B1 with Korg Triode

From https://www.korg.com/caen/news/2015/012212/ :

  • High reliability and long life.:
    The unique design and state of the art Japanese production facility ensures the Nutubes are built to the highest standard and offer up to 30,000 hours of continuous operating life. The high reliability means that it can be attached directly to the circuit board with confidence knowing that it will not need to be replaced regularly like a 12AX7.
But stuff happens.

Does the Nutube glow on the side that is not producing sound?

Measure the voltages at the test points outlined in the B1 Korg manual. Are they still good?

Some pictures of your build may be helpful.
Welp, although I got held up and procrastinated 6 months before even cracking the chassis open (jeez where does the time go) ... it appears to simply be the NuTube failing on that channel. Ordered a replacement from the shop just now. NOt sure why this happened, but I do tend to leave it on all the time, maybe I'll stop doing that. I also have al the parts for a PSU project ready to start for this, maybe now is the time! Thanks guys for the help.

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Hmm I missed the don't leave it on memo. When mine failed I measured all of the build test points and one channel was correct and the other the values were not right. Someone told me to take a very close look at the fine wires and one was broken. I ordered a new tube, replaced it and it seems to work fine now.
 
HI Andrewhogge

Welcome to the club. See my post 8524.

You are the eleventh person at least to report a Nutube with a broken heater wire on the left (!) side of the nutube. It seems they have severe QA and QC problems.
The nutube either works or the left heater wire breaks. Mine did worked for about two to three weeks.
 
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Welp, although I got held up and procrastinated 6 months before even cracking the chassis open (jeez where does the time go) ... it appears to simply be the NuTube failing on that channel. Ordered a replacement from the shop just now. NOt sure why this happened, but I do tend to leave it on all the time, maybe I'll stop doing that. I also have al the parts for a PSU project ready to start for this, maybe now is the time! Thanks guys for the help.

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This recently happened to mine, in fact the broken filament looks the same as yours pictured, on the left side. It happened around the time of the peak solar activity. Possible voltage spike? Probably coincidental. One of my hard drive wall warts crapped out at that time, too. I stopped leaving mine on 24-7 a while ago. Though I believe turning on/off cycles is more stressful to traditional tubes, not sure about the Nutube. I assume it's the same, though. When it blew there was a nice pop out of the left channel, but not damaging to anything downstream, including my ears.
 
I have been introduced to these many years ago, as a result of my encouraging a EE friend to investigate the design.

The result being there are five variants built and a original Spec' as well.

I have had the original spec on long term loan, and really enjoyed what it could do with my 845 Monoblock Amp's even with the added gain that was present.

I have a Monoblock KB1 to be built, with bespoke built VC's for the role.

The intention is to house the Korg Nutube in a Panzerholz casing and house the whole of the Electronics in a Airtight Panzerholz or Permali Chassis.
 
Not so much a comparison but an awakening when I was working on audio units and removed the top plate. Striking the top plate cover, held by my fingertips, it very much sounded like a bell. Sure this isn't a speaker being tested, but non the less it was surprising to hear such a clear and long lasting resonance. Then I attached a self adhesive sound sheet and the bell mostly disappeared into a dull thud. Since this isn't so much a viable problem in electronic gear itself, it gave me some idea of the extent to which this problem exists even in a speaker cabinet.
Panzerholz seems to be an improvement yet, I wonder about its availability and cost. Might be worth it if it cuts down on the labor/hassle of treating a cabinet being built.