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VSSA Lateral MosFet Amplifier

Hello Lazzy Cat,

It seems that you cannot receive PMs any more.

Would it be possible to get the PCBs for your amp? I would like to also know how to go about payment.

Would it be possible to use this to make a multi channel amp?

Thank you very much.

Regards,

Bertrand

Next week I will receive 50 assembled VSSA PCB-s. First I have to send prepayed orders and than inform here about the amount of PCB-s still available for interested DIY-ers. So be around. ;)
 
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Compared to which PSU?

Both channels working?

That's vs. Simple unregulated double mono +-35V, 300VA, 60000uF per channel PSU. Both working, thanks! Although, with new smps supply only. Can't get one channel to work on my linear supply due to strange psu behaviour when a speaker is connected. Psu output voltage drifts to positive or neg rail deliberatly. Must be a psu channel fault.
 
For members interested in the two feedback caps AC behave. Done simulation before, but here is realtime measure of caps AC behave in feedback position. Maybe best to download picture to be able to study better (zoom in/out).
For Esperado: see lighblue line and please don't shoot me :no:, but maybe help suggestions to get it stable in higher band. Like motion feedback on speakers, i think it will form the sound envelope presented, but last is what i think now, realtime trials later has to confirm or shoot it down. Those two caps for lightblue plot was awfull expensive at RS, but Digikey has better cost.
Regards Ricky
 

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That's vs. Simple unregulated double mono +-35V, 300VA, 60000uF per channel PSU. Both working, thanks! Although, with new smps supply only. Can't get one channel to work on my linear supply due to strange psu behaviour when a speaker is connected. Psu output voltage drifts to positive or neg rail deliberatly. Must be a psu channel fault.

That is why I'm using unregulated SMPS. Regulation normally interfere with/to audio modulation, causing a mess.
 
Last mail from you is about the permission to use VSSA sch to your needs.
I had send-you 1 PM and 2 or 3 mails, since this one. Please PM-me an address where i can write-you in a more secure way.
I was afraid to had wrote something witch had make-you crossed against me.

Contrary to you, with your impressive and beautiful designs, nothing to admire looking at me: Just an old fart. The few things i know is just the effect of time, curiosity and passion for music. Just i was lucky enough to had two paralleled careers, both as a sound engeneer and an audio designer. It gives a more 'global' and insecure way to look at the numerous evils waiting for us when we have this incredible claim to reproduce sound universe with dirty bits of string :)
see lighblue line and please don't shoot me
I'm just curious to read your comments on your listening results. Why to shoot at somebody dreaming of perfection :)
 
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So BYRTT, have you powered up your VSSA yet?
Sorry not yet, finally had all bits and pieces hardware by 09. this month, but have not had time, and time i've got i had spended on other audio topic where that impedance measure unit from post #2445 is running all time.
I was waiting for your comparison with regular PSU and SMPS, as well as your listening impressions
First tests will be with SMPS and all bits and pieces as suggested/recommended. After that other PSU's. Then stuff like post #2445for trying reach best as possible reproduction in setup.
Just curious.
Me too, nearly my thoughts in VSSA domain 24/7, but will NOT rush VSSA together and starting circuit smoke as a consequence of hurrying. Expect my first impression in not more than 10 days.
 
I'm just curious to read your comments on your listening results. Why to shoot at somebody dreaming of perfection :)
Just ironic about the shooting, reality was that your knowledge about trouble with that cap size is true up against my dreaming. Look at phase plot for the cap at high end. Phase looks like falling as leaving audio band where my measure unit can't discover behavour anymore. If it's because it becomes an inductor there with increasing AC impedance it can't sit there alone without a clever helper network to amend misbehavour. I put this cap on hold untill later, just bought two with other bits and got positive over the AC plot, therefor post/sharing.
Had been digging to your earlyer suggested motional feedback (bought 42 inductors for trials) and that started something untill further unbeliveable in sound presentation in room. If the direction i am heading under these tests holds in the end, you are a real hero for my speakers :worship: their owner and the way to have headphones/studio like sound in room. Discovered some days ago when hardworking speaker guys posted to this thread that you last month started thread about motional feedback and got mood spoiled by critical members. I am very sorry for this, but can say if any comfort, that if my experience in motional feedback holds the positive direction, i will post at that thread to support for your suggestions.
I did do big mistake other day, i used to have two Sansui stereo amps to drive 2x10" SPH-250KE botton and 2x5" Alpair 10.2 for top all in sealed cabs, now have only one amp, but little luck because top is fullranger so present i run one box L/R. By zeal and not thinking i tried little MF network right at amp :no:, and now it needs repair :(. No output devices broken, but suspects the little feedforward circuit has lost a device, but have not had time to investigate. From that mistake, now MF networks are placed at speaker cable end with these amps. Amps are old and restored but fine specs like DC-300kHz with both VFB and feedforward.
Because i have got used to bandwidth from DC and up, more and more learn to understand circuits (thanks everybody) and their sound, i think the importance of that feedback caps AC-outriggers behavior measured in post #2445, will get me investigate there later to push more correct audioband groupdelay and maybe musical performance.
Drunk NO, Dreamer :)
 
Look at phase plot for the cap at high end.
Yes, you just measure the wire's inductances.
Had been digging to your earlyer suggested motional feedback (bought 42 inductors for trials) and that started something untill further unbeliveable in sound presentation in room. If the direction i am heading under these tests holds in the end, you are a real hero for my speakers :worship: their owner and the way to have headphones/studio like sound in room.
I was talking about motional (and inductance) impedance *compensation*. The purpose is just to let the amp loaded with a near flat impedance, and, so, not to have to deal with frequency variable current/voltage ratios. It has an influence on the feedback phase near the resonance, and change the Thiele and Small parameters with benefits, of course.
Sorry about your misadventure. We have a French proverb which says: "Who try nothing get nothing".
About your cap fear, you will make your mind with your ears. It depend so much of the speakers you'll use. (and of the records you play ;-)
 
Brytt,
I was the one who brought up Christophe's conjugate network thread and I wish that he would continue it. Perhaps he could do it as a blog and then you don't have as much of the negative comments from those who seem to have a specific answer in mind, no matter any evidence to the contrary. I think and understand that Christophe was correct in his assumptions and reasoning and there was more to go with that. How can you ever go wrong with a flat impedance loading of an amplifier, no matter the topology?
 
I think and understand that Christophe was correct in his assumptions and reasoning
The idea is not mine, but came from a friend designing enclosures at "La maison du haut parleur".
No assumptions, but practical improvements with many various Loudspeakers.
Not that kind of improvements you are not sure about, and need careful listening séances to figure out if you are not fooling yourself. Immediate, obvious, and amazing changes that you can hear and measure both in acoustical response curves and waterfalls.
"Faster", more analytical, drier, basses, with no resonances. Suddenly, basses and quick drums are separated, and the hit of the kick hammer on the skin as well as the mediator on the strings are obvious.
Low medium cleaned from halo or impasto, specially on male voices.

Of course, if your enclosure have lack of basses, it will increase this defect.
No input about 2x25 300VA sizing ? :rolleyes:
Well, VSSA can give-you ~ 80W with +-35V DC on 8 ohms.
A 300W Analog PSU will be perfect for one channel. A little undersized (on my taste, i would go for 500VA) for two, but it will work.
 
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