Swapped 300k Lin for 500k Log in my LP and...

E

Emopunk

New member
So,

after all the readings here and there, I decided to swap my stock 300k linear volume tapers for 500k genuine Gibson audio pots (PPAT-500). The sound of the guitar definitively improved, but what I find weird is that at around 5-6 (depending on the amp settings), I have no sound out of the guitar.

This is my wiring at the moment, just to check that my technician did everything right (I didn't dare to do it myself):

2rddf2u.jpg


Is it just something I have to get used to? Should I have used other brand/linear pots instead?
 
Re: Swapped 300k Lin for 500k Log in my LP and...

Go back to the tech - there is no way that volume cutting out is normal.
 
Re: Swapped 300k Lin for 500k Log in my LP and...

Are you saying that somebody charged you money for the soldering work in the photograph?
 
Re: Swapped 300k Lin for 500k Log in my LP and...

AlexR said:
Go back to the tech - there is no way that volume cutting out is normal.
Click to expand...

Do you have any idea what could possibly be wrong? When I am using distortion I can go lower on volume pots, anyway; but when on clean channel, it's like I described.
I also found this discussion where they seem to have the same problem and someone sorted it out by installing resistors on the pots.
 
Re: Swapped 300k Lin for 500k Log in my LP and...

Non buono!

Take the guitar back to the tech, and tell him what he ****ed up.

Just from looking at the soldering job on the left 2 (the tone pots are still factory from what I understand and therefore out of the discussion),the chances are good that he borked one of the pots.

Emopunk said:
Do you have any idea what could possibly be wrong? When I am using distortion I can go lower on volume pots, anyway; but when on clean channel, it's like I described.
I also found this discussion where they seem to have the same problem and someone sorted it out by installing resistors on the pots.
Click to expand...
AAAH...

How far can you roll off the volume and still get an actual signal under overdrive? Almost all the way?

I´m thinking you might just not be used to the fast initial rolloff of an audio taper pot... But installing the resistiors however entirely defeats the purpose of replacing the pots for 500k.
 
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Re: Swapped 300k Lin for 500k Log in my LP and...

Zerberus said:
Non buono!

Take the guitar back to the tech, and tell him what he ****ed up.

Just from looking at the soldering job on the left 2 (the tone pots are still factory from what I understand and therefore out of the discussion),the chances are good that he borked one of the pots.


AAAH...

How far can you roll off the volume and still get an actual signal under overdrive? Almost all the way?

I´m thinking you might just not be used to the fast initial rolloff of an audio taper pot... But installing the resistiors however entirely defeats the purpose of replacing the pots for 500k.
Click to expand...

Yes, almost all the way to 0 when distorted. According to some of the posters in that thread, installing the resistor should not affect tone. Who's right on this thing? I am confused! :eek13:
 
Re: Swapped 300k Lin for 500k Log in my LP and...

If you have usable sound (not a tinny, fizzy mess that sounds like an old radio) almost all the way to zero, it is in fact very likely primarily you not being used to the way an audio taper pot reacts. The initial effect is very large and then becomes smaller and smaller.

Installing the pulldown resistors WILL affect the tone, because you thereby have 2 resistors in parallel, significantly reducing the overall resistance of the assembly to a value BELOW that of the smallest resistor /pot used in that part of the circuit. This is as basic as basic electronics gets.

The formula for parallel resistance is: Rtotal = R1×R2/(R1+R2)

For example, if you have a 500k resistor wired across the poles, and keep the 500k pot, you now effectively have a 250k pot. If you follow teh advice of the person in that thread and use a 100-220k resistor, you will be left with an effective pot value of between 83.3333333333333k for the 100k and 152.77777777777777 for the 220k.

To calculate the extreme 100k example for reference, using R1 for teh 100k resistor and R2 for the 500k Pot: R total= 100x500 /(100+500) = 50,000 /600 = 83.3333333333
 
Re: Swapped 300k Lin for 500k Log in my LP and...

audio taper pots...ewwwwwwww.

In all seriousness, not the greatest solder job, looks like the iron might not have been hot enough at times leaving him to hold it there too long. Audio pots are weird though, it will be a quick drop off. Also, installing a resistor will most certainly affect the sound....a pot is just a variable resistor!
 
Re: Swapped 300k Lin for 500k Log in my LP and...

OOOH, wait, i just realized something: They´re not talking about a resistor in parallel to the pot, but between teh 2 non grounded lugs.

While this will almost certainly have a tonal effect, it will be much less pronounced than one would expect from a large change in pot value. WHt that resistor essentially does is modify the taper in the lower area... essentially it does nothing until the pot is turned back far enough to approach the value of the resistor, and when that happens it basically "flattens" the logarithmic curve of the pot...

That should in fact be a viable workaround after all, definitely the cheapest solution to the current issue. I would recommend a 220k for that purpose on a 500k pot.
 
Re: Swapped 300k Lin for 500k Log in my LP and...

Zerberus said:
OOOH, wait, i just realized something: They´re not talking about a resistor in parallel to the pot, but between teh 2 non grounded lugs.

