Strange 5534 thermal shutdown

[Svart]

When you used the FC caps, did you use them in a bipolar arrangement or just single?

EDIT: also, was anything hooked to the outputs when you were doing the testing?

 

[Samuel Groner]

When you used the FC caps, did you use them in a bipolar arrangement or just single?

Not sure what you mean? C102/C106/C202/C206 are Panasonic SU, C105/C205 are Panasonic NHG. I never tried different ones, as I wanted them to be bipolar or as small as possible. I measured the (single) FC just for reference and to make sure that my DVM is not measuring crap.

Was anything hooked to the outputs when you were doing the testing?

I tested both with and without load (a tape desk). No difference. PlugIn-power on/off doesn't matter either.

Samuel

 

[bcarso]

[quote author="Samuel Groner"]

But what was the impedance to ground at the n.i. input to begin with?

The PADs are 10k+1k shunt if out and 10k series/1k shunt if in.

A 1k to ground is brutal, and is attentuating and loading down the mic capsule something fierce.

I don't like it either, but I didn't want to try several values, so I just used one that will work. However, one would still think that 11k should be well enough, but it's not.

how can the R101/C101 node sit at zero volts? Aren't you pulling up on a FEt drain in the electret capsules?

PlugIn-power is switchable.

Samuel[/quote]

So...you are saying that you didn't have the problem when the pad was engaged, i.e., with the n.i. input tied to the 10k/1k junction?

 

[Svart]

oh i thought you meant that you took out the bipolars and put in the FCs instead.

 

[Samuel Groner]

So...you are saying that you didn't have the problem when the pad was engaged, i.e., with the n.i. input tied to the 10k/1k junction?

Yep. Did realise that pretty late, though.

Samuel