output and phone out @ the same time from AD15VT

[petemoore]

  The AD15VT cuts the output to speaker when the phones/line output has a cable plugged into it.
  is it possible to trick or treat the AD15VT [VOX Valvetronix] into supporting output to speaker while the phone output is also plugged to a slave amplifier?
  Perhaps it could be as simple as using a TRS plug [into the phones/line output] with the ring open?
  I would like to try in with the ''preamp output'' driving another amplifier while the speaker output is active.

[MrStab]

i think it's this schem: http://www.valvetronix.net/docs/AD15_30Servicemanual.pdf

i would've thought just shorting the switching jack contacts would've sufficed, but seems there's some transistor work going on. maybe Q6's Base (on Page 4) receives voltage from PHONE DT when DISconnected, shorting signal with Q7, but then is switched out and grounded when a plug is inserted.

so it could be a case of cutting the R37/R22 junction from the switch, AND shorting the switching contacts?

maybe.

[MrStab]

Perhaps it could be as simple as using a TRS plug [into the phones/line output] with the ring open?

i thought for a second having no sleeve-ground connection might work, but then you'd still have the  physical contacts on Tip & Ring to deal with

[PRR]

> TRS plug [into the phones/line output] with the ring open?

Yes. (While it is two fingers, they are shorted together, so you can't ground one and leave the other live.)

Or just shove your mono-plug half-way in, to the first notch. Not robust in crazy stage-work, but adequate for smaller less polished gigging.