Technical question(s) about pot values

Rex_Rocker

Well-known member
I'm debating about switching the pots for the bridge pickups on my Les Pauls from 500K to 250K (or 300K if I can find one) and it's got me curious. I was talking about it on my JB thread, but I figured it might be worth a thread of its own.

My reasoning is I have a bit of an EQ going before my amp in my HX Stomp just shaving off a bit of high-end subtly (less than 1dB). I wonder if I can do without it if I switch to a lower value pot. Is there a way of predicting by how many dB the resonant peak would be attenuated with pot values? What is even the resonant peak of the JB?

I'm a huge nerd for measurements. I love reproductability and predictability. And I'm sure the result won't be the exact same because the resonant frequency on a JB is not actual high-end but high mids, but if I can get some numbers, I can at least start picturing what the result would be and if it's going to be what I'm looking for or not.

I like the tone I get from a single 500K for the most part. Especially with flabbier amps (or, in this case, amp sims) like Rectifiers. But the EVH model I am using right now is super attacky and sometimes need taming. The JB is doing the heavy lifting as it's EQ'd very much in the ballpark for what I want right now. And I like that with a higher value pot, the pickup feels more "open" not just in the highs. The extra high-end (or I suppose high mids in the case of the JB) shift the focus away from the mud in the low and core mids. So I wonder if won't be making things worse rather than better by dropping down to 250K.

The other main question is if I can maybe have what I want in a push pull. Like have the pot behave as a 500K one if I pull up on it, and as 250 if I push down on it to have the option of having both if the mood strikes or if I'm using a different sim, or if I'm going for a brighter tone for whatever reason.

So... any ideas? Hit me up with some mathz. :D
 
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I think it is worth experimenting, as it is pretty cheap to do, and you will get to know what you like. Before I did push-pulls, just swap them out for a different value and if you like both (before & after) sounds, you can do push/pulls (or better, push/push). We can speak in generalities, but only you can say if you like the way it sounds with you playing through your rig.
 
You can simulate a 250k volume pot (when it is full open) by using crocodile clips and put another 500k resistor across the outer lugs.

For the tone pot all you have to do is turn the 500k port down to where it reads 250k and you simulate 250k.

The amplitude of your resonance peak is hard to compute and also depends on the input impedance of the first active stage of your rig.
 
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So... if I wanted to go through with my push pull ideas, could somene please point me to what terminals the resistor should be added? And which should be jumpered? I assume those two terminals should connect to the outer and inner lug of the pot, right? And to to gound? What goes to ground?

FWIW, I want the "down" position of the switch to be 250K and the up position to be 500K, please.

Please and thank you. :D
 
Are you someone who uses the volume control for dynamic effect
Or just wide open and GO

On my Gibson with the audio taper 500k pot "master volume master tone not individual "

I back the volume down a quarter turn and raise the pickups to the edge of breakup

Then used the volume to clean up or lead

If you just leave it wide open all the time you may not see much difference in the values used
 
Are you someone who uses the volume control for dynamic effect
Or just wide open and GO

On my Gibson with the audio taper 500k pot "master volume master tone not individual "

I back the volume down a quarter turn and raise the pickups to the edge of breakup

Then used the volume to clean up or lead

If you just leave it wide open all the time you may not see much difference in the values used
I'm the guy who uses the volume wide open all the time, really. Just some backing off from time to time, but it's rare.

I do hear a difference, though, from changing values. I don't think it's subtle. Especially not based on the graphics freefrog shared. There is a 4dB difference in one from going to 500 to 250.
 
I did notice humbuckers are much brighter with higher value pots

Most everything i have is humbuckers with 500k pots

I have one set of Carvin pickups that are a bit dark
I have thought about going to one meg posts in that one

But I like having another flavor
 
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