Bottlehead Forum

Bottlehead Kits => Eros Phono => Topic started by: Bryon on November 10, 2014, 12:13:35 PM

Title: EF86 matching?
Post by: Bryon on November 10, 2014, 12:13:35 PM

In an earlier post PJ clarified that the EF86 cathode current in the Eros is controlled by a transistor to enable the newer variants of EF86 to bias properly. Would you then be able to use unmatched tubes without issue.  I would guess that would be the case, but wanted to check before I put some tubes with widely varying values [but both test over 100%] in my Eros. 

thanks

Bryon

Title: Re: EF86 matching?
Post by: Paul Joppa on November 10, 2014, 02:32:18 PM

Within the normal range of variance as we have measured it over the years, there should be no problem. There are always differences, and some of them (but not all!) will be related to the actual bias used, but these are minor and usually unaudible.

FWIW, microphony is probably the most audible difference between tubes - and thus the most easily diagnosed!

Title: Re: EF86 matching?
Post by: Bryon on November 10, 2014, 04:26:00 PM

Thanks for the quick response, Paul.

 I'll give it a shot.

Bryon