DIY audio: what are you building?

[mwhouston]

2 hours ago, RankStranger said:

Altec rebuild. I’ve been putting it off because I don’t want to stop listening to them for that long

Show us an image of the speakers. 

[RankStranger]

@mwhouston
 

 

more info here 

 

Edited December 15, 2023 by RankStranger

[mwhouston]

Close but no cigar, amp finished but yet to start external PS. Brds. are LJM Class AB 120W. Have most parts for the PS  just wanted to get the amp done. I have a little time as waiting parts for a commission job. 

[playdough]

1 hour ago, mwhouston said:

Close but no cigar, amp finished but yet to start external PS. Brds. are LJM Class AB 120W. Have most parts for the PS  just wanted to get the amp done. I have a little time as waiting parts for a commission job. 

Nice work, 

[mwhouston]

3 hours ago, playdough said:

Nice work, 

Thanks mate. 

[RankStranger]

 

I’ve completed the third and final (Ha! As if ) iteration of my Wayne Colburn BA2018 linestage preamp. I'm starting to feel like Marge Simpson with her Chanel suit but I've had three or four other pretty good preamps in the system and I'm yet to hear one I like more. 
 

 

The biggest change is that, after years of anxiously futzing about with balanced connections, cables and converters, I've allowed myself to become completely unbalanced (lol) and feel 100% better for it.

 

 

To some of you this box probably looks like an hilarious Rube Goldberg machine of redundant complications. I'm ok with that. This is just how I could do the things I wanted to do without four years of trade school and/or forty years of field experience. I've tried to use what I do know to have a bit of fun without causing any sonic degradation and, as far as I can hear, I've been successful in that. 

  

Here's where I've ended up:

- A Schurter filtered AC inlet
- a 50VA triad magnetics medical-grade (to utterly misquote Mr Pass, if it's good enough for dialysis it's good enough for music) toroidal transformer
- a Glassware bipolar lv-reg PSU
- An EIZZ 4-way input selector
- a DACT-style smd 21-stepped attenuator
- Duelund 26GA tinned solid copper wire in cotton and oil for audio signals
- Multicomp gold-plated, pure copper rca sockets that @andyr mentioned somewhere on the forum
- half of a Rod Elliot P05 PSU with a discrete 10VA transformer, which drives:
- an LED input indicator
- LM3914-based LED volume-level indicators
- an AliExpress VU meter driver-board and VU meters, the signal wires of which are galvanically-isolated from the audio circuit with the redundant bal-SE converter transformers
- A slightly-modified/butchered 320mm aluminium enclosure from AliExpress

 

 

I was worried about potential interference from the VUs and LEDs (I worry a lot about interference. Can you tell?) so I put in a defeat switch for the P05, just in case any of it was audible. I don’t think it is, at least in my current system configuration. I still have an earth leak or some grounding issue somewhere. It's not bothering me enough to chase down at the moment but I'll need to address it at some point. 

That brown thing is an organic, dielectronic, cryometrically-isolated quantum-state resonator and definitely not a bit of decking off-cut I jammed in there because my sticky came unstuck. No siree. Nope. 

 

So, to sum up, I've ended up where I wanted to - insofar as the operation and "features" go - and it certainly sounds superb (which I can’t really take credit for. But I didn’t F it up, which is something). It's not as elegant as I imagined, either in an aesthetic or tactile sense but it's not bad for a (mostly) first go.

 

I've become distracted from my planned Altec rebuild by an idea for a hifi rack which won’t leave me alone so that's next. 

[mwhouston]

3 minutes ago, RankStranger said:

 

I’ve completed the third and final (Ha! As if ) iteration of my Wayne Colburn BA2018 linestage preamp. I'm starting to feel like Marge Simpson with her Chanel suit but I've had three or four other pretty good preamps in the system and I'm yet to hear one I like more. 
 

 

The biggest change is that, after years of anxiously futzing about with balanced connections, cables and converters, I've allowed myself to become completely unbalanced (lol) and feel 100% better for it.

 

 

To some of you this box probably looks like an hilarious Rube Goldberg machine of redundant complications. I'm ok with that. This is just how I could do the things I wanted to do without four years of trade school and/or forty years of field experience. I've tried to use what I do know to have a bit of fun without causing any sonic degradation and, as far as I can hear, I've been successful in that. 

