Re: mic preamp modification

rex wrote:

> On Sat, 09 Apr 2005 02:31:45 +0100, Pooh Bear
> <rabbitsfriendsandrelations@xxxxxxxxxxx> wrote:
>
> >rex wrote:
> >
> >> On Fri, 8 Apr 2005 22:29:21 +0100, John Woodgate
> >> <jmw@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> >>
> >> >I read in sci.electronics.design that rex <notat@xxxxxxxxxxxxxxx> wrote
> >> >(in <i5qd51dstese4da78r80l933v66id016vg@xxxxxxx>) about 'mic preamp
> >> >modification', on Fri, 8 Apr 2005:
> >> >>These are not smd parts. They are radial lead, about 5mm dia x 10 mm
> >> >>long. It was hard to read them in the circuit but I didn't see anything
> >> >>other than the 0402 that could be a value, so I assume it might mean
> >> >>4000 somethings.
> >>
> >> >0402 is almost certainly a date code for April 2002.
> >
> >I reckon Feb 2004 personally.
> >
> >> Ah, yes, never thought of that. The important stuff must have been
> >> somewhere else on the thing that I couldn't see.
> >
> >V.likely. See my 'correction' post. If it's as you describe it's certainly an
> >electrolytic cap.
>
> These are definately electrolytic caps on the input. They have a stripe
> down one side for polarity. I was reading the information by looking
> through various gaps between frame and other devices with a binocular
> microscope. I thought I found all the information, but now I agree I
> must have missed the value/voltage. Naturally, the side of these things
> that I could easily see had no useful information.
>
> Most of the rest of the board is SMT.
>
> >Do you have any way of getting a schematic ? Mic amps are one of my
> >specialties. I'll give you my advice for free.
>
> I haven't really tried yet. I kind of assumed that they weren't likely
> to give me one if I wasn't an authorized service person. I'll ask them
> now though.
>
> Thanks for the offer. If I get lucky I'll contact you.

You're very welcome.

If the thread dies up, you can actually email me at my posted address ! Yes I know
it looks silly - but it keeps the spammers away whilst offering a simple solution
to the problem !


Graham


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