amp trem pot to treadle?

[ryan summit]

hey fellahs
i had an idea that iwanted to run past you guys
i recently got an old acoustic 150
the verb and tremelo on it are so good
soim actually using a footswitch with it
id really like to be able to change the trem speed
without walkin over to the amp

my idea
swap the trem pot with a 1/4 inch jack
get an empty treadle
and install the pot in there

is there any reason i cant do this?

[skullservant]

You might even be able to put the pot on a 3PDT switch, so that you can switch back and forth from the amp's knob to the expression control via the foot treddle. Just make sure you match up the value of the potentiometer and I don't see why you wouldn't be able to!

[ryan summit]

so that would involve adding a jack
and leaving the knob on the amp
i was thinking of removing the pot
and putting the jack in its place

[skullservant]

Yeah. I was just thinking if for whatever reason you didn't want to bring the extra treddle for whatever reason you could just flip the switch to bring it back to stock.
But your way would also work!
Just make sure it's a stereo jack that you use!

[ThePastRecedes]

You may have to use a isolated jack if the faceplate is metal and grounded

[ryan summit]

yessyess
thats smart
especially if i ever wanna sell it
probly about the same work
except for sdrillin a new hole
actually theres a speaker output that dont work
i could just put a stereo jack in that hole
and wire it back to that
is it tough to make it so
the amp knob works until i plug in the treadle
ir would a toggle switch work better
wait if im just havin signal go through pot in treadle
why do i need a stereo jack?
thats a real question
not bein a dick

[skullservant]

A stereo jack is used for expression control cause you need to connect all 3 legs of the potentiometer to a leg on the jack!
You could use a switching stereo jack, which when nothing is plugged in would bypass the jack entirely!

[ryan summit]

aha gotcha
yeah switching jack would eliminate toggle
and no need for drilling
and ill keep the grounding in mind
thanks dudes
i guess first i gotta figure out value of pot
and see if theres any expressions that already have it
im so glad this gonna work
and yeah if i can just solder to as many existing points as possible
that would ease my mind a bit
thanks skulls

[skullservant]

No problem dude!

[TweedBassman]

whoa whoa whoa miss lippy.

while in theory this might work, you could have a few big issues:

Right now, the signal that controls the LFO speed on the trem goes from point A - trem speed pot- Point B. By putting a jack, some cable, the treadle/pot, more cable, and then back into the amp you've increased the resistance, capacitance, and noise introduction before and after the trem speed pot so there may not be enough current on the signal to 'drive' that trem speed signal down the cable, through the pot, and all the way back up the cable.

NOT saying it can't be done... it'll probably work fine. but, i'd first take out the trem speed pot, measure the impedance to see what you need, then 'tack in' (crappy temp solder job) a stereo TRS jack where the pot was, throw a long TRS cable on it, then put another TRS jack and the original pot on the other end of the cable (you could use alligator clips on that end). check to see if the noise increased, and if the speed sweep is the same, etc.

[ryan summit]

so try it out
before i drill any holes
or cut the original stuff out?
good call
i am kind of a cowboy when it comes to this stuff
measure twice?
eff that
smash that little frik in there

[TweedBassman]

HULK SMAAASH

no really test it beforehand i'd say.

Actually, try this: turn the speed allll the way down. use alligator clips to attach a TRS jack to each lug of the trem speed pot, if you can get to it. then throw an expression pedal on there. see if it works. I'd guess that the pot's value is not 10k like most expression pedals but at least you'll get an idea of where to start.

P.S. i don't think the Acoustic 150 is tubes but avoid the large caps and obviously unplug while working etc... fried ryan is not on the breakfast menu.