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CSP3 front tubes (Read 4687 times)
Archie
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CSP3 front tubes
05/03/19 at 16:25:44
 
Does anyone know if it's okay to use 6DJ8 (PCC88) type tubes in the rear two spots in the front of the CSP3?  The manual says the front spot is okay but it doesn't list them for the next two spots.  Before I read this I put PCC88s in all three spots.  Last night I was getting some popping through the speakers occasionally (in bursts).  The really odd thing is that since the anniversary mods to my CSP3, I get a short "whooop" at turn on but with the PCC88s the "whooop" is significantly longer and louder and is even there when I power down.  Some of this is mod related but some seems tube related too.  These effects are predominant in the left speaker although faintly there in the right.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Lon
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Re: CSP3 front tubes
Reply #1 - 05/03/19 at 17:10:36
 
I think that the PCC88s (7DJ8s) should be fine, I've used them in the past in CSP preamps. I get that "popping" too on the CSP3-25--my theory is that it's the voltage regulator tube inside (mainly I theorize this because I have the Anniversary mods on a CSP2+ which I don't believe include a voltage regulator tube and it does not "pop"; I get that sound also on my SE84UFO3 25th Anniversary Monoblocks.) Not sure why the "pops" would be longer with the PCC88s but I don't think they are doing damage.
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HR-1,ZTPRE,ZBIT,ZROCK2,SEWE300B,CSP3-25mod,Taboo MkIV;Rega RP3 all GrooveTracer mods;PSAudio:PST+DSD,P15,NPC,PowerBases,AC-12 pwr cbls,Reference spkrcbls;Mapleshade SamsonV3;VooDoo:Cremona+Amati interconnects, IsoPods; headphones:Sennheiser HD800S,ZMF Ori,Oppo PM1
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Archie
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Posts: 2731
Re: CSP3 front tubes
Reply #2 - 05/03/19 at 23:40:00
 
Just to be safe, I put the 6N1p-EVs back in the two rear slots.  My startup "whooop" was back to "normal" and so far, no pops.  The pops came well after warmup before so I'll see what happens later tonight.

I meant to write 7DJ8 before, as you correctly wrote.  Do your noises come from predominantly one channel or both more or less equally?
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Lon
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"Love without
guts is
worthless!"
Philip K. Dick

Posts: 23305
Re: CSP3 front tubes
Reply #3 - 05/03/19 at 23:55:43
 
The noise comes from both in the Monoblocks, which makes sense. I think the noise may come more prominently from the left with the CSP2 but the difference is slight.

Odd that the pops are coming from the PCC88s. I haven't used them in a while perhaps not with the CSP3, maybe only with the CSP2+ . . . mainly because they're not my favored tube type. With my CSP3 with the 25th mods I'm using three Amperex Bugle Boy Holland 6DJ8; no popping so to speak.
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HR-1,ZTPRE,ZBIT,ZROCK2,SEWE300B,CSP3-25mod,Taboo MkIV;Rega RP3 all GrooveTracer mods;PSAudio:PST+DSD,P15,NPC,PowerBases,AC-12 pwr cbls,Reference spkrcbls;Mapleshade SamsonV3;VooDoo:Cremona+Amati interconnects, IsoPods; headphones:Sennheiser HD800S,ZMF Ori,Oppo PM1
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Archie
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Posts: 2731
Re: CSP3 front tubes
Reply #4 - 05/04/19 at 00:20:42
 
My theory is the PC88s are causing the pops and they certainly seem to enhance the "whooop."  I'll probably leave the 6N1Ps in the back spots since Steve confirms their use in the Manual.  I have the initial impression that I've better gain with them in.  I was worried that the PC88s might have been faulty but that will take a lot of tube swapping to figure that out.  I did reverse the two tube's positions and that didn't make a difference.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Archie
Seasoned Member
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Posts: 2731
Re: CSP3 front tubes
Reply #5 - 05/04/19 at 17:22:47
 
With the 6N1P-EVs in the middle two spots I'm not getting anything weird happening now.  I right experiment further with tube swapping but for now, I'll stick with the manual recommendations as they seem to be working.
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ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
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Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. Dick

Posts: 23305
Re: CSP3 front tubes
Reply #6 - 05/04/19 at 19:01:43
 
I've run 6DJ8 and 6922 in all spots since I got the preamp 11 months ago and despite some minor noise at times everything works quite well. There are subtle differences between driver tubes, 6N1P are good; I prefer some others but it is all so subjective.
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HR-1,ZTPRE,ZBIT,ZROCK2,SEWE300B,CSP3-25mod,Taboo MkIV;Rega RP3 all GrooveTracer mods;PSAudio:PST+DSD,P15,NPC,PowerBases,AC-12 pwr cbls,Reference spkrcbls;Mapleshade SamsonV3;VooDoo:Cremona+Amati interconnects, IsoPods; headphones:Sennheiser HD800S,ZMF Ori,Oppo PM1
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