JJ preamp tubes - repeated problems
I purchased an amplifier that came with stock tubes made by JJ. There were problems with the amplifier so I replaced some tubes and then figured out it was the pre-amplifier tubes and small tubes. The manufacturer in this case who is McIntosh did send me replacement tubes and they worked for a month or so and then began to crackle. Now I have to figure out which of the six small tubes is creating a problem.
I'm curious to know if manufacturers test the tubes that they use in the amplifiers before they ship them out? Maybe they test fine and then go bad within a month. I'm very suspicious they don't bother testing their tubes.
Judging by the process to test individual tubes and when you have 24 tubes on an amplifier I can understand them not giving them much attention during the manufacturing process. Maybe they expect people to replace all the tubes just like the power cords they send out.
.Many replace the stock tubes immediately with gold lions which seems like an easy choice. Maybe manufactures do test their tubes and they're just using a poor manufacturer.
Do others have tube problems with McIntosh amplifiers?
If they are preamp tubes, they should last 2000-10000 hours depending on the design of the preamp. Obviously there is something wrong. While I don’t particularly like the sound of JJ tubes, they might not be at fault and I would hope Mac would inspect the tubes they buy before they install or send them out. All the best. |
I have used JJ tubes for the past 7 years, in my case re-branded tubes with the McIntosh logo on them. The 12ax7 tubes are quieter than the 2 Gold Lion 12ax7 tubes I am using in the line stage. This weekend I will swap out the Gold Lions for 2 McIntosh (JJ) tubes. I have no such problems with them and never have. The McIntosh tubes were purchased from Audio Classics. |
I had a pair of 6550 (output) tubes (in an amp) redplate for way longer than I ever should have let them, and nothing like that happened. I'd like to see that 6922, @samzx12 , pics? |
@stereo5 , I am using a quad of JJ (first time with JJs for me) 6SN7s in a SLP05, and the reason I went with JJs was because a friend of mine related basically the same as you did. So far I have no problem with them. |
@immatthewj I didn't take a picture after pulling out the tube. |
