resistor (trimpot) to a pot

[kin0]

Hay, I am modding my cray baby cgb95 right now and I want to do this mod
" replace the 33K resistor with a suitable high-quality trimpot (something like 100K lin) - then you can tweak the wah/woh all day... Do the same with the 390Ω resistor (a 500Ω or so linear will work fine) to get adjustable gain/bass response. Just remember to set them to the correct value before installing, so you'll know where you are when you start."

I just want to use potentiometers to tweak them outside the enclesure. I want to go between 33k and 68k with the first one and between 270 and 450 (or at least 330).
Is it possible?

[Bad Chizzle]

I use regular pots for trim pots often and just mount them inside, so I see no reason why you couldn't just mount them as a control for the unit. The only thing I can think of that may be a down side for you is if one extreme setting or another goes to far for the circuit. In this case you can put resisters in line with your pot or pots to limit your ability to swing too far one way or the other. Much like if you were installing a input pot and you place a 1k resister from your ground lug to ground, so that you can never have a no input setting.

I hope I made this clear, and it's helpful!

[kin0]

Sorry, but I don't really understand how to do it. If you can tell me which pots to buy (I mean which value) and how to connect (where to put each lug) and also what resistor to put in parallel and where (sorry for being nooby its my second job). I done the true bypass and the led (white) so far and it works good. I am going to paint the enclesure too. If it is important what things I am going to change.

[Bad Chizzle]

I'm sorry, I'm not familiar with your circuit. Just start off by getting regular pots in whatever values the mod calls for. It should actually work fine by doing that alone.

[kin0]

so just to buy a pot instead of a trimpot. okay. Another question. How do I install a trimpot (or a pot) instead of a resistor. two lug to the resistor holes and one to the ground?

[dune2k]

Without knowing much about the circuit:
It's simple math. For the first pot you want this:
Range: 33k to 68k
Difference is: 35k
There are no 30k or 40k pots around. But you can add a resistor in parrallel to a pot.
Using a 50k pot the resistor would have to have ~117kOhm. Next readily available value is 120k (gives you ~35.29k).
Solder this resistor to the outer two lugs of the pot.
To make the pot travel between 33k and 68k add a 33k resistor in series with the pot (wired as a variable resistor, google it).

Same with the other pot.

[kin0]

Okay, so solder 50k pot with 120k resistor between lug 1 and 3. Connected in series with 33k resistor. And to connect lug 1 and 3 to the resistor holes? Also and linear pot or not linear (don't remember its name).
And which values to do with the second one. cause i didn't really understood how oyu calculate all this.

and can i put a pit instead of a trim here too

[Derringer]

Okay, so solder 50k pot with 120k resistor between lug 1 and 3. Connected in series with 33k resistor. And to connect lug 1 and 3 to the resistor holes? Also and linear pot or not linear (don't remember its name).
And which values to do with the second one. cause i didn't really understood how oyu calculate all this.

and can i put a pit instead of a trim here too

http://fuzzcentral.ssguitar.com/mccoy/bufferlayout.gif

yes, but it won't be very useful because you'll either just max it out or set it to some value and then never touch it again
a trimpot is best for that application, but if you really hate trimpots you could just try a jumper between the middle(4) and left trace

and you really should remove that image and just post a link instead
see that part where it's written "This PCB and layout are not to be posted on any other site than Fuzz Central without written permission" .... that's there for a reason

[kin0]

How can I modify my post?

And  what about the first two? what to do with them?

[dune2k]

You can't modify a post after a certain amount of time (here)...

The link I used to calculate all this is this one: http://www.sengpielaudio.com/calculator-paralresist.htm
Then I checked in an online shop for the next highest value available (for both pots and resistors).

I'd start with a linear pot here, but depending on what you alter a log pot could be better. You have to try it out yourself.

[kin0]

okay thanks for help. For the second one in need a 1K POT in parrallel with 220 ohm resistor in series with 270 ohm resistor. And should I connect the pot like this?
http://www.iimmgg.com/image/6a8e6cb017c19fd93a70c21746227e80

[kin0]

Can you tell me which lugs of the pot connect to the holes of the resistor? It is the last thing I need to know before I'll begin to mode the circuit.

[kin0]

Common. Can someone please help?

[Bullet79]

forget the resistor.... just use 100k pot for the Q and 1k pot for the other one...  dont worry it will not explode.. doesnt matter what type of pot will do.. solder to lug 1&2 or 2&3... either
NOW JUST DO IT,..

[petemoore]

  DMM with testclip/probes [allows hands to twist potshaft].
  Pot, resistors.
  Measure pot, 100k is more like 93k?...within tolerance, we'll round it off to 100k for discussion.
  Measureing the left side and the right side of a pot [wiper to an outside lug], adding right and left always adds to the pot-total-value, the 'resistive wafer' in the pot is a fixed value, the wiper creates a 'tap' point [connects] somewhere in the middle of the wafer...one side of the pot is a variable resistor, the other side is a variable resistor...when one sides value goes up, the other goes down, the wafer value is fixed...they always add to the value of the wafer [the outside lugs are permanently connected to the ends of the resistive wafer.
  Put a parallel resistor...to any resistance to decrease total...handy !
  You can reduce the total value and range of a 100k pot to 50k by placing a 100k fixed resistor across the 100k potwafer. A couple 100k's paralleled = 50k, a couple 100k's seriesed = 200k.
  >Stop resistor on a pot...place 1 resistor lead on 1 outside lug...[hangit off the pot]. Example: 4.7k + 10k pot...the 4k7 isn't adjustable and is in the path [stop resistor], the range available from a 10k pot with 4k7 stop resistor starts at 4k7 through 14k7, I like this for Fuzzface Bias Trim resistance.
  Paralleling any resistor [decreases value] is easy with a pot that is set up as a variable resistor [wiper and 1 outside lug] if testclip/wires are used...clips right to any resistor that can be physically accessed with the clips.
  Increasing a fixed, installed resistor value requires lifting/splicing/inserting additional R value.