EVOL! Posted December 16, 2011 Share Posted December 16, 2011 Last year a coworker gave me his old, unused Acoustic BC-1 bass combo. It's been in my basement for the past year so last night I decided to test it out before bringing it up to the rehearsal space. When I turn it on the light above the on switch just says "TEST" and no sound comes out. I looked at the fuses and both appear to be OK, but I am not ruling a blown fuse out. Any bass players out there own an Acoustic amp and can give me some idea what TEST means? The amp is old and discontinued so finding info on it on the internet has been tough. Here is a photo of what the BC-1 model looks like Link to comment Share on other sites More sharing options...
Jeff-7 Posted December 16, 2011 Share Posted December 16, 2011 The only thing I can suggest is looking to see if you have a blown tube, my fender amp made 0 sound at all when it had a blown power tube - but the light still worked. Other than that someone more knowledgeable than I would have to jump in. Link to comment Share on other sites More sharing options...
EVOL! Posted December 16, 2011 Author Share Posted December 16, 2011 The only thing I can suggest is looking to see if you have a blown tube, my fender amp made 0 sound at all when it had a blown power tube - but the light still worked. Other than that someone more knowledgeable than I would have to jump in. Thanks, but she's SS. No tubes. :( Link to comment Share on other sites More sharing options...
Jeff-7 Posted December 16, 2011 Share Posted December 16, 2011 Oh, definitely no idea then! Link to comment Share on other sites More sharing options...
Dub-T-123 Posted December 17, 2011 Share Posted December 17, 2011 Have you checked to see if the speaker came unplugged or something simple like that? Link to comment Share on other sites More sharing options...
EVOL! Posted December 17, 2011 Author Share Posted December 17, 2011 The whole face plate lights up when it is functioning normally and in this case it does not so I am ruling out that the speaker is unplugged. Need to find out what the hell this TEST light means. Argh! Link to comment Share on other sites More sharing options...
Gaolee Posted December 17, 2011 Share Posted December 17, 2011 That's an unusual one, and I think it was probably built in the late 1980s, but I could be wrong. Since it is as old as it is, it might have some capacitors which are getting tired and/or have failed. That's not unusual. Acoustic used some caps which are the size of a large beer can, and those almost never are a problem, but some of the smaller ones can get tired. I'm hardly a tech, so take anything I say with a certain amount of skepticism. Now you have the disclaimer. Here's what I would probably do with it. Start by pulling the fuses to see if they are OK. Acoustic put an internal fuse in some amps, and this might be one of those. You will have to pull the amplifier out of the cabinet, but that's straight forward. As long as it is out, take a look at all of the solder joints and capacitors. If the caps are beginning to bulge, they are about done. I personally wouldn't attempt to replace caps myself, and I have found most competent techs have very little trouble figuring out old solid state amps anyway. I'm not a competent tech, so I take it to one. The amp is worth making functional. I'm not sure it will have any value as a collectors item, but it will be a bomb proof piece of equipment and it will sound very good when you get it working. I still play through Acoustic amps built in the 1960s and 1970s, so they hold up well with minimal maintenance. The amp in my avatar photo is a 360 built in 1968. Link to comment Share on other sites More sharing options...
EVOL! Posted December 17, 2011 Author Share Posted December 17, 2011 Issue is resolved. That TEST light is the amp saying, "I am warming up so relax, skippy". I had to leave the amp on for a good five to ten minutes before the blue Acoustic face plate lit up. Now it turns right on. I still did not get any sound at that point so I plugged another cab into the speaker extension and got sound. Turns out that with this amp the head is not internally connected to the speaker. You have to run a cable (that's what that mysterious jack at the bottom of the back is) from the head to the cab. Strange setup for a low wattage bass combo. Link to comment Share on other sites More sharing options...
Andy R Posted December 18, 2011 Share Posted December 18, 2011 Issue is resolved. That TEST light is the amp saying, "I am warming up so relax, skippy". I had to leave the amp on for a good five to ten minutes before the blue Acoustic face plate lit up. Now it turns right on. I still did not get any sound at that point so I plugged another cab into the speaker extension and got sound. Turns out that with this amp the head is not internally connected to the speaker. You have to run a cable (that's what that mysterious jack at the bottom of the back is) from the head to the cab. Strange setup for a low wattage bass combo. Hmmm strange it has a Warm up time and it is not tube?.... Guess it could be time to let the capacitors charge??? I dunno Link to comment Share on other sites More sharing options...
Gaolee Posted December 18, 2011 Share Posted December 18, 2011 Some of the caps they used are as big as your arm. They are enormous. If you wait a month with the amp unplugged, it can still have well charged capacitors. The separate jack is pretty common Acoustic practice. Link to comment Share on other sites More sharing options...
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