Custom preamp buid.

[zitherman]

Im now onto my 3rd 51p bass build but want to do it a little different. In addition to the single coil pickup im going to add a mm pickup but i still want it to look clean with just 2 knobs.So im thinking dual concentric volume control,and a dual concentric bass/treble control with a mm type preamp.Also the abilty to switch it to passive and have one of the tone knobs become a passive tone control.I wouldnt mind a couple of mini switches.ie pickup selector and battery switch(for passive selection.Is there anyone on here able to build a preamp to do this.cheers

Edited December 12, 2021 by zitherman

[Jimothey]

52 minutes ago, zitherman said:

Im now onto my 3rd 51p bass build but want to do it a little different. In addition to the single coil pickup im going to add a mm pickup but i still want it to look clean with just 2 knobs.So im thinking dual concentric volume control,and a dual concentric bass/treble control with a mm type preamp.Also the abilty to switch it to passive and have one of the tone knobs become a passive tone control.I wouldnt mind a couple of mini switches.ie pickup selector and battery switch(for passive selection.Is there anyone on here able to build a preamp to do this.cheers

Have you tried messaging @KiOgonI've heard nothing but good things about his wiring looms but I dont know if he does preamps....... 👍🏻 

[zitherman]

Cheers.i havnt contacted anyone just throwing out an enquiry.Ive looked at lots of the pres currently available but none seem.to be what im looking for.Im not in a hurry as im only starting this one

[Passinwind]

19 hours ago, zitherman said:

Im now onto my 3rd 51p bass build but want to do it a little different. In addition to the single coil pickup im going to add a mm pickup but i still want it to look clean with just 2 knobs.So im thinking dual concentric volume control,and a dual concentric bass/treble control with a mm type preamp.Also the abilty to switch it to passive and have one of the tone knobs become a passive tone control.I wouldnt mind a couple of mini switches.ie pickup selector and battery switch(for passive selection.Is there anyone on here able to build a preamp to do this.cheers

 

That's quite a big ask, I would just use at least three pots personally. I can do custom preamps to a fairly high standard but I'm in the US and it wouldn't be cheap for what you want. I'm also quite backed up at the moment. You'll need a very custom tone pot, for starters. This is the only readily available option I'm aware of: https://www.omeg.co.uk/potentiometers/unswitched/p20/p20-3-concentric/

 

You'll most likely need to buy at least ten of those pots, but you can try pinging Omeg and see if they are willing to do a one-off for you. And then it has to fit in your cavity route, how deep will yours be? A two gang one (ie no passive option) will fit in even a standard Fender route just fine though IME. But again, there are no stock ones like that AFAIK, you will have to custom order. I recently went through that with a different needed feature set and Omeg were great to deal with.

 

If you used a pickup selector and only one volume control you could do volume/passive tone on a concentric pot, I think this is a better bet.

 

Power switching without transient pops is problematic as well, but a typical MM preamp draws so little power that I wouldn't bother.

Edited December 13, 2021 by Passinwind

[zitherman]

Thanks passinwind for a comprehensive reply.i realise its quite a complicated idea.I wondered if one of the controls on the tone pots could switch to passive mode when switching the voltage off.Im not keen on the modern styling with 4 or 5 knobs and prefer a simpler look.might have to have a rethink. Cheers

[Passinwind]

1 minute ago, zitherman said:

Thanks passinwind for a comprehensive reply.i realise its quite a complicated idea.I wondered if one of the controls on the tone pots could switch to passive mode when switching the voltage off.Im not keen on the modern styling with 4 or 5 knobs and prefer a simpler look.might have to have a rethink. Cheers

Normally when you switch into passive mode the power doesn't actually get switched off, the signal path just changes and the preamp stays in standby to avoid the nasty switching pop I alluded to. With a standard preamp bypass switching scheme like that it's no problem to port to a passive tone control, and Noll sells a cool tone pot meant to allow for exactly that (ie active section and passive section on one control shaft), although I think it works even better with the passive tone control section just always being engaged, a la Sadowsky. Noll set it up so the passive part only engages at settings below 12 o'clock, which is quite clever. While unfortunately that pot is not suitable for a MM preamp, it works perfectly for many of the other usual suspects though. It still won't help you in a two hole control  build however, as it's not in a concentric format.

 

Best of luck! 

 

 

[zitherman]

Thanks once again for another knowledgeable reply.Im in no rush with this build as im trying out binding for the first time as well as some inlay.Gives me time to think about the electronics.😀