wont hurt to make it a few mm bigger
50 x 60 mm is so nice size that it will stay hehe
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...
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...
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.
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.
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.
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.
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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...
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...
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Only Lazycat and Shaan have built.
They said sounds good....someone more build?
Look good... very small pcboard... a Brazilian friend asked me to watch for him to say if it is a good idea to assemble.
I would like to see pictures of Shaan amplifier and harmonic distribution from Lazy Cat...if possible, naturally.
A friend is asking my opinion to start to build or not.
regards,
Carlos
They said sounds good....someone more build?
Look good... very small pcboard... a Brazilian friend asked me to watch for him to say if it is a good idea to assemble.
I would like to see pictures of Shaan amplifier and harmonic distribution from Lazy Cat...if possible, naturally.
A friend is asking my opinion to start to build or not.
regards,
Carlos
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Not a good idea IMO. I mean, it's a symmetrical amp and...
Okay let's wait and watch... anything can happen in diyaudio.
TSSA BIGBT is under way, yesterday i soldered the first step parts on second board. I am away next week (winter holliday to snow) so when i am back i achieve Lazy instruction for CCS testing.
Marc
Hello
You know I built several time my verizon.. Nothing came close sound wise to that little amp.
I do built several Pass amp & other famous clone to over 23 years.. Honestly nothing gave that pure, dynamic, detailed deep sound.. These not to degrade any amps, I still listening Pass amplifiers sometimes and they are great.
BUT!!! When your ear adopt to these little amp sound hard to go back to listen other amps. Probably yours even sound better with that small, compact size PC board, who knows, it would be great to compare one day. Regular sized resisters not bad also because you can pick your favorite brand or test each place different type (for some fine tuning)
All do my amp a bit different still the same basic circuit.
Soon I will test the amp with lateral mosfet to. Mr. Wahab helped me to have my version converted to lat. mosfet.
I prefer to use JFet 2SK170BL/2SJ74BL on the input instead BC550C/560C. You can test it also just need to turn 180 degree the JFet.
With power mosfet I'm not sure how would sound, soon I'll test it.
All do now I'm busy with other projects.
Enjoy your amp, keep try to improve because after my experience (believe me I have some, I spent ### hours) these amp (because use only a few parts) very sensitive to the parts you use.
To me a miracle how these little amp perform compare to any other amp, I mean tube, SS etc.
Greetings Gabor
You know I built several time my verizon.. Nothing came close sound wise to that little amp.
I do built several Pass amp & other famous clone to over 23 years.. Honestly nothing gave that pure, dynamic, detailed deep sound.. These not to degrade any amps, I still listening Pass amplifiers sometimes and they are great.
BUT!!! When your ear adopt to these little amp sound hard to go back to listen other amps. Probably yours even sound better with that small, compact size PC board, who knows, it would be great to compare one day. Regular sized resisters not bad also because you can pick your favorite brand or test each place different type (for some fine tuning)
All do my amp a bit different still the same basic circuit.
Soon I will test the amp with lateral mosfet to. Mr. Wahab helped me to have my version converted to lat. mosfet.
I prefer to use JFet 2SK170BL/2SJ74BL on the input instead BC550C/560C. You can test it also just need to turn 180 degree the JFet.
With power mosfet I'm not sure how would sound, soon I'll test it.
All do now I'm busy with other projects.
Enjoy your amp, keep try to improve because after my experience (believe me I have some, I spent ### hours) these amp (because use only a few parts) very sensitive to the parts you use.
To me a miracle how these little amp perform compare to any other amp, I mean tube, SS etc.
Greetings Gabor
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