Do my preamp tube sockets need to be cleaned?
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muncybob
Posts: 2,972
I notice every now & then a slight crackling noise. You won't hear it when music is playing but you can hear it no matter what the source is and increasing volume doesn't alter it. Tube pins look good. Sockets need to be cleaned? I sure hope it's nothing any more serious. I plan to remove and reinstall the tubes several times hoping that "scraping" in the socket does the trick. Any other way to clean the sockets?
Yep, my name really is Bob.
Parasound HCA1500A(indoor sound) and HCA1000(outdoor sound), Dynaco PAS4, Denon DP1200 w/Shure V15 Type V and Jico SAS stylus, Marantz UD7007, Polk L600, Rythmik L12 sub.
Parasound HCA1500A(indoor sound) and HCA1000(outdoor sound), Dynaco PAS4, Denon DP1200 w/Shure V15 Type V and Jico SAS stylus, Marantz UD7007, Polk L600, Rythmik L12 sub.
Comments
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Could just be a noisy microphonic tube. But, it is worth disconnecting from power and cleaning by inserting a few times with this on the pins...
https://www.amazon.com/DeoxIT-Gold-Brush-Contact-Conditioner/dp/B0015A7CYG -
Short answer is yes clean them. While deoxit gold is good the red deoxit has more cleaner action per Caig.
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I've read that using the Deoxit gold leaves a residue that is not something that should be present in areas of high temps?
Got to playing around with various tubes in my line stage left channel. Starting to think I have some noisy tubes. Finally found one that was dead quiet, at least for the short time I had to listen to it. I've heard this crackling noise before and sometimes it goes away without doing anything. Is this indicative of a noisy or microphonic tube?Yep, my name really is Bob.
Parasound HCA1500A(indoor sound) and HCA1000(outdoor sound), Dynaco PAS4, Denon DP1200 w/Shure V15 Type V and Jico SAS stylus, Marantz UD7007, Polk L600, Rythmik L12 sub. -
Microphonic is pretty easy to diagnose. Turn on let get up to temp turn volume up a little and take a small wooden stick and lightly tap on the tube it will ring like church bells if it is microphonic. Some you can just use a finger they're that bad. Maybe you need to tighten the socket contacts if they are not grabbing well.
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Curious to see how this turns out for you. I actually just started having a little bit of the same issue.Analog: MoFi MasterTracker > MoFi UltraDeck > Sutherland 20/20
Digital: Cambridge CXC / Streaming > Cambridge CXN v2
MastersounD Dueventi > Rosso Fiorentino Certaldo or Arcam rHead > Hifiman HE4XX
Discogs -
Any electrical connection should be periodically cleaned. I will be cleaning all my interconnect and power connections this summer. That includes the AC lines at the breakers, and the breaker connections to the AC bus.Lumin X1 file player, Westminster Labs interconnect cable
Sony XA-5400ES SACD; Pass XP-22 pre; X600.5 amps
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Three 20 amp circuits. -
Bud, I would be interested to know what materials and procedures you use to clean.Yep, my name really is Bob.
Parasound HCA1500A(indoor sound) and HCA1000(outdoor sound), Dynaco PAS4, Denon DP1200 w/Shure V15 Type V and Jico SAS stylus, Marantz UD7007, Polk L600, Rythmik L12 sub. -
Yes, use a pipe cleaner and deoxit
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! -
Fuzzy dental pics work too.
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Pro Gold and whatever materials are required for the application, which will vary.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 -
doug has some rca tools and kits you may want to look at
https://douglasconnection.com/products/connector-cleaning-kits-supplies/2 ch- Polk CRS+ * Vincent SA-31MK Preamp * Vincent Sp-331 Amp * Marantz SA8005 SACD * Project Xperience Classic TT * Sumiko Blue Point #2 MC cartridge
HT - Polk 703's * NAD T-758 * Adcom 5503 * Oppo 103 * Samsung 60" series 8 LCD -
Just something to add to this subject....since I added a Belles amp to my rig, which I love BTW, and had to go back to RCA connections for my pre amp to amp connection, my tube hiss from my pre seemed quite a bit louder. It was starting to bug me so I started swapping out power cords and removing pins...to no avail. I decided to clean all 4 tube pins w deoxit gold and pop them back it. The result was a pretty good decrease in the hiss....I think. Later today Im pulling the pre out of the rack, blowing it all out, and clean the tube sockets also. After that in my upcoming rack re-org, every connection is getting cleaned w Deoxit Gold!
