Tubes
heiney9
Posts: 25,165
I bought a lot of 7 tubes from a very nice lady in Germany. I was really only interested in a particular matched pair of Valvo's and the rest were a bonus. All the tubes tested between 75-90% of NOS according to the seller and at this point I have no reason to not believe.
I finally put in the pair of Valvo's and one is pretty noisy. Lots of low level hiss and occasional soft popping. It seems after they warm up for about 30 minutes they are much quieter and no popping, but still some low random hiss.
I cleaned the pins with deoxit. Is there anything I can do to quiet these down or is this a sign they are on their way out? I am working with the seller for a partial refund...........but as usual I'd rather have working tubes than the $$$. These are among the rarer Valvo's produced and I'm hoping there is some way to salvage them.
H9
I finally put in the pair of Valvo's and one is pretty noisy. Lots of low level hiss and occasional soft popping. It seems after they warm up for about 30 minutes they are much quieter and no popping, but still some low random hiss.
I cleaned the pins with deoxit. Is there anything I can do to quiet these down or is this a sign they are on their way out? I am working with the seller for a partial refund...........but as usual I'd rather have working tubes than the $$$. These are among the rarer Valvo's produced and I'm hoping there is some way to salvage them.
H9
"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
Post edited by heiney9 on
Comments
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I guess that's just the "soul" talking (re: your sig)
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well if its just that one tube then that would seem to narrow it pretty good, have you damped the tube....if it gets better as it warms then it may be very slow to reach optimum bias.
RT1 -
I haven't dampened the tube and actually when I first installed them...........before cleaning the pin's, it was just one tube, after cleaning they both were acting up, but the original one was acting up more. So dampening can help this issue? Tonight when I get home I'll install them and let them sit for a good hour and see if they quiet down. After cleaning and re-installing them they were so noisy and were popping I only left them powered up for about 15 minutes.
I even put in a different rectifier because I thought maybe there was a mismatch, etc. That didn't help at all. I've since put in a couple different pairs of tubes with no issue so I doubt it's the pre-amp.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
is this a sign they are on their way out? I
Yes.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Yes.
That's what I thought. Is it possible they could test well (as in the good section) and still be on the way out? Seems like a silly question, but since I don;t have a tube tester I have no experience with how the testing relates to real life use.
I have access to a tester here in town thru a member of our Rockford audio group.
Bummer, because I really like the sound of the late 50's Valvo's made in Hamburg of which these are.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
It is thermionic noise based on the description. Are they high gain tubes like ECC83s? Sort of comes with the territory (although of course some are noisier than others).
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mhardy6647 wrote: »It is thermionic noise based on the description. Are they high gain tubes like ECC83s? Sort of comes with the territory (although of course some are noisier than others).
ECC81/12AT7.
Please explain further"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
Hiss is usually random (shot) noise from the electrons cooking off the cathode and impinging on the plate. 12AT7 isn't really high-gain, so I basically rescind my conjecture.
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These are unlistenable. The hiss/popping is pretty loud. When I get a chance I'll roll them in and let them power up for an hour or so and see if they quiet down.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
Hiss is usually random (shot) noise from the electrons cooking off the cathode and impinging on the plate.
That does seem to be the case here.....would explain the popping as well.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Is it possible they could test well (as in the good section) and still be on the way out?
Depends on what they were tested for and on what they were tested.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
The seller on Ebay has made a partial refund for the noisy tubes. Very nice and accommodating seller from Germany. She had a little issue with English, but a very nice lady with excellent communication.
Another great E-bay transaction.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
