Tubes failing in decware csp2+, Help!!
Jan 9, 2011 at 4:35 PM Thread Starter Post #1 of 24

Eronel

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Hello All,
 
So ive just returned home after  2+ week vacation to find my csp2 with an audible hum through my hd 800s, ive already ordered a new set of tubes for it it, but untill they get here im sort of in a fix. My Zen TABOO has a 12ax7(not sure, could be 12au7 or 12at7) out front and i was wondering will it blow up the transformer or cause permanent damage in the csp2, should i just wait it out till my new trio of 6922s arrive? i'm a newbie to the world of tubes so any help or suggestions would be greatly appreciated.
 
Jan 14, 2011 at 9:39 PM Post #2 of 24

Skylab

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I know this was almost a week ago, but you absolutely cannot use a 12AX7 or 12 AU7 in place of the 6922 in the CSP-2. You need to use a 6922 or 6DJ8. Did you call Decware?
 
Jan 15, 2011 at 2:08 AM Post #3 of 24

Eronel

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thank you, i didnt end up using either as i thought the information i was receiving was false. i overnighted a trio of jj 6922's and a bendix 6106, my only problem now is the quite noticeable hum coming through my hd 800's. i ordered a trio of the 6n1p's that shipped with my csp to begin with as i hope that will get rid of the problem. Could you reommend a brand of 6922's that hopefully would be much less noisy?
 
Jan 15, 2011 at 10:16 AM Post #4 of 24

Skylab

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I have used JAN Sylvania 6922's in the CSP and had absolutely zero hum with any headphone I tried.  You can get these from tubedepot.com.
 
Jan 26, 2011 at 3:57 PM Post #5 of 24

Eronel

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thanks for the advice Skylab, i purchased and received a trio of jan sylvania 6922, now i have a new problem that has arisen from the amp itself i believe. W/hen i start the amp now, the tube on the left when looking at the amp from the front arcs (which is what i believe flashes of light within the tube and the accompanying loud crack through whatever is plugged into the amp are) with no matter what tube i put in there, after a few seconds it rights itself and everything plays normal with now loss in fidelity. I'm perplexed by this and before i contact Steve and send the amp back for repairs id like to know whether i should just let it happen or treat this more seriously?
 
Thank you.
 
P.s. there is still an audible hum through even my dt 990/600 ohm
 
Jan 26, 2011 at 4:06 PM Post #6 of 24

Frank I

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The tubes you are buying could be or could have caused problems. I use three matched Genalkex reissues in my CSP-2 amp without ever a problem. I suggest you sen d the preamp back to Decware to have it checked. Only use the tubes the manual tells you and dont stick the 12AX7 into the CSP-2 I hope you did not try that and for my use which my amps run 12 hours a day zero tube failures. None. I would only buy from reputable dealers and my favorite is Jim McShane in Chicago second up is Upscale Audio with Kevin Deal these are the best matched tube checked properly and the two of those guys are the best at what they do, My favorite is the Genalex 6922 reissues an incredible tube IMO
 
Jan 26, 2011 at 4:08 PM Post #7 of 24

PFKMan23

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tube arcing indicates a bad tube, although consequently, now the amp may be damaged as well.  The first thing I'd do is get a new tube in there and then go from there.  As far as microphonics go, have you tried cleaning the tube pins with some deoxit and a wire brush or something similar?
 
Jan 26, 2011 at 5:27 PM Post #8 of 24

Skylab

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You need to contact Steve. 
 
Jan 26, 2011 at 7:14 PM Post #9 of 24

Eronel

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ok so i just got home and decided to try my fate and i plugged in the 6n1ps i had on hand and there was no arcing whatsoever with it, i tried switching to a different one of the three sylvania 6922's and it arced with that one as well and only in that tube socket the other positions didnt arc or pop whatsoever with the other 6922's in there, later on i will try putting in the horrendously noisy trio of jj 6922's to see if the arcing persists only in this tube variant.
 
And lastly, what is the proper procedure to take when swapping tubes? wait an hour then swap or turn the amp off and unplug it then swap the tubes and power it back up?
 
Jan 26, 2011 at 7:15 PM Post #10 of 24

Skylab

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I normally wait 30 minutes after turn-off before changing tubes.
 
