#1
I came across an ancient primative strobe tuner in the school storage room, oddly enough it was in brilliant internal condition. Knowing me, I raped its tubes thinking I might be able to get some use, or money, from them.

All the following tubes are in perfect condition and read

77-48-30 C.G.CONN LTD.
188-5 made in U.S.A


4 x 6V6 GT
1 x ECC83
1 x 6SC7


The following are unmarked except for their names

1 x 5U4GB
1 x 5Y3 GT
1 x 6SN7 GT3


Any info would be appreciated.
#2
I know the 6V6 is used as a power tube in some amps. The 5U4GB sounds like it could be an exchange for the preamp tube. The ECC83 sounds familiar. I would post this in the "Gear Building and Customizing" thread if you don't get satisfactory responses here. Also check the internet. I just typed in 5U4GB and found out it is a black plate rectifier tube.
#3
I know that the 6v6 are poweramp tubes, the 5u4 and 5y3 are rectifier tubes, and the ecc83, 6sc7 and 6sn7 are preamp tubes, but thats all I could figure out.

Think emailing Conn directly could be of any help?
#4
You might be able to download a circuit diagram on the thing that would tell you. If its very old that may not be an option. Hang around, there are a lot more knowledgable forumites than I. You could try emailing some boutique amp makers, they might be nice enough to help, might even get an offer.
#5
Ecc83 are the same as 12AX7. 6Sc7 is a rather rare preamp tube, used in the 50s mostly. The 6SN7 is a preamp tube, most notably used on the Komet Concorde amp, which was discontinued because 6SN7s are so hard to find.
If you can get pictures of them I may be able to identify them. I'd also be interested in buying some of these tubes, so PM/email/AIM me if you want to sell and we can work out a price.
Last edited by Roc8995 at Sep 26, 2007,
#6
I will get pictures to you tomorrow, tonight I need my sleep. Thanks for the info!