L'Amp: A simple SIT Amp

what's stopping you?

once i connected my dac with srpp ouput to SIT L'amp directly to Alpair 10p, 1 channel only and very loud. tested on slow music Ingram Washington ‎– What A Difference A Day Makes

but for sure it's not practical :D

:)

hmm, I'm still learning... CCDA tube front end in Soundhappy's schematics also looks interesting.
 

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Hello everybody,

This is my first message on this forum (at least since 11 years). There is so much information on this website nowadays, it makes things a bit confusing.... So please let me know if I'm posting my message in the wrong place or if I'm asking a question already answered.

I'm currently building a Zen9 but since few days I have been contaminated with the SIT virus, so I'm building now both a Zen9 and a "L'Amp" and they will both share the same power supply.

The SIT amp is based on a 2SK180 SIT which runs with a pair of 2SK170/2SJ74 upfront.

I have also added a tracking Aleph CCS, same as the one designed by Nelson for the ZEN9 / Aleph amplifier. And sure I have also added the cap multiplier (There are such nice goodies in the Zen 9 design, it would be a pity to not implement them on the "l'amp.")

I did a quick check with LTspice using the spice model 2SK180 made by Le Createur de L'Amp", and the voltage gain jump from 4x (with the 23 Ohm resistor and a +83V power supply source) to 6x with the "tracking aleph CCS" powered at 60V . This is a nice expected improvement, (both amps operate on the same sweet spot VDS=37V ID=2.1A VG=-6.33V)

I was wondering if somebody used the Aleph as a CCS for the "L'amp". I have seen somewhere in the 300 pages of this thread a CCS based on the 4N37 optocoupler but no the tracking Aleph CCS.

Do I miss something? Any reason why people avoided this nice CCS or should I replace my glasses an reread the 300 pages?

here is a copy of the schematic:

SIT amplifier base on l'Amp + tracking Aleph CCS V DF,


And the bode plot
SIT amp + Aleph CCS bode plot by DF

Next step will be the THD curves with and without aleph CCS.
The real stuff might differ significantly from the spice model anyway.

PS: Despite my kiwi flag, English is not my native language (I'm a Kiwi with a very strong french accent) so sorry if my spelling or if my bad sentences hurt your eyes!
 
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I was wondering if somebody used the Aleph as a CCS for the "L'amp". I have seen somewhere in the 300 pages of this thread a CCS based on the 4N37 optocoupler but no the tracking Aleph CCS.

Do I miss something? Any reason why people avoided this nice CCS or should I replace my glasses an reread the 300 pages?

I also have not seen someone realized SIT + Aleph CCS. Since I really like my AJ and L'amp, I'm very interested in this. :)
 
Papa's Shade pucks amp from BAF is close enough

change Mu stage above to Aleph and that's it

change lower stage to SIT , that's it

both amps covered in same lecture , see Oootoobe

I was not aware about the Papa's video on youtube (my interest in class A solid state amp started 2 weeks ago) .

I have watched one of them this morning with my first coffee.... (the one with the cascode). Wow! It was like being in a electronician Walhalla !
 
I have run some THD simulation with LTspice today, with and without the aleph CCS.

I found a THD of ~0.7% @1W/1kHz with the 23Ohm resistor powered @ 83V, and 0.6% with the Aleph CCS.

Michael measured a THD of ~0.16% @1W/1kHz on his 2SK180 light bulb amp(same sweet spot Vds=37/Id=2.1A).

It is good to see that the Aleph CCS improves the THD a bit however I'm not too much concerned by the discrepancy between the model results and his measurements. Models are models...