shamrock.
Active Member
I picked up an Au-3900 as part of a cheap deal with a bunch of stuff
the lid has a bit of surface rust which looked a bit ominous but I plugged it in anyway and gave it a burst .
Everything worked and sounded pretty good. I did an ab with a fully recapped and restored (by someone else) Au-505 that I own .
The weatherbeaten original old au3900 had a lot more mojo than the restored au505
it sounded way better in the low end and lower mid range.
They have similar power output specs, but the 3900 also seemed to be more powerful.
The only negative with the 3900 was that anytime the vocalist sang s or t it sounded really distorted and bad.
I was just going to flick the amp as is but rethought this as it would be a pretty good amp to do my first recap with. I have started dismantling the unit and cleaning it up.
To remove the indicator plug from the front panel can I just pull it until it comes out (Ive put up a photo), dont want to break it.
Ill respray the top, and look to replace the caps,clean everything up inside, deoxit all the pots and switches, remove the transistors and replace the paste on the heatsink .
Anything else I should pay particular attention to?
the lid has a bit of surface rust which looked a bit ominous but I plugged it in anyway and gave it a burst .
Everything worked and sounded pretty good. I did an ab with a fully recapped and restored (by someone else) Au-505 that I own .
The weatherbeaten original old au3900 had a lot more mojo than the restored au505
it sounded way better in the low end and lower mid range.
They have similar power output specs, but the 3900 also seemed to be more powerful.
The only negative with the 3900 was that anytime the vocalist sang s or t it sounded really distorted and bad.
I was just going to flick the amp as is but rethought this as it would be a pretty good amp to do my first recap with. I have started dismantling the unit and cleaning it up.
To remove the indicator plug from the front panel can I just pull it until it comes out (Ive put up a photo), dont want to break it.
Ill respray the top, and look to replace the caps,clean everything up inside, deoxit all the pots and switches, remove the transistors and replace the paste on the heatsink .
Anything else I should pay particular attention to?