DIY audio: what are you building?

[Spinnergeoff]

Here are a couple of speakers I've built and sold this year. A 12" three-way firstly, with a Coral midrange and unbranded other bits (!), and a 10" Peerless + Coral below. I have to keep selling to make room for the next build, and pay for more materials. Not done for profit, just for my own satisfaction as a retired guy with a history of music appreciation and as a retailer in the music and hifi world. It's hard parting with things that you've made sound just the way you like them, but that's the way it has to be! My next project will be underway soon, another biggish three-way model. Each one is different.

Edited September 16, 2017 by Spinnergeoff
clarify picture positioning

[mwhouston]

Nice build look flash. I build and sell for the same reasons as you. I build for myself and then after a while put them up for sale to pay for the next build. 

[Steven Hinchliffe]

I like the front porting@spinnergeoff [emoji5]

Sent from my SM-G900I using Tapatalk

[mwhouston]

One of the two 6L6 SE UL amps I built a few months back is extremely quiet. My 15" Beyma concentrics are 99db effcient and even with my ear stuck right in the cone there is no him, buzz or hiss of any kind. I thought I would try it playing head phones.

 

I really felt I would hear a hum here through the phones but no, no hum, nothing, dead quiet. I used the ESP resistive network idea to break down the higher output voltage of a power amp (though only 2W) to drive the phones. The network presents 8ohms to the amp so it thinks it is driving speakers.

 

I found it a little shill on some tracks but excellent on others. The fact that it was absolutely dead quiet made me want to continue to listen but in the end I went back to my Oatley-Burson (V5i-D)  battery power portable triode headphone amp. The Burson chip makes this an extremely lush sounding portabl triode head phone amp and really hard to beat. But the experiment was worth while with mainly pleasing results. 

[mwhouston]

The Prada box houses an ESP inspired two stage OPAMP preamp with OPA227 chips. It also has some Cornell Dubilier and Solen  audio caps and all 0.7mm solid silver wiring throughout. Alps Blue Velvet and solid brass knob. 

 

 

[mwhouston]

Another case where the simple teak made a big difference.

 

I have been swapping in and out between my DIY 1920's tubed "Intermezzo" (all 330mW of it) and my DIY 6L6 SE UL amp "Silver Supreme". I was disappointed at how Intermezzo was sounding when I have really enjoyed it in the past. I was blaming the 6L6 amp feeling that comparatively it was making Intermezzo sound poor. Then I remembered I have been changing speaker Xover points and treble loudness recently and had not played Intermezzo on the new setup..

 

Intermezzo sounded dull and in-dynamic. Not how I remember it. I can alter the tweeter level by 1.5 and 3db. I raised it 1.5db and the music was back. Noy only did the whole sound lift but it sounded more dynamic and whole. Much better.

 

The Silver Supreme 6L6 amp goes out to 47KHz where Intermezzo only goes to 15KHz due to the fact its nickel core input transformer only goes to 15K. Lifting the treble by 1.5db brought it all back in balance.

[selectedgrub]

Making speaker cradle stands

 

 

[mwhouston]

Not sure anyone else has done this but I put together a book of my DIY valve power amps. I called it the "The retro-thermionic valve amplifier book". It has 19 double sided gloss pages of photos of my builds over a number of years. On the back the underneath on a few power amps and some ideas about valve amps.

 

The book is 210mm X 210mm and is meant to be more of a pictorial than a literary masterpiece.  On the bottom of each page is just the name of the amp and a few details. I spent time freshening up the images which were mostly sharp and good colour and I think it has paid off. I hope to do an equivalent for my DIY valve preamps. The hat I got in Bali where a computer controlled sewing machine sews lettering on to a cap. 

 

I'm taking orders for the book or just wait for the film. Lol.

 

 

[RoHo]

Piccie shows several years DIYing.

Top is the pre-amp using Allen Wright's FVP5A circuit.

Below is the power amp "medley".  What we have is the power supply at the bottom.  It includes two separate supplies (transformer, valve rectifier, pi filters with chokes). It can power either of the two power amps.

First power amp (top middle) is single ended based on Vinylsavor Tomas's 6CB5A design.  Lundahl interstage transformers feature in the nude and it can use a number of (cheap!) Russian pentodes on the input.

Second power amp below this is push-pull using 6B4G valves for outputs into Lundahl transformers.  Input stage is Allen Wright's PP2C which uses 6H30 valves.

What have I learnt? Valve amps, especially with multiple transformers and chokes are too heavy.  Single ended and push-pull amps both sound good. I hate cutting metal. I probably can't be bothered switching between power amps just for the hell of it. I need a bigger rack, especially as I intend to add a 4P1L pre-amp which is in the component-gathering stage.

Under the first amp is a headphone amp which was a recent, just-for -the-heck-of-it build.  Uses eBay boards/kit based on a variation of Nelson Pass's Zen design.  No valves so not worth talking about  

Edited October 12, 2017 by RoHo

[mwhouston]

@RoHo mate, fantastic effort. From he who builds everything and especially tube power amps and preamps I know the hours and hours of labour which go Into these.

