Replacing tubes in tube amps
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Hi! Sorry for a real newbie question. I just bought my first tube amp that uses 6922 EH tubes. I am thinking of buying a few replacement tubes for future need. Can I buy any brand of 6922 - are they all the same? Or does it have to be the 6922 EH (which as far as I understand means Electro-Harmonix and most likely is a company name(?)) that came with the amplifier? I also wonder if tubes wear out only when I play music or also when the amp is turned on (and the tube becomes hot). Thanks in advanced sorry for the low skill. If my questions don't make sense, I appreciate getting help asking them properly. /Jonas
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rastus
833
Apr 2, 2019
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"USN" is basically a QC check, that used to mean you heard them before they killed you... that benefits you today as a gate keeper from getting crap nos tubes, showing you where some of the best tubes were kept, from those batches made in the 60's. Factoid; George Breed was a Navy Officer: https://patents.google.com/patent/US435679A/en

https://patents.google.com/patent/US435679

https://www.ebay.com/itm/Amperex-USN-CEP-6922-Gold-Pin-Tube-NOS-Tested/153366399851?epid=141074788&hash=item23b5598b6b:g:fiUAAOSwM5lcWfrl
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(Edited)
Apr 2, 2019
ElectronicVices
2004
Apr 2, 2019
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Crazy how expensive some tubes have gotten, my MiniWatt SQ's were 170 matched pair and certified low noise when I got them. Now I would have to pay roughly $400 to get a "backup" pair. Anything that ever left the Heerlen plant for Amperex demands a premium.
Apr 2, 2019
rastus
833
Apr 3, 2019
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Well,, it turns out that “tribal knowledge” is real valuable, and very hard to reproduce, because it, the real stuff, is nearly undocumentable... that elusive state,, of getting it,, just right... look at what the folks at the new WE are going through, to try and re-re-create the 300B,, to put the magic back in the “bottle”. Sophia did a good custom Chinese collorbaration job with the new Royal Princess 300B, and their latest iteration of the 6SN7 gets great reviews, but both very pricey. I though, do not see any reason why we may not be able to up the power whilst actually bettering the sq, with some of the newer surface/materials technologies available.
Apr 3, 2019
ElectronicVices
2004
Apr 2, 2019
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This depends on the amp and whether or not it is auto-biasing (think "self-adjusting"). If auto-biasing the manufacturer should list compatibility. 6922 tube sockets share connector pins with 6DJ8, ECC88, E88C, E188CC/7308 Some can use PCC88 or 7DJ8's but they are not a 1:1 compatibility with 6922's as the heater voltage is different than 6922. I like tube depot and the tube store but I would definitely wait for coupon codes/sales as they run at a premium compared to ebay. I recommend at least getting a matched pair (assuming your amp runs two tubes), if a single tube (this is a dual triode model) I would select the "Balanced Triodes" option that some sellers offer. I personally pay for the extra low noise certification when spending more than 30-40 bucks on a tube. Tell me what amp your using and I can speak more to specifics.
Apr 2, 2019
misterbister
1
Apr 3, 2019
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Thank you!
Apr 3, 2019
ElectronicVices
2004
Apr 3, 2019
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No trouble, bought Lyr many years ago and they share the same tube type so it's one I'm familiar with. The Lyr can handle a variety of similar tubes as well like the PCC88's and some others. With that amp it's damn near night and day between stock RCA 6DJ8's and the Phillips MiniWatt SQ's I use. I found the Matsushita tubes to be a nice cheap upgrade at $40 to 60 a pair, that's a Japanese company who had Amperex help them design and build their tube production line.
Apr 3, 2019