VSSA Lateral MosFet Amplifier

[Lazy Cat]

Originally Posted by tinitus

wont hurt to make it a few mm bigger

50 x 60 mm is so nice size that it will stay hehe

[shaan]

Hi all.

Today I did the mosquito coil test on the input pair to see how it copes with a very different thermal condition than normal or moderate. The results are exciting.

I lit the coil and first touched the npn bjt with it. The offset climbed from 1mV to ~100mV within a second and from there quickly fell to ~20mV within next 2 seconds and stayed there. After 6-7 seconds of torture the coil was removed and within next 10 seconds offset went back to 1mV. The same thing happens every time I place the coil head on either the npn or pnp bjt, but offset goes the opposite polarity for the pnp.

Nice. Very nice and smart. This is how I like it.

Next - the room heater torture. Stay tuned...

[Lazy Cat]

Hi Shaan

VSSA tempco is rock 'n' roll stable in all stages, also with VAS pair mounted on the main heatsink. Output bias 160 mA is almost constant regardless of temp, thanks to TLVH431 reference. VAS current response is from 12 mA to 16 mA from cold start to 55°C and doesn't change the output bias, not even a bit.

[fredlock]

Originally Posted by Lazy Cat

That's possible of course, lets say PCB and semiconductors in the package. For that purpose I would have to prepare some sort of installation instructions documentation.

That sounds terrific! Will be waiting.

[shaan]

Considering the simplicity of this amp, the THD figures the sim shows are plain unbelievable at 0.002% at 20V P-P output into 8ohm, in class-ab! Much lower than the previous two simmed versions. And the sound equally confuses me. Transparency is the bottomline of this amp. Mysterious. LC, maybe this "nothing new" design is the ultimate example of how accurate and sonically pleasing a three stage class-ab symmetrical cfb amp can be, with such a small and easy to build circuit. Marvellous, finally the SSA front end can match the exemplary offset control of the classic LTP, or at least come very close. I am pretty sure great things are gonna happen in the near future as more and more fellow people here adopt this input config as a standard preference for all their amps.

[Lazy Cat]

Yes Shaan it is really amazing how good VSSA sounds for such a small parts count.

Just listening them right now while I'm writing this.

P.S. Try to get the ALF08NP16V5 mosfet and hear the difference according to 2SJ/SK.

[shaan]

Originally Posted by Lazy Cat

Yes Shaan it is really amazing how good VSSA sounds for such a small parts count.

Just listening them right now while I'm writing this.

Yeah same here.

P.S. Try to get the ALF08NP16V5 mosfet and hear the difference according to 2SJ/SK.

Not available here...

[Tyimo]

Hi Lazy Cat!

Which one is better: the SSA, the VSSA or the TSSA?
Did somebody compared this amp to the F5???

Greets:
Tyimo

[vgeorge]

Originally Posted by Tyimo

Hi Lazy Cat!

Which one is better: the SSA, the VSSA or the TSSA?
Did somebody compared this amp to the F5???

Greets:
Tyimo

I have compared the TSSA with F5 and Aleph J and it beats both of them easilly. I don't think you can go wrong with any of the SSA familly.

[shaan]

Originally Posted by vgeorge

I have compared the TSSA with F5 and Aleph J and it beats both of them easilly. I don't think you can go wrong with any of the SSA familly.

G R E A T
R
E
A
T

Thanks for the info george. Many would wonder wheather the SSA family really has that "something" usually found in some exotic, luxorious, hot, bulky and expensive offerings. Now, some won't any more; and the rest are just a "try" away.

Happy listening...