PRS John Mayer Silver Sky Volume Pot doesn´t work anymore

[alantig]

Nicely done!

 

[Guitar54]

Hey guys,
it has been a while. I swapped the old pot back then with the new one sent to me by PRS. The repair was quite tricky because the caps of the pots fit very tight. I had fear to break the pickguard, but in the end it worked. I soldered the wires onto the new one like they were before and put everything back together. After that, the pot worked fine like it should again. Its exactly the same like he old one and also the resistor on it is the same. You can see it if you look at the coloured rings on it. Now my SS works perfectly fine again and i have played several gigs since the repair. No problems anymore. If some of you wants to see some pictures you can check my Instagram via the link below. Cheers!

https://www.instagram.com/p/CEB1HulnLEy/

Thanks for the update. I too have a new POT coming. Did your POT come with the resistor already attached? They tweak the resistance to be 275k ohm. Hence my bet is each POT have differing resistors to take into account the POT tolerance.

 

[Philipp Elfers]

Thanks for the update. I too have a new POT coming. Did your POT come with the resistor already attached? They tweak the resistance to be 275k ohm. Hence my bet is each POT have differing resistors to take into account the POT tolerance.

Yes, the resistor was already soldered onto the pot. I dont think that the tolerence woild have that much of an effect, because the difference cant be not more than +-5% . You can tell it by the golden ring on the restistor. The meaning of the rings is normed. If you look at the table, the rings on the resistor mean 2,40 MOhm with a tolerance of +-5%. You can look up the colours in the first link below. I measured my restistor on the old pot and its 2,43 MOhm. So it is easily in the tolerance band and i think it wont make a difference imho. I dont know how high the restistance is with the potentiometer in parallel, so if you didnt repair your guitar yet that would be intestesting to measure the new pot including the resistor. My old pot ist broken an has no restistance at all, lol. Cheers!

https://www.electroschematics.com/resistor-color-codes/

 

[Guitar54]

Thanks Philpp....I did get actually 2 POTS - seems they double shipped...maybe because I live like an hour away from the factory...haha. Anyway, I decided to not replace at this point since everything is working. I did open up the guitar and de-oxed the pot and also re-soldered some badly soldered wires. Maybe I had a cold solder joint. Couple of things...1) I see your replacement has a 0 on it. Mine too have numbers - one is 4 and the other a 5. I measured them both and they are about 266K ohms with the resistor. My original is about the same. So they take a 300K ohm pot and bring it down. I have a 2020 Sky - since they are continually tweaking things at the factory based on Mayer's continually changing his guitar. I've heard this but can't verify. JM did say something about this in the 2021 launch party...so who knows. 2) My pups measure about 6.1 K ohms each. 3). Going back to the POTS - P4 is 266K Ohm w/R, 300K w/o R, R is 3.3 Meg Ohm (ORG-ORG-Green-Gold), P5 is 266K w/R, 300K w/o R, R is 2.7 Meg Ohm (Red-Purple-Green-Gold).

What colors is your R? Can't tell from picture. Looks like Red-Green-Blue-Gold which is 25 Meg Ohm per this calculator...so we have some disagreement...haha. One of us is reading the charts differently. I hate the charts and always revert to a simple calculator. Bottom line is all of my POTS are at about 266K ohms. So PRS is using the Resistor to bring the resistance down from 300K Ohms to around 260K on the 2020 versions with 6.1K ohm pickups. My bet is the range has been 260K to 275K ohms based on the many articles I've read. Since no one makes these value POTS, they use a resistor...cool idea actually.

https://www.digikey.com/en/resource...ors/conversion-calculator-resistor-color-code

Oh and I took one of the resistors off of the POT to measure it and my dang meters only go up to 2M - so no reading...haha. Kinda verve's the Meg versus K discrepancy we have.

 

[Philipp Elfers]

I corrected the value to 2,4 MOhm in my previous post. Your calculator is right, and i have a Multimeter that can measure MOhm. I just didnt read properly in a hurry. My restistors Color (the old one) is red, yellow, green, gold, so its alright. Nice to know that they are trying around with the combinations through the years. My SS is from 2018 btw., so its first generation. I dont know what they are trying to improve, but you can theoratically simulate the circut of the SS in an electrotechnical simulation software. Maybe im gonna do this after my bachelor thesis is finished in a few weeks.

 

[Guitar54]

No problem! It's cool to be able to share this stuff! As for 2018 vs 2020, I'm not sure about this tweaking but it seems small tweaking. Agree with you on what is trying to be improved. For my 2020, I like the overall sound in all pickup combinations. I have many USA fender Strats - and actually just bought a Lincoln Brewster Strat with Dimarzio's in it. Standard. The bridge pickup is too treble ly. and the neck pickup is a bit bassy. I've even offset the pups from left to right...versus the SS which is super balanced and sounds great.

Aside - I'd be real interested in what you come up with on the simulation software. super interested. I have electrical engineering background...that doesn't mean much except I do all my electronics on my guitars and have built an amp so I'm more electronic than engineer! haha. So ya - for sure I'd totally be jazzed about what you do in simulating this stuff for the SS. I will send you a DM with my direct email address. Thanks!!