  

Here's where I've ended up:

- A Schurter filtered AC inlet
- a 50VA triad magnetics medical-grade (to utterly misquote Mr Pass, if it's good enough for dialysis it's good enough for music) toroidal transformer
- a Glassware bipolar lv-reg PSU
- An EIZZ 4-way input selector
- a DACT-style smd 21-stepped attenuator
- Duelund 26GA tinned solid copper wire in cotton and oil for audio signals
- Multicomp gold-plated, pure copper rca sockets that @andyr mentioned somewhere on the forum
- half of a Rod Elliot P05 PSU with a discrete 10VA transformer, which drives:
- an LED input indicator
- LM3914-based LED volume-level indicators
- an AliExpress VU meter driver-board and VU meters, the signal wires of which are galvanically-isolated from the audio circuit with the redundant bal-SE converter transformers
- A slightly-modified/butchered 320mm aluminium enclosure from AliExpress

 

 

I was worried about potential interference from the VUs and LEDs (I worry a lot about interference. Can you tell?) so I put in a defeat switch for the P05, just in case any of it was audible. I don’t think it is, at least in my current system configuration. I still have an earth leak or some grounding issue somewhere. It's not bothering me enough to chase down at the moment but I'll need to address it at some point. 

That brown thing is an organic, dielectronic, cryometrically-isolated quantum-state resonator and definitely not a bit of decking off-cut I jammed in there because my sticky came unstuck. No siree. Nope. 

 

So, to sum up, I've ended up where I wanted to - insofar as the operation and "features" go - and it certainly sounds superb (which I can’t really take credit for. But I didn’t F it up, which is something). It's not as elegant as I imagined, either in an aesthetic or tactile sense but it's not bad for a (mostly) first go.

 

I've become distracted from my planned Altec rebuild by an idea for a hifi rack which won’t leave me alone so that's next. 

Looks very good. Well done. 

[betocool]

5 hours ago, RankStranger said:

 

I’ve completed the third and final (Ha! As if ) iteration of my Wayne Colburn BA2018 linestage preamp. I'm starting to feel like Marge Simpson with her Chanel suit but I've had three or four other pretty good preamps in the system and I'm yet to hear one I like more. 
 

 

The biggest change is that, after years of anxiously futzing about with balanced connections, cables and converters, I've allowed myself to become completely unbalanced (lol) and feel 100% better for it.

 

 

To some of you this box probably looks like an hilarious Rube Goldberg machine of redundant complications. I'm ok with that. This is just how I could do the things I wanted to do without four years of trade school and/or forty years of field experience. I've tried to use what I do know to have a bit of fun without causing any sonic degradation and, as far as I can hear, I've been successful in that. 

  

Here's where I've ended up:

- A Schurter filtered AC inlet
- a 50VA triad magnetics medical-grade (to utterly misquote Mr Pass, if it's good enough for dialysis it's good enough for music) toroidal transformer
- a Glassware bipolar lv-reg PSU
- An EIZZ 4-way input selector
- a DACT-style smd 21-stepped attenuator
- Duelund 26GA tinned solid copper wire in cotton and oil for audio signals
- Multicomp gold-plated, pure copper rca sockets that @andyr mentioned somewhere on the forum
- half of a Rod Elliot P05 PSU with a discrete 10VA transformer, which drives:
- an LED input indicator
- LM3914-based LED volume-level indicators
- an AliExpress VU meter driver-board and VU meters, the signal wires of which are galvanically-isolated from the audio circuit with the redundant bal-SE converter transformers
- A slightly-modified/butchered 320mm aluminium enclosure from AliExpress

 

 

I was worried about potential interference from the VUs and LEDs (I worry a lot about interference. Can you tell?) so I put in a defeat switch for the P05, just in case any of it was audible. I don’t think it is, at least in my current system configuration. I still have an earth leak or some grounding issue somewhere. It's not bothering me enough to chase down at the moment but I'll need to address it at some point. 

That brown thing is an organic, dielectronic, cryometrically-isolated quantum-state resonator and definitely not a bit of decking off-cut I jammed in there because my sticky came unstuck. No siree. Nope. 

 

So, to sum up, I've ended up where I wanted to - insofar as the operation and "features" go - and it certainly sounds superb (which I can’t really take credit for. But I didn’t F it up, which is something). It's not as elegant as I imagined, either in an aesthetic or tactile sense but it's not bad for a (mostly) first go.

 

I've become distracted from my planned Altec rebuild by an idea for a hifi rack which won’t leave me alone so that's next. 

Love me a pair of good VU meters. Care to share a link? Looks awesome. The Volume LED idea is excellent!

 

Cheers,

 

Alberto

[RankStranger]

58 minutes ago, betocool said:

Love me a pair of good VU meters. Care to share a link? Looks awesome. The Volume LED idea is excellent!

