L'Amp: A simple SIT Amp

[Michael Rothacher]

I believe Generg is working on a mu follower.

My CCS is just as you suspect, a self-biased IXYS with a 1 Ohm source resistor.

[ra7]

Well, I would prefer the CCS solution over the choke load one. I have the IXTH devices on hand.

How about a balanced solution? The way Papa did it in ZV1: Balanced Lite (you gotta love the play on titles!). Gets rid of the output cap, more power, less distortion.

This SIT is just really a part for part replacement for the MOSFETs, with a few changes in part values in the circuits. You could probably go through the entire Zen series, right?

[Michael Rothacher]

It certainly has potential.

I have something balanced on the workbench right now, but I'm not going to preempt myself this time.

Originally Posted by ra7

This SIT is just really a part for part replacement for the MOSFETs, with a few changes in part values in the circuits. You could probably go through the entire Zen series, right?

In the sense that they are both transistors, yes.

Most of the Zen series uses enhancement MOSFETS with feedback, and these SITs don't exactly have a lot of gain to spare. And, of course, you must account for their need for negative bias voltages (Depletion Mode).

But, from a high-level topology standpoint, yes, you can plug them in and see what happens.

[Zen Mod]

Originally Posted by Michael Rothacher

I believe Generg is working on a mu follower.

do not expect him so soon ;

too much variants to pick one from ........

[generg]

I had some exchange with ak4396 concerning the MU follower! he simulated a solution and I was impressed by his skill....

But all the honor is to him to publish his idea......!

[juanitox]

so this morning return to the fixed bias with a 9V alcaline battery a 10K bournes pot and 2K res . my 10uf epcos film on the input Rca . and turn on , i 'v got 16V at 2,6amp , a little more gain , great sound again but no more quiet or transparent as with the bypass source res .. so back to 1ohm res again , swap the input cap and rewire the bypass Caps.. turn on 15V at 2,33amp i defintly prefer the sounds, more relaxed , highs like cymbals seems more clean than before ...

i still don't know why in my amp the fig 11 sounds better perhaps it's the input capacitor ? but the Epcos MKS is not a bad one in other amps ?

anyway , the Sit sounds good and is quiet now so thnank you again michael

[Michael Rothacher]

Well, vive la difference.

[generg]

here comes my simple Mufollower circuit......

you can alternate the connection of the 10k Pot coming from point A, the drain of the SIT, to point B, the source of the SIT......
as far as I can say B offers more gain and more bass to my Tone Tubbies and in simulation offers a bit less distortion.

I will continue my experiments when my "experimental" heatsinks come and I can compare with my standard constellation, crippled F4. (waiting now for four weeks ..)

[juanitox]

ohh i forgot , when i rewired my Star gorund i had hum back again in the speaker. so i put the bridge - wire at few inches form the starground ( , source res, bypass cap , rca ground, speaker ground) and the hum disappear .

[Zen Mod]

Originally Posted by generg

here comes my simple Mufollower circuit.........

I like it