Babelfish M25, SissySIT - general building tips and tricks

Well I was able to figure out the problem I. My right channel. It was a broken wire from the RCA to the PCB. Still a PITA replacing it, but better than the alternatives.

I was able to dial the bias in and the offset only drifts a little 10-6 mv in the right and 15-5 mv in the left.

Now time to take the amp off the bench and put it back in the system.
 
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My Sissy is making sweet music now!

Thanks to Zen Mod for an awesome design!
And of course Nelson!

Prass got me a new set of THF-51's with the right
VGS and the system came right up!

Here are photos for inspection by Mighty Zen Mod!
 

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Official Court Jester
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ANOTHER MAJOR pcb OOKOOP of Omniookoop ZM

Boyz and Girlz

I made a major mistake with SissySIT R2 pcbs*** ( besides that one with short between two resistor pads) - resulting in fact that with (wrong) Edcor 600:15K there is normal expecting gain, while with (proper) Edcor 600:600, prescribed Jensen and prescribed Cinemag - there is gain of just 6db , instead of 12db

bummer was while I was mental juggling with two Edcors and Cinemag and Jensen , among several other things always incorporated in pcb optimization, I made a mistake and took Edcor 600:15K in option , even if his 600:600 cousin is intended for use

so , fix is easy, both channels - cut one tiny trace , solder tiny wire from point A to point B

will post graphical info about fix tomorrow, now going to deeeeeeeeeeepest corner of room, to be embarrassed for a while

****that one having 6-legged optocoupler and just soldering pads for SIT ( instead of proper footprint for P channel mosfet)
 
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My Sissy is making sweet music now!

Thanks to Zen Mod for an awesome design!
And of course Nelson!

Prass got me a new set of THF-51's with the right
VGS and the system came right up!

Here are photos for inspection by Mighty Zen Mod!

Celebration for one more SissySIT joining the world!!! :cheers:

Is that the 3U/400mm case? What are your temperatures like with the top cover on? Did you get the back panel pre-drilled or did you drill it yourself?

Very nice amp! Are those thermal switches on the heatsink at the back?

This build deserves a 'fugly'!!! :cheers: :cool:
 
Celebration for one more SissySIT joining the world!!! :cheers:

Is that the 3U/400mm case? What are your temperatures like with the top cover on? Did you get the back panel pre-drilled or did you drill it yourself?

Very nice amp! Are those thermal switches on the heatsink at the back?

This build deserves a 'fugly'!!! :cheers: :cool:

Thanks! Just finished it last night.

Yes, only had a 3U/400 case to use - we'll see how it works.
I'll transplant if I have to.
I have 75C thermal switches on it.

I did the back panel with step-drills, dremel cutoff wheels, and some filing.
 
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Official Court Jester
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Looks like I missed something. May be I didn't follow every post, so, where is writen that I have to use edcor 600:600 and not 600:15k? Every shematic I see shows the 600:15k, so it's already bought. Not a problem, I may use them elsewhere.

do not worry, I'll explain clearly all possible dilemmas

600:15K is working without any change needed, so you're good