Pot k values for the active J pups in my Millennium Plus J/J?

fourstringbliss · #1 03-12-2013, 12:27 PM

I'm removing the Millennium preamp from my Millennium Plus J/J and I'm going to be installing an Audere instead. I won't be able to buy the Audere until next month, so I want to wire it up using regular pots. What k value should I use so I can wire it up in a v/v/t/t setup?

Thanks!

line6man · #2 03-12-2013, 12:52 PM

Pots are valued in Ohms, not "k." "k" means 1*10³.

The usual value for low impedance pickups is 25k, 50k or 100k, depending on personal preference.

Lo-E · #3 03-12-2013, 12:59 PM

Just be sure that the pickups themselves are, in fact, active. If they are, they'll have an extra wire to connect to the 9V power supply (the battery).

If they have that extra wire, they're active and the above values will work great.

Often, basses will have a preamp paired with passive pickups and still be called active basses. In these cases, you will not have that extra 9V wire on the pickups and to wire them in a passive circuit you would want to use pots valued 250K or 500K.

fourstringbliss · #4 03-12-2013, 01:06 PM

Quote:

Originally Posted by line6man

Pots are valued in Ohms, not "k." "k" means 1*10³.

The usual value for low impedance pickups is 25k, 50k or 100k, depending on personal preference.

I just meant 25k, 50k, 100k, etc.

Thanks for the info, though!

fourstringbliss · #5 03-12-2013, 01:17 PM

Quote:

Originally Posted by Lo-E

Just be sure that the pickups themselves are, in fact, active. If they are, they'll have an extra wire to connect to the 9V power supply (the battery).

If they have that extra wire, they're active and the above values will work great.

Often, basses will have a preamp paired with passive pickups and still be called active basses. In these cases, you will not have that extra 9V wire on the pickups and to wire them in a passive circuit you would want to use pots valued 250K or 500K.

These pickups each have a white, black, and red wire, so they are active.

fourstringbliss · #6 03-12-2013, 01:22 PM

Quote:

Originally Posted by line6man

Pots are valued in Ohms, not "k." "k" means 1*10³.

The usual value for low impedance pickups is 25k, 50k or 100k, depending on personal preference.

What would be the tonal difference between 25k, 50k, and 100k with these pickups?

mmbongo · #7 03-12-2013, 01:22 PM

I'd replace the pickups as well. Those pickups always sounded muffled and dark to me...no real snap to them. I ended up selling mine rather than go through all that though, but now I think it would have been worth it to replace the preamp and put some DiMarzio Area J's or SGD Neo's in it. Those basses are superbly built. Never liked the electronics, though.

fourstringbliss · #8 03-12-2013, 01:31 PM

Quote:

Originally Posted by mmbongo

I'd replace the pickups as well. Those pickups always sounded muffled and dark to me...no real snap to them. I ended up selling mine rather than go through all that though, but now I think it would have been worth it to replace the preamp and put some DiMarzio Area J's or SGD Neo's in it. Those basses are superbly built. Never liked the electronics, though.

I'm with you. I think I'm going to replace them with a set of SGD Neo's. Everything else about the bass is suberb but the electronics. Years ago I would have sold the whole thing but now I want to improve the weak parts. I though about using Dimarzio Ultra J's but both pickups are the same width and I'm concerned about the idea of using two bridge pups and the strings lining up with the pole pieces. I'll just go with a pup that uses bar magnets.

Cadfael · #9 03-12-2013, 01:45 PM

The number of wires or their colour says nothing about the PUs (if they are high or low impedance).

If they are high impedance (between 6-15k) you should use 250k or 500k pots. If they are low impedance (about 2k) you should use 25-50k.

For a VT/VT wiring (one volume/tone pot per PU), the passive controls should be between the PU and the preamp. The value of the pots depends on the impedance of the PUs (high/low) and not on the preamp (active/passive). Behind/within the preamp, mostly the pots should be 25k or 50k.

A passive wiring for temporary use only makes sense if the PUs are high impedance PUs. So, the pots should have 250k or 500k. With 4 pots I would first try 500k pots. If the sound is too harsh, change the volume pots to 250k ...

fourstringbliss · #10 03-12-2013, 02:20 PM

Quote:

Originally Posted by Cadfael

The number of wires or their colour says nothing about the PUs (if they are high or low impedance).

If they are high impedance (between 6-15k) you should use 250k or 500k pots. If they are low impedance (about 2k) you should use 25-50k.

For a VT/VT wiring (one volume/tone pot per PU), the passive controls should be between the PU and the preamp. The value of the pots depends on the impedance of the PUs (high/low) and not on the preamp (active/passive). Behind/within the preamp, mostly the pots should be 25k or 50k.

A passive wiring for temporary use only makes sense if the PUs are high impedance PUs. So, the pots should have 250k or 500k. With 4 pots I would first try 500k pots. If the sound is too harsh, change the volume pots to 250k ...

So, you're saying that if I'm not making the bass, mid, and treble of an active pickup system then I should use regular guitar pots. 25k pots are good for active system tone controls, but you're saying that in a v/v/t/t setup I should use either 250k or 500k pots.

These are stacked J-pups so I'm thinking I should use 500k pots.

Cadfael · #11 03-12-2013, 02:27 PM

It depends on WHERE the pots are in your system and WHICH PUs you have.

You have to check with a multimeter if they are high or low impedance PUs. This has primarily nothing to do with active / passive.

Pots between "normal" high impedance PUs (90% of all PUs?) and an active preamp (with or without integratend EQ) have to (should) have between 250k and 500k.

The value of the pots inbetween the preamp (EQ etc.) depends on the manufacturer of the preamp.

Between preamp and jack, normally low impedance pots (25k-50k) are used.

For stacked high impedance Js (humbuckers) you normally use 500k pots ...

fourstringbliss · #12 03-12-2013, 02:29 PM

Quote:

Originally Posted by Cadfael

It depends on WHERE the pots are in your system and WHICH PUs you have.

You have to check with a multimeter if they are high or low impedance PUs. This has primarily nothing to do with active / passive.

Pots between "normal" high impedance PUs (90% of all PUs?) and an active preamp (with or without integratend EQ) have to (should) have between 250k and 500k.

The value of the pots inbetween the preamp (EQ etc.) depends on the manufacturer of the preamp.

Between preamp and jack, normally low impedance pots (25k-50k) are used.

For stacked high impedance Js (humbuckers) you normally use 500k pots ...

Gotcha. I'm looking to wire these into a v/v/t/t setup with no preamp (other than the preamp in each pickup, since they're active). I should use 500k pots and wire them similar to a Les Paul, right?

Cadfael · #13 03-12-2013, 03:10 PM

Right ...

Wrong ...
There are two different LP wirings!!!

As you will have no toggle switch, HOT from the jack (or tone pot) has to go to the "left" lug. The right lug has to be soldered to the housing (as usual).
HOT from the PU has to go to the middle lug.

So, the volumes have to be soldered similar to a Jazz Bass.
The rest is like a normal LP wiring.

Or to make it short: Liker an LP bass wiring without toggle switch ...

fourstringbliss · #14 03-12-2013, 03:33 PM

Quote:

Originally Posted by Cadfael

Right ...

Wrong ...
There are two different LP wirings!!!

As you will have no toggle switch, HOT from the jack (or tone pot) has to go to the "left" lug. The right lug has to be soldered to the housing (as usual).
HOT from the PU has to go to the middle lug.

So, the volumes have to be soldered similar to a Jazz Bass.
The rest is like a normal LP wiring.

Or to make it short: Liker an LP bass wiring without toggle switch ...

Excellent! Thanks!

fourstringbliss · #15 03-12-2013, 03:50 PM

So, I'm wiring the volumes like this:

where the hot from each pickup goes to the middle volume pot lug. The right volume pot lug is soldered to the back of the pot. The left volume pot lug is then wired to the middle lug of its respective tone pot and then from that middle lug to the output jack, right?

Steve Dallman · #16 03-12-2013, 05:39 PM

I have a Peavey Accellerator 5 string I bought in 1996. I have found the pickups to be excellent. The pickups are active and if wiring for VVTT should use 1/10th the value of pot you would use in a passive pickup bass, and the tone caps should be 10X the value you'd use in a passive pickup bass. I'd use 50k audio taper pots, and .47uF caps. (25kA would be fine, and .22uF would be good as well. If hard to source, 100kA would work fine.

My VFL pickups are anything but dark.

line6man · #17 03-12-2013, 06:10 PM

Quote:

Originally Posted by Steve Dallman

I have a Peavey Accellerator 5 string I bought in 1996. I have found the pickups to be excellent. The pickups are active and if wiring for VVTT should use 1/10th the value of pot you would use in a passive pickup bass, and the tone caps should be 10X the value you'd use in a passive pickup bass. I'd use 50k audio taper pots, and .47uF caps. (25kA would be fine, and .22uF would be good as well. If hard to source, 100kA would work fine.

My VFL pickups are anything but dark.

I've never heard of anyone using capacitance that high for a tone control, even at a low impedance. While it is true that the frequency cutoff shifts with impedance, that sounds rather extreme.

FWIW, EMG usually specifies 0.1uF for their active pickups.