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Which pot?????

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  • Which pot?????

    This is going to sound stupid but here I go I have a Les Paul that I just installed a JB into and I was going to try to use a resistor to lower the 500k pot to 250k.
    Do I do this to the tone, Volume or both?????

    Thanks

  • #2
    Re: Which pot?????

    LP....Why the change from 500k to 250k in your LP?
    Amps: 66 Fender BF Pro Reverb Combo,1973 50 Watt Marshall Head,Marshall 4x12 A/V Cab,Vox ToneLab LE,Vox VTH Valvetronix 120 Head,Vox AD 2x12 Cab,Roland Cube 20X

    Guitars: Several Stratocasters,2 Fender Telecasters,Gibson SG Standard,Tokai Love Rock Les Paul,Dean Acoustic.

    Pickups: SD SSL2,SSL5,Twangbanger,Antiquity Surfers,59N,Seth Lover N/B,Dimarzio Fred,Dimarzio VPAF N,Fender Fat 50s,Fralin SP43 Bridge,Brobucker,Antiquity Texas Hot.

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    • #3
      Re: Which pot?????

      If its a 500k pot, you put a 500k resistor across the outside two terminals to make it a 250k pot.

      But as John said, why do it . . . unless its just a sonic experiment.

      Comment


      • #4
        Re: Which pot?????

        ya I just wanted to try it as I have read the Jb sound better with a 250k pot but which one the tone or volume?? I like the way it sound now but it might sound even better who knows

        Comment


        • #5
          Re: Which pot?????

          Do the volume pot...Putting a 500k resistor across your 500k will give you 250k,but you might not like the taper? I Like using the correct value pot from the get go...

          John
          Amps: 66 Fender BF Pro Reverb Combo,1973 50 Watt Marshall Head,Marshall 4x12 A/V Cab,Vox ToneLab LE,Vox VTH Valvetronix 120 Head,Vox AD 2x12 Cab,Roland Cube 20X

          Guitars: Several Stratocasters,2 Fender Telecasters,Gibson SG Standard,Tokai Love Rock Les Paul,Dean Acoustic.

          Pickups: SD SSL2,SSL5,Twangbanger,Antiquity Surfers,59N,Seth Lover N/B,Dimarzio Fred,Dimarzio VPAF N,Fender Fat 50s,Fralin SP43 Bridge,Brobucker,Antiquity Texas Hot.

          Comment


          • #6
            Re: Which pot?????

            Just to reinforce what John said, do this, but leave the volume on "10". Use it just to see what the sonic affect is. If you actually try to lower the volume, you may get unpredictable results.

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            • #7
              Re: Which pot?????

              thanks Kent thats what I call going above and beyond the call of duty

              Comment


              • #8
                Re: Which pot?????

                Kent; thats pretty cool . . . and informative.
                Do you have software that develops that chart, are did you just draw it from calculations?

                My original comment about, "leaving the volume on 10", comes from a parallel volume control experiment that I did in the early days of the forum. For some reason, when I did the parallel resistor trick, as I turned the volume from 10 to around 7 or 8, the volume actually went up. Then as I continued to zero, it came back down. I had this weird peak at 7 or 8.

                Unfortunately, I needed to get the guitar together, and have never really investigated farther, why that happened.

                Comment


                • #9
                  Re: Which pot?????

                  Originally posted by ArtieToo
                  Kent; thats pretty cool . . . and informative.
                  Do you have software that develops that chart, are did you just draw it from calculations?
                  That was just done from an EE program based off of a pup model ( I guessed at the dist.cap. of the pup), I chose a sine sweep and did a fixed dB voltage probe trnasferred to graph function. It doesn't have a o scope function though. It mention this, because it doesn't matter here; but it still erks me.
                  To answer your question more fully though, yes I've done the math, and unless I'm in a hurry, I try to figure the math first, then check it to verify with the program. Why? It is actually is more work to *guess* at the values and keep manually changing them back and forth. I've got about three different programs, but only really use one. Unless you are going to be laying out entire amp schematics a lot of the other features you don't need.
                  And there is quite a bit of Pspice delving to use some of the higher functions ... I don't do Pspice programming, so I avoid node commands and such like the plague ...
                  Sad thing is those graphs look great, but transfer to emf and paint files crappy, manily due to the resizing crap. I also like it, beacuse when I print out schematics and graphs, my copyright, date, design number etc. all appear at the bottom automatically ... Not seen here of course, (and I did say this was simplified) as I just wanted to show the volume differences.

