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How to simulate having volume controls?

E

Electricblue

Feb 1, 2011
1,204
49
Norfolk
#1
Hi there, I'm adding some resistors and caps to my parallel-to-jack jazz bass.

It came with 250k pots all around, and a 0.047uf tone cap. How can I replicate this setup again, but without having the actual controls there? I would preset it as having all the controls on full.

It's just I'm "sealing up" my bass soon so I want to make sure I definitely have the tone I like before the point of no return.

line6man, the father of all things involving a schematic, I'm looking at you :hiding:
 
#2
May I add that I'm not looking to decrease the output, but just generally roll just the very top end from the tone of the instrument.

Does a parallel resistor roll off highs or just decrease the output altogether?

Just to recap, I'm looking to create the original jazz bass circuit, but with fixed values, all at maximum.
 
#5
Electricblue said:
Thanks buddy :) Isn't 120k a bit low? I mean I know it's the mathematically correct way to do it. Would it roll of highs or just lower the output?
Click to expand...
In VVT, each volume pot is 250K. With both volumes at max that's two 250K in parallel, so 125K. Other resistor and cap is tone controll when fully open. It drops volume by less than 1dB, not something you will notice. Main effect is damping resonant peak of pickups => warm HF response
 
#6
recnsci said:
In VVT, each