Help Needed Biasing VT100

Lim Eng Huat

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Oct 31, 2002, 9:50:26 AM10/31/02

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Just replaced the lot of 6922 on Audio Research VT100 need help and
information on biasing the tubes. Thanks in advance.

Xavier van Unen

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Oct 31, 2002, 10:56:26 AM10/31/02

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Check out:
http://mycollins.net/audio/artube1.html
He has an "online" biassing help.

Regards Xavier.

P.S. It ain't quick and easy....

Tim Williams

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Nov 1, 2002, 4:29:46 PM11/1/02

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"Lim Eng Huat" <eh....@pacific.net.sg> wrote in message
news:3DC14332...@pacific.net.sg...

VT-100??? What about 807???

(What about biasing Fred?)

(What's that about calimero stage?)

Eheh..

Tim

--
"Hey, back in high school I was voted most likely to be a Hillbilly,
mental patient or Chimpanzee!"
- Homer Simpson

Fred Nachbaur

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Oct 31, 2002, 4:55:44 PM10/31/02

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Tim Williams wrote:
> "Lim Eng Huat" <eh....@pacific.net.sg> wrote in message
> news:3DC14332...@pacific.net.sg...
>
> VT-100??? What about 807???

Same-oh same-oh.

> (What about biasing Fred?)

Biasing Fred? Fred doesn't need any more biasing, he's already as biased
an old cuss as you'd care to meet.

Oh, biasing the 807! That's different.

For pentode mode, Vg2=300, Vg1 will be around -35v.
UL mode, assuming it behaves much like a 6L6, around -70v with Vp=500.

But I'm sure that the OP will scratch his head in wonder at my
stupidity, since he clearly stated that the tubes he's biasing are
6922's. Which aren't even output tubes, so I don't know where the
biasing question arises. Curiouser and curiouser.

> (What's that about calimero stage?)

I think Gregg said he's bringing the tequila. :)

> Eheh..

Jeez, Tim, you've been hanging around Gregg, Maaark and me too long.
You're starting to chuckle Canuckian!

Fred

Tim Williams

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Nov 1, 2002, 6:10:40 PM11/1/02

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"Fred Nachbaur" <fnac...@netscape.net> wrote in message
news:3DC1A64...@netscape.net...

> > VT-100??? What about 807???
>
> Same-oh same-oh.

Hrm. Got pronunciation wrong again.
I meant, "what's that about .. ?"

> But I'm sure that the OP will scratch his head in wonder at my
> stupidity, since he clearly stated that the tubes he's biasing are
> 6922's. Which aren't even output tubes, so I don't know where the
> biasing question arises. Curiouser and curiouser.

LOL...cought you off-center! :P
He's talking about an Audio Research VT100, which I can only presume
is an amplifier also containing 6922s.

> Jeez, Tim, you've been hanging around Gregg, Maaark and me too long.
> You're starting to chuckle Canuckian!

That wasn't "Eh? Eh?", that was "heheh" without the first H. :)

Xavier van Unen

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Nov 1, 2002, 1:48:36 AM11/1/02

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Hi François

> >Just replaced the lot of 6922 on Audio Research VT100 need help and
> >information on biasing the tubes.

> The VT 100 and VT 100 MK II use 8 x 6922. You don't need to do anything
> after changing the 6922's.

No, that's not true. I've just done a VT100 and it was no fun at all...
Check the VT100 user manual for biasing details.
You'd really want 6922's with matched sections to make your life easier.

Kind regards Xavier.