Another pot value question

[mntngrown]

I think DavidRavenMoon gave me the partial answer in the other thread, but I was hoping for more knowledge. I installed active (SD AJB-5's), which came with 100k pots, but just used the existing, (EMG setup), 25k and 50k pots, since I have a 4 control setup. I also wanted to hear the new pups before deciding to swap anything else. They fixed my issue so I'll keep them in.
What change would I notice if I put in 100k pots that came with the pup's? Does a higher value pot just affect volume at a given setting or is it more complex than that? Sorry Newbie here.

[luknfur]

Don't know what David told you but he knows the tech side of stuff and that's probably about as good as you're going to get.

I know the trial and error side not the tech side but I know enough to know you're dealing with active pups and appropriate resistance so proper function of them. If the manufacturer recommends 100K pots and you have them put them in - they know they're stuff and if you want them to function as desinged you'll comply. You're talking 4's times the resistance of a 25k and that's a chunk proportionally.

I can also tell you there's no substitute for experience - only your ears can tell you what the difference is going to be. My guess is you will definitely hear a difference. Let us know if you don't.

[mntngrown]

What confuses me is why a passive P/U uses 250-500k and actives use 25-100k. What David told the guy in the thread I mentioned was that he could use any value from 25-250k for his active EMG's. He preferred 100k for EMG which normally ships 25k, so I guess it's a personal preference thing. I'll probably try the 100's some time soon but my controls are V/V/B/T, 4 knobs and SD only sent me 3 pots, so I will get a 4th I guess. The other concern I have is that the onboard circuit boards "CTS" might be better matched to the existing low value pots. I guess I should see if there is an "electronics for dummies" book available.

[Le Basseur]

Hey,
It's me who asked a few days ago about the EMG's pots' values (and got the answers from DavidRavenMoon,for that matter).
It looks that a volume pot's value w./ active PU is rather a tolerant issue (it might be 25k as well as 100k...as well as 250 or 500k?!),though I think that a low-impedance device like an active PU asks for a low-value pot for a reason (the same issue as with Ernie Ball volume pedals:for active basses,25k version,but for passive 250k/500k).
The low-value LINEAR pots in an active preamp config is another thing,these pots being a part of a given filtering stage (correction).
..or am I wrong?
Regards,

[luknfur]

I haven't messed with actives using various pot values cause I rarely use active pups. I have tried a 25K pot on a passive pup and it was useless, choked the output down to nothing. The difference between a 250K and 500K pot with passive pups is minimal and to me not worth messing with for the most part. Seems like the noticeable break is around 100K - but how many 150 and 200k pots have you seen around.

I don't get hung up on the tech side cause I don't make this stuff I just use it which is as simple as driving a car as oppposed to creating one. The why to me is irrelevant because it's just speculation anyway and we all hear something different. Only 1 in 10,000 people can accurately identify a given pitch and most probably not only aren't musicians but aren't even aware of the gift. Most people can't hear the lower frequencies of the human range. Ad infinitum.

I could install the various pots in an active setup and know in not much more time than it takes to post this - and you can too. I can tell you I've done everything wrong imaginable more than once in wiring up a bass and I've never damaged anything in the process so there's nothing to lose.

To me if you're going to make the stuff, knowing the why's matters, otherwise pretty pointless when you can easily do it and know and trash the speculation which is all it is till you do it anyway. In as much, the people who do make this stuff designed it and tested it and if they recommend a given pot value it flows that it's the most optimal performance wise for the application. The probability of improving on that is a long shot - unless you know as much or more than they do. And even if you did there's been an engineering student on TB that couldn't even wire a P bass to get it to work - but he could explain all the related theory.

None of which is to say not to ask why or not to experiment. Just go ahead and do it and some why's will express themselves in the process, some won't. Regardless, then you'll know the results - and isn't that what you really want to know anyway. If you want to ponder the why's google "firebottle."

[mntngrown]

Thanks for your time. I'll let you know if I notice a difference.

[knuckle_head]

In general terms the lower the resistance of a pot the darker its inherent tone. Hence the want for 250K pots on Fender single coils and 500K on humbuckers.

How dark dark is is waaayyy subjective.