Hi Andrej, my radarToday's VSSA shootout brought some very interesting results hehe
. Did you do bridging/ballanced, looks like only one cable for each speaker and 3 times VSSA amp 
, or is the interesting behind the curtain 
, HEY maybe you got "FIRST ONE" in one of those boxes . If i am on track you for sure got power. Regards Ricky
All three are pure VSSA amps, each a little different and the absolute winner we picked out from this shootout. Major improvement in sound quality. 
I can tell only that VSSA improvement idea came out directly from the First One tests, performed intensively lately. First One was made in seven
different versions and the winner brought some important experiences, also very good results at listening tests. Final version of PCB for the First One is now in production.
I can tell only that VSSA improvement idea came out directly from the First One tests, performed intensively lately. First One was made in seven
different versions and the winner brought some important experiences, also very good results at listening tests. Final version of PCB for the First One is now in production. 
Christophe,
Are those improvements with the board as delivered or have you modified the circuit for your improvements.
Lazy Cat,
Could your design be used for a commercial product? I am wondering if it would be cost effective and would you be interested in a commercial project if the price was not to high for a commercial self powered speaker and could it be made in commercial quantities with available parts?
Are those improvements with the board as delivered or have you modified the circuit for your improvements.
Lazy Cat,
Could your design be used for a commercial product? I am wondering if it would be cost effective and would you be interested in a commercial project if the price was not to high for a commercial self powered speaker and could it be made in commercial quantities with available parts?
My experience with L.C.'s VSSA is pure fiction (simulations). For the moment...
But i use and can work on a a very similar amp (same topology, main difference is a cascoded VAS and +-70V PSU).
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Lazy Cat I would be very interested in using your amps in a commercial product if the price is right. I would of course need other things with it as it will be in a biamped self powered speaker application. I am looking at electronic crossovers to go with the amplifiers and would love it if that could be done. I really don't want to have to create the amplifiers and I don't think from all I have been reading that I want to use chip amps, I just don't see that as being a great alternative. I will send you a PM when I get a chance.
Steven
Steven
And why not two bridged VSSA (if the power is enough) for the cone and a single one for the tweeter ?
Can bring a 'coherency' advantage, simplify the supplies, the stock, the maintenance etc...
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Christophe,
That is exactly what I have been thinking. That is why I asked if these could be bridged. I am not even sure that I will need more output power than a single unit could do. My original test models used a simple Harmon Kardon amp with only 90 watts per channel through passive crossovers and that was enough to drive most people out of the room. So a dedicated amp with a true 50 watts just on the bass speaker may be plenty and about 15 or 25 max on the dome tweeter would probably get you in the same range. The H/K only used two output devices per channel, they are Toshiba transistors and that was really loud.
That is exactly what I have been thinking. That is why I asked if these could be bridged. I am not even sure that I will need more output power than a single unit could do. My original test models used a simple Harmon Kardon amp with only 90 watts per channel through passive crossovers and that was enough to drive most people out of the room. So a dedicated amp with a true 50 watts just on the bass speaker may be plenty and about 15 or 25 max on the dome tweeter would probably get you in the same range. The H/K only used two output devices per channel, they are Toshiba transistors and that was really loud.
Christophe's proposal could be close.All three are pure VSSA amps..........Major improvement in sound quality.
Just checked your Pictures of First One hmmm......
Reference leds at CCS......
One more smd bjt/fet device under PCB for CSS......
Or maybe last is for some sort of virtuel groundpoint for feedback caps or capacitance multiplier for same point......
Give up.....
......but very nice of you Andrej that Qoute post #2425: VSSA improvement will be detaily described after all VSSA modules will be shipped out.
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Bridge brings several advantages: More dynamic margin, less distortions, improved common mode power supply ripple rejection, no big current in the ground. I love-it and the way it sound.
Yes Christophe, that is what my friend wanted me to do with the chip amps. One on each side of the plus and minus of the speaker. A balanced drive system. I could do that if the cost wasn't prohibitive to do that. Then I guess you could run each side at lower voltage and have the drive control. Of course I would also want to have the conjugate network to correct the impedance curve of the speaker right after the two units. We are talking about having the power amps almost on the speaker terminals in a self powered speaker, solves lots of other issues. No wires to really worry about except for the high impedance inputs.
Hi Christophe. I have 8 nice modules from Andrej, need 2 for testing PSU ways to go (SMPS/CM/Linear or mix) in coming months, thereafter 4 modules for my two way speakers. You can borrow two modules for at least 6 months if interested and time/calendar allow.
Ricky
