[HAM] Best 12AU7 now 6550 now EL34

[Brad Baker]

On Sun, Mar 9, 2008 at 1:34 AM,  <goffmac747 at aol.com> wrote:
> Hi Kon,
>
>
>
>  Excuse my ignorance. If Marshalls use two different tubes, an EL-34 and
>  a 6550, does that mean these are interchangeable? Can a 122 use EL-34's?
>
>  Goff
>

These tubes are not interchangeable.  The tube sockets will need to be
rewired.  Also EL34s need about 250 ohms of resistance in the cathode
circuit for self bias.

-- 
---  b r a d  b a k e r  ---\\