From bw@ashbysolutions.com Tue Mar 13 09:19:14 2012
Subject:Re: Art Tube Preamp and Vent

Hi Bob,

The 'other two buttons' are a phantom power switch, and a phase reversal
switch.

Phantom Power -- This is required by some condenser and ribbon
microphones, and isn't needed by a keyboard. I'd recommend not turning
it on, because it puts 40-50VDC on the input line. Most devices filter
that out well, but there are a few that don't. It has no benefit, and
potential issues: turn it off.

Phase Switch -- This is only necessary to prevent out-of-phase issues
between channels in a larger system (multitrack recorder, PA system).
Since your organ only represents one channel of audio, the position of
this switch is of no consequence.

Dialing in the preamp is easy: Adjust the first knob to get the
preferred amount of warmth/growl/dirt, then adjust the second knob to
compensate for any level changes, and to make sure that you don't
overdrive the mixer or amp. If you are using the Vent for most of the
overdrive, then the first knob should be set pretty far to the left.

Regards,

-BW

Bruce Wahler
Ashby Solutions.com^(TM)
bw@ashbysolutions.com
http://music.ashbysolutions.com
877.55.ASHBY (877.552.7429)

On 3/13/2012 12:07 PM, BD wrote: