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Switching off Active Electronics

stevensivak

stevensivak

Supporting Member
Dec 24, 2014
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Ann Arbor, MI
#1
So....

This question concerns all active basses, but in particular a G&L MJ-4...

So the question is can active electronics be shut off and revert to
a passive bass? Some basses seem to have this function (Sadowsky?)
but if they don't have it, can a micros switch be added?

No unplugging would be necessary and ......
 
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#4
stevensivak said:
hmmmm..... all active basses have preamps so not sure if your comment would apply to
ALL or my passive system....
Click to expand...

most active basses have passive pickups with a seperate preamp, emg's active pickups are different they've got an internal preamp inside the pickup plus the normal preamp/eq, you can't bypass the internal preamp, so they cant be used without a battery.
 
#11
I think the answer to your questions are probably "yes" and "maybe, but..". The only experience I have with active basses is my Alembic Epic; and it's either active or nothing at all. It's my impression that yes, most active basses can be both, and that most of them have a switch so you can choose what you want. Don't know for sure, but I would imagine that switching to passive mode would accomplish what you're looking for, anyway. But you'd have to look at the wiring diagram to be sure.:)
 
#12
If the pickups are passive you can wire it so that the preamp is bypassed with a switch. But, in most cases you will lose the tone controls. And if the pickups were designed specifically for the onboard preamp they may be low impedance pickups, which won't sound very good without the preamp. So the answer is a definite maybe.
 
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#13
GIBrat51 said:
I think the answer to your questions are probably "yes" and "maybe, but..". The only experience I have with active basses is my Alembic Epic; and it's either active or nothing at all. It's my impression that yes, most active basses can be both, and that most of them have a switch so you can choose what you want. Don't know for sure, but I would imagine that switching to passive mode would accomplish what you're looking for, anyway. But you'd have to look at the wiring diagram to be sure.:)
Click to expand...
Turnaround said:
If the pickups are passive you can wire it so that the preamp is bypassed with a switch. But, in most cases you will lose the tone controls. And if the pickups were designed specifically for the onboard preamp they may be low impedance pickups, which won't sound very good without the preamp. So the answer is a definite maybe.
Click to expand...

Correct me if I am wrong, but I think Alembic "activator" pickups are somewhere between active and passive pickups. I mean, I think they are passive pickups with very low output. The preamp is not internal to the pickup, but it really is needed to make the pickups usable. So, there is no passive mode on an Alembic.

In the non-Alembic world, preamps that are used in conjunction with passive pickups are used in a couple different ways. My OBP-3 is a preamp that is essentially taking its input from a passive VVT wiring harness. So, I can bypass it and run passive VVT. I think other preamps have the pickups connected directly to the preamp and the volume and balance controls are connected directly to the preamp as well. In this scenario, I think bypassing the preamp is a little more problematic.

Please correct me if I am wrong.
 
#14
Regarding the Alembic Epic; yes, you're correct. But, either it's pickups must run thru the powered preamp to get any output, or else the pickup's output is so low, that it's not discernable at all; mine is like playing a solid body bass unplugged. As for any other active bass; like I said, I really don't know; and don't want to, really. One active bass is quite enough for me, thank you; and as long as the battery's good, the Alembic fills the bill very nicely.:D
 
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#16
stevensivak said:
loosing tone and volume controls would obviously be a show stopper - literally and figuratively....
but not clear if that is always the case- NOT talking about an Alembic bass....
Click to expand...
As a couple of examples - a Sadowsky that is configured with the passive high end roll-off will run with the preamp bypassed and will maintain tone control. A Lakland 01 series will work passively but without tone controls. The Lakland AJ, on the other hand works only actively, though it could be wired to work like an 01. Any bass with the active EMG's will only work actively, and as noted, the Alembics don't function well at all without the preamp in the circuit. I have an active P-Bass with passive pickups and there is no simple way to wire it up to bypass the electronics at all.

So I stand by my previous statement - it's a definite maybe.
 
#18
stevensivak said:
losing tone and volume controls would obviously be a show stopper - literally and figuratively....
but not clear if that is always the case- NOT talking about an Alembic bass....
Click to expand...
It is possible to have a passive tone control when the active preamp is turned off. Sadowsky calls it the "Vintage Tone Control" which is active in both the active and passive circuits. When in passive mode, the bass and treble controls do nothing. It's possible to wire most other aftermarket (or even OEM) preamps with a bypass switch, usually a push-pull on one of the control knobs or an actual toggle switch. Fodera basses are equipped that way. I've installed Aguilar and Pope Flex Core preamps configured with active/passive switches and passive tone controls.
 
#20
JACink said:
To active pickups no.

To active basses (which are mostly passive pickups + preamp) yes.
Click to expand...

i think perhaps the OP wants a switch to just "turn off" the bass entirely intead of unplugging it, maybe i'm wrong. this can be done with EMGs, but yes they will of course go dead.

stevensivak said:
loosing tone and volume controls would obviously be a show stopper - literally and figuratively....
Click to expand...

i don't agree there, but it's personal. having a switch that bypasses both pots and connects the pickup directly to the output is common on some shredder type guitars, and coincidentally i have such a switch on a bass with an active EMG pickup. there is a huge difference between having both controls at ten, and having both controls removed from the circuit. it's a neat feature, but i guess not for everybody, or even not for every pickup.
 

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