Resistances off, issue? -- update: FIXED!

SammyJ · 9463

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Offline SammyJ

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18 and 26 are wired together, do you see the LED at B3 illuminating? 
Yup, all 4 LEDs seem to be illuminating

If you swap tubes between channels, do these elevated voltages follow a particular tube?

So I swapped the tubes and the high voltages seemed to follow the tubes. 

18,19,20,26 are all within spec (right around 85V)

7,13,14,15 are all now 135.  So -- I'm assuming this means I didn't wire up anything incorrectly?  Bad tube or does it just need time?

Thanks again for all of your help guys!



Offline Paul Birkeland

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I would give the tube 100 hours of constant run time to settle in. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline SammyJ

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Sounds good!  Sadly, I'm not traveling on business, won't be home till Friday night.  I'm assuming it's safe to attach to my turntable and amp during this break-in process and listen to music?  Just want to make sure given the elevated voltages that it wouldn't likely damage any components downstream or internally.

Thanks again for all of the help, can't wait to give her a listen!



Offline Paul Birkeland

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Yeah, you may notice a bit of a gain difference between channels, but that should settle out as the tubes cook in.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline SammyJ

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OK, so after about 30 hours of constant run, the sound is still quite off.  A few issues so far:

1. Left channel (with the tube containing high voltages) seems to have quite lower sound output (at least a ~10db diff, measured very unscientifically).  The effect follows the tubes during a swap. 
2. Overall gain is quite low, compared to my amp's built in phono-stage.  Compared to a line in from a DAC, there's likely a gain difference of about 15db, maybe more.  Is this normal?  Will it improve as the tubes cook?
3. The sound can still be a little muddy, but I truly expect this clears up once the gain issues are addressed.


All that being said, I'm really happy I've been able to get it up and running.  This was my first major electronics project, so the fact that I've even gotten this far makes me really happy.


For now, I'll continue to let it run, but if there's anything I should be on the lookout for, I'd love the advice.

thanks!
S



Offline SammyJ

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Also, probably bears mentioning, the Reduction is being fed by a Sumiko Pearl with a 5mV output, so it should be in the Reduction's sweet spot.

The receiver/amp expects 2.5mv on the phono input, which the Pearl happily provided.  On the line input, it expects 200mV.

thanks!

S



Offline SammyJ

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Reply #21 on: June 22, 2014, 10:54:40 AM
OK, so after running well over 100 hours, no improvement in tube.  I flipped it over this morning and the B side was still throwing high voltages (in the 140v range).  That's also the channel that has the very low gain.  I think it's maybe a bad tube.

What should I do next?  Should I reach out for a replacement tube?

thanks guys,
S



Offline Paul Birkeland

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Reply #22 on: June 22, 2014, 12:18:47 PM
You can send the tube back to us and we will mail you a replacement.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline SammyJ

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Reply #23 on: July 12, 2014, 07:09:23 AM
Got my replacement tube in yesterday -- thanks Joshua!

Fired it up and instantly it sounded much better.  I'm going to let it run for another 100 hrs before anything critical, but already this thing sounds AMAZING.  Phenominal sound staging, clarity.  Really just incredible.

I wish there were a little more gain, but I guess you could always add the Integration.  Superb clarity and sound, but had to turn the dial on my Solid State amp way up.