Help troubleshooting amp
>>"I switched both pairs of 6550's from left to right. Now no signal in either channel!"<< >>"This leads me to beleive that the trouble rests with the amp."<< >>>>>>>>>> Just a guess, a bad shorted 6550 tube. The bad tube may have damaged something in the right channel. Installing the bad tube in the left channel may have caused damage there as well. Post a thread on Audio Asylum on their tube forum and ask your question. http://www.audioasylum.com/audio/tubes/bbs.html |
I had the same problem with my VTL MB450's. A bad tube blew the main output fuse on one of the amps but the tubes themselves still lit up because there was a small amount of current going through them. The fact that there was current going through them mislead me to thinking that the problem was not the tubes. I would agree with Jea48 that a bad tube on the right side when switched to the left side blew a fuse on the left side as well. I would check the fuses (use a volt meter) on this amp to see if indeed they are blown. If they are, you need to replace the fuses and the tubes before proceeding any farther. Scifi |
Hi Jond. Sounds to me like a bad tube[shorted] took out the cathode resistors in one channel and when you swapped them to the other channel, the same bad tube or tubes took out the cathode resistors in the other channel as well.If you have a tube tester, It would be a good idea to test all these tubes to ascertain what tube/tubes are shorted before putting them back in. Is your amplifier a self biasing circuit or can you bias each tube idividually? |
