies to GregWormald...

Airborne vibration really does affect turntables. Poul Ladegaard was a vibration analyst for B&K Instrumentation in the 70's and he was very clear that his tests showed that airborne vibration is an issue for turntables. I hope you find this information helpful and not so much absolute garbage.

....I have a concrete floor and my tables isolated. I don't have any feedback or obvious sonic issues with my tables even when playing at 110db and people dancing all over the floor. ...

That's good to read, although I must note that when "playing at 110db with people dancing all over the floor", about the only sonic issue one could detect would be if the needle jumped right out of the groove.

....it would be beneficial, prudent and appreciated that those who post on some of these topics, especially when it comes to turntables, arms, cartridges, phonostages etc that they have not used or are not intimately familiar with just not post some generic advice.....There is nothing that beats real life experience so let's all live it first and discuss our experience thereafter.

The OP asked for ideas. I think he is entitled to them without your efforts to narrow the discussion.

BTW generic advice that is correct is much more useful than the purely experiential advice you want to see, which will be useless to anyone without the same TT/arm as you, on the same isolation as you, on the same support as you, in the same room placement as you, in the same room as you, with the same speakers as you. Who on earth is that useful to except yourself and any acolytes who copy your whole life?

<<to GFuNK>> ....do not post if you have nothing to say.

This coming from the man who regularly posts "vinyl rules OK" being his entire post (sometimes just a troll), he now demands specifics or silence from others.

Not sure I get the gyst of this, Tax. It seems to me that the OP (DGV) asked for opinions on isolation systems for turntables which is pretty well what members have responded to.

I must be confused because post #29 about some vinyl rip aiding isolation around the turntable doesn't make sense to me.

Well the OP asked for ideas, and post 29 suggests that playing vinyl rips is an idea that eliminates vibration issues while preserving the sound of your vinyl.

The 25% of vinyl-playing audiophiles who play vinyl because they love the music (as opposed to loving the record itself and the TT itself) might see this as a great idea.

....Turntables come in many shapes and sizes ....
Some of us have audio rooms ...in need of improved floor support. ....
So the suspended tables get a few points for attempting to address these ...issues.
For non-suspended tables the floor problem becomes an issue. ....
Rubber inner tubes can be ....
Suspended "bungee" or "hockey strap" systems also work a treat ....
Once you start looking at commercial alternatives ....
As these sources are often focused on the scientific or engineering community ....
So when faced with a choice of isolation solution it would be good to look at the problem at a high level to decide which is best for you.

For example what is the total weight of your turntable?....
....one should consider if the turntable .... is heavier than the stand it sits on.
If for example you use an active correction system ....
To address this you need to ....
On wooden floors the stand will rock the floor ....
....one should consider a high mass stand....
An active system ..... Active systems typically have....
Passive systems ....are often chosen for ....
.... see if there are springs used. All systems with springs will ....
.... Active systems will actually be better than no isolation at all. So will Passive systems.

Compare the published isolation specifications, ....
.... commercial isolation solutions for your non-suspended table ....the sonic improvements far outweigh the negatives....
Suspended tables using additional suspension systems are a whole nother discussion.

caliburn, I love your post!

But others won't! It is all generalities. Apparently that is unwelcome and we have been counselled to keep quiet. Shhh!

<<to Arg who suggested putting the TT next to the subwoofer to liven up the sound for those who want a livened-up sound>>
Not all audiophile want to liven up the vinyl sound that way....

hi jaspert, I couldn't agree more! But is it clear that some do.

[Batty]

With regards to airbourne vibration, I find that the Rock benefits from removal of the perspex cover rather than leaving it in the up hinged position to act as a 'satellite dish'. I suspect this is pertinant to all TTs with a hinged lid.

[Arg]

With regards to airbourne vibration, I find that the Rock benefits from removal of the perspex cover rather than leaving it in the up hinged position to act as a 'satellite dish'. I suspect this is pertinant to all TTs with a hinged lid.

what about leaving it in the down position?

[caliburn]

Airborne vibration really does affect turntables. Poul Ladegaard was a vibration analyst for B&K Instrumentation in the 70's and he was very clear that his tests showed that airborne vibration is an issue for turntables. I hope you find this information helpful and not so much absolute garbage.



That's good to read, although I must note that when "playing at 110db with people dancing all over the floor", about the only sonic issue one could detect would be if the needle jumped right out of the groove.

caliburn, I love your post!

But others won't! It is all generalities. Apparently that is unwelcome and we have been counselled to keep quiet. Shhh!

hi jaspert, I couldn't agree more! But is it clear that some do.

