Help - Running full Active and Passive signal paths side by side

mrhilger

mrhilger

Oct 13, 2009
9
1
4,551
#1
I have an SR505 that I want to make both active and passive. Switchable of course. I know it is an easy mod if you have a preamp post volume/ blend controls. The problem for me is that the preamp I am using has a vol/ blend control in addition to the eq section. I could easily replace the existing controls with this but with the preamp I will be using I only need three holes since the pots are stacked. I have two more to work with. My idea is to use a 62 jazz bass circuit with two concentric pots for these holes. This by itself would be easy to do as well. The question that I have is it possible to put a switch in that would allow me to switch between each signal path? All the information I could find doesn't show how I can split signals from two pickups. In the end I would like to have a fully functioning active pathway and be able to switch to a fully functioning passive pathway. Is someone able to help me with this?
 
Last edited:
#2
A few thoughts...
- What preamp are you using? Someone may have advice related to the specific product.
- Why not switch the concentric pots to single pots and redo the wiring if all you are really trying to do is fill the extra holes?
- If you do proceed down your current path, you are thinking about it wrong. You do not need to split signal. You could achieve the same thing by stacking. Have your passive circuit, then run that into a switch that either sends your signal through the active circuit or (when in passive mode) bypasses the active circuit.
- Generally if you cannot find any information on something that you want to do with electronics on a bass, there is a good reason (other solutions likely work better). Noting that sometimes not doing it the normal way can be innovative. In your case, I think the market already has better solutions than what you are proposing. I currently have several basses with active/passive preamps. One of my favorite things about them is that the passive circuit still functions in active mode (meaning that I have treble roll off on an active circuit which is a nice control to have).
 
#3
I would like to use an Audere Classic preamp that accepts input from two pickups. It's configured with Vol/blend, bass/treble, and high mid/ low mid controls. Since it accepts inputs from both pickups I don't know how to I should setup the passive circuit. If I am understanding you correctly you are running your passive controls into the preamp and they still function when the preamp is engaged. The examples I have seen require you to run your last passive control into the preamp, If I am correctly understanding you, that would be just fine and in fact desirable. I would have two passive controls. One for each pickup. That is where I am getting confused. What I don't understand is how to do the wiring and what type of switch to get. Would I just be running each passive vol/tone pot into the preamp?
 
#4
My active/passive setups are preamps that were designed to run active passive so the passive circuit is built into the full active harness that was supplied. You could run the volume and tone control before/after. I would imagine preference would be for after to give the preamp access to unmodified signal. The point of my comment was not really passive control location, it was that your goal is really to switch in the active circuit to the existing signal loop and not to split the pickup signal. While you could wire the pickup signal into a switch that either goes to the Audere or a passive circuit, this would result in a weird dual volume control setup and not allow you to use the passive tone when the active circuit is engaged. You could do it, but I do not know why you would want to. Again, one of my favorite active/passive circuit features is having the passive tone control in an active circuit. It is a reasonably popular option on East, Nordstrand, and Audere preamps (probably a few others too).

For the Audere, I would not bother running a passive circuit (unless you want to add the passive tone control that they offer to the active circuit). They advertise and in my experience deliver passive tone when everything is set flat (had an Audere in a modified Peavey Millennium Plus).

What is your goal with adding the passive circuit? If you are trying to fill holes, there are better ways to do it. If your concern is related to battery failure, I really would not worry about it. This concern is frequently overblown IMO. If you are really worried about your battery dying on you before a gig, test it, and/or replace it.

I would argue that instead of trying to do what you are proposing, your better options are...

1. Live with what you have and plug the extra holes
2. Buy non-concentric pots for a few controls and fill all the holes that way
3. Buy a different preamp that already does what you want (active/passive and 5 control setup)

My point being, I think you are choosing the more complicated option in your proposal and I do not see why you would want to go that route. I believe less complicated options will deliver better results.
 
Last edited:
#5
Points well taken. Simple would probably be better served by just getting a preamp that does what I want and be done. No need to reinvent the wheel here;) Thank you for sharing. I agree I am probably going for a more complex solution than necessary. On a side note, I was doing a little more research on the 62 jazz bass configuration and the extra load created by having two tone controls would probably not be desirable.
 
  • Like
Reactions: ahadl2500
#8
mrhilger said:
I would like to use an Audere Classic preamp that accepts input from two pickups. It's configured with Vol/blend, bass/treble, and high mid/ low mid controls. Since it accepts inputs from both pickups I don't know how to I should setup the passive circuit. If I am understanding you correctly you are running your passive controls into the preamp and they still function when the preamp is engaged. The examples I have seen require you to run your last passive control into the preamp, If I am correctly understanding you, that would be just fine and in fact desirable. I would have two passive controls. One for each pickup. That is where I am getting confused. What I don't understand is how to do the wiring and what type of switch to get. Would I just be running each passive vol/tone pot into the preamp?
Click to expand...

Short answer is: you can’t set up an Audere preamp for active/passive operation. Its design is an active volume/blend arrangement. Which means the volume and blend takes place inside the preamp. There’s no provision for sidestepping the active circuit.

From the Audere website:

Can I add an Active/Passive Switch?

Not possible but our design addresses the most common reasons players want an A/P switch, which are:​

1) Sound issues - we do not screw up your sound with a lot of distortion.

2) Battery issues - we have a LED battery meter.

3) Electronic failure - the switch would reduce not increases your reliability.
Click to expand...

It’s a major deal breaker for some people that Audere doesn’t have a passive operation option.

I suppose you could get around it using switches to route each pickup to either the preamp or a passive volume/tone stack. But you’d be far better off just swapping the Audere for a preamp that does have a bypass or switchable passive mode.
 
Last edited:
  • Like
Reactions: Crater
#9
Sounds like the John East J-TONE does what you want. I haven’t used one (I’m not a Jazz kinda guy) but I have other John East units and they are top notch.
 
#10
Thanks for the reply, but this is not a jazz bass so that wouldn't work. Also, on my jazz basses that also use an Audere preamp, I find that I use the midrange tone controls the most. The j-tone doesn't offer control over the midrange.
 
#11
40Hz said:
Short answer is: you can’t set up an Audere preamp for active/passive operation. Its design is an active volume/blend arrangement. Which means the volume and blend takes place inside the preamp. There’s no provision for sidestepping the active circuit.

From the Audere website:



It’s a major deal breaker for some people that Audere doesn’t have a passive operation option.

I suppose you could get around it using switches to route each pickup to either the preamp or a passive volume/tone stack. But you’d be far better off just swapping the Audere for a preamp that does have a bypass or switchable passive mode.
Click to expand...

I am probably leaning towards a different preamp, but I am curious about adding a switch. Is there a single switch that would allow me to route both pickups to either a passive path or the active path?
 
#12
mrhilger said:
I am probably leaning towards a different preamp, but I am curious about adding a switch. Is there a single switch that would allow me to route both pickups to either a passive path or the active path?
Click to expand...

The only practical switching solution I can think of would be to delve into the complexities of a rotary switching scheme if you just want to use a single switch.

FWIW I think there would be an annoying pop when switching between active and passive with this sort of arrangement. And I also suspect you’d get at least some noise from the preamp if it were active with no pickups attached since it would still see the wires and switch and try to amplify that.
 
You must log in or register to reply here.
Top Bottom
Back