SD-1 with 12AX7 as Diode.

[CrazyMisfit]

hey there,  just wondering if anyone has a schematic or detailed diagrams of how to add a 12XA7 to replace some clipping diodes for an SD-1.  I know this has been brought up before.  Once from myself, and once a some time back when.  I am hoping someone has done it and would really like to see how and hear (if possible) how it turned out...

Thanks.

[Melanhead]

hmmm .... not exactly sure but it may work like using a transistor as a diode ... A 12AX7 is a dual triode ... maybe you just take use the grid and cathode to make the diode ... the heater will run off 6 to 12V depeding on how you wire it but seems to me that the heater draws a rather large amount of current ... Not sure what you'd do with the plate...

Sorry I'm not much help as my tube knowledge is limited and forgotten 

I guess my question would be: is it worth the work ? .... I'd love to hear the diff before attempting it. I'm sure it looks cool and has a certain tube "Mojo" but .... hmmmmm

[A.S.P.]

http://www.elixant.com/~stompbox/smfforum/index.php?topic=24757.0

[Johan]

someone on this forum experimented with using a tube as diod for clipping a few years back ( might find it in the archives? ), and I believe the verdict was "it works, but not really worth the trouble" kind of thing....

johan

[MartyMart]

You would probably get a better result from using a Ge transistor ( low gain and leaky ) as a diode.
I think there have been posts about this also ..
It would actually "fit" in the pedal too !!

MM.