Need schematic Crate TX-50D "limo" main board

[ampman72]

Hello.  I hope I am posting this in the right section, if not I am sorry.  I have been in touch with loud technologies and they sent me the mic board schematic and the 18 different versions of the DSP board.

For those interested, I need to find the source of 5 volts DC on the speaker outputs. This tends to bias the speakers, which is not a good thing for the speakers or the sound of the amp, which you might imagine.

Thank you

Toby

[Enzo]

If DC offset is the problem, I'd bet my lunch money your power amp IC is bad.  After all, it is the entire powr amp.  is it a TDA1562?

[ampman72]

Sure is.  TDA1562Q to be exact.  I wanted to look at the schematic to see if there was perhaps a leaking coupling capacitor between the chip and the outputs, but when I followed the traces, they pretty much go from the outputs straight back to pins on the TDA1562.
They only run about $8.00 at mouser, which they have three different mfrs.  do you have a preference of mfr?

Thanks for your response.

[Enzo]

Really?

I looked in Mouser and all of the ones I saw listed were from NXP, and they were all non-stocked types.  Minimum order was 400 pieces.

Did you see something  different?

I have no idea what Crate sells them for.

www.bdent.com has them in Phillips brand for $16.

www.digikey.com lists them for $10 each, but shows none in stock.

You could also google the part number and I bet a number of suppliers would show up there.

And try your favorite parts sellers.

[J M Fahey]

I bought a Philips branded one in Buenos Aires for around U$S 7, but I know they´re often falsified, so I don´t really trust it until "real life" tested. If they work, they´re very interesting chips, producing high power from unboosted 12V batteries.Whenever possible I´ll post my findings.

[ampman72]

Thanks guys.  I'll post results once I get one put in.