lm3875 at 94V

hi i dont have enough parts at stash,run out of good transformers and hi curent regulators ,and in sort of hurry to finish amp.at +-45v dc is it better to drop 10v with 2sc1943, 2sc5200 or put them in output(dont care i need pair more i have stash) ,sort of using 3875 as first stage but on 94v still :D ? i know neither solution is good but i need to have spare amp in few days from now,so cant wait for parts to arrive.

i think is lot better to put in output but want to make sure i didnt miss something.
 
ok this should work, i will try this afternoon to make then post if it is working and why not,but i will use 3875
 

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Absolute maximum ratings are 94V rail to rail when no signal is present and 84V rail to rail when a signal is present.

Your measured 94Vdc may not be worst case.
How high could that go when mains is at it's highest?

I suggest that you build a non feedback voltage regulator using a Zener and emitter follower (Pass has examples) to bring your supply down to +-40Vdc, or lower.

A capacitance multiplier could also drop significant voltage to enable your chipamp to survive.
 

tomchr

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2009-02-11 12:58 am
Calgary
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