Hi everyone.

I was looking over some auctions on you know where,and saw a couple of
things that confused me.

Someone was selling 12AU6 tubes and offering them as an adequate
substitute for the 12AV6 tube. Is this correct? Was this a common
sub?

The other was a recent auction where a seller sold a pair of GE 5965
tubes as "computer grade" 12AU7's. Are they at all compatible? (the
12au7 and any of the 12AV7 variants.) I have an Ampex monoblock that
uses 12AU7's. It has been fun for me to swap out the 12AU7's and check
out the different sounds, but I have some different 12AV7s and I'd like
to know if I could try those as well without a meltdown.

Thanks for any and all input!

"Michael" > wrote in message
ups.com...
> Someone was selling 12AU6 tubes and offering them as an adequate
> substitute for the 12AV6 tube. Is this correct? Was this a common
> sub?

No, the AU6 is a pentode, while the AV6 is a triode (something like 1/2
12AX7) with two diodes, for detector/AVC service in a radio.

> It has been fun for me to swap out the 12AU7's and check
> out the different sounds, but I have some different 12AV7s and I'd like
> to know if I could try those as well without a meltdown.

All of the 12A*7 series are compatible AFAIK, but a direct coupled circuit
might get some heartburn if you put in the wrong one.

Tim

--
"I've got more trophies than Wayne Gretsky and the Pope combined!"
- Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms

The 5965 is a sort of 12AY7: it has a gain coefficient of 47, while the
12AU7/ECC82 has a much lower one, about 17. It is said to be a plugin
replacement for the 12AV7. I think it could be used as a replacement for
the 12AT7/ECC81, which has a even higher gain (about 60), but the ECC82
seems quite another beast: biasing is very different.
Generally speaking, if the designer placed a certain tube there, I stick to
it, unless I'm not able to find a replacement.

Ciao

Fabio


"Michael" > ha scritto nel messaggio
ups.com...
> Hi everyone.
>
> I was looking over some auctions on you know where,and saw a couple of
> things that confused me.
>
> Someone was selling 12AU6 tubes and offering them as an adequate
> substitute for the 12AV6 tube. Is this correct? Was this a common
> sub?
>
> The other was a recent auction where a seller sold a pair of GE 5965
> tubes as "computer grade" 12AU7's. Are they at all compatible? (the
> 12au7 and any of the 12AV7 variants.) I have an Ampex monoblock that
> uses 12AU7's. It has been fun for me to swap out the 12AU7's and check
> out the different sounds, but I have some different 12AV7s and I'd like
> to know if I could try those as well without a meltdown.
>
> Thanks for any and all input!
>

Michael wrote:

> Hi everyone.
>
> I was looking over some auctions on you know where,and saw a couple of
> things that confused me.
>
> Someone was selling 12AU6 tubes and offering them as an adequate
> substitute for the 12AV6 tube. Is this correct? Was this a common
> sub?
>
> The other was a recent auction where a seller sold a pair of GE 5965
> tubes as "computer grade" 12AU7's.

The 'computer grade' 12AU7 is the 5814. The heater is 0.35a vs 0.30a,
otherwise electrically the same. Very rugged. Cheers, JLS

> Are they at all compatible? (the
> 12au7 and any of the 12AV7 variants.) I have an Ampex monoblock that
> uses 12AU7's. It has been fun for me to swap out the 12AU7's and check
> out the different sounds, but I have some different 12AV7s and I'd like
> to know if I could try those as well without a meltdown.
>
> Thanks for any and all input!

"Tim Williams" > wrote in message
...
> "Michael" > wrote in message
> ups.com...
> > Someone was selling 12AU6 tubes and offering them as an adequate
> > substitute for the 12AV6 tube. Is this correct? Was this a common
> > sub?
>
> No, the AU6 is a pentode, while the AV6 is a triode (something like 1/2
> 12AX7) with two diodes, for detector/AVC service in a radio.
>

Not to mention that they all (the triode half) seem to sound way ****tier
than 12ax7's - I built a compressor around the tube, pretty much slavishly
rippin' off the application example), and got more noise than I bargained
for...
> > It has been fun for me to swap out the 12AU7's and check
> > out the different sounds, but I have some different 12AV7s and I'd like
> > to know if I could try those as well without a meltdown.
>
> All of the 12A*7 series are compatible AFAIK, but a direct coupled circuit
> might get some heartburn if you put in the wrong one.
>
> Tim
>
> --
> "I've got more trophies than Wayne Gretsky and the Pope combined!"
> - Homer Simpson
> Website @ http://webpages.charter.net/dawill/tmoranwms
>
>