Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Noticed this in a trash 🗑�🚮 picked Crate
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After a little research maybe it's possibly a TDA2030 or LM1875 ?

 :loco

Quote from: saturated on December 24, 2024, 02:00:42 PMAfter a little research maybe it's possibly a TDA2030 or LM1875 ?

TDA2030 was what I was thinking as well.  Here is their G10XL schematic which may be similar.

Well guys I decided to play around with this amp  :P

I thought it would be cool to try and fix it.

Unfortunately it works  :grr

I tried it with headphones and yeah gtg  :lmao:

So I thought well....instead of looking up the pinout of the critter let's do some probing

First order of the night was connecting a speaker

IMG_20260715_013605179 (1).jpg

Then I piped in some signal and started probing away.  I do fully intend to look at the data sheet and schematic that was kindly provided thank you  :dbtu: but I thought it would be cool to maybe try and determine (anything) before having a look.

So I took DC voltage readings on each pin

Then looked for signal on each pin power off probably a dumb idea  :lmao:

Then I looked for signal on each pin power on and whether or not it was affected by the volume control.

Results as follows
IMG_20260715_021413311_HDR (1).jpg

Unfortunately I had an overabundance of volume controlled output as in three outa five  :grr

And never did I have the input signal uncontrolled by the volume knob.

But...I just assumed there would be
-input uncontrolled by volume pot
-output controlled by volume pot

So maybe it's time to take a look and see what the expected results are.

 xP

Volume adjustments usually happen in the preamp.