Can a regular pot be used in place of a trim pot ?

[Pine]

In a schematic that calls for a 500K trimpot, will a regular 500K pot work the same?

[Mike Swan]

Yes, absolutely.

[gez]

Depends on the circuit, what the trimpot is doing etc.  In many cases the trims are there for bias so there's not a wide range of tuning you can do before you bugger up things.  replacing a trimpot with a pot and stop resistors might be the better way to go.  Again, all depends on the circuit.

[MartyMart]

Yes of course .......but it wont fit "inside" the enclosure  :cry:
Its only worth doing this for :
A - testing/breadboarding
B -  if its a function that you "want" to have control of outside the box

If its for "bias" or something similar that you wont want "moving about"
then dont do it  !

Cheers,
Marty.

[Pine]

I want to use it for a gain knob on the "Boutique boost" schematic found at general guitar gadgets at http://www.generalguitargadgets.com/diagrams/joam_lo_sm_b.gif

[MartyMart]

I want to use it for a gain knob on the "Boutique boost" schematic found at general guitar gadgets at http://www.generalguitargadgets.com/diagrams/joam_lo_sm_b.gif

Do you mean "R7" - the 500k pot ?  .. I dont see any small "trim pots" on
the schematic, so yes all three of the pots at the top of the schem are
meant to be "real pots" outside the enclosure ( box )  
I tend to use 16mm "Alpha" popts for all my builds, you can get all those
values from various places, www.smallbearelec.com   for instance .

Cheers,
Marty.

[Mike Swan]

Pine, is this the schematic:
http://www.generalguitargadgets.com/diagrams/joam_sc_b.gif

You can use a regular pot for the gain pot, but I don't think it's worth it. Just use your guitar's volume knob to adjust the "input gain" to the effect.

[formerMember1]

martymart:
i got a 10k trim pot 16mm "Alpha"  and 100k of the same. why does mine have like ten notches in it when you turn it? like it doesn't rotate like a normal pot on a guitar. it stops at certain points.   :?:

i am using them to bias a transistor. can i still use the 10k pot for the volume control after i am done using it to bias?
thanks

ps:i am using it in a dallas rangemaster clone.
also, do you know where to put two pulldown resistors(2.2M) so it doesn't pop when the effect is bypassed. i am building it on a terminal strip according to geo fx. actually it is the austin treble blaster.

sorry for the off topic :roll:

[Hal]

martymart:
i got a 10k trim pot 16mm "Alpha"  and 100k of the same. why does mine have like ten notches in it when you turn it? like it doesn't rotate like a normal pot on a guitar. it stops at certain points.   :?:

you bought a pot with "detents."  Don't buy these, they are annoying

PINE:

did you mean to say "can I use a trim pot instead of a normal pot?"??

[Pine]

martymart:
i got a 10k trim pot 16mm "Alpha"  and 100k of the same. why does mine have like ten notches in it when you turn it? like it doesn't rotate like a normal pot on a guitar. it stops at certain points.   :?:

you bought a pot with "detents."  Don't buy these, they are annoying

PINE:

did you mean to say "can I use a trim pot instead of a normal pot?"??

No, the parts list calls for a trimpot, to be mounted externally

[gez]

the parts list calls for a trimpot, to be mounted externally

Hint: it helps if you tell us what the project/schematic is and link to it...

[petemoore]

am using them to bias a transistor. can i still use the 10k pot for the volume control after i am done using it to bias?
 Yes...I think so...you can temprorarily place a pot as a bias resistor, set the bias using the pot, remove the pot without readjusting it, measure it and replace with fixed resistor for permanent bias set. Use the pot for something else.
 For setting resistance I sometimes use pot + resistor. For instance I want to be able to adjust between 33k and 68k...a 33k stop resistor and a 50k pot allows adjustments between 33k and 83k [no need for running out and getting a 100k pot, also the adjustment tuning is finer.
 FF's I like to use a 10k and 4k7 stop resistor. This makes fine tuning the actual values easier than using a 20k...
 Apples/Oranges/One Odd/Three of the other...

[Pine]

the parts list calls for a trimpot, to be mounted externally

Hint: it helps if you tell us what the project/schematic is and link to it...

Sorry; http://www.generalguitargadgets.com/index.php?option=content&task=view&id=93&Itemid=121

It is the project called "Boutique Boost" on this page

[MartyMart]

the parts list calls for a trimpot, to be mounted externally

Hint: it helps if you tell us what the project/schematic is and link to it...

Sorry; http://www.generalguitargadgets.com/index.php?option=content&task=view&id=93&Itemid=121

It is the project called "Boutique Boost" on this page

Pine - sorry, OK we get it now  !!
Thats your "input gain" trim pot and YES you can use a regular pot just
like the other two in the schematic/parts list .
However, your "guitar" volume pot is an "input" pot to the circuit .... !
So you could just use say a 470k resistor direct from the input jack
socket tip to the top of the 1M reistor which goes to ground and not
bother with that 500k pot, control volume with your gtr vol control
Make sense ?

Cheers,
Marty.

[Pine]

the parts list calls for a trimpot, to be mounted externally

Hint: it helps if you tell us what the project/schematic is and link to it...

Sorry; http://www.generalguitargadgets.com/index.php?option=content&task=view&id=93&Itemid=121

It is the project called "Boutique Boost" on this page

Pine - sorry, OK we get it now  !!
Thats your "input gain" trim pot and YES you can use a regular pot just
like the other two in the schematic/parts list .
However, your "guitar" volume pot is an "input" pot to the circuit .... !
So you could just use say a 470k resistor direct from the input jack
socket tip to the top of the 1M reistor which goes to ground and not
bother with that 500k pot, control volume with your gtr vol control
Make sense ?

Cheers,
Marty.

Marty, do you mean attach it to the top of the resistor labelled R1 in the layout?

[petemoore]

It can be nice to have the 'second guitar volume control' on your box's input, for setting Max gain at a level less wooly sounding...for matching pickups output levels to the input of the box, the Guitvol does the same thing, but trying to stop at an exact 8.5 guitar volume setting while playing can be 'inaccurate' or hard to do, having the pregain setter on the input makes your choice of Max gain available at full CW guitar volume.

[MartyMart]

Marty, do you mean attach it to the top of the resistor labelled R1 in the layout?

Yes, so input jack to board --> 470k --> top of 1M  ( R1 ) --> etc
As Pete said though, an input volume pot can be handy !!
Cheers,
Marty.

[gez]

Make life easy, replace the 500k with a pot and ditch the 1M resistor (R1); it's superfluous, the pot is acting as a pulldown for biasing the FET.