7179's in Eic HF-81 Question

[shacky]

I had some suggestions to use 7189 or equiv Russian OP tubes in my HF-81.

Currently have Russian 6BQ5's and don't need new yet but have a question.

I've been reading about not to use 6BQ5's in something like Scott 222C designed for 7189 because bias is too much for the 6BQ5's.

Is reverse true with Eici - not enough bias for the 7189?

 

[dcgillespie]

Shack -- Because the Eico is cathode biased, it should work quite well with any member of the 6BQ5 family of tubes. Cathode bias designs adjust automatically to the needs of the particular tube(s) installed, so that too much or too little bias doesn't really become an issue for concern with that type of biasing method.

Dave

 

[drknstrmyknight]

6P15P-EV have a higher voltage rating than 6BQ5's, no problem subbing them for 7189's in the Eico, I ran one for years with 6P15P-EV's.

 

[Patrice B]

I have a quad or Russian 7189 right now in mine. No problems...

Patrice

 

[kvflyer]

I have been using the Soviet Military surplus 6pi14pi-ev (6П14П -ЕВ) tubes in an HH Scott 299 for years. They work well and more importantly, I am able to keep my Telefunken 7189 tubes as backup. The downside is that the supply has dried up considerably since the 90s and the price of them when you find them has risen (Just like air fares!).

 

[shacky]

Sounds like maybe I should stick with plain 6P14P and leave the EV's to guys that need 7189.

I have matched quad of 6P14P in there now and they sound great. Bought 8 and Narodow matched a quad out of them for me.