Hi Arg,

No worries.

Suspended tables - belt driven.

Most have the motor sitting on a separate plane to isolate the motor from the table plinth.

A set of springs or orings or other compliant material is then used to allow the bearing platter and armboard to "wobble" freely independent of the motor.

Turntables I include in this list are SME, LINN LP12, SOTA, THORENS 160's 320's etc, Michell Gyrodecs, Basis and Avids (no offence to other brands of suspended school designs, but these are just examples)

One issue when a belt is used to drive these designs is the belt tension will pull the platter and bearing towards the motor pulley and the spring suspension of the table will fight this (Youngs Modulus) and cause a "bobbing motion" between the platter and the motor.

There isn't much you can do to rectify this other than using a non-suspended design. Some tables like the Audionote address this with 3 motors and 3 belts. Ths provides more even tension and centers the platter more effectively thus allowing for suspension and centering.

A VPI HR-X with the airbladder feet will also display some suspended turntable attributes but the supension tends to be a little firmer than those listed above.

So if you have a real non suspended unit like a TW Acustic then it would further benefit from a suspension system to isolate it from floor modes. This will add some of the isolation that the tables listed above enjoy whilst providing the benefits of fixed motor to platter operation. You wont lose the magic of the image focus or other non-suspended benefits.

Specifically on non-suspended table you must support the motors and the table on the same plane. I do not recommend separating these on 2 separate compliant platforms as you will introduce the "yawing" "bobbing" motions from the suspended school of designs.

You should maintain the original design objective not to have movement between the platter and the motor (by that i mean macro movement - not what happens in all bearings with precession - I call this micro movement and it is not discussed here).

Airborne feedback is another problem entirely and I tend to like music loud. To attenuate in room soundwaves is challenging more from WAF factor than anything else. You need to build a big shroud.

Foam lined hinged shroud like they used to make for dot matrix printers is one method. Hinged for access to the table it should match any decor with it's 1980's beige sides and smoked perspex access lid (not!). Ugly but effective at reducing noise to the inner compartment.

Best is another separate room for the table with acoustic panelling to stop noise. One friend of mine has that luxury and it was conveniently located in an old converted bathroom next to the sound lounge (only an audiophile would remove bathrooms from a house ;-)

So I would suggest you visit the manufacturers websites, download the brochures and compare the vibration attenuation data. If one is 99% efficient at a given frequency and the other is 94% efficient at the same frequency then you have to make the decision based on price and WAF factors. Also compare the published specifications across a range of frequencies.

In personal experience I have used the passive 1/2hz MinusK Negative Stiffness systems under big tables and some smaller ones - Spiral Groove for example (all non-suspended) to good effect. I will try one under a suspended Gyrodec soon and see if it makes a sonic difference worth the investment. I would envisage the passive system will be sympathetic and lower the noisefloor further.

I havent used an Active System under a suspended table but this would be worth investigating as to how it would interact with the compliant suspension of the table.

I have used them under non-suspended tables and they work well on concrete floors.

Hope that is a little more specific as to my experience with tables and isolation.

[proftournesol]

Hi Arg,

No worries.

Suspended tables - belt driven.

Most have the motor sitting on a separate plane to isolate the motor from the table plinth.

A set of springs or orings or other compliant material is then used to allow the bearing platter and armboard to "wobble" freely independent of the motor.

Turntables I include in this list are SME, LINN LP12, SOTA, THORENS 160's 320's etc, Michell Gyrodecs, Basis and Avids (no offence to other brands of suspended school designs, but these are just examples)

One issue when a belt is used to drive these designs is the belt tension will pull the platter and bearing towards the motor pulley and the spring suspension of the table will fight this (Youngs Modulus) and cause a "bobbing motion" between the platter and the motor.

There isn't much you can do to rectify this other than using a non-suspended design. Some tables like the Audionote address this with 3 motors and 3 belts. Ths provides more even tension and centers the platter more effectively thus allowing for suspension and centering.

I havent used an Active System under a suspended table but this would be worth investigating as to how it would interact with the compliant suspension of the table.

Funk Firm deal with this by putting a DC motor on the sub-chassis and using a 3 point asymmetric 'Vector Drive' with 2 slave pulleys. Most passive isolators I've tried under the PT suck all the life out of the sound, it seems better to leave the suspension to it's own devices although coupling the turntable to the Sound Mechanics table by replacing the PT baseboard with a thick end-grain balsa board sitting directly on the table does help, presumably by increasing the effective mass of the plinth.

