Let's talk resistors!

[JasonE]

I have been testing out the compressor pedals that I bought recently and had my 594 in my hands and remembered that it had the push pull taps on it. I pulled both up, wow. This guitar has a set of 57/08s in it that I bought from the PRS website in 2016 or early 2017. They are hotter than my other sets of these pickups. The experience of this made me decide to buy some resistors and put them in my CU22 that I had the PTC put 57/08s in back in 2009. The splits on the guitar with the resistors is much better. I want that for this guitar too.

I pulled out my 2011 DGT and took the backplate off to see how they wired the resistors into that guitar from the factory since they use the same switch and made an interesting discovery. All of the wiring schematics on the PRS site show a 1.1k resistor for the neck pickup and a 2.2k resistor for the bridge. My DGT, from the factory, has a 2.2k resistor on the neck pickup and an 8.8k resistor on the bridge pickup. I scoured the internet and found some confirmation that these are the values they used to use. I am wondering when and why they changed the values of the resistors. I plan on verifying the values in my 594 before I put the resistors in my CU22 today.

Was anyone aware they used to use higher values?
Does anyone know when they made the change?

I am assuming they made the change because they wanted to thin the pickups out more when tapped. This also means that this will be a variation in tone across the DGT line over the years. I don't know if they had the resistors in the first DGTs and then went to the values in mine and then changed them. If they did that means there are three different versions of the tap in these guitars over the years.

 

[JasonE]

Well, I opened the 594 up. I found out why I have not had phase issues. I flipped the wires on one pickup when I put them in. PRS must have told me to do that when they gave me the color codes for wiring it up.

Another surprise, it has a 1.1k resistor on the neck pickup but has an 8.8k on the bridge. The guitar is a 2016. Now I really wonder when they changed the values of the resistors they are installing.

I am glad I opened it up. I found a ground wire loose in it. I haven't had any ground issues and surely won't once I reattach it.

 

[garrett]

Interesting! I haven't seen anything about PRS using other values.

My 594 is a 2016, fairly early on, and it has the usual 1.1k and 2.2k.

The higher the value, the more of the tapped coil remains, so that makes a pickup sound less "split". I experimented with different values on a different guitar with a Suhr Thornbucker+ set and it was pretty fun. I think I landed at 4.7k bridge and 3.3k neck. Anything above that sounded too humbucker-y to my ears.

I doubt if I'd notice a difference between 1.1 and 2.2 on the neck, but 2.2 to 8.8 should make it sound a lot beefier in tapped mode.

I'm fairly convinced that at some point in the '10's PRS got a slammin' deal on like a million resistors. Every one I've seen above S2 level has the same 1/2 W carbon composite 1.1k neck and 1/2 W metal film 2.2k bridge.

 

[JasonE]

Interesting! I haven't seen anything about PRS using other values.

My 594 is a 2016, fairly early on, and it has the usual 1.1k and 2.2k.

The higher the value, the more of the tapped coil remains, so that makes a pickup sound less "split". I experimented with different values on a different guitar with a Suhr Thornbucker+ set and it was pretty fun. I think I landed at 4.7k bridge and 3.3k neck. Anything above that sounded too humbucker-y to my ears.

I doubt if I'd notice a difference between 1.1 and 2.2 on the neck, but 2.2 to 8.8 should make it sound a lot beefier in tapped mode.

I'm fairly convinced that at some point in the '10's PRS got a slammin' deal on like a million resistors. Every one I've seen above S2 level has the same 1/2 W carbon composite 1.1k neck and 1/2 W metal film 2.2k bridge.

My 594 is a 2016 as well and definitely has the 8.8k resistor on the bridge pickup. It thins out quite about with the 57/08s I put in it. I don't really remember what the taps sounded like with the 58/15 pickups in it. I took those out not long after I bought the guitar. I am now wondering what I would think of them if I swapped them back. I really like the way it sounds with these hotter 57/08s.

