[AMRadio] GZ34 Tube

[Nick England]

The GZ34/5AR4 is an indirectly heated rectifier which means all the
tubes in the rig (or audio amp) get to heat up before B+ comes on
line. That's why loys of audio designs used them. For some reason, you
find the GZ34 particularly with EL34 outout tubes (which the Eico 730
has and which has driven the cost up - as I recall it can be used as
an audio amp).

Anyway, slow B+ start -up is nice but obviously not critical so a 5U4
or solid state substitution ought to be OK. Note the 5U4 draws 3A fil
current compared to 2A for the 5AR4 - check the 730's xfnr rating.



On Thu, Feb 10, 2011 at 11:35 PM, David Hollander <n7rk at cox.net> wrote:
> Hi Ron - You might also consider one of the new Russian 5AR4/GZ34's. I
> believe they are in the $10-$20 range.
>
> Here is one for $15.
>
> http://www.tubedepot.com/5ar4.html?gclid=CPmDuquj_6YCFSdtgwodqA4Cfg
>
> The audio guys use the old ones and they go for $100 plus dollars.
>
> 73,
>
> Dave N7RK
> --