 

A personal dislike is open frame trannies whether power trannies or OPTs. When I use open frame, generally Edcors, they go in the base under the bonnet.

 

I'm a little as you are I'm not a big fan of swapping out power amps and preamps just for a listen. And I never A/B alone. Currently I have two 6L6 power amps and one 6V6 power amp (SE UL) which I rotate, slowly. So one amp may be in play for a month then I may switch for another for a month and sometimes I dont switch for six months or more. I also have a DIY 250W class D which gets occasional air play.

 

When I say I never A/B if a piece of gear doesn't sound right it is either fixed or goes. I enjoy the "character" of each amp etc. and enjoy the differences. But I had my brother's 6T9 back here which he bought from me years years ago. I could hear my more recent amps were better and therefore after some minor repair went back to him with no regrets. Still a nice sounding little power amp.

 

Lately all my builds have been SE ULs even amps like the Decware EL84 which was designed as a strapped triode, ended up a UL amp. I just like thier more even frequency response and thier superior drive - all 2Ws of it. With 99db efficient 15" coaxials speakers two Watts is stacks of power and head room.

 

Once again top effort we should get tougher for a listen to each other system. 

[RoHo]

1 hour ago, mwhouston said:

@RoHo mate, fantastic effort. From he who builds everything and especially tube power amps and preamps I know the hours and hours of labour which go Into these.

 

A personal dislike is open frame trannies whether power trannies or OPTs. When I use open frame, generally Edcors, they go in the base under the bonnet.

Thanks, mwhouston.  Sadly I have zero woodworking skills so my amps look particularly daggy next to yours!

The open framed Hammonds do look a bit "rugged".  It's all about compromise.  Having them on top leaves more room underneath for big polypropylene caps and the like.  And I like the slim-line chassis which are not deep enough to accomodate them anyway.  I would prefer to use those black transformer covers but then that's more expense and more, ugh, drilling.  I'll just say it's all part of the new industrial-chic design style.  

 

[Nada]

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[Owen Y]

Beautiful work @RoHo

I'm not a metalworking enthusiast myself. much preferring wood to work with.

Have admired Thomas Mayer's stuff since the Sound Practices era - esp admire his discipline of building with jigs, threading it all together with rod & nuts, then slips it all into slim wood veneered sleeves.

 

I remember too, Allen's FVP preamps from his 'cookbook' - how do you like the tube hybrid phono performance?

Also, comments please on how you like the sound of your various amps.

Re. the weight of the amps, you may know the expression 'Dunker Factor'  .

 

Me, I've built various SE triode amps, but have settled on DHT PP for past few yrs.

 

Cheers, Owen

http://darklanternforowen.wordpress.com/

[RoHo]

16 hours ago, Owen Y said:

Beautiful work @RoHo

I'm not a metalworking enthusiast myself. much preferring wood to work with.

Have admired Thomas Mayer's stuff since the Sound Practices era - esp admire his discipline of building with jigs, threading it all together with rod & nuts, then slips it all into slim wood veneered sleeves.

 

I remember too, Allen's FVP preamps from his 'cookbook' - how do you like the tube hybrid phono performance?

Also, comments please on how you like the sound of your various amps.

Re. the weight of the amps, you may know the expression 'Dunker Factor'  .

 

Me, I've built various SE triode amps, but have settled on DHT PP for past few yrs.

 

Cheers, Owen

http://darklanternforowen.wordpress.com/

Thanks, Owen.

I learned a lot from Tomas' blog.  More recently he seems to have become a commercial kit supplier and so he doesn't publish schematics.  A shame for us DIYers as he had great applications using inexpensive valves like the 6CB5A.

I'm only an occasional vinyl listener but my impression of the phono stage is that is in line with Allen Wright's crisp and clear "house sound".  "I want speed and I want definition" I remember him stating in a forum way back.  So it's all that and with good bass too.  

On the sound of the amps.  I'm still getting a handle on their differences.  I hate quick-swap A/B comparisons.  My short-term audio memory is poor and find that I listen in a fundamentally different way in this situation.  I just end up confused and frustrated.  Instead I'll listen to just one amp for ages then swap when I feel like it.  ATM all I can say is that they're both good with no marked shortcomings.  I should say that my speakers roll off at 70 Hz with below that handled by active subwoofer - probably making it easier for the SE amp.

Rod

[mwhouston]

3 minutes ago, RoHo said:

Thanks, Owen.

I learned a lot from Tomas' blog.  More recently he seems to have become a commercial kit supplier and so he doesn't publish schematics.  A shame for us DIYers as he had great applications using inexpensive valves like the 6CB5A.

I'm only an occasional vinyl listener but my impression of the phono stage is that is in line with Allen Wright's crisp and clear "house sound".  "I want speed and I want definition" I remember him stating in a forum way back.  So it's all that and with good bass too.  

On the sound of the amps.  I'm still getting a handle on their differences.  I hate quick-swap A/B comparisons.  My short-term audio memory is poor and find that I listen in a fundamentally different way in this situation.  I just end up confused and frustrated.  Instead I'll listen to just one amp for ages then swap when I feel like it.  ATM all I can say is that they're both good with no marked shortcomings.  I should say that my speakers roll off at 70 Hz with below that handled by active subwoofer - probably making it easier for the SE amp.

