|
Title: Biasing the Expression from EL34 to 6V6??? Post by: Mitch on December 19, 2008, 10:32:57 PM Guys-
just got my Expression & I'm knocked out with it- however I want to swap out the stock EL34's and pop in some tung -sol 6V6's to lower the volume level- I have a multi-meter etc... do I need to re-bias & is there a way of biasing this amp safely? Cheers! Title: Re: Biasing the Expression from EL34 to 6V6??? Post by: Mitch on December 20, 2008, 08:36:06 PM Actually Nik answered this one for me (does that guy ever sleep!) I quote-
As for the Expression, very easy. You see the 1R resistor on each power tube socket? You will measure across that using meter set to DC Volts. You will read milivolt range. As for 6V6s, go for 20-25mV reading on the meter. I will have to check the plate voltage on this thing but I think, 400V if I recall. Many thanks Nik! Thought It'd be cool to post for the rest of ya... Title: Re: Biasing the Expression from EL34 to 6V6??? Post by: Mitch on December 23, 2008, 01:53:59 PM Guys-
just want to share my good experience with fitting Tung Sol 6V6's- re-biasing was a breeze to around 21 ma assuming 400v on the plates- changed V1 to a 12AT7 / ECC82 and I'm very pleased with the tone- about half the power to 16 watts now- plenty for home & recording use- sweeter pre-amp overdrive - much less 'kazoo' now more 'bloom & grunt' & now more easier to get Power tube distortion... easy tweaks... sounds more like a hotrodded marshall with maybe an TS808 boosting the mids slightly... Merry Xmas! Title: Re: Biasing the Expression from EL34 to 6V6??? Post by: hywelg on December 23, 2008, 07:52:30 PM We'd all be interested in some clips if you can manage it.
Have a Good Christmas Title: Re: Biasing the Expression from EL34 to 6V6??? Post by: mcinku on December 24, 2008, 11:25:16 AM +1 for the clips
;) |