Modifying a JMP1c to sound brighter. Noob questions

[The Dude]

Agree- probably not mod related. Some manufacturers have methods for mitigating microphonics in high gain stages. You might see a rubber grommet around the tube, or maybe heat shrink tubing, etc.

[bruzanhd]

Thank you folks. I ironically did have a mesa 12ax7-a that I swapped in and yes I've never had to deal with it before. Really I was only worried since the tube was initially good but became microphonic later on.

[Chuck H]

Thank you folks. I ironically did have a mesa 12ax7-a that I swapped in and yes I've never had to deal with it before. Really I was only worried since the tube was initially good but became microphonic later on.

I've done this a dozen times. Not the least of which was in the presence of a respected amp manufacturer. I had to make sure I had stable tubes on hand just to present my design in it's intended function.

At that time I did actually use Mesa rebranded Shuguang tubes that had been tested (by Mesa and myself) for microphony in the V1 spot in my design.

Finding what can work for your own amp in todays world is different. Shuquang is gone () There are no Rusky tube suppliers stepping up to the criteria as I understand it. Some are ok with power tube offereings. But 12AX7's suitable for V1 in high gain amps??? I'm not sure that's still happening with new tube offerings. The trend toward digital replication of the vintage amps should be heeded. I think we're looking at the end of tubes with current market problems and efforts demonstrated by "even" Fender. Tubes are going by by. Now or soon.

[Greg Robinson]

Shuquang is gone ()

Shuguang is back - CEDist/Antique Electronics started carrying them again fairly recently, as did Tube Amp Doctor, and I'm sure others.
I have no idea what the story is, always tricky getting RELIABLE info out of China.

Anyway, FWIW, I've always had best luck with JJ tubes. I see vastly differing reports from different people on the different sources (JJ - Slovakia, New Sensor - Russia, Shuguang - China, PSVane - China). Only conclusion I've been able to draw is that chain of custody seems the most important. Whatever deal each vendor has with their source and how they're handled/shipped from factory to warehouse, and then from warehouse to the individual.

For me here in Australia, I purchase JJ from CEDist, and what must be a couple thousand tubes/sets, JJ has been most reliable for me - only 2 failures in the last 18 odd years - one EL34 out of a quad that immediately redplated even at reasonable bias voltages, and a GZ34 that had a dead filament out of the box, but was salvageable with resoldering the pin. Haven't tried Shuguang in years but had about a 50% failure rate when I did, and New Sensor I had mixtures of excessive screen current in about 1/3rd of power tubes, and frequent heater to cathode failure in preamp tubes.

Others report wildly different experiences, and my above theory is the only rationalisation I can think of.

[Chuck H]

Thanks Greg. I hope this is good news about Shuguang. With your own experience I guess it's less so for you though. The last info I had found was a few months ago and PSVane was said to be a startup by a couple of big cooties from the old Shuguang and it was hinted that Shuguang might never be reestablished.?. As you said, info from China... The PSVane tubes seem to get mostly poor reviews from members here. Which I didn't expect considering the report that they were born from the Shuguang legacy. My understanding from many years ago was that Shuguang was always mediocre for bulk orders. But their tested and rebranded tubes (like Mesa) were expensive but generally good. I guess we'll see what new developments bring.

Thank you for updating me.

[Greg Robinson]

Thanks Greg. I hope this is good news about Shuguang. With your own experience I guess it's less so for you though. The last info I had found was a few months ago and PSVane was said to be a startup by a couple of big cooties from the old Shuguang and it was hinted that Shuguang might never be reestablished.?. As you said, info from China... The PSVane tubes seem to get mostly poor reviews from members here. Which I didn't expect considering the report that they were born from the Shuguang legacy. My understanding from many years ago was that Shuguang was always mediocre for bulk orders. But their tested and rebranded tubes (like Mesa) were expensive but generally good. I guess we'll see what new developments bring.

Thank you for updating me.

It's definitely still good news for me, with the influence of supply/demand and the inflation of prices. Hopefully should put some downward pressure on prices having another big name back in the game, though I never considered PSVane to be a "big" player.

Yes, from what I understand PSVane was an "offshoot" of Shuguang (founded by former staff?), though originally focused on the -Audiophile- end of the market. They stepped up to the plate with "budget" options for us lowly musicians after the Shuguang fire, but that met with mostly poor reviews from what I saw. I didn't want to chance anything and didn't try any myself, so this is only hearsay.

And yes, my experience with rebranded Shuguang tubes like Mesa, GT/Fender, Ruby, etc, was better, I just never found the price premium worth it. I'll stick with what has served me well until I have reason to question that, and I suggest others do the same, as I can't otherwise roconcile the wildly differing reports I see shared.

[Chuck H]

It's definitely still good news for me, with the influence of supply/demand and the inflation of prices. Hopefully should put some downward pressure on prices having another big name back in the game,..

Absolutely this ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I just looked into it a little and it seems TAD is "selecting" and rebranding some current Shuguang tubes. Which may be a good sign but the premium they're charging looks too high to me.