Tube Amp Problem
108.222.186.121 |
||
| Posted on August 16, 2014 at 12:17:50 | ||
|
Posts: 3022
Location: western Missouri Joined: October 9, 2001 |
A (somewhat long) tale of woe: I have a Jasmine Serenade Tube integrated amp. Several months ago I noticed that the sound field had shifted somewhat toward the left channel; the right channel still played, but at a reduced level. I took it to a local repair shop where I had had successful work on various pieces done in the past. After 2 weeks they told me the problem was related to bad resistors related to the headphone amp and had been fixed. Ignorant as I am about such things, I brought it home. The only cost was the original diagnostic fee. Unfortunately the channel imbalance, while not as severe, still persisted. I took it back, they agreed it wasn't right, and, after another 5 weeks, called to tell me it was now fixed and charged me just an additional $11.00 for the replacement of a couple of capacitors.. For a week the amp performed perfectly and in fact sounded even better than ever. But here's where the plot thickens! Just before I took the amp in for repair the first time, I had ordered a pair of supposedly new Valve Art EL 34 tubes from someone on eBay. I got the tubes weeks ago, but didn't try them until today. Almost immediately after installation I noticed a slight crackling sound from the right channel, but nothing too serious-or so I thought. Unfortunately I chose this moment to go upstairs to grab a snack. (I probably should mention that as I was about to install these "new" tubes, I noticed some scuffing at several spots around the base; I attributed this to the possibility that the seller had installed them to check them out.) When I returned a few minutes later, smoke was billowing around the right channel EL 34 and the cracking sound in that channel was much louder. I shut everything down and after it cooled off, replaced those tubes with a pair that I knew were working correctly. Unfortunately the right channel is deader than a door nail. The right channel speaker, however, seems to be just fine. Since I'm relatively inexperienced with tube gear, I'd appreciate any and all opinions and/or comments about the situation I've described. Is the most likely culprit the repair having gone bad? Or a bad tube? Or...? And finally, is it possible to hazard a guess about the type and/or extent of the damage this tube blowing up might be? Thanks in advance for any responses.
|
|