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Cleaned sockets and tubes and while it seemed to make a slight difference, the crackle/hiss was still there at about 12 o'clock on the volume dial. I then did what I should have done initially(and was suggested), replaced the line tubes. Problem solved. I didn't do this initially because the tubes in the pre were supposed to have been better quality tubes. So now I'm gonna be searching for another pair of matched 6DJ8s. Any recommendations?Yep, my name really is Bob.
Parasound HCA1500A(indoor sound) and HCA1000(outdoor sound), Dynaco PAS4, Denon DP1200 w/Shure V15 Type V and Jico SAS stylus, Marantz UD7007, Polk L600, Rythmik L12 sub. -
yeah I did a bit of research and according to some pretty knowledge people....alot/all of the hiss has to do with the tubes themselves. I am going to clean my other 2 sets and further test my theory later this week.
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Noise at half-way up (in terms of resistance, not necessarily control travel) on a resistive attenuator can be an intrinsic problem, as the impedance of the attenuator is highest at 50% attenuation -- again, that's not necessarily "half way" up physically speaking on an audio (logarithmic) taper potentiometer. This is one of the reasons why I (FWIW) prefer a transformer-type attenuator (constant impedance). It is certainly possible for some tubes to be worse than others, but the "12 o'clock" comment might also be indicting the 'volume control' itself.
EDIT: Also FWIW, I am not a big fan of the 6922 family of dual triodes -- noise being one of several reasons why
You might want to try a pair/set of 7308s if you haven't already. They tend to be a little better behaved (and prices reflect their relative desirability). That's what I ended up putting in my Bottlehead Seduction phono preamp way back when.
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What is "relaxed top end" saying when a tube is described?Yep, my name really is Bob.
Parasound HCA1500A(indoor sound) and HCA1000(outdoor sound), Dynaco PAS4, Denon DP1200 w/Shure V15 Type V and Jico SAS stylus, Marantz UD7007, Polk L600, Rythmik L12 sub. -
FWIW: If I said it (not that I'd be likely to), I would mean "not edgy in the treble". A Peerless
KO10DT silk dome tweeter has a relaxed top end compared to a JBL 075 earpiercer.
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Hey Bob - are these the BB I sent you? If so, and that's the issue, LMK and I'll send you something else - I may even have some 7308's - I'll look tonight!VA HT HK AVR20II, Sony S9000ES CD/DVD/SACD, Polk Audio RC80i / Polk Audio CSi3, 60" Panasonic Plasma, Nordost / Signal Cable A2 / Wireworld / Pangea / Magic Power
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Audible Illusions L1 Preamp
Vincent MFA based Cocci Tube Preamp
Pho-700 Phono Pre
Signal Cable Silver Resolution IC's -
Cleaned sockets and tubes and while it seemed to make a slight difference, the crackle/hiss was still there at about 12 o'clock on the volume dial. I then did what I should have done initially(and was suggested), replaced the line tubes. Problem solved. I didn't do this initially because the tubes in the pre were supposed to have been better quality tubes. So now I'm gonna be searching for another pair of matched 6DJ8s. Any recommendations?
Some tubes are just finicky. That's why I have so many pairs. These little glass gems are 40-60 years old and no amount of testing is going to weed out a slightly noisy tube. It's part of using tubes in a system. Not every single one is going to be 100% all the time.
But you did the right thing as the number 1 issue with noisy tubes is dirt, corrosion, crud on the pins and in the tube socket.
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! -
Hey Bob - are these the BB I sent you? If so, and that's the issue, LMK and I'll send you something else - I may even have some 7308's - I'll look tonight!
Very nice of you to offer, PM sent.Yep, my name really is Bob.
Parasound HCA1500A(indoor sound) and HCA1000(outdoor sound), Dynaco PAS4, Denon DP1200 w/Shure V15 Type V and Jico SAS stylus, Marantz UD7007, Polk L600, Rythmik L12 sub.