                  My original comment about, "leaving the volume on 10", comes from a parallel volume control experiment that I did in the early days of the forum. For some reason, when I did the parallel resistor trick, as I turned the volume from 10 to around 7 or 8, the volume actually went up. Then as I continued to zero, it came back down. I had this weird peak at 7 or 8.

                  Don't know what to say to that, sounds a bit odd. I've notice rather interesting effects using variable load volume controls with pups of different DCR/Z ... That gets a bit odd.
                  You'll also note that it shows that the two section commercial approximation of an audio taper pot, what is sold as audio taper, not a true log taper ... notice how the traces don't fall exactly evenly spaced according to the knobs position relative to the dB output level.
                  Last edited by Kent S.; 08-24-2004, 07:39 AM.
                  ::::To sound reinforcement engineer::::
                  ... What? ... ::::snicker:::: ...Yes, ... Right, ...
                  Could we please have everything louder than everything else ? ...

                  Comment


                  • #10
                    Re: Which pot?????

                    Wow... lots of information. Here's something simpler that will let you use your ears more than theory, although the theory does make sense once you hear the difference.

                    You can simulate the sound of replacing your pots by unscrewing the end of your guitar cable and bridging a resistor across the the connection there. This way you don't have to solder or even remove the backplate. You can then tape it there and play away to get a idea for what the end result will be. You could even record it before you install the resistor and then afterwards to get a good comparison. If you like it, I would recommend switching out the pots. I tried to install the resistors myself messed it up, but I am a beginning solderer...so I had a pro install 250k pots.

                    You can get more info on the whole thing here: http://www.projectguitar.com/tut/potm.htm
                    Carvin SC90 (Jazz neck, CC bridge)
                    Fender Aerodyne Telecaster (stock pups: tele bridge and p-90 neck)
                    Ampeg Reverberocket combo

                    http://emayhem.com/toptenidols
                    http://emayhem.com/the_fords
                    (note: these songs were not recorded using the gear mentioned above...)

                    Comment


                    • #11
                      Re: Which pot?????

                      I hardly think a plotted frequency graph counts as mere theory ... Plus, you have to load it from the pup side, not the output side, it doesn't quite give the same result, this may be okay, but better off to do it right the first time.
                      Last edited by Kent S.; 08-24-2004, 12:20 PM.
                      ::::To sound reinforcement engineer::::
                      ... What? ... ::::snicker:::: ...Yes, ... Right, ...
                      Could we please have everything louder than everything else ? ...

                      Comment


                      • #12
                        Re: Which pot?????

                        Originally posted by Kent S.
                        I hardly think a plotted frequency graph counts as mere theory ... Plus, you have to load it from the pup side, not the output side, it doesn't quite give the same result, this may be okay, but better off to do it right the first time.
                        Good point regarding where to put the resistor. However, I personally find it hard to imagine in my head how a graph sounds...
                        Carvin SC90 (Jazz neck, CC bridge)
                        Fender Aerodyne Telecaster (stock pups: tele bridge and p-90 neck)
                        Ampeg Reverberocket combo

                        http://emayhem.com/toptenidols
                        http://emayhem.com/the_fords
                        (note: these songs were not recorded using the gear mentioned above...)

                        Comment


                        • #13
                          Re: Which pot?????

                          Just use a Gibson 300k pot, close enough to a 250k. They generally run under spec anyways....
                          www.soundclick.com/failedgrace
                          www.myspace.com/robert_sherman
                          http://www.facebook.com/profile.php?id=1513342220

                          T4D got a new gig!

                          (Please send sig worthy material!)

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                          • #14
                            Re: Which pot?????

                            Originally posted by mjsever
                            Good point regarding where to put the resistor. However, I personally find it hard to imagine in my head how a graph sounds...
                            Oh course, equipment permitting, you can always reach over to an EQ and alter the tone from the effected area (shown on the graph) to mimmic to tone and then switch back and forth between them ...
                            ::::To sound reinforcement engineer::::
                            ... What? ... ::::snicker:::: ...Yes, ... Right, ...
                            Could we please have everything louder than everything else ? ...

                            Comment


                            • #15
                              Re: Which pot?????

                              Originally posted by Robert S.
                              Just use a Gibson 300k pot, close enough to a 250k. They generally run under spec anyways....
                              Only problem there is if he doesn't want linear, and wants audio instead ...
                              ::::To sound reinforcement engineer::::
                              ... What? ... ::::snicker:::: ...Yes, ... Right, ...
                              Could we please have everything louder than everything else ? ...

                              Comment

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