My DGT is a 2011 and the resistor on the bridge pickup is the exact same one as in my 2016 594. I found some posts on the net about people finding 8.8k resistors on their bridge pickups. I put the 1.1k and 2.2k resistors in my CU22 this weekend and like what they are doing. I am definitely curious as to when they started putting the resistors in and when they changed the values to what they use today.

 

[shinksma]

"Let's talk resistors!"

No.

Resistance is futile. You will be assimilated.

Anyway...I have nothing to add right now, other than the interaction of electronic components (resistors, caps, etc) all have the "scientific" reason for what they do, but there is some seemingly-magical mysterious element that happens with pickups that is often hard to quantify - and I'm sure, ultimately, that there is a perfectly good scientific explanation (once you characterize the pickup fully), but the mystique around it all makes for far more fun...

 

[Bogner]

When It Comes To Some Of These Smaller Parts I Often Wonder If Stock On Hand, Availability From Parts Distributors, Assembly Error (Sounds Much More Harsh Than I Mean It To Sound), Etc Play A Role In Some Way? We May Never Know Though...

 

[ViperDoc]

Interesting! I haven't seen anything about PRS using other values.

My 594 is a 2016, fairly early on, and it has the usual 1.1k and 2.2k.

The higher the value, the more of the tapped coil remains, so that makes a pickup sound less "split". I experimented with different values on a different guitar with a Suhr Thornbucker+ set and it was pretty fun. I think I landed at 4.7k bridge and 3.3k neck. Anything above that sounded too humbucker-y to my ears.

I doubt if I'd notice a difference between 1.1 and 2.2 on the neck, but 2.2 to 8.8 should make it sound a lot beefier in tapped mode.

I'm fairly convinced that at some point in the '10's PRS got a slammin' deal on like a million resistors. Every one I've seen above S2 level has the same 1/2 W carbon composite 1.1k neck and 1/2 W metal film 2.2k bridge.

You can estimate the output of this type of split using a voltage divider calculator: https://ohmslawcalculator.com/voltage-divider-calculator

The Thornbucker + bridge pickup has an average DC resistance of ~9K ohms. Call the split coil a 4K5 resistor (R1). If you have a 4K7 to ground when tapped (R2), you are essentially sending ~50% of the dropped coil into the output and raising the remaining coil's output by that amount. In essence, your tapped tone is like a 6.7K pickup.

3K3 on your 7K Thornbucker neck pickup is a touch less than 50%. Call it 5K1+.

A cool way to test this is with a 5-10KL pot to ground. Dial in the exact resistance, measure and swap with a fixed resistor of choice.

 

[JasonE]

"Let's talk resistors!"

No.

Resistance is futile. You will be assimilated.

As long as it is 7 of 9 assimilating me, I am in.

 

[gush]

You can estimate the output of this type of split using a voltage divider calculator: https://ohmslawcalculator.com/voltage-divider-calculator

The Thornbucker + bridge pickup has an average DC resistance of ~9K ohms. Call the split coil a 4K5 resistor (R1). If you have a 4K7 to ground when tapped (R2), you are essentially sending ~50% of the dropped coil into the output and raising the remaining coil's output by that amount. In essence, your tapped tone is like a 6.7K pickup.

3K3 on your 7K Thornbucker neck pickup is a touch less than 50%. Call it 5K1+.

A cool way to test this is with a 5-10KL pot to ground. Dial in the exact resistance, measure and swap with a fixed resistor of choice.

Geee.......forgive me for suggesting this but it would be cool to leave a pot on the guitar so that value could be adjusted.

 

[ViperDoc]

Geee.......forgive me for suggesting this but it would be cool to leave a pot on the guitar so that value could be adjusted.

No forgiveness needed. That would be cool. I find once I like a certain value, I don't change it. But if you want to test drive a range, you just have to fit the pot into the cavity without the pot legs breaking or grounding out on something. Maybe you could fit it on a small piece of tag board and configure an access hole in the control cavity cover. Having done this sort in the past, I find it's usually more hassle than its worth. But it's easy in testing to keep the cover off and attach the pot with a wire and test to your heart's content. Then throw in a 1/4W MF of the set value and you're done.