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Bendix 6106 burn-in behavior

I've read that the Bendix 6106 can be a very good rectifier tube, but that it takes a couple hundred hours to burn in. And that during that time it can misbehave.
I've been burning in an NOS JAN Bendix 6106 for about 50 hours or so. Today I notice a slight hum on my phono channel, and the volume on the left phono channel is way down. However, on other sources, both channels are hum-free and have appropriate volume matching.
Do I have a bum tube? Or is this a normal behavior during 6106 burn-in? Preamp is Supratek Cortese with LCR phono stage. The seller has said he's willing to swap tubes to ensure my satisfaction...
Thanks, in advance, to anyone who has some experience to share.
Markus
128x128markusthenaimnut
atmasphere's avatar
atmasphere
11,936 posts
 
@roberjerman is correct- unless the idea of 'burn-in' is extended to the idea that some percentage of parts will suffer 'infant crib death' due to manufacturing defects, as is apparently so in this particular case.

rodman99999
6,171 posts
 
Glad you got it resolved. Of course, being the highest-gain, and earliest, circuit of a preamp, a phono stage would be the most(noticeably) affected, by a misbehaving rectifier. How basic! I was hoping; getting old would take longer!
markusthenaimnut's avatar
markusthenaimnut OP
375 posts
 
In my correspondence with Nick he did not directly advise me or suggest that the 6106 was incompatible with the Cortese. But I do recall reading a post somewhere to that effect. But he doesn't call it out on his substitution list, so maybe that should have given me a clue. 
charliee's avatar
charliee
191 posts
 
So Mick did not give you a straight answer on whether or not 6106 is a go, that doesn't help. So all you know is that you had a problem because the tube you tried was bad. Mick is on vacation right now, don't know if he is answering emails or not until he returns. It would be really good to know as I planned on using the 6106 in the Pinot Phono stage that I ordered. I did use the Bendix 6106 in my Syrah Pre Amp with no problems. 
markusthenaimnut's avatar
markusthenaimnut OP
375 posts
 
Correct - not a direct answer. But I will be following up with him on this and other similar questions.

BTW, don't underestimate the stock tube configuration. I think I personally had become somewhat infatuated with the idea of rolling tubes, and a subsequent experience has me wondering if what I heard was due to the way I had my cables dressed, because I experienced hum again, then remembered the cautions documented in the owners manual about the sensitivity of the preamp to nearby external sources of electrical fields. Re-dressing my cables eliminated that hum.
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