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Discussion in 'Pickups & Electronics [BG]' started by azureblue, Jan 12, 2014.
can a preamp be rewired from volume and balance, to 2 volume controls?
Volume and blend pots are not usually a part of preamp wiring. Most preamps just have an input and an output, and you can wire whatever passive controls you want.
I should have been clearer - I meant on board bass preamp. I have a V/V pre in my main bass , and have gotten used to it, and I have a V / B pre in another bass I would like to change to V / V...
Again, that has nothing to do with the preamp, unless it has PCB-mount pots. Wire your passive controls however you want.
who said anything about passive? not me. I thought the word "preamp" would lead someone to conclude that the basses are not "passive".
Volume and blend pots are passive components. The preamp is the active part, and it bears no relation to your choice of passive components. You can wire passive components in any way you want, as long as you end up with a signal to feed into the preamp's input.
Here's a diagram that works for most setups.
I did it with my BART pre. Easy mod.
Not true... many preamps have the entire set from pickup input through the jack...
It depends on the preamp, really.
Some preamps, like the Glockenklang for instance would be quite tricky to go from vol/blend to vol/vol.
Yeah or the vol pot is in the middle of the circuit, or on the output of the circuit (like stingrays). If the pots are mounted to a PCB, it might be physically difficult to do as well.
OTOH, there's a good chance it's not too hard to do.
So, what pre is it?
No, more often than not, preamps are non PCB-mount. Look at all the preamps on the market and check.
In any case, if you have a preamp that is PCB-mount, it's just a bit more work. All you have to do is desolder all pots on the PCB, and resolder the pots you're keeping with short lengths of wire, so that the PCB can be moved from its physical location to allow clearance for the new pots. Then, wire your new pots, and make appropriate connections and jumpers on the PCB.
^No, sorry, you're incorrect...
It depends on the preamp... preamps like the Aggies, it's really easy...
Preamps like the Glockenklang with PCB-mount pots, you may as well buy a new preamp... NOT easy, believe me.
I have only seen a handful of preamps with PCB-mount pots. Like Glockenglang or Fender.
It's easy to desolder pots from the boards. It's not like you're trying to deal with SMT components. Pots are through-hole components that can be replaced with wires.
That being said, it's usually more trouble than it's worth to do the modifications.
Change your other bass to volume/balance.
listen to line6man (always a good idea )
most systems are passive through the volume/pickup selection part, only going into the preamp circuitry after all the blending.
a few are not, with separate inputs for each pickup and the blending and volume handled after the preamping part, but that is more rare.
anyway, why change from V/BL to V/V anyway? what do you think you're gaining?
This is my point... Best bet is to sell one that requires modification (if that's what is there) and replace with one as you've said, such as an Aguilar or a Sadowsky
Just for understanding:
A vol pot that's within the preamp lets you dial the tone without any loss,
while the passive vol pot will roll off highs as soon as it's not on 100%, right?
Seems reasonable to me to make the control arrangement on two basses match and if the OP prefers V/V isn't that reason enough? I would say that anyone who can't pull a pot off a preamp pcb probably should not be mucking around inside their bass at all. It really isn't hard at all. My active Fenders have external blend controls and volume pots that are electrically inside the preamp. In fact the preamp is mounted to the bass by soldering it to the volume pot leads. So unsolder the pot, put a jumper from wiper to top of the pot on the pcb and a 25k resistor (the volume pot value in this case) between the wiper and the ground lead of the pot on the pcb. Now the internal volume pot is electrically replaced and set to max and the line6man circuit will give the OP the V/V controls desired. However, the exact details depend on the preamp so if the OP wants to know more we need to know which preamp the bass has. Of course it could turn out that none of us is familiar with that preamp....
Volume pots do the same thing, no matter where you put them, but there tends to not be as much loss when the volume pot is placed after the buffering, because the pickup coils see a constant input impedance.
Fixed it for ya
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