# 12AU7s.....does anybody here use/need any?



## StevieMac (Mar 4, 2006)

I'm sifting through my "stuff" and, for some unknown reason, managed to accumulate several NOS/ANOS 12AU7s. They're good ones as well e.g. IEC Mullard etc, but I have no immediate use for them. If someone here has a legitimate need for them however i.e. they actually intend to put them into service, I could probably be persuaded to pass some of them along. Does anyone know of any circuits they were ever used in? Nearest I can figure, I may have picked them up to tame the volume in an overly loud amp or possibly to reduce feedback in the mic channel when playing harp.


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## traynor_garnet (Feb 22, 2006)

I could use some. The Reverb and Trem in my Garnet amp uses these and I all have right now is some cheap 80s/90s stuff stuffed in there. Let me know what you are thinking.

In many circuits you can swap 12au7 and ax7s but they are not _true _substitues and the odd time you can burn out a 12au7 if you cram it in a 12ax7 slot. Something about heater current or bla bla bla . . . somebody with technical knowledge will surely chime in LOL

Very cool of you to do this.

TG



StevieMac said:


> I'm sifting through my "stuff" and, for some unknown reason, managed to accumulate several NOS/ANOS 12AU7s. They're good ones as well e.g. IEC Mullard etc, but I have no immediate use for them. If someone here has a legitimate need for them however i.e. they actually intend to put them into service, I could probably be persuaded to pass some of them along. Does anyone know of any circuits they were ever used in? Nearest I can figure, I may have picked them up to tame the volume in an overly loud amp or possibly to reduce feedback in the mic channel when playing harp.


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## dcole (Oct 8, 2008)

I think it's the other way around. 12AU7's can handle a larger plate current / power dissipation and may be designed to do so in a circuit. If you throw in a 12AX7 it may blow due to its lower current handling.


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## mhammer (Nov 30, 2007)

http://www.ax84.com/index.php/oldprojects.html?project_id=firefly


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## dcole (Oct 8, 2008)

That would be an instance where a12AX7 would burn out quickly and not sound good.


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