Old Soul

[codyt]

So Scryer is still on top?
I got ZM-itch again for a next amp and trying to decide which one should be next. So many choices...B2J is still the king for me.

Let's just say I find the Scryer hard to beat. That said, it comes down more to preference and mood.

 

[twitchie]

Shindengen 2SB206 - any reason not to?

 

[Zen Mod]

as long they survive first signal burst, any will do

same as testing matches - this one works, this one works, this one works

 

[Dendrobium]

frankly, LuDEF was sorta surprise ......... but most wakoo of them all is still - Old Soul

I still remember when you told me this in LuDEF thread, stuck with me in back of head, now wanted to build mini amp for headphones and thought why not experiment a bit, see what the rage is about. Either this or Mr. Penitente Spettacolo, not sure which one wakoo-ier, but any Zen amp is safe bet.

Lowered rails to +-15, so had to increase the Vbe setting resistor, (i guess i will do 50-Si, 33-Ge or something like that), lowered bias, Input cap C1 lowered because my VAS's output impedance is not that high to need 1mF.
One thing i didn't get is why C2 (C106 on original sch) has to be so big, in AC, DC, and transient analysis i saw no changes playing with the value...hmm..
Not sure what else should be done, just posting for quick sanity check.

 

[Zen Mod]

C2 - 470uF

more, the merrier

why so big - simply allowing me to avoid any calculus

though, I reworked practically all of my amps with Square Law OS to current-mirror biasing scheme

no change in sound, but I'm finding it firmer and more stable (borderline swing) than opto based

example - SissySIT (42)

 

[Dendrobium]

Thanks for the tips

C2 - 470uF

more, the merrier

why so big - simply allowing me to avoid any calculus

though, I reworked practically all of my amps with Square Law OS to current-mirror biasing scheme

no change in sound, but I'm finding it firmer and more stable (borderline swing) than opto based

example - SissySIT (42)

Thanks for the tips mucho apreciando

I put together current mirror version of Old Soul but i dont feel comfortable messing with it too much, not sure about values and dont want to spoil the broth.

I guess for low power application maybe it wont matter, but i am pushing rails a bit low-ish though, maybe CM makes some difference in real world? I dont know i am chicken and just want it to work and hesitant to stray from blazed path.

Is miller cap (C109 on original) necessary in the in the end? I know you put them on some, not on others..

 

[Zen Mod]

miller cap is not mandatory, though, clever to put blocking cap on CCS itself

take care of dissipations - you must use bigger one for your Q9 .......... and program higher Iq there

quick glance - I can't see anything else needing change