While this will almost certainly have a tonal effect, it will be much less pronounced than one would expect from a large change in pot value. WHt that resistor essentially does is modify the taper in the lower area... essentially it does nothing until the pot is turned back far enough to approach the value of the resistor, and when that happens it basically "flattens" the logarithmic curve of the pot...

That should in fact be a viable workaround after all, definitely the cheapest solution to the current issue. I would recommend a 220k for that purpose on a 500k pot.
Click to expand...

Well, I indeed happen to have both 130k and 220k resistors here at home. Should I buy some alligator clips to see which works best or should I go straight to the 220k?
 
Re: Swapped 300k Lin for 500k Log in my LP and...

That looks like an amateur soldering job. I am not at all surprised if something isn't working right.

That said, are you sure that you aren't just used to linear taper? I.e., is your sound really cutting out completely at 5-6, or is it just quieter than it was with the old pots?
 
Re: Swapped 300k Lin for 500k Log in my LP and...

ItsaBass said:
That looks like an amateur soldering job. I am not at all surprised if something isn't working right.

That said, are you sure that you aren't just used to linear taper? I.e., is your sound really cutting out completely at 5-6, or is it just quieter than it was with the old pots?
Click to expand...

I think I explained in the above posts that when using distortion I can get usable tones down to almost 0. The change is more abrupt when on clean channel.
In my first post I also asked "Is it just something I have to get used to?". Gibson stock 300k pots were indeed linear, and I was used to them.
 
Re: Swapped 300k Lin for 500k Log in my LP and...

Emopunk said:
I think I explained in the above posts that when using distortion I can get usable tones down to almost 0. The change is more abrupt when on clean channel.
In my first post I also asked "Is it just something I have to get used to?". Gibson stock 300k pots were indeed linear, and I was used to them.
Click to expand...

You have stated that you have "no sound" on 5-6 when clean, and that you do have sound over the entire range with more gain. I asked what I asked to make it crystal clear whether "no sound" is being used literally (i.e no sound at all) or figuratively (i.e. much less sound than before the swap).
 
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Re: Swapped 300k Lin for 500k Log in my LP and...

ItsaBass said:
You have stated that you have "no sound" on 5-6 when clean, and that you do have sound over the entire range with more gain. I asked what I asked to make it crystal clear whether "no sound" really means NO SOUND, or if you were exaggerating.
Click to expand...
I would define it like close to no sound; but this is at living room levels on my amp, I can't say it's any better at 'stage' volume at the moment.
 
Re: Swapped 300k Lin for 500k Log in my LP and...

Emopunk said:
I would define it like close to no sound; but this is at living room levels on my amp, I can't say it's any better at 'stage' volume at the moment.
Click to expand...

Hearing that confirms my initial suspicions: 1) You were being figurative with your use of the term "no sound," and 2) You are playing very quietly while noticing these problems.

I think there is certainly the possibility that the problem might only be that you are playing with audio/log taper pots very quietly in your living room. I would hold further judgment on the pot swap until you can turn up to a "real-world" volume.
 
Re: Swapped 300k Lin for 500k Log in my LP and...

ItsaBass said:
Hearing that confirms my initial suspicions: you are playing very quietly while noticing these problems.

I think there is certainly the possibility that the problem might only be that you are playing very quietly in your living room. I would hold further judgment on the pot swap until you can turn up to a "real-world" volume.
Click to expand...
This afternoon I have rehearsal with my band, I will pay some attention to the issue.
 
Re: Swapped 300k Lin for 500k Log in my LP and...

Emopunk said:
Well, I indeed happen to have both 130k and 220k resistors here at home. Should I buy some alligator clips to see which works best or should I go straight to the 220k?
Click to expand...

Definitely not a bad idea, and especially when experimenting with wiring options having a few ´gators around is never a bad idea, anyway.

I would personally probably go straight to the 220k, because I think that´s where the taper issue is starting to throw you a curveball. But it´s definitely not a bad idea to take the guitar out for a real world spin and see how it performs under those conditions before "re-modding", either ;)
 
Re: Swapped 300k Lin for 500k Log in my LP and...

Zerberus said:
Definitely not a bad idea, and especially when experimenting with wiring options having a few ´gators around is never a bad idea, anyway.

I would personally probably go straight to the 220k, because I think that´s where the taper issue is starting to throw you a curveball. But it´s definitely not a bad idea to take the guitar out for a real world spin and see how it performs under those conditions before "re-modding", either ;)
Click to expand...

Ok so I played with my band today and with my Mustang III v2 set at 4/10 volume (plenty loud if you ask!), the volume roll off was more reasonable and I still could hear a clean channel @2 if not @1 on the pot. In the meanwhile I also arranged some alligator clips with wires so I could eventually still try the 220k resistance to see how it looks. Do you people agree?
 
Re: Swapped 300k Lin for 500k Log in my LP and...

Sorry, I don't want to bump this old thread, but I wanted to let you people know that I tried to improve the overall electronics job that was in my guitar. So together with a friend we did the job that you can see in the attached pic. Please be patient, since it's my first full rewiring in a guitar and let me know how it looks to your eyes. Thanks!


2m296ie.jpg
 
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