 

Cheers,

 

Alberto

Thanks, Alberto. I think I’m going to add some more resistance to dim the LEDs a bit but I’m overall happy with how it turned out. It was based on the project at this link http://www.learningaboutelectronics.com/Articles/LM3914-dot-bar-display-driver-circuit.php

 

the driver board is here https://a.aliexpress.com/_mtzT2ZQ and the vu meters are here
https://a.aliexpress.com/_mrIKcqs but there are dozens of listing for the same or similar

 

aliexpress being what it is, I ended up with a spare stereo driver board and a single vu meter, both of a different type. If you’re interested pm me

Edited December 26, 2023 by RankStranger

[mwhouston]

Well into a tube and chip integrated for another. These PCBs are a hell of a lot of work.

Edited December 29, 2023 by mwhouston

[mwhouston]

Just completed and now listening to a tube and chip integrated. Fast and crisp. Absolutely dead, dead quiet thanks to CMRR. 80Wpc, 300VA power tranni, choked power cord, rodium RCAs, RFI/EMI power filter, heavy duty speaker binding posts and 2U 19” rack mount. At the members request a low filter switchable cut of 6db at 150hZ. Also a 24 step step attenuator. . 

Edited January 5, 2024 by mwhouston

[Addicted to music]

@mwhouston

 

I cant blow it up nenough to see the details on that integrated chip,  do you have any data on that?

Edited January 6, 2024 by Addicted to music

[mwhouston]

55 minutes ago, Addicted to music said:

@mwhouston

 

I cant blow it up nenough to see the details on that integrated chip,  do you have any data on that?

Looks like 0.005 to 0.01% distortion at 50W. Now thats low but the tube warmth from the (now upgraded) Russian 6N3-EB should add a little tube richness. At least that’s how it sounded. 
 

https://www.digikey.com/htmldatasheets/production/555092/0/0/1/tda7294.html

 

[Addicted to music]

6 minutes ago, mwhouston said:

Looks like 0.005 to 0.01% distortion at 50W. Now thats low but the tube warmth from the (now upgraded) Russian 6N3-EB should add a little tube richness. At least that’s how it sounded. 
 

https://www.digikey.com/htmldatasheets/production/555092/0/0/1/tda7294.html

 

 

Very nice Matt,  

 

these chip amps are indestructible,  has short circuit protection, 4-8ohm drive.    I pulled apart a Behringer 3031A studio monitors that sound really good and was surprised that it had these chip amps,  one for the tweeter and one for the bass driver.  They have been thrashed to death by the owner and they still sound bloody good.   Even though they were trashed,  both tweeter and kevlar drivers are flawless,  surprised at the beating it takes, because its way within limits and the chip amp being indestructable.

[mwhouston]

9 hours ago, Addicted to music said:

 

Very nice Matt,  

 

these chip amps are indestructible,  has short circuit protection, 4-8ohm drive.    I pulled apart a Behringer 3031A studio monitors that sound really good and was surprised that it had these chip amps,  one for the tweeter and one for the bass driver.  They have been thrashed to death by the owner and they still sound bloody good.   Even though they were trashed,  both tweeter and kevlar drivers are flawless,  surprised at the beating it takes, because its way within limits and the chip amp being indestructable.

On the PCB there is soft start and speaker crowbar protection via relay. And the chips would have voltage and current limiting. Lot of protection. 
 

Mark. 

 

 

[Addicted to music]

4 hours ago, mwhouston said:

On the PCB there is soft start and speaker crowbar protection via relay. And the chips would have voltage and current limiting. Lot of protection. 
 

Mark. 

 

 

 

BTW mark, 

 

take my hat of to you on how neat its built.  job well done!

[mwhouston]

26 minutes ago, Addicted to music said:

 

BTW mark, 

 

take my hat of to you on how neat its built.  job well done!

Thanks for the nice compliment. I treat DIY audio as art having both form and function. Both must be in harmony. 

[mwhouston]

While waiting for a large tube power tranni to arrive from EVATCO for another EL3N amp Im pressing on with the PS for my finished LJM amp. 100,000uf bypassed. 

[mwhouston]

In Stereophile mag over the last few years a lot of integrated amps have been reviewed. Integrated seem to be coming back. Some with streamers,DACs etc.Most are very compact. Being so compact I would have thought they would have gone with Class D amp modules. But no Class AB appears to dominate. In fact there are very few are Class D types. 
 

Of the Class AB amps I’ve built over the years I have always been impressed how good they sound and how quiet they are. This includes seven Holton based amps and two with  LJM modules. As Mr Holton once said to me over the phone, there is a lot of life left in Class AB. From the rush of Class AB compact integrated amps coming out I’d have to agree. 

