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Finally built a adapter to test my 300Bs on my Eico 667
- Thread starter audiobliss
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Nice! What settings do you use?
I found this posted by someone that uses the 2A3 settings on his model 666, which is basically the same as the 667.
I use my Eico 666 to check 300B's as thus:
1) Use the 2A3 settings but with 5v filament.
2) Set grid to -10
3) 122 to 130 tests like new, based on 2 New Svetlana, 4 new Sovtek,
and 2 new standard Chinese 300B's.
2A3 settings:
grid 17 (set at 10)
plate 82
235111
111111
4
1
leak: 2 and 3
merit 2
Regards
Bob H."
I use my Eico 666 to check 300B's as thus:
1) Use the 2A3 settings but with 5v filament.
2) Set grid to -10
3) 122 to 130 tests like new, based on 2 New Svetlana, 4 new Sovtek,
and 2 new standard Chinese 300B's.
2A3 settings:
grid 17 (set at 10)
plate 82
235111
111111
4
1
leak: 2 and 3
merit 2
Regards
Bob H."
Great, thanks!
I built the full adapter box to give me all of the pre-octal tubes just in case I need it. If the settings aren't in the 667 manual, they are in the 666 manual. Leave the un-listed selectors at "1". That will ground the extra pins.
Single adapters also work just fine, all depends what you need. I've got a few pre-war radios with various types of tube in use so I just built the box rather than multiple individual adapters. Eico actually sold a version of what I made but when you find them it costs dumb money. A DIY version is dead simple, pin 1 to 1, 2 to 2, etc until you run out of pins.
Single adapters also work just fine, all depends what you need. I've got a few pre-war radios with various types of tube in use so I just built the box rather than multiple individual adapters. Eico actually sold a version of what I made but when you find them it costs dumb money. A DIY version is dead simple, pin 1 to 1, 2 to 2, etc until you run out of pins.
I read all your post on the subject during my research and they were very helpful. I bought the 667 back in 2005 but been wanting to test a few used 300Bs for the past year, then I realized it couldn't do it without a adapter, and 300B wasn't even listed in the charts. So I am happy I made a deeper dive into Google.
Having just bought a new tube preamp that can use a bunch of different tubes, I was inspired to revisit my stash, so I also opened up 667 and clean and calibrated it for the first time since I bought it.
So I have been testing my tubes, all my 6sn7 test good, but 90% of my 6922s that I thought was new, test bad.
Mostly EH and Sovteks, and a few NOS Teslas. I use the settings on the new sheets.
Is there a known issue with testing 6922s .?
don't think I've ever tested one on mine, honestly not sure if the settings work or make any sense at all. I know some of them frankly do not.
@ConradH has a spreadsheet on his website that you can download and plug in the settings and it will tell you the voltage and current things are being tested at, and a look at the datasheet should tell you if those values make any sense. Can fiddle with it from there to get some sort of reasonable datasheet values if needed.
@ConradH has a spreadsheet on his website that you can download and plug in the settings and it will tell you the voltage and current things are being tested at, and a look at the datasheet should tell you if those values make any sense. Can fiddle with it from there to get some sort of reasonable datasheet values if needed.