Jan 26, 2011 at 10:41 PM Post #11 of 24

Frank I

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Quote:
ok so i just got home and decided to try my fate and i plugged in the 6n1ps i had on hand and there was no arcing whatsoever with it, i tried switching to a different one of the three sylvania 6922's and it arced with that one as well and only in that tube socket the other positions didnt arc or pop whatsoever with the other 6922's in there, later on i will try putting in the horrendously noisy trio of jj 6922's to see if the arcing persists only in this tube variant.
 
And lastly, what is the proper procedure to take when swapping tubes? wait an hour then swap or turn the amp off and unplug it then swap the tubes and power it back up?

you also need a good tube vendor why would you want JJ only current porduction any good is Genelex reissues 6922. If you looking NOS you need to buy from good dealers or you going to ruin the amps and push Steve patience if  your not properly maintaing the amp properly and that  means reliable tubes. JJ are bad tubes and my vendors won't sell them
 
 
Feb 8, 2011 at 4:46 PM Post #12 of 24

Eronel

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s now that time has passed, the arcing problem has diminished to the point where it only happens occasionally. i can live with that. the hum persists but is easily drowned out by music playing. Now isnt a good time for me to send my amp into decware because im in the process of moving, but i will consider it after that is done. ive noticed that arcing occurs in the left and right channel tube sockets, more often now in the right side as opposed to the left of earlier. Any other thoughts?
 
I highly prefer the sound of the JAN-Sylvania 6922's as opposed to other tubes ive tried, but it seems that these tubes started the chain of events which led to this arcing problem. I'm not willing to take the next step (mullard, amperex, telefunken) as they are extremely cost prohibitive being a college student with very little disposable income.
 
I will call steve tomorrow to try and get to the root of the problem, but im not holding my breath as it seems my once dead quiet amp is now arcing and humming regardless of tubes.
 
Feb 8, 2011 at 5:00 PM Post #13 of 24

Frank I

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Quote:
s now that time has passed, the arcing problem has diminished to the point where it only happens occasionally. i can live with that. the hum persists but is easily drowned out by music playing. Now isnt a good time for me to send my amp into decware because im in the process of moving, but i will consider it after that is done. ive noticed that arcing occurs in the left and right channel tube sockets, more often now in the right side as opposed to the left of earlier. Any other thoughts?
 
I highly prefer the sound of the JAN-Sylvania 6922's as opposed to other tubes ive tried, but it seems that these tubes started the chain of events which led to this arcing problem. I'm not willing to take the next step (mullard, amperex, telefunken) as they are extremely cost prohibitive being a college student with very little disposable income.
 
I will call steve tomorrow to try and get to the root of the problem, but im not holding my breath as it seems my once dead quiet amp is now arcing and humming regardless of tubes.



Send the amp in. The tubes are bad and the amp probably damaged. Use good vendors that sell quality tubes and the more you keep using those bad tubes the worst it will get.Using the incorrect tube types as the 12AX7 if you ran them in the CSP-2 your amp damaged. If you know those sylvania are bad why do you insist on using them.
 
Feb 8, 2011 at 9:49 PM Post #14 of 24

Eronel

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I never used non-spec tubes in it, Where i live even amp technicians know squat about tubes so i took his advice with a grain of salt. let me be clear, that the only tubes i have put in that amp have been spec'd for it, and recommended by other users including skylab among others. Those tubes are The factory 6n1p, jj 6922's which were bright and brittle, and finally the JAN-Sylvania's, which sound amazing.I also swapped rectifiers for a Bendix 6106, which died after a couple of days worth of use dont quite know whether it was the amp or a crappy tube but it was under warranty so i returned it. The hum that i hear is small enough that i have to listen for it, depending on the impedance the phones i'm using. The arc within these tubes happens AT MOST once a week, other wise the amp performs EXACTLY as it should. The humming began 3 or 4 weeks ago when i returned from a month long vacation. The amps were both unplugged from an outlet and the isolation transformer i have powering them so I assumed that the tubes were on their way out because the amp was humming and output was severely decreased. So the humming has persisted but the amp performs fine with zero loss in output, this is something i can live with. ill most likely switch to the 6n1ps in lieu of investing in top dollar 6922's.
 
Feb 9, 2011 at 3:59 PM Post #15 of 24

Frank I

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The CSP-2 I have has absolutely zero hum. Send it in or not its your call. I hear no deficiency and I reiterate only buy tubes from reputable reliable vendors. I have only used an handful of dealers in the twenty years of owning tube gear and I can count on one hand the amount of tube failures I have had in that many years. If it were my amp I would have Decware go over it and make sure it is working properly
 

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