EL37s in ST70?

[artclone]

What would I need to do to run EL37s in my ST70? I have a few laying around.

-Thanks

[kheper]

What would I need to do to run EL37s in my ST70? I have a few laying around.

-Thanks

According to the specs:

http://www.r-type.org/pdfs/el37.pdf

Va max = 800V
Vg2 max = 800V
Pda max = 25W
Ih = 1.4A

Looks like you are ok with the specs.

No need to tie pin 1 (Vg3) to pin 8 (cathode) as with the EL34.

"The EL37 has a high value of mutual conductance compared with the valves it is sensibily equivalent to. At 11.0 mA/V it is almost twice the value of the KT66 and the 6L6. A Mullard engineer said of the EL37 'that unlike similar valves it only needed a whiff of signal to drive it to full output. A single triode was all that was required to drive it'."

The gm of the EL34 is 11.0 mA/V as well.

I have absolutely no experience whatsoever with this tube, but it appears to be a retro-fit with the EL34. Better ask someone here who has run them in the st-70 before experimenting.