BOSOZ help

[raincheck]

Ive built a 2 chassis BOSOZ, Ive tested the power supply along time ago without issue. Everything is dual mono, including the same transformers from Nelson's article. Ive increased the power supply capacitance to 14,000 microfarad and changed C103-106 from 10 uf to 100 uf. Everything else is the same as the article except for Harris diodes to build the bridges
The preamp chassis connects via an "umbilical cord". I also have a separate wire that connects both chassis grounds together.

When I was adjusting the preamp's gain and input pots, I think I overloaded the imput of one channel as dumb *** me had his scope probe on x10. What would the amplitude limit on the inputs??? As I i had a 20 volt sqare wave coming into it for a brief time. Would this cause damage??

I also found that I fried one of my power supply channels(took out the bridges, zeners, and mosfet) after some testing. I dont think I shorted anything and sure cant find any potential shorts so Im in the proccess of repairing the power supply for that channel.
Can someone please explain what C103-106 do and especially if its a problem that Ive increased that capacitance from 10uf to 100uf each? Could this be any cause of concern??
Thanks,
Tom

[Nelson Pass]

Originally posted by raincheck
When I was adjusting the preamp's gain and input pots, I think I overloaded the imput of one channel as dumb *** me had his scope probe on x10. What would the amplitude limit on the inputs??? As I i had a 20 volt sqare wave coming into it for a brief time. Would this cause damage??

In a word, no.

[jupiterjune]

Can someone please explain what C103-106 do and especially if its a problem that Ive increased that capacitance from 10uf to 100uf each? Could this be any cause of concern??

Well, I don't have a schematic in front of me, but I will take a stab at it. If those were 10uf each, then one is to filter the ripple off of the zener stack so the gate of the mosfet gets a nice ripple-less input. The other one (assuming it is connected between the output and the ground) is just filtering off some high freqency noise that might be at the output of the regulator. I changed that one to 100uf as well, no problems. It shouldn't be problem with the zener stack filter either (but I didn't try it, so I could be wrong).

The BOSOZ power supplies are a bit touchy. Mine went "poof" (burnt bridges) and I never did figure out why. The preamp circuit seems to be pretty robust, though.

JJ

[raincheck]

Thanks Nelson!!! for making my speaker sing!!!
I was thinking i must have screwed somethin up

[raincheck]

Another

[raincheck]

one at a time

[raincheck]

Thanks Jupiter June

[raincheck]

and....

[raincheck]

Thanks

[raincheck]

Im using 4A/600 V Harris "stealth" soft recovery diodes on my power supply. To repair a one channel I have to use 4a /600v Fairchild "stealth" soft recovery diodes as I couldnt find the Harris ones.

Should I heatsink these diodes?????? I didnt think they I needed them but now I wonder as I had a power supply channel fail and I cant figure out why.

Thanks!!
Tom