Bottlehead Forum
General Category => General Discussion => Topic started by: comanche on September 19, 2016, 09:01:46 PM
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Hey Doc; guys,
What is the deal with the cold war tubes that came with my Reduction ?
They test practically dead on my TV-7 as 6922 s or 6DJ8 s.
42/ 50 - 52/50 and 50/50 - 52/50 respectively.
I realize that they are not 6922s but thought they were the equivalent.
Thanks for your time and prompt attention.
Billy
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Josh tests the tubes we buy before he packs them. We use a TV-10 that I have had for 25 years. It holds calibration well, has been consistent when compared to other testers and is maintained. So there are a couple of possibilities. Possibly we goofed, and if you want to send them back we will test them and certainly replace them if they measure out of spec. The other possibility is that your tester is calibrated differently than ours and thus giving different readings. Again we would need the tubes back to test to figure out if this is the case.
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Are you sure the settings were correct, do they match these?
6DJ8 6.3 EV7-6080 20 - D 3 62 Triode #1. TB 11-6625-274-12/1 w/ C3
6DJ8 6.3 EV2-1030 20 - D 3 62 Triode #2. TB 11-6625-274-12/1 w/ C3
6922 6.3 EV7-6080 21 - D 3 50 Triode #1. TB 11-6625-274-12/1 w/ C3
6922 6.3 EV2-1030 21 - D 3 50 Triode #2. TB 11-6625-274-12/1 w/ C3
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Hey Doc and all;
I didn't have the test results in front of me when I posted last night.
I exaggerated a bit. sorry
I have since edited in the correct values 42/50 - 52/50 & 50/50 - 52/50 that I had written on the tubes.
Also, just re-tested after cleaning pins with 600grit and a little contact cleaner. Same results. Correct settings.
I'm pretty positive my TV-7 is accurate. I get basically the same results with my Hickok 539C.
I just wondered if these are the readings that I should get on those particular tubes. I am not familiar them.
I don't really need them replaced, as I was only using them to run in the unit for a bit. I have acquired many sets of various
6922s over the past few decades and just put in a pair of GE gold pins last night. (mid 60s) (saving some real specials for after the upgrade)
Doc, I'm really digging your phono stage and have already built the upgrade but haven't felt the desire to add it yet.
Thanks for your time and prompt attention.
Billy
ps. kinda nice to be called a newbie...too bad everything still hurts ::)
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What voltages are you reading in the amp with the tubes?
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Head,
All measurements were within their correct range as I finished the assembly.
I ran it about 30 hours and only measured the tubes after I pulled them and while looking for a balanced pair
of the GE's. I only had 9 of them, but did find two that were very close. They are in the Reduction now.
I was really just wondering if the supplied tubes were bad or if the readings that I got were typical.
ie. do I trash them or stash them in my box of Russian tubes ?
thanks,
Billy
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Well, if the tubes were bad, they wouldn't give correct voltages. They do, so they are fine.
Don't get too hung up on tube testers, they don't make music...