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Author Topic: BKP Pots - 550K vs Push/Pull  (Read 3037 times)

MerlinTKD

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BKP Pots - 550K vs Push/Pull
« on: June 02, 2013, 08:05:05 PM »
So in the course of upgrading my guitar, I'm now looking at maybe switching out pots. Problem is, The guitar's already wired with Push-Pulls (these, IIRC). Also, last time it was rewired, my tech put in a really nice cap - I don't recall what, exactly, but I remember it made a huge difference.

Now, honestly, I don't really use the coil-split; with PK's in a basswood guitar, the split sounds thin and plinky. The PK's are almost single-coily as they are, so it seems sonically redundant. On the other hand, getting enough brightness is not a problem I have with this setup, so the increased top end of the 550's concerns me.

So, which should I go for? With what I've got, will the CTS Push/Pull's be any better? Should I just ditch the P/P altogether and go for the BKP 550's? Or should I just leave it all the hell alone?  :lol:
LTD M-207: Painkiller bridge, Painkiller neck

BigB

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Re: BKP Pots - 550K vs Push/Pull
« Reply #1 on: June 02, 2013, 09:04:34 PM »
If you already have decent quality pots and cap and are happy with the tone and the pots action and feel, why change anything ?
Have: Crawlers, BGF 50/52s, Mules, ABomb, RiffRaff
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MerlinTKD

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Re: BKP Pots - 550K vs Push/Pull
« Reply #2 on: June 02, 2013, 09:09:51 PM »
Well, mainly because I got those pots without knowing their quality. I mean, I got them from AllParts, I know they're decent, but the LFR and stock pickups I had on this guitar were decent, but the OFR and BKP's are WAAAYYYY better! :lol:

On the other hand, the difference between them and the BKP/CTS pots may be negligible. That's what I'm trying to find out. :)
LTD M-207: Painkiller bridge, Painkiller neck

BigB

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Re: BKP Pots - 550K vs Push/Pull
« Reply #3 on: June 03, 2013, 08:04:31 PM »
Well, mainly because I got those pots without knowing their quality. I mean, I got them from AllParts, I know they're decent, but the LFR and stock pickups I had on this guitar were decent, but the OFR and BKP's are WAAAYYYY better! :lol:

On the other hand, the difference between them and the BKP/CTS pots may be negligible. That's what I'm trying to find out. :)

wrt/ tone, they'd have to quite bad (or broken) to make an audible difference for a same effective value.

For two given audio taper pots with the same nominal values, differences will be effective value (+/- 10% tolerance is the standard, so most 500K pot will in fact be somewhere between 450 and 550K - more often less than 500K from experience), taper (could be anything from 45/65 to 30/70, there's no norm here, "audio taper" only means they are not 50/50), and how "stiff" (or not) they feel. Taper and feel are a very personnal taste (quite a few guitar players prefer linear taper for the volume pot FWIW). Effective value do impact tone (the higher the value the brightest the tone), and can be an effective "micro-optimization", as far as I'm concerned I usually use the higher values for the neck and the lowest ones for the bridge so I get a clearer neck and a warmer bridge. On a bright LP with vintage (brighter) pups you may even want to use 300K pots for the bridge as a builtin low-pass filter.

Also and for the record, BKP 550K CTS reportedly have a kind of steep taper - lot of attenuation from 10 to 9 - which you may or not like depending on how you use your volume pots.
Have: Crawlers, BGF 50/52s, Mules, ABomb, RiffRaff
Had : Slowhands (n&m), Trilogy (b)

MerlinTKD

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Re: BKP Pots - 550K vs Push/Pull
« Reply #4 on: June 03, 2013, 11:33:58 PM »
Wow, great info, thanks! Lots of stuff I didn't know there. :)

So I'm thinking pots are not a priority change for me then... I actually wouldn't mind a stiffer feel, but it's not imperative. I do have one question, for clarification: when you mention taper, you're describing percentages, I'm guessing? But percentages of what, please?
LTD M-207: Painkiller bridge, Painkiller neck

BigB

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Re: BKP Pots - 550K vs Push/Pull
« Reply #5 on: June 04, 2013, 11:29:52 AM »
I do have one question, for clarification: when you mention taper, you're describing percentages, I'm guessing? But percentages of what, please?

"Normal" pots are linear, which means that at the middle point of the pot's course you should be at 50% of the pot's value ie given a 500K pot set at mid-point, you should have (roughly) 250K between left lug and center lug and 250K between right lug and center lug.

Now the human ear's response curve wrt/ volume is not linear but logaritmic, so when you use a linear pot for audio volume, you end up with almost of the volume increase in the first half of the pot's course (going from fully closed to fully opened) and almost nothing in the second half, so we have "audio taper" pots which are supposed to more or less correct this by having an uneven taper, ie when the (500K) pot is set at mid-point you have something like 350K from  first lug to center lug and 150K from second lug to center lug, which would in this case make for a 70:30 taper.

Note that while linear pots are a major PITA as amp's volume or gain pot - where you usually want to have a fine control on the lower half of the course (Fender Hotrod Deluxe users should know what I mean :mrgreen:) -, they can be fine on a guitar where you usually go from fully opened to less opened, so having a finer control on the upper half of the course _might_ be what you want, depending on how much gain you use and what effect on your tone you expect from rolling down you guitar's volume.  That's something you have to try out by yourself to find out wether you like it or not.
Have: Crawlers, BGF 50/52s, Mules, ABomb, RiffRaff
Had : Slowhands (n&m), Trilogy (b)

MerlinTKD

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Re: BKP Pots - 550K vs Push/Pull
« Reply #6 on: June 05, 2013, 04:57:10 PM »
Awesome info (again)! Thanks!
LTD M-207: Painkiller bridge, Painkiller neck

Dave Sloven

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Re: BKP Pots - 550K vs Push/Pull
« Reply #7 on: June 11, 2013, 01:19:12 PM »
Just to add another variable, I'm wondering if anyone has used these Mojotone push-push (not push-pull) pots and if they fit in the body cavity of a Gibson SG.  I'm guessing they might because the depth is the same as the push-pull version. Cavity depth needed to accommodate switch and pot on either is the same, i.e., 1 5/64" or 1.108"

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I contacted an ebay seller of these here in Australia and he recommended the push-push as easier to use (the price difference is $2 more each).  I have seen some different opinions.  Some say that they are faster and there is not the problem of pulling the knob off when trying to pull it up; others say that they aren't as durable but this may be due to people pulling on them when they are in the 'down' position, which is apparently a no-no.

I'm assuming that they sit up in one setting and down lower in the other (just like a push-pull), just that the action is different.  The action sounds similar to the switch on an effects pedal.
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