[andyr]

Oohhh, @mwhouston - I hope you've got your flame-proof undies on, Mark!  

 

[mwhouston]

45 minutes ago, andyr said:

Oohhh, @mwhouston - I hope you've got your flame-proof undies on, Mark!  

 

Well it is my observation from a reasonable source. Others may not agree but what are they basing their observation on.  
 

Just an aside my first TT in the early 70s was a Leak. They are still making amps. The latest very retro looking, packed full of digital wonders and a powerful Class AB amp. And bass treble control. 

[playdough]

"Not normal hiding under the bed"

So a few weeks ago I posted some home made interconnects, to conclude,,,,,,,

I've done something a little er,,,,,,,,off the beaten path and about as DIY as it comes. Something that's been tested over the last 6 months with a single Power Amp and SMPS LED Driver, wanted to make sure that it was no type of fire hazard/risk to my speaker drivers/house.

 

At this point, I've gone ahead made the backing plane out of Aluminium sheet and added to the set up, so at this stage with a  new minty hot off the press miniDSP Flex 8 still in the condom, have 8 channels of power amplification, with what I found under the bed. All the cable interconnects are hand made from silver teflon coax and Reen/Neutrik connectors are lovely things.

Problem was, divorce, I was ordered to  sell my amps and give over the money. I was able to keep my speakers.

 

A little broke however, the old Alpine Amp array was a Car Audio Pro winner in the 90's and kept, filed away, never seen by the X.

 

So I dug in, and Frankensteined this er, thing out of pure passion for DIY Audio.

 

Powered up the first time ok, no smoking, smelly things or cooking.

Noise floor is non existent, all channels run faultlessly, which was encouraging. No grounding problems, loops or other faults to chase.

 

Plenty of grunt from 14.9v some 60 amps nominal from the 3 supplies, so actually an outrageous amount of power on tap.

Current draw at idle is 3.5A total, so makes a little manageable heat.

The compact power amp array is ok solid over the last week, so to complete the job, will make a steel stand and slot it in out of site.

 

Having the array standing will help with heat management.

I'll post again after that happens.

 

Might buy in some new mains powered "normal" amps in future, however this will have to do for now.

I feel no guilt, there is beautiful music and no longer hiding under the bed.

DIY Forever

 

playdough

[mwhouston]

1 hour ago, playdough said:

"Not normal hiding under the bed"

So a few weeks ago I posted some home made interconnects, to conclude,,,,,,,

I've done something a little er,,,,,,,,off the beaten path and about as DIY as it comes. Something that's been tested over the last 6 months with a single Power Amp and SMPS LED Driver, wanted to make sure that it was no type of fire hazard/risk to my speaker drivers/house.

 

At this point, I've gone ahead made the backing plane out of Aluminium sheet and added to the set up, so at this stage with a  new minty hot off the press miniDSP Flex 8 still in the condom, have 8 channels of power amplification, with what I found under the bed. All the cable interconnects are hand made from silver teflon coax and Reen/Neutrik connectors are lovely things.

Problem was, divorce, I was ordered to  sell my amps and give over the money. I was able to keep my speakers.

 

A little broke however, the old Alpine Amp array was a Car Audio Pro winner in the 90's and kept, filed away, never seen by the X.

 

So I dug in, and Frankensteined this er, thing out of pure passion for DIY Audio.

 

Powered up the first time ok, no smoking, smelly things or cooking.

Noise floor is non existent, all channels run faultlessly, which was encouraging. No grounding problems, loops or other faults to chase.

 

Plenty of grunt from 14.9v some 60 amps nominal from the 3 supplies, so actually an outrageous amount of power on tap.

Current draw at idle is 3.5A total, so makes a little manageable heat.

The compact power amp array is ok solid over the last week, so to complete the job, will make a steel stand and slot it in out of site.

 

Having the array standing will help with heat management.

I'll post again after that happens.

 

Might buy in some new mains powered "normal" amps in future, however this will have to do for now.

I feel no guilt, there is beautiful music and no longer hiding under the bed.

DIY Forever

 

playdough

The setup looks OK. The divorce may have a silver lining. All got to hide away was a tent.

[playdough]

49 minutes ago, mwhouston said:

a tent.

They can be spiteful things.

 

Yea, definitely silver plating on all the conductors ! 

55 minutes ago, mwhouston said:

The setup looks OK

Starting to get it to disappear into a 3D soundstage , I feel spoilt eating cherries  listening to some nice .flack files. life is easier.

[playdough]

Sorbathane, nice. some little ones to go under the horns. 

Had measurable results with these. Real deal.