Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

[Jack_TriPpEr]

The following link to a forum post covers the issues that occur when converting a 500K pot to a 250K pot in context of using that pot as a volume pot or tone pot. https://forum.seymourduncan.com/showthread.php?167485-Remind-me-again-how-do-I-turn-a-500K-pot-into-250K-with-resistors

So, do any of those issues exist when using the converted pot as a Spin-A-Split, in this case converting the 500k pot to 100K? And, are there any additional issues that arise that are not covered in the linked thread?

 

[Jack_TriPpEr]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

Minor typo earlier: this would be converting a 250K pot (not 500K pot) to 100K... for use as a Spin-A-Split

The following link to a forum post covers the issues that occur when converting a 500K pot to a 250K pot in context of using that pot as a volume pot or tone pot. https://forum.seymourduncan.com/showthread.php?167485-Remind-me-again-how-do-I-turn-a-500K-pot-into-250K-with-resistors

So, do any of those issues exist when using the converted pot as a Spin-A-Split, in this case converting the 500k pot to 100K? And, are there any additional issues that arise that are not covered in the linked thread?

 

[Artie]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

Just curious, but why do you want 100k? I'm looking at the spin-a-split mod article now, and they actually show using 500k.

 

[beaubrummels]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

I’ve seen this idea talked about, and it sounds like some guys successfully did it, but when I put a parallel resistor across the outside lugs, basically I then had a 1k pot that was always turned halfway down; because the 500k that was on the lugs was always sending half the signal to ground around the center output lug. I immediately dismissed the idea, because really you need the variable wiper to sweep both resistances uniformly to behave like a normal pot. At least that was my takeaway. If someone can enlighten me how they got it to actually work, making a particular value pot behave like a different value pot, I’m open to trying it again. Maybe I didn’t do it right.

 

[Jack_TriPpEr]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

Just curious, but why do you want 100k? I'm looking at the spin-a-split mod article now, and they actually show using 500k.

In the forum search results about Spin-A-Split, it keeps mentioning some guy named ArtieToo recommending 100K pots. :9:

 

[Jack_TriPpEr]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

Just curious, but why do you want 100k? I'm looking at the spin-a-split mod article now, and they actually show using 500k.

Also, could you post a copy of that spec? I just browsed through the SD wiring diagrams webpage, didn't see it covered there.. and Richard Irons blog about the spin-a-split happens to mentions 500K pots but not in a way that implies he is recommending them.

https://www.seymourduncan.com/blog/the-tone-garage/guitar-wiring-explored-the-spin-a-split-mod

 

[Clint 55]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

500k and 250k plain old don't work. It compresses the useful portion of the split between 1 and 2 lol. Even 100k is unnecessary. 25k or 50k work the best. You also have to convert them to no load pots so 10 is full series.

 

[Jack_TriPpEr]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

500k and 250k plain old don't work. It compresses the useful portion of the split between 1 and 2 lol. Even 100k is unnecessary. 25k or 50k work the best. You also have to convert them to no load pots so 10 is full series.

Linear or audio taper?

 

[Clint 55]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

Linear

 

[ItsaBass]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

As recently discussed in a spin-a-split related thread, pot value does not have the same effect on e.q. that it does when used as a regular volume control. That is, a higher value pot does not equal more treble, and vice versa.

A regular volume control works by acting as a controlled leak to ground. The higher the max resistance value, the less treble leaks around the pot to ground, even when it is set to max resistance.

A spin-a-split pot works as a shunt. That is, it doesn't work by controlling a leak to ground; it works by controlling a leak around one coil.

When the pot is set to maximum resistance, it provides a difficult path for the current from the first coil, so that current passes through the easier path: the second coil. The result is that you get a humbucker.

When it is set to minimum resistance, it provides an easy path for the current from the first coil, so that current bypasses the second coil. The result is that you get a single coil.

