• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

HH Scott LK-72A, 6U8A options?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hope this isn't boring! My Scott LK-72A has 2 sockets labeled 6U8A, 6GH8! I ran Amperex from France versions of 6G8HAs for years. Update time for my rebuilt amp, so new tubes in place of worn. I looked up subs for both tubes and neither are listed as such. There is one 6U8A sub that starts 6C, but this amps particular printing, (unlike some other areas) is crystal clear. It's 6GH8. (G) Schematic shows 6U8A and a listed sub in the RCA manual and sub-book. So,...I looked at the specifics for these pentode-triode tubes in RCA-30, and they are very nearly identical! New 6GH8s will be going back in. Just an odd variation in our Thermionic world! Thanks and good luck with your music!
 
Member
Joined 2004
Paid Member
Not sure if there is a question here. Are you looking for options, i.e. additional subs/equivalents? There are the European equivalents (ECF82) as well as the American 6KD8 and the premium 7687. The 6BL8 (Euro ECF80) is close and some prefer its sound to the 6GH8a/6U8a. Can’t think of any 6Cxx equivalent. Good luck with you refreshing your Scott.
 
Last edited:
Member
Joined 2004
Paid Member
... New 6GH8s will be going back in. Just an odd variation in our Thermionic world! Thanks and good luck with your music!

If you wanted to continue to use 6GH8a tubes I can personally recommend the Yugoslavian variety which sounds great in my modified Dyna SCA35. Better yet, although I have not used them myself but many users report that, Amperex made in France 6GH8a’s are the best of the breed as far as I can tell. Hope this helps.
 
Amperex 6GH8As made in France

! bought 9 NIB Amperex made in France more than 15 years ago. I believe I got them for a couple of tuners, and liked them. Finally having an Amplitrex AT1000 tester, I had a way to test them more definitively than than before. While all 9 are good, 2 performed strongest and I put them in the Scott LK-72B. I've gotten some different types of French Amperex pulls over the years and they all seemed real nice. That's why I pounced on the NIB 6GH8As on Ebay, but nobody else bid on them. Thanks for sharing your info and thinking!
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.