Any ideal why someone would convert a Ampeg b25 power tubes to 6GH6. And what kind of effect does this have on the amp?
Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
Ampeg b25 conversion?
- Thread starter fuzzy beard
- Start date
They probably had some 6GH6s laying around & knew how to convert the sockets, it's not that hard to do. What's it supposed to have, 7027, 6L6GC?
Oops, never mind. It's the little phase inverter tube next to the power tubes?
Probably because the stock 7199 PI tube is hard to find & expensive; I couldn't find a datasheet right away but it may have the same pinout as the 7199. It would sound different but if you like the sound I'd leave it alone....
Probably because the stock 7199 PI tube is hard to find & expensive; I couldn't find a datasheet right away but it may have the same pinout as the 7199. It would sound different but if you like the sound I'd leave it alone....
http://site.tubedepot.com/pdf/7199_6u8.pdf
and
7199 Tube Types
NOS
Oops. Actually do you mean 6GH8? It is a triode/pentode similar to the 6U8 with same pinout. Otherwise, same reason for the sub, NOS 7199 price hike.
and
7199 Tube Types
NOS
Oops. Actually do you mean 6GH8? It is a triode/pentode similar to the 6U8 with same pinout. Otherwise, same reason for the sub, NOS 7199 price hike.
You looking at this one?
Invalid Link Removed
As said above, it's the PI that was changed, not the power tubes and the reason was a shortage of 7199s. The B25/B18/B15NC-D amps (basically all the two channel 50 watters ampeg made in the late 60s/early 70s) used the same layout with a 7199 PI and 7027 power tubes but those tubes arent really used in much else and have gone out of production.
Invalid Link Removed
As said above, it's the PI that was changed, not the power tubes and the reason was a shortage of 7199s. The B25/B18/B15NC-D amps (basically all the two channel 50 watters ampeg made in the late 60s/early 70s) used the same layout with a 7199 PI and 7027 power tubes but those tubes arent really used in much else and have gone out of production.
