[epaludo]

Need help here guys.
Sorry, NEWBIE !!!!!!
I wanna upgrade my HD2 tubes.
What kind of tubes will fit in my amp? I think a GE 5751 or RCA 5751 would replace the 5751 and a 12BH7A the ECC99, but i'm not sure ...
I would like to know if you think necessary upgrade both ECC99 and 5751 or just one of them?
Which tubes (model/where) i can get for replacing them with a sound improvement?

 

[Hi-Finthen]

Quote:

Originally Posted by epaludo /img/forum/go_quote.gif Need help here guys. Sorry, NEWBIE !!!!!! I wanna upgrade my HD2 tubes. What kind of tubes will fit in my amp? I think a GE 5751 or RCA 5751 would replace the 5751 and a 12BH7A the ECC99, but i'm not sure ... I would like to know if you think necessary upgrade both ECC99 and 5751 or just one of them? Which tubes (model/where) i can get for replacing them with a sound improvement?

I understand you could contact Dr. Lloyd and he has a stock of tubes @ his cost + shipping, and for other specific information.

I read he isn't a believer of the use of specific tubes and their characteristics as we the rabid believe to experience...

But I would suggest giving him a call .....

Good luck~

 

[kitaoji]

Confirm with Dr. Peppard if a 12BH7A can replace the ECC99 tube in the HD2. But right now I really like my GE 12BH7A replacing the ECC99.

My main combo right now is ECC99 + 1983 JAN NOS Philips 5751. I like this with my SR325is and K701s.
But I just got new tubes, and the GE 12BH7A + GE 5751s (1955 JG-5751 black plate triple mica, unknown grey plate double mica). Both the grey plate and the black plate sound great with the Grados, but I like the black plate with the K701s more.

Give the new production Tung Sol 12AX7 a try. It's more fun than the Sovtek 5751.

 

[Balisarda]

I got ahead of myself. My HD2 hasn't even reached the building stage yet (according to the queue on MAD's website) and I already bought several NOS 5751 and 12BH7(A) tubes for tube rolling!

I am SOO looking forward to the arrival of this amp!

 

[indelibo]

I use the GE 5751 black plate triple mica with the stock ECC99 and have noticed some improvement.

 

[Balisarda]

I asked Lloyd whether the 12BH7 or 12BH7A are acceptable alternatives to the ECC99 output tube. He responded:

"The 12BH7 (the A just indicates a controlled heater warm up version for the transformerless B&W TVs of the 50's--no significance for us) is a reasonable alternative to the JJ ECC99. You can get NOS or currently manufactured versions."

He e-mailed me the HD2 instruction manual, which lists the 12BH7(A) as an acceptable alternative to the ECC99. It also warns against using vintage NOS ECC99 tubes with the HD2, because they are not pin-compatible with the JJ ECC99.

Happy tube rolling, and enjoy your music!