Good call. I noticed a pot's been added and the pinout is wrong on some of the TO-92s as well.
This what I referred that I also published in the 1970's.... one feedback line to compl input emitters. This is much better than two independant paths. Modified input is good addition.
Is one mosfet enough buffer from speaker generated signal getting back into amplifier stage ??
Thx - RNM
I found it here.http://www.diyaudio.com/forums/solid-state/248105-slewmaster-cfa-vs-vfa-rumble-461.html#post4087224. It's likely going to change.
At low frequencies, where it really matters, the source-gate capacitance is low enough and the gate impedance high enough to do not produce any noticeable current in the gate, don't you think ? And, remember, we have set a big highway for those signals to flow back in the amplifiers stages (in reverse): the feedback ;-).
At hf, with the high impedance of the tweeter (coil's inductance) and the low one of the amplifier...
I simulated a lot of solutions. Any buffer introduce distortion and phase rock'nroll at HF, here, with not enough benefits, distortion's side.
And you will see, if you try to tweak-it, that, as the Lazy cat VSSA, it is highly optimized yet. Hours on this, playing with the currents and impedances of each stages.
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Thanks, I sure did miss that Schmo... like you said it is going change anyway. I think that the double sided board is mandatory for it. The servo is needed for more than one reason.😀
Posted below - the toner "works" ( I found the "bugs").
Toner image is the big .BMP image 300dpi/ 76 X 102mm.
OS
You must either use 2 red's per cascode or one UV/blue/white.
Cascode needs at least 2.5V Vf .... even a green would do (2.6V Vf).
You should wait till Thimios builds it - the Baxandall/Hawksford is untested !
OS
I think I just spotted one in your schematic. I think the note at the bottom should read R10 - 13 can be 470R, not R11 - 14.
You did not know ???
- buy away - http://www.diyaudio.com/forums/group-buys/257057-slewmaster-project-boards-5.html#post4099408
He sold out of the "simple" CFA-X - this "Kypton" is the successor.
But , you could buy the OP boards and you would then be ready for
ANY of the IPS's.
OS
Will do. He's even faster than Terry. He'll likely have it running tomorrow. I was also wondering if R15 & 16 were going to become a trim pot?
Yup , a bug ! My housecleaning is not complete.
I think the Board (toner) is right - I double checked my CBE/ ECB To-92's
(BCxxx and Ksa/Cxxxx).
OS
Nope , but R14/17 can be either 68R or 82R (gain) ... would be either 27.5X
or 33X. R 14-17 are large 1-2w resistors - NO trimmers.
OS
I check the pinouts of the transistors too. That's how I noticed I mixed a few of mine up. Everything looked right on the board, just mixed up silkscreen.
You are right - <8ppm with Main current FB R at 1K/39R.
Now , we have "cookers" at the feedback node (3w hot babies) 😀.
(but only 2 instead of 4) ...
Matched the vssa input pair-
But the "pitchfork villagers " don't like the diamonds.
OS
Found something even better !
Wait on the "Kypton-V".
The one below is indeed different. Both in its Bode response and
design.
30-40db gain margin @ 20K. .00005% THD20K.
This is a common Japanese setup (pioneer , sansui) ... we have not
explored this "avenue" yet.
OS
Wait on the "Kypton-V".
The one below is indeed different. Both in its Bode response and
design.
30-40db gain margin @ 20K. .00005% THD20K.
This is a common Japanese setup (pioneer , sansui) ... we have not
explored this "avenue" yet.
OS