Following that understanding, you can see that if the spin-a-split pot value is lower, it is more likely to allow some current leakage through the pot, even when you have it set to max resistance (i.e. set to "full humbucker"). And when the spin-a-split resistance value is higher, it will allow less leakage. This means that a lower value pot gives you less of the full contribution of both coils than does the higher value. In other words, with a lower value, you can never get the true "full humbucker."

Now, this is not necessarily a bad thing. In fact, you can use it to your advantage, if you actually NEVER want the full humbucker. Say you never want to be able to get the full output of the humbucker, but only want about 3/4 of it at max, with the ability to dial it down to 1/2 the humbucker with the spin-a-split. Well, then you just use a relatively low-value pot, e.g. your 100K or a 50K.

It's also worth mentioning that, of course, the higher the output of the pickup, the greater its ability to leak through the pot. So you need to shift your values upward when the pickup in question is high output.

 

[Artie]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

Wow! That was a long time ago. I don't even remember it. But 100k, or even 50k pots, are easy to find at places like Mouser or Digi-Key. I'd need to actually play with one again to remind myself what works best.

 

[Jack_TriPpEr]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

As recently discussed in a spin-a-split related thread, pot value does not have the same effect on e.q. that it does when used as a regular volume control. That is, a higher value pot does not equal more treble, and vice versa.

A regular volume control works by acting as a controlled leak to ground. The higher the max resistance value, the less treble leaks around the pot to ground, even when it is set to max resistance.

A spin-a-split pot works as a shunt. That is, it doesn't work by controlling a leak to ground; it works by controlling a leak around one coil.

When the pot is set to maximum resistance, it provides a difficult path for the current from the first coil, so that current passes through the easier path: the second coil. The result is that you get a humbucker.

When it is set to minimum resistance, it provides an easy path for the current from the first coil, so that current bypasses the second coil. The result is that you get a single coil.

Following that understanding, you can see that if the spin-a-split pot value is lower, it is more likely to allow some current leakage through the pot, even when you have it set to max resistance (i.e. set to "full humbucker"). And when the spin-a-split resistance value is higher, it will allow less leakage. This means that a lower value pot gives you less of the full contribution of both coils than does the higher value. In other words, with a lower value, you can never get the true "full humbucker."

Now, this is not necessarily a bad thing. In fact, you can use it to your advantage, if you actually NEVER want the full humbucker. Say you never want to be able to get the full output of the humbucker, but only want about 3/4 of it at max, with the ability to dial it down to 1/2 the humbucker with the spin-a-split. Well, then you just use a relatively low-value pot, e.g. your 100K or a 50K.

It's also worth mentioning that, of course, the higher the output of the pickup, the greater its ability to leak through the pot. So you need to shift your values upward when the pickup in question is high output.

Great info, very clear description - thank you for taking the time to detail all this.

BTW, i did a search and found the recent thread you mentioned. Linking it here:
https://forum.seymourduncan.com/showthread.php?335756-Spin-A-Split-Using-2-separate-SC-s-Pot-Value-Question&p=4337105&highlight=Spin-a-split+50k#post4337105

 

[Jack_TriPpEr]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

500k and 250k plain old don't work. It compresses the useful portion of the split between 1 and 2 lol. Even 100k is unnecessary. 25k or 50k work the best. You also have to convert them to no load pots so 10 is full series.

As recently discussed in a spin-a-split related thread, pot value does not have the same effect on e.q. that it does when used as a regular volume control. That is, a higher value pot does not equal more treble, and vice versa.

A regular volume control works by acting as a controlled leak to ground. The higher the max resistance value, the less treble leaks around the pot to ground, even when it is set to max resistance.

A spin-a-split pot works as a shunt. That is, it doesn't work by controlling a leak to ground; it works by controlling a leak around one coil.

When the pot is set to maximum resistance, it provides a difficult path for the current from the first coil, so that current passes through the easier path: the second coil. The result is that you get a humbucker.

When it is set to minimum resistance, it provides an easy path for the current from the first coil, so that current bypasses the second coil. The result is that you get a single coil.