[Dismord]

Interestingly I have some Decca and RCA stereo LP's that also have rumble.

Btw: have you shared your system details in the showcase or any other threads? Would love to hear your experiences with various carts. Maybe you could start a thread if you haven't already so we don't digress from the OP's intent in this one.

I can't remember if I've listed my collection of audio junk anywhere on this forum. I'm somewhat paranoid about doing so as I've twice been burgled of all my audio gear. The last time I was stupid enough to list what I had and identify myself elsewhere on a newsgroup. They caught the buggers trying to sell my Revox B 77. It came out during the court case they were part of an organised racket that combs the web for specific gear, not just audio gear either, that can be linked to known individuals - they even take orders ! However, I'll list my audio stuff on whichever section you'd care to nominate as I've remained assiduously anonymous here.
As to recorded rumble on old mono LP's apparently they didn't' worry much about rumble in the vertical plane in those days as mono cartridges then didn't reproduce it. Might be an just another urban myth though.

[Dismord]

With regards to airbourne vibration, I find that the Rock benefits from removal of the perspex cover rather than leaving it in the up hinged position to act as a 'satellite dish'. I suspect this is pertinant to all TTs with a hinged lid.

Too true. Sadly for those who are paranoid about their LP's gathering dust whilst playing I've yet to encounter a turntable that didn't benefit from removing the cover during playback.

[wolster]

Too true. Sadly for those who are paranoid about their LP's gathering dust whilst playing I've yet to encounter a turntable that didn't benefit from removing the cover during playback.

That certainly applies to my LP12, even though owners seem to be divided on the issue.

[proftournesol]

Too true. Sadly for those who are paranoid about their LP's gathering dust whilst playing I've yet to encounter a turntable that didn't benefit from removing the cover during playback.

No real benefit to removing the lid on the PT

[MarkT]

Too true. Sadly for those who are paranoid about their LP's gathering dust whilst playing I've yet to encounter a turntable that didn't benefit from removing the cover during playback.

Yes , thin perspex dust covers tend to vibrate a bit when playing music fairly loudly......I always used to
remove it on the Linns , Voyd and PT decks I had , and I think they sounded a little better that way.

The Pioneer/Exclusive P3 has a very heavy dustcover made from thick toughened glass with wood side panels.
Looks a bit strange but it is very effective , no vibration at all with it , and I hear no improvement at all by removing it.

[Dr Good Vibe]

Great explanation caliburn, there is many years of knowledge there boys.

[Arg]

... 'livens it up'.... which seems to be a priority for many audiophiles.

Not all audiophile want to liven up the vinyl sound that way....

.... Most passive isolators I've tried under the PT suck all the life out of the sound,....

Ahem.

[proftournesol]

Something caught in your throat Arg?

[Arg]

Amen.

[Tax]

The OP asked for ideas. I think he is entitled to them without your efforts to narrow the discussion.

Well the OP asked for ideas, and post 29 suggests that playing vinyl rips is an idea that eliminates vibration issues while preserving the sound of your vinyl.

"So what is your ultimate isolation for your TT gear" is the OP.

I don't see neither your posts nor GFunk's posts mentioning what TT's or isolation you are using.

Post #29 and your defence of it seems quite churlish.

I am not sure what the issue is but I am getting a sense that you may not like the vinyl format or members who prefer using mainly vinyl. Is this so?

I don't mind any format each has it's advantages and disadvantages. Currently listening to my 47 Labs transport and DAC.

[Young Skywalker]

One issue when a belt is used to drive these designs is the belt tension will pull the platter and bearing towards the motor pulley and the spring suspension of the table will fight this (Youngs Modulus) and cause a "bobbing motion" between the platter and the motor.

I raised this very point with Conti and he said it was a total non-issue compared to the horizontal run out observed in all of the turntables he has examined.

Specifically on non-suspended table you must support the motors and the table on the same plane. I do not recommend separating these on 2 separate compliant platforms as you will introduce the "yawing" "bobbing" motions from the suspended school of designs.

The question then becomes, is the noise from the motor being fed into the turntable more objectionable than any microscopic change in belt tension during playback? Dietrich Brakemeier in Germany (he made the Apolyt turntable) and A. J. Conti of Basis seem to believe that it is essential to isolate the motor from the turntable.

Best is another separate room for the table with acoustic panelling to stop noise. One friend of mine has that luxury and it was conveniently located in an old converted bathroom next to the sound lounge (only an audiophile would remove bathrooms from a house ;-)

But how does one then optimise SRA for each LP when the turntable is another an adjacent room? Could one not argue that correct SRA is more important to the sonic result than any potential negative influence of air borne vibrations, assuming a well designed turntable?

