Still Freaking Out Over Tube Noise


Welcome to my third installment of this nightmare. I am using my second pair of RT 12AU7's that are making more noise than music and I am about to lose it. This cannot be a common characteristic of tube equipment!!!!!! Why are these tubes so noisy in my preamp (CJ PV10A)???? (The RCA red labels that came with it weren't noisy at all, but they are used up.) The dealer I bought them from is a state away (tube availability is dour in Atlanta) and it is a pain to ship these things back and forth. Would switching to Mallards be a good idea? Some other brand? Try another pair of RT's? Poke my ear drums out??? How can I get my sanity back???

Thanks!!!

Brad Day
bday0000
you sound like a prime candidate for those "audiophile full service tube dealers". They will charge you 2-3 times more than other places, however you can be rest assured they have been tested for microphonics and are matched.

I would recommend Mullard cv4003s(12au7). They make my Air Tight amp sing.
Could you direct me to a couple of those "audiophile full service tube dealers"? I am willing to try anything at this point...

Thanks!!!!

Brad
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Why don't you contact CJ? Maybee there is aproblem with your unit or you could buy a pair of tubes from them.

Chuck
I agree to buy the stock tubes from CJ. They test them extensively. Your unit will also sound like it did when it was new. If there is still a problem, send the whole unit to CJ. They'll make it right, and will check the whole unit from top to bottom.
upscaleaudio, Vintage tube services, and Tube World are all places where the tubes are tested extensively.
Sorry, if I am in a little late on this thread, but what kind of "noise" are you hearing? Is it microphonics? Or is it just bad tubes? Have you ruled out any other possible causes? There are many different "noises", and it would help with diagnosis if we knew what you're hearing, and if it is all the time, or when you just turn it on, or only when you play it loud, or does it ever go away, or what?
I agree, use a known service! Of the "big three" mentioned" here, Andy at Vintage Tube Services (www.vintagetubeservices.com) knows tubes, has testing procedures and equipment that the others DON'T, so that when you buy a Mullard, you get a MULLARD and not a rebranded Brimar (I won't mention names!) Andy is definitely "the man"!
How do you guys get in touch with Andy? I have called his number about 30 times at different times and on different days over a 2 week period, and he never answered the phone. I finally got my tubes somewhere else.
Who sells Brimars as Mullards? Name names! I don't know why they would. The price on them is about the same. The Mullards factory codes are etched in every tube, and the internal structure looks nothing like a Brimar. Who is doing this?

It makes no sense. Funny how stuff happens. Just like the rumor that someone is counterfeiting Telefunken including the diamond in the glass. They would have no idea about the manufacturing business.
Here is the deal with your preamp. And we retube them DAILY. The PV-10, 11, and 12 have a bit of gain and no feedback. They sound great, but if there is any pimple on the tube, you will hear it.

So the tubes have to be quiet. They also need to be tight and won't shake apart. If you have noise, there is noting you can do except put in the best tube. If you have microphony....the tube rings constantly and will not stop....you may want to consider, if it is out of warranty anyway, rubber mounting the transformer. I know guys that have done this and it helps. But it takes a bit of time as it is tight. The transformer vibration is picked up through the tube pins and slowly over a period of time it shakes loose internally.

If you want ease, find some RFT 12AU7. They seem to hold up. We don't sell them, as people look for something more "sexy". We use the Mullard CV4003. This is about the only tube that works well, and even at that only about 10% pass muster here to be used in those!