Following that understanding, you can see that if the spin-a-split pot value is lower, it is more likely to allow some current leakage through the pot, even when you have it set to max resistance (i.e. set to "full humbucker"). And when the spin-a-split resistance value is higher, it will allow less leakage. This means that a lower value pot gives you less of the full contribution of both coils than does the higher value. In other words, with a lower value, you can never get the true "full humbucker."

Now, this is not necessarily a bad thing. In fact, you can use it to your advantage, if you actually NEVER want the full humbucker. Say you never want to be able to get the full output of the humbucker, but only want about 3/4 of it at max, with the ability to dial it down to 1/2 the humbucker with the spin-a-split. Well, then you just use a relatively low-value pot, e.g. your 100K or a 50K.

It's also worth mentioning that, of course, the higher the output of the pickup, the greater its ability to leak through the pot. So you need to shift your values upward when the pickup in question is high output.

Would a pot value of 1 Meg be high enough to negate the need for a No Load pot feature? I am imagining with 1 meg resistance, the amount that the two coils are not in full humbucking mode would be negligible (?)

 

[ItsaBass]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

Would a pot value of 1 Meg be high enough to negate the need for a No Load pot feature? I am imagining with 1 meg resistance, the amount that the two coils are not in full humbucking mode would be negligible (?)

I think even 500K would be enough. Unless perhaps it's a very hot pickup.

 

[Clint 55]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

Ya but then there's no purpose of using a dial. It goes from split at zero to partial at 1 to mostly full at 2. Just use a 50k linear no load.

 

[blueman335]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

Did you say bridge or neck HB? I'd never use a 250K on a neck HB. It's a warm slot with a lot of string energy, and they need bright pots to keep high end & clarity (which prevents muddy tones).

As soon as you dial down the 2nd coil on a spin-a-split, treble is increased, and mids and volume are reduced. That's the beauty of it, which is why that mod is so effective in the neck slot.

I like warm, full-sounding bridge PU's (which has been the subject of spirited discussions here over the years) and 250K is as warm as I'd ever go for that location. Wouldn't consider 100K, nor a 1 meg.

 

[ItsaBass]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

That's what taper selection is for. You have audio, reverse audio, and linear tapers to choose from. One of them will give some semblance of a suitable taper. If I had that problem, I'd go with an audio taper pot instead.

FWIW, I use 500K linear pots for my series Jazz Bass, which is the same concept as spin-a-split, and not necessarily weak pickups (A5, approx. 9K each).

 

[ItsaBass]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

Did you say bridge or neck HB? I'd never use a 250K on a neck HB. It's a warm slot with a lot of string energy, and they need bright pots to keep high end & clarity (which prevents muddy tones).

As soon as you dial down the 2nd coil on a spin-a-split, treble is increased, and mids and volume are reduced. That's the beauty of it, which is why that mod is so effective in the neck slot.

I like warm, full-sounding bridge PU's (which has been the subject of spirited discussions here over the years) and 250K is as warm as I'd ever go for that location. Wouldn't consider 100K, nor a 1 meg.

As explained above, and in the last spin-a-split thread in which you said the same thing, the typical guitar pot approach does not apply here. Higher value pots are not "brighter" in this case. They just provide a slightly more "complete" humbucker.

 

[Jack_TriPpEr]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

I think even 500K would be enough. Unless perhaps it's a very hot pickup.

Ya but then there's no purpose of using a dial. It goes from split at zero to partial at 1 to mostly full at 2. Just use a 50k linear no load.

Summarizing -tell me if i am misconstruing here:
Clint and ItsaBass seem to confirm that 500K resistance is enough to allow both coils to be fully engaged in series mode - and hence no need for a No Load feature, but Clint says 500K is not enough resistance to have a normal taper. Clint says a higher pot value - like 50K - fixes the taper.

If i construed that correctly, then 1 Meg pot - without a No Load feature - seems to handle all concerns (?)

 

[Clint 55]

Re: Any issues w converting a 500K pot into a 100K pot for use as a Spin-a-Split

No, the usual values of 250k, 500k, and 1 meg don't taper. You have to use smaller. 50k works the best. Then you have to no load it.