Rod

I tend to leave an amp or component in for weeks then swap to what I want to compare with. If I find I want to go back after a few days to what I had then it shows what I really liked . Generally flicking between two components  playing the same track over and over proves nothing. Long term listening over a wide range of music asks the question; "can I live with this"?

[Owen Y]

I totally agree with you both - I always advise never to A/B, unless you want to drive yourself nuts

With long term listening, you develop a good sense of a component's strengths & weaknesses.

 

Cheers, Owen

http://darklanternforowen.wordpress.com/

[Guest]

@mwhouston

Keen on a cap Mate, suits the geek in me, how do I sign up ?

 

[mwhouston]

On 5 October 2017 at 2:10 PM, mwhouston said:

Not sure anyone else has done this but I put together a book of my DIY valve power amps. I called it the "The retro-thermionic valve amplifier book". It has 19 double sided gloss pages of photos of my builds over a number of years. On the back the underneath on a few power amps and some ideas about valve amps.

 

The book is 210mm X 210mm and is meant to be more of a pictorial than a literary masterpiece.  On the bottom of each page is just the name of the amp and a few details. I spent time freshening up the images which were mostly sharp and good colour and I think it has paid off. I hope to do an equivalent for my DIY valve preamps. The hat I got in Bali where a computer controlled sewing machine sews lettering on to a cap. 

 

I'm taking orders for the book or just wait for the film. Lol.

 

 

Yes I know I'm quoting myself. But I guy just bought a retro-thermionic amp book. When he saw it on FB he said he wanted one. I thought he was joking but explains he has been following my retro-thermionic blogspot for years and also my other blogs. And said he loves my stuff. I had a chance to get a second print so he bought the original. Posted it off today.

 

Golly!

[Spinnergeoff]

I have just completed and put these up for sale - my latest build, large format floor standing speakers. The bass box (rear ported) is 100L with a 12" Atomix woofer, Marantz midrange and a little soft dome neodymium magnet tweeter in a custom made housing dressed up with an aluminium front plate. There's also a rear-firing Magnavox paper cone midrange for more spacious sound. The top housing didn't need to be sealed as all those smaller drivers are solid backed, not open. The 15" Pioneer woofer I intended to use didn't achieve the results I hoped for, so the Atomix went in with an extra plate, which also acts as a front panel vibe damper. I've put bits of mdf inside on all the other panels to deaden them a bit too. 

Sound quality is engaging, detailed but not harsh, bass down to 40Hz, handles most styles of music well. I won't put anything up for sale unless I find them enjoyable, and I've some pretty good benchmark speakers to go by, including Alon V, Mirage M790 and Coral Flat 10.

Cosmetics are better than some I've done, but still rough. I've used pine sides with a light cherry stain, and metallic charcoal paint for the front and top. They are decidedly industrial in looks, drawing on (at least in part) the famous Technics SB-7000 for inspiration.

I enjoy the craft of building and the challenge of doing something different each time, but I'm totally out of space at home so some have to hit the road, so to speak. I'm not game to give the wife the total speaker and amplifier count around here - it's best to just keep them rotating and hide some under the house temporarily; let's just say conservatively a dozen pairs of speakers and as many amps, a mix of receivers, integrateds, and two pre-powers.

 

[mwhouston]

Grills, WAF?

[Spinnergeoff]

10 hours ago, mwhouston said:

Grills, WAF?

Wife Acceptance Factor? That's probably a lost cause with these ones. 

[Upfront]

More like re-building than building. Still a fun part of the hobby!

[mwhouston]

Some images of a tube HP amp I built for a non-SNA member. Simple 6AS7 and 12AU7. Sounds good. I have built one of these before.

 

 

[bvuka2013]

Looks great, Mark

How much would one of these simple HP amps cost to build?

[mwhouston]

The headphone amp I posted a little earlier had some real problems. Over the last week I have been able to solve all of them. Firstly a loud hum; removed one earth wire and added another - fixed, then up to this morning it would distort on some heavy going rock passages.  It appears my Pi server and HDMI audio ripper put out better than 2V. The E88CC driver tube is biased at 1.5V. The driver tube was being overdriven. By scaling back the Pi volume to 30% and then bring up the volume on the amp there is now no distortion on even the heaviest drum filled and bass filled tracks.

 

One problem is still to be solved. Though the power tranni is in spec for HT current  the filament current is 12% under-spec. The tranni gets very hot. I have a bigger beefier tranni on the way. Hopefully it will fit on the top plate, it should being only marginally bigger. 

 

The sound of this very simple HP amp is excellent, it looks as good as it sounds and once the new tranni is fitted it will be a keeper. Drives both 250ohm phones and  32ohm phones with ease. 

 

http://retro-thermionic.blogspot.com.au/2017/11/sanctum-simple-tube-headphone-amp.html

 

 

 

Edited November 10, 2017 by mwhouston