Edited by Young Skywalker, 26 March 2012 - 09:27 PM.

[caliburn]

I raised this very point with Conti and he said it was a total non-issue compared to the horizontal run out observed in all of the turntables he has examined.



The question then becomes, is the noise from the motor being fed into the turntable more objectionable than any microscopic change in belt tension during playback? Dietrich Brakemeier in Germany (he made the Apolyt turntable) and A. J. Conti of Basis seem to believe that it is essential to isolate the motor from the turntable.



But how does one then optimise SRA for each LP when the turntable is another an adjacent room? Could one not argue that correct SRA is more important to the sonic result than any potential negative influence of air borne vibrations, assuming a well designed turntable?

Hi Aaron,

Agree with Conti entirely. Absolutely essential to isolate motor from table. even the belt still transmits noise to the platter. So it becomes a choice the designer has to make. With AJ's superior suspension the need for isolation from a third party platform is a moot point. His tables are superb.

On non-suspended tables however you can benefit from improved isolation. I have heard isolators work under phono stages, dacs, cd transports and of course tables. Worth trying if you can get one on approval.

SRA - I set for 92 degrees using microscope and then leave it alone for most records.

[GFuNK]

"So what is your ultimate isolation for your TT gear" is the OP.

I don't see neither your posts nor GFunk's posts mentioning what TT's or isolation you are using.

Post #29 and your defence of it seems quite churlish.

I am not sure what the issue is but I am getting a sense that you may not like the vinyl format or members who prefer using mainly vinyl. Is this so?

I don't mind any format each has it's advantages and disadvantages. Currently listening to my 47 Labs transport and DAC.

I think you need to relax tax.

I don't own a turntable, quite like them though. What mechanical engineer wouldn't admire them for what they are?! Unfortunately I don't have the money to spend on a decent one though.

I'm a noise and vibration engineer so I thought I could offer something to this thread anyways.

Ah the infamous post 29 that you can't seem to move on from, your living in the past!

Still not a bad suggestion to get the vinyl sound without insonification feedback.

I recall a system at the last hifi show in melbs that performed an ADC at the turntable at some crazy sample and bit rate, transmitted the digital signal wirelessly to a receiver elsewhere and performed the DAC for amplification and playback. Interesting concept but it relies on your faith in the digital reproduction I guess.

Edited by GFuNK, 26 March 2012 - 10:05 PM.

[Young Skywalker]

Thanks for sharing your knowledge, Mark. Very much appreciated by all, I am sure.

Worth trying if you can get one on approval.

I am certainly keen to examine the improvement, if any, that proper isolation may bring to amplification which uses vacuum tubes.

I think that an SRA of 92 degrees can work well for the majority of LPs, however it is those vintage RCA Living Stereo and Decca LPs which require one to drop the rear of the arm by a considerable amount in order to unlock the soundstage.

[frankn]

I've been looking around for something to add extra isolation to my Clearaudio AvantGarde Magnum tt.
Several companies make isolation devices using opposing magnets, Clearaudio themselves- Magix2, another interesting set are named Spike Sound Will. Both have had good write-ups. Has anyone used these type of products on solid (ie non-suspension) turntables?

[Arg]

"So what is your ultimate isolation for your TT gear" is the OP.

...and "what are your ideas". And it's OK to answer the OP in those terms.

I don't see neither your posts nor GFunk's posts mentioning what TT's or isolation you are using.

As I said in post #9, it's in the next room and that's pretty much the ultimate.

Post #29 and your defence of it seems quite churlish.

I was only trying to explain its relevance to the OP, which you said you didn't grasp. Just trying to help. No need to take aim at me for that.

I am not sure what the issue is but I am getting a sense that you may not like the vinyl format or members who prefer using mainly vinyl. Is this so?

Not at all. Goodness knows how many times I have emphasised that we all prefer what we prefer and that's fine.

And I'm quite fond of my vinyl rig. But I am less fond of the Mystique of Vinyl and some of the factual errors that get posted in that line.

I don't mind any format each has it's advantages and disadvantages. Currently listening to my 47 Labs transport and DAC.

+1 to that!

[Dr Good Vibe]

Boy's, Boy's, Boy's.

[Gabba]

One of the lab isolation tables from uni... mmm. They would do the trick.

Edited by Gabba, 27 March 2012 - 07:13 PM.