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Help!  Valve Art 274B Failure (Read 7734 times)
Doug
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Help!  Valve Art 274B Failure
02/16/19 at 22:28:33
 
Another VA 274B just failed in my Torii Jr.  I won’t be using any more VA 274B’s.  Took out the bad tube and replaced it with a Sophia Electric 274B Aqua, which I’m also using in my CSP3 25.  I was all set to rebias the amp and noticed the OA3’s were not lit up and my multimeter is showing zero voltage.  Did a fuse blow when the 274B failed?  Is that why the OA3’s are dark?  The OA3’s couldn’t have failed, could they?  

Appreciate any thoughts on this before I unhook everything and open the amp to check for a bad fuse.

Thanks, Doug
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Jay’s CD2T-Mk3
Denafrips Pontus II
ZROCK2 25th Mods
CSP3 25th & Custom Mods
PAP Quintets with Voxativ 1.6
First Watt J2 or Cary 300SEI
driving Voxativs—no crossover
LFD NCSE driving 15” Woofers
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Lon
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"Love without
guts is
worthless!"
Philip K. Dick

Posts: 23313
Re: Help!  Valve Art 274B Failure
Reply #1 - 02/16/19 at 22:35:37
 
Is the fuse in the incoming power outlet on the Jr. as it is on many of the other amps? Easy to check that. In my experience if a rectifier fails, the fuse blows, other tubes are saved. . . .
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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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Lon
Seasoned Member
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"Love without
guts is
worthless!"
Philip K. Dick

Posts: 23313
Re: Help!  Valve Art 274B Failure
Reply #2 - 02/16/19 at 22:37:57
 
Just looked at the manual and yes, the fuse appears to be in the IEC inlet. Just unplug the power cord and flip open the little compartment in the front with a key or small screwdriver or dime. There may also be a spare fuse in the little fuse holder as well. . . .

Hope it's just a fuse and you're back in biz.
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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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Doug
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Posts: 272
Re: Help!  Valve Art 274B Failure
Reply #3 - 02/17/19 at 05:45:14
 
Thanks for the quick reply, Lon.

The amp powers up just fine, with the new Sophia rectifier and the el34’s lighting up; only the OA3’s are dark, and I get no voltage on my multimeter when attempting to set the bias.

I think I recall reading that there are two or three internal fuses in the Jr., but of course I can’t find that information now.  I guess I’ll open it up tomorrow and take a look.  

Do you have any additional thoughts or ideas?
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Jay’s CD2T-Mk3
Denafrips Pontus II
ZROCK2 25th Mods
CSP3 25th & Custom Mods
PAP Quintets with Voxativ 1.6
First Watt J2 or Cary 300SEI
driving Voxativs—no crossover
LFD NCSE driving 15” Woofers
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Lon
Seasoned Member
****


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

Posts: 23313
Re: Help!  Valve Art 274B Failure
Reply #4 - 02/17/19 at 12:25:10
 
Okay, I didn't realize the other tubes have power. . . .

Yes, it is possible that there are fuses inside, I know that Steve has added a little fuse box inside the Monoblocks I have and I am unfamiliar with the Torii Jr. and he may have added interior fuses to that model. I think your plan of going inside to looks makes the most sense short of calling Steve on Monday. Hope you can get it going!
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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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Geno
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Re: Help!  Valve Art 274B Failure
Reply #5 - 02/17/19 at 17:44:36
 
I went through this a while back with my Zen. One of the internal fuses was bad. You could just replace all of the fuses while you have it open.

Also, after replacing the fuses, unplug your power cord from the wall before plugging into the amp. After plugging into the amp, then plug into the wall. I was not doing this and blew 2 more fuses before I realized what was happening.

Geno
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(2)SE84UFO(Balanced Monoblocs) OR Sansui AU-222
Crown sub amp
Cambridge Audio CXN(ModWright) • ZBIT
SL-1210MK5(KAB Mods) Soundsmith Aida MKll cart • Darlington Labs MP-7
Otari MX5050-Bll2 R2R
ZLC Power Cond.
Lii Audio PT-10/W-15 in open baffles
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Doug
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Posts: 272
Re: Help!  Valve Art 274B Failure
Reply #6 - 02/18/19 at 05:18:16
 
Spent the day on our home remodel project and didn’t get to open the amp today.  I’ll get to it tomorrow morning and let you know what I find.  Your assistance is much appreciated!

On a side note, what’s the best way to list your system parts and pieces on forum posts the way you guys have done it?
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Jay’s CD2T-Mk3
Denafrips Pontus II
ZROCK2 25th Mods
CSP3 25th & Custom Mods
PAP Quintets with Voxativ 1.6
First Watt J2 or Cary 300SEI
driving Voxativs—no crossover
LFD NCSE driving 15” Woofers
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Geno
Seasoned Member
****


Without music, life
would be a mistake.

Posts: 1988
Re: Help!  Valve Art 274B Failure
Reply #7 - 02/18/19 at 13:31:45
 
Go into My Center. Select Profile. Then Options. In the Signature box, type in what you want. Save at bottom.
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(2)SE84UFO(Balanced Monoblocs) OR Sansui AU-222
Crown sub amp
Cambridge Audio CXN(ModWright) • ZBIT
SL-1210MK5(KAB Mods) Soundsmith Aida MKll cart • Darlington Labs MP-7
Otari MX5050-Bll2 R2R
ZLC Power Cond.
Lii Audio PT-10/W-15 in open baffles
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Doug
Seasoned Member
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Posts: 272
Re: Help!  Valve Art 274B Failure
Reply #8 - 02/18/19 at 23:33:01
 
Thanks Lon and Geno!

Three fuses sit directly below the rectifier tube socket in the Torii Jr.  The one feeding the OA3’s had blown.  Back in business now!

Doug
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Jay’s CD2T-Mk3
Denafrips Pontus II
ZROCK2 25th Mods
CSP3 25th & Custom Mods
PAP Quintets with Voxativ 1.6
First Watt J2 or Cary 300SEI
driving Voxativs—no crossover
LFD NCSE driving 15” Woofers
  IP Logged
Lon
Seasoned Member
****


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

Posts: 23313
Re: Help!  Valve Art 274B Failure
Reply #9 - 02/19/19 at 00:43:43
 
Great news Doug!
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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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Geno
Seasoned Member
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Without music, life
would be a mistake.

Posts: 1988
Re: Help!  Valve Art 274B Failure
Reply #10 - 02/19/19 at 04:06:08
 
Glad to hear that you’re back on track!
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(2)SE84UFO(Balanced Monoblocs) OR Sansui AU-222
Crown sub amp
Cambridge Audio CXN(ModWright) • ZBIT
SL-1210MK5(KAB Mods) Soundsmith Aida MKll cart • Darlington Labs MP-7
Otari MX5050-Bll2 R2R
ZLC Power Cond.
Lii Audio PT-10/W-15 in open baffles
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Colin B
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Posts: 21
Re: Help!  Valve Art 274B Failure
Reply #11 - 02/20/19 at 05:31:59
 
Nice! What size/rating are the fuses? I like to keep a collection of spare parts in case things go wrong.
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Doug
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Posts: 272
Re: Help!  Valve Art 274B Failure
Reply #12 - 02/26/19 at 04:26:23
 
The bad fuse was 5 amp.  I didn’t pull the other two fuses, but one of them looked to be quite hefty....kind of looked like a wrapped guitar string.
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Jay’s CD2T-Mk3
Denafrips Pontus II
ZROCK2 25th Mods
CSP3 25th & Custom Mods
PAP Quintets with Voxativ 1.6
First Watt J2 or Cary 300SEI
driving Voxativs—no crossover
LFD NCSE driving 15” Woofers
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Colin B
Verified Member
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Posts: 21
Re: Help!  Valve Art 274B Failure
Reply #13 - 02/26/19 at 17:05:08
 
Cool, thanks. I've got a few of those laying around so I should be good. The heavy wound two are slow-blow fuses, probably of a similar rating.
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