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G'day, and Help!

Posted: Tue Jul 12, 2011 5:11 am
by TimA4h
Hi All :) I was introduced to PG amps by a mate here in Australia, and have been using Tantrums for over a year now, and LOVE them. I've been researching why I am getting distortion on my 500.2, and have read lots of great tips... EXCEPT! I cant get the damn cover off! I've unscrewed all screws on the bottom of the base, as well as the screws around the speaker/power terminals and RCA inputs on the ends. but it still doesn't come off. Does anyone know how to convince this Phandora's box to open so I can diagnose its issues?

Thanks heaps in advance :D

Re: G'day, and Help!

Posted: Tue Jul 12, 2011 6:17 am
by ttocs
welcome to the phorum.

use a bigger hammer :)

sorry could not resist. Unfortunatly I am not familiar with the tantrums but I bet it will not take long before someone that knows tells ya.

Re: G'day, and Help!

Posted: Tue Jul 12, 2011 8:26 am
by stipud
You might not have to disassemble it at all. Usually a small amount of distortion is caused when the crossover pots oxidize. So to fix it all you have to do is turn the crossover, gain, bass boost, etc. pots up and down a whole bunch of times to clear out the oxidization. Let us know how that goes.

Oh and welcome!

Re: G'day, and Help!

Posted: Tue Jul 12, 2011 11:51 am
by dedlyjedly
On the tantrum amps, you have to remove the black plastic knobs from the potentiometers in order to get the cover off. They're typically on there pretty good and don't feel as if they come off, but they do!

Re: G'day, and Help!

Posted: Wed Jul 13, 2011 3:12 am
by TimA4h
Thanks for the replies all, super helpful! So I sat there for 5 minutes turning the crossover, sensitivity, bass and freq pots back and forward, then fired up the amp again. Same thing :( So I thought I'd open it up and take a look. Its in pretty damn good shape! Only two caps had any kind of 'oxidisation' around them, and it was a very tiny amount. SO I thought I'd plug in a 300.2 I have. SAME ISSUE! So I followed your advice stipud (from Amplifier Distortion and DC-Offset Info), and tested the outputs with my DMM I have no idea if its relevant for car audio, but I tested all three amps I have (2 chan running sub, 4 chan running mid/high, and 2 chan (the problem child) running mid bass. Here are the figures:

SIDE LEFT RIGHT
SUB 0.1 0.1
Midbass 4.3 1.1
Midrange 7.4 11.4
High 24.2 1.8


So according to this, my mid/high should be distorting more than my mid-bass. but they're not!

Re: G'day, and Help!

Posted: Wed Jul 13, 2011 8:46 am
by stipud
Hmmm if you've got the same issue on multiple amps, have you considered that the noise might be coming from the source?