I turn power up the Stang Ray, let it warm up for a few minutes, switch it out of standby and it sounds GREAT - for 5 minutes. Then the volume cuts in half and the tone goes away. When put back into Standby mode, there is 5 - 10 seconds of noise after going into standby.
Called Dr Z and spoke to someone who advised me to change the tubes.
I powered it up again and took the grill cover off and looked at the tubes. The 12AX7 (which is under that metal tube cover) had absolutely no glow to it at all - so I guess its a no brainer that the 12AX7 needs to be replaced.
My question is this. Do I just go out and buy a 12AX7? How do I find the BEST one for the amp? Does the amp need to be tweaked after replacing tubes to keep its pristine tone?
Is this something a novice like me should attempt, or should I take it to a good amp tech to ensure it gets done right?
First off, you're more than capable of changing the preamp tubes. Preamp tubes do not require the amp to be re-biased, so you can change EF86s and 12ax7s to your heart's content. Just make sure the amp is off, and that the tubes have cooled. Pull out the old tube, and gently install the new tube, being careful to align the pins properly.
As far as choices go, I doubt there's anyone out there who would say that NOS tubes aren't better tubes. But you'll just have to decide if they're worth the money to you. For new production tubes, I've been favorably impressed with the Chinese 12ax7 tubes I got from ARS Electronics. Fantastic tubes for around $12. Much better to my ears than JJ's or Sovtek. As far as NOS tubes go, I think most tone snobs agree that the Telefunkens are the cream of the crop, with Mullards (NOT the reissue Mullards) not that far behind. Check out Myles' website for LOTS of great info about tubes. www.guitaramplifierblueprinting.com
I don't know for sure. I bought my Stingray used, so I'm not sur if mine were stock tubes. But my Ray has a Dario Miniwatt EF86, and a Sovtek 12ax7. I have purchased a bunch of NOS tubes though, so I'm going to do some experimentation. I'm fairly certain I'll keep the Dario because they have a great reputation. And I'm 99% sure I'll swap the 12ax7, because I have some vintage Telefunkens and Mullards on the way.
I put in a new 12ax7 today - nothing fancy - a JJ Electronics tube. The noise that happened after going back into standby has been eliminated, but unfortunately I still loose about half my volume after about 5 minutes of playing.
I think something is heating up to cause this problem.
In regards to the PI tube, Doc typically uses the Sovtek 12AX7LPS, which has a spiral filament, which is nearly impossible to see any discernable glow coming from it.
Besides, if the PI tube is dead, you get no sound.
Last Edit: Mar 26, 2008 6:03:42 GMT -7 by hdahs143
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