So, other than the explanation of the problem, can you recommend a tube "brand" of distributor that will supply some better tubes. I'm 60 years old and my experience tells me that even NOS tubes have no guarantee, even if they were designed better...maybe I'm wrong. Specifically, I have a Marshall Origin 20C, and it would be cool for someone with experience with this amp to let me know if a "new" tube set can make this amp sound better?? thx
Not really a discussion on tube microphonics as much as a unique way to repair broken internal welds. Let's get back on point and figure out a way to deal with this problem of tube microphonics. I have an amp on the bench with 4 EL84 tubes that are ALL microphonic. Swapping out for new tubes (preamp and power) does not help. Client says that the amp just started howling after he brought it home. They have a resonance around 330 Hz and 390 Hz. Put your finger on any tube and it stops. Finally made an aluminum damper PLUS two O rings on the two center tubes. It's been wailing all afternoon with no problems. I've had individual tubes do this but this is the first amp I have ever seen do this.
How old is the amp? Bad components? All four power tubes have gone microphonic in my Boogie Mark IV, which I'm pretty sure hasn't been serviced since the original owner bought it. Surely the caps need to be replaced at this point. I'm will to bet a few other things have drifted and damaged the tubes.
So, other than the explanation of the problem, can you recommend a tube "brand" of distributor that will supply some better tubes. I'm 60 years old and my experience tells me that even NOS tubes have no guarantee, even if they were designed better...maybe I'm wrong. Specifically, I have a Marshall Origin 20C, and it would be cool for someone with experience with this amp to let me know if a "new" tube set can make this amp sound better?? thx
0:42 811A triode.
Great!
Not really a discussion on tube microphonics as much as a unique way to repair broken internal welds. Let's get back on point and figure out a way to deal with this problem of tube microphonics. I have an amp on the bench with 4 EL84 tubes that are ALL microphonic. Swapping out for new tubes (preamp and power) does not help. Client says that the amp just started howling after he brought it home. They have a resonance around 330 Hz and 390 Hz. Put your finger on any tube and it stops. Finally made an aluminum damper PLUS two O rings on the two center tubes. It's been wailing all afternoon with no problems. I've had individual tubes do this but this is the first amp I have ever seen do this.
How old is the amp? Bad components? All four power tubes have gone microphonic in my Boogie Mark IV, which I'm pretty sure hasn't been serviced since the original owner bought it. Surely the caps need to be replaced at this point. I'm will to bet a few other things have drifted and damaged the tubes.
Have you tried this solution yet? I would love to know all about it!