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previous: Don Symes Where wires go thru holes, are any ... -- 9/28/1999 2:29 AM

Re: the Amp got dropped and don't work right no more.

9/28/1999 4:41 AM
Psycho Bass Guy	Re: the Amp got dropped and don't work right no more. The wiring looks good. I had to resolder all the major connections to the faceplate, so I checked it thoroughly. The bend to the unit is in the rack ears on the front which doesn't affect the interior chassis in any way. It has a three-piece steel frame which really does a great job of isolating everything but the faceplate. (Although the power tubes were mounted inside and they bought it.) This amp is even more point to point than my old SVT with a super clean and logical layout. My only complaint is a small ribbon cable which has obviously been fixed before (and not very well). I question the logic in using a ribbon cable in a high volume bass amp between a major structural juncture. Another cool plus is a three way power level selector switch which looks like it turns on the tubes in pairs for more crunch at lower volume. Since this is a sort of variable standby, it may be part of the problem as it is just a pot-type switch. It still shouldn't cause an over bias or blown fuse and at worst would open up and run all six tubes continuously or be intermittent and cause audible popping. I can see that bias current is applied as only two tubes at a time by the switch and the amp itself super quiet, so I think it is ok. There are also two separate switches for standby and run on the front panel with corresponding LED's(which don't work but are getting voltage). All the trannie connections were unhurt, but there was an absolute shitload of glass everywhere. I know glass is an insulator, but is there any way a small piece could be goosing the bias? I vacuumed out the chassis and don't think there is any left, but you never know. It cherryplated the tubes in about one minute and it was always the same sockets that would cherryplate.(bad socket?) This is baffling without the DMM, but I always try to shoot the thing in my head first. I am really bugged by this one.

9/28/1999 4:41 AM

Psycho Bass Guy

Re: the Amp got dropped and don't work right no more.

The wiring looks good. I had to resolder all the major connections to the faceplate, so I checked it thoroughly. The bend to the unit is in the rack ears on the front which doesn't affect the interior chassis in any way.
It has a three-piece steel frame which really does a great job of isolating everything but the faceplate. (Although the power tubes were mounted inside and they bought it.) This amp is even more point to point than my old SVT with a super clean and logical layout.
My only complaint is a small ribbon cable which has obviously been fixed before (and not very well). I question the logic in using a ribbon cable in a high volume bass amp between a major structural juncture.
Another cool plus is a three way power level selector switch which looks like it turns on the tubes in pairs for more crunch at lower volume. Since this is a sort of variable standby, it may be part of the problem as it is just a pot-type switch. It still shouldn't cause an over bias or blown fuse and at worst would open up and run all six tubes continuously or be intermittent and cause audible popping. I can see that bias current is applied as only two tubes at a time by the switch and the amp itself super quiet, so I think it is ok.
There are also two separate switches for standby and run on the front panel with corresponding LED's(which don't work but are getting voltage).
All the trannie connections were unhurt, but there was an absolute shitload of glass everywhere. I know glass is an insulator, but is there any way a small piece could be goosing the bias? I vacuumed out the chassis and don't think there is any left, but you never know.
It cherryplated the tubes in about one minute and it was always the same sockets that would cherryplate.(bad socket?)
This is baffling without the DMM, but I always try to shoot the thing in my head first. I am really bugged by this one.

Replies:

Carlo Hi PBG, What's wrong with the DMM? ... -- 9/28/1999 5:46 AM
A.S I fixed a Fender a couple of weeks ... -- 9/28/1999 9:07 AM