Can active bass pickups be used passive ? The reason I ask is I have an old Heartfield pickup I'd like to use in a bass I'm building but the Heartfield DR basses were active .
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pickup ?
- Thread starter redboy1975
- Start date
Well, not exactly no. No if it is a truly active pickup.
Active now means different things in different basses. Active pickups, like EMG actives, have three leads - signal, ground and battery +. Other basses use passive pickups into an onboard preamp, and have two leads, signal and ground. Those pickups, like the EMG HZ, can be used with or without a preamp, and have been wired both ways by those manufacturers that use them as OEM. Unfortunately, the basses using the preamp are called active basses by some, causing confusion.
To further add to the confusion, some passive pickups have a separate shield lead in addition to the signal and ground leads, which one may be red and can be confused for the battery lead on an active pickup. If this is the case, then using an ohmmeter on the leads will help determine which it is. If passive, you should get a reading on two of the leads that is similar to other pickups of the same type. If it is active, you will not get a reading, or may read something in the millions of ohms.
Please post pix of the pickup so we can try to determine which it is.
So line6man is correct if it is a truly active pickup, but he did not ask enough questions to fully explore the issue.
Hey thanks for the input . The more I researched the more confusing it became . The bass they came out of had a preamp . I'll see about some pics later on , I can't do much from work . Thanks a bunch
Do you have an ohmmeter? If memory serves from all those years ago, since you have a preamp, the pickups themselves may be passive and similar to J-bass pickups - @ 7 kohms or so. If they are, you can use them passively with a conventional volume & tone circuit.
Most pickups are actually not active. It's the preamps in the controls that "activate" them. As mentioned before, EMGs are one of the few kinds that actually are active pickups.
In the case of your Heartfield pickups, I found this in an internet search "the basses electronics were active. The pickups were low Z output and hum cancelling. These basses were made at the Fender Japan facility." The low z mention makes me believe that these pickups will NOT work in your passive application.
In the case of your Heartfield pickups, I found this in an internet search "the basses electronics were active. The pickups were low Z output and hum cancelling. These basses were made at the Fender Japan facility." The low z mention makes me believe that these pickups will NOT work in your passive application.
What wires are on the pickup? If only 2, it's passive. If 3, you'll need an ohmmeter to check the values. If it is over 5+ ohms across any 2 leads, it is passive. Active will read very low, usually unsteady reading.
'Lo Z' usually means it is active, because it has an internal preamp/buffer that lowers the output impedance, and that'll require a battery for power and most likely 3 leads: +, -, and shield.
All active pickups I've come across need battery power to get decent signal from, but they can be used with/ without a separate preamp.
'Lo Z' usually means it is active, because it has an internal preamp/buffer that lowers the output impedance, and that'll require a battery for power and most likely 3 leads: +, -, and shield.
All active pickups I've come across need battery power to get decent signal from, but they can be used with/ without a separate preamp.
Then you have not ever actually used real active pickups, like EMG's. They will not work without the battery, because they have the preamp chip built into the body of the pickup.
A low impedance passive pickup, like on a Jack Cassady bass, will have the low reading, but it will be stable. If there is any instability, that may point to a pickup coil or winding issue.
"All active pickups I've come across need battery power..."
... they just don't need an add'l preamp.
EMG's, Ibanex ADX series, LO-Z, and Mighty-Mites are like this, and the meter doesn't want to give a quick, solid reading- usually slowly falls to lower value.
(maybe I need a better meter, tho).
"'Lo Z' usually means it is active, because it has an internal preamp/buffer..."
... they just don't need an add'l preamp.
EMG's, Ibanex ADX series, LO-Z, and Mighty-Mites are like this, and the meter doesn't want to give a quick, solid reading- usually slowly falls to lower value.
(maybe I need a better meter, tho).
"'Lo Z' usually means it is active, because it has an internal preamp/buffer..."
Firstly, 5 Ohms would be a direct short.
Active pickups should not have a low DC resistance. EMGs in particular do not have low impedance windings, but it does not make any difference how a coil is wound. Attempts to measure DCR will provide a reading of the components of the buffer that comes after the coil, not the coil itself.
Well, I've seen pickups read as low as 5.7/ 5.8k (passive) and worked fine- Not shorted, and wanted to keep the readings all within range, not 'near' the limit. Keep it in context.
As far as readings on active pickups, there were None stated, high or low. Just noted that a reading will not be like reading Ohms on a passive pickup.
YMMV...
You're correct- missed the 'k' in the original post, and it sure is all-important: makes the diff.
Meant to type '5k+', and didn't catch it in the quick proof-read.
Long days will do it, missed the 'k' in post 11 as well, hope it was 'understood', tho.
BTW- I like the attn to detail, and it does prevent misunderstandings, thanks.
suffix, tho?
Meant to type '5k+', and didn't catch it in the quick proof-read.
Long days will do it, missed the 'k' in post 11 as well, hope it was 'understood', tho.
BTW- I like the attn to detail, and it does prevent misunderstandings, thanks.
suffix, tho?
