#1
Hey all,

I recently purchased a Behringer VT999 (I know how most people feel about Behringer as a company but this pedal is a nice pedal).  It is obviously a starved plate system as the tube only gets warm to the touch and on some tubes you can't even see the heater glow.  With that said, it does make a difference on the sound when you swap tubes and sounds pretty good so I know the tube is somehow in the circuit and affecting the tone in a good way.  With that said, I was wondering if you could mod this pedal somehow (even take it to my amp repair guy) and put in kind of a knob or something that you could actually bias the tube to the correct voltage, or even just play around with different voltages to it to see how it affects tone?  I didn't know if this is a no no b/c the way starved plates are built, or if it is something you could actually do?  In my searching all I found was the voicing mods, but I'm not interested in that, just seeing if I can crank the voltage up to the tube section somehow to see the result?


#2
There are a number of reasons why this might not work.

The higher plate voltages may overheat the traces or other components, ruining the pedal.

A 9v power supply may not work with the pedal anymore, which may put more stress on other components of the pedal than what they're designed for.

Unless you actually dissect the pedal and draw up a schematic, its going to be very difficult to know if what you're proposing is possible.
Quote by TheSennaj
And well yes, I'll enjoy the carpal tunnel and tendonitis, because trying to get one is clearly smarter than any word you have spoken thus far.
#3
Quote by T00DEEPBLUE
There are a number of reasons why this might not work.

The higher plate voltages may overheat the traces or other components, ruining the pedal.

A 9v power supply may not work with the pedal anymore, which may put more stress on other components of the pedal than what they're designed for.

Unless you actually dissect the pedal and draw up a schematic, its going to be very difficult to know if what you're proposing is possible.

That is what I was afraid of, I was just curious so thought I'd ask.  I might take it to my tube amp guy in the future and see what he thinks.  I'm not sure it would even make that much of a difference tone wise, I just know starved plate is running like 5X lower juice than a normal preamp tube in an amp.
#5
Might be possible to do a bias mod in theory, though I'm not sure how effective it would be, particularly depending on what your "ideal" is. I'm assuming you're looking into running it at a higher voltage, which is what would be problematic due to the original power requirements. Around 9V and below might be feasible though.

Granted, I'm just speculating here.
Originally Posted by evening_crow
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