Grateful Dead Music Forum

You can copy and paste the link below to see the whole manual, pdf file. I couldn't get it to link here.
file:///home/chronos/u-ea21871b1dc008fe8ff6987c4d16ef9d443a6aef/Downloads/Tru-Tron+3X+manual+rev1.pdf

From page 18 in the manual:
"PHOTOMOD WARM-UP TIME
A very important aspect of the characteristics of the PHOTOMODS (optocouplers) that
control the filter frequency is that they have “WARM UP” time! For best results, leave the
power on and the sweep in DOWN DRIVE, with no input for about 10 minutes before you
start to experiment with the settings or play using your last settings.
Most people cannot hear the difference in sweep due to this “light history” effect, but for
maximum accuracy of control settings it is best to “warm-up” the photomods in this way - if
you have time. If you don’t have time for this warm-up period, the unit might sweep a bit
high at first, but will gradually settle to its usual operating range."

But interestingly the manual describes the LED this way:

13. FX status: This two-color LED tells when the effect is powered on and whether it is in FX or BYPASS mode. LED BLUE – filter effect is activated. LED GREEN –
effect BYPASS mode. LED OFF – no power to the unit, but TRUE BYPASS (the
factory default internal jumper setting) will still pass the signal if the footswitch is
in the right position.

So that if the manual was written with consistent terminology - the "leave the power on" in the warm up time section means "power to the unit" rather than "filter effect is activated".

From my perspective it doesn't make any sense at all to not leave the photomod warmed up on a device that is either true or buffered bypass. Needing to put a true bypass loop around a true bypass loop to keep it warmed up is kinda sorta really really silly. The only reason I could imagine for doing so would be to preserve something with a limited component life - and I'd like to know about that if that was the case.

Does anyone have any input on whether the TruTron (or a MuTron) needs to be "Warmed Up"?

I've never noted any warm up needed. I play the Tru when I playing my combo-amp stuff. Plug it in. Let it rip. I do use and OBEL guitar always, but that's the first effect I check, and it typically sounds right with minimal futzing. The Mu is in the SMS > GCX rig. It comes on with the Furman gizmo.

I have no opinion on this. Do envelope filters need to stretch before the big game? We all know that tubes need to warm up. I've not heard that effects that are solid state need the same attention. In something like an Mc2100 those big can capacitors may need time to fully charge if it's been dormant a while. Tiny caps on a PC board?

Nevermind. Just re-read Hippieguy's post. I personally don't hear it. But maybe it's already seeing the warm up before it takes much demand.

Peace & Happy Holidays! Sorry for the blather.
M

"Well don't cha know that:
Happiness, is a warm Tron.
(shoop shoop ahhhhahhh)
Happineeeess is warm Tron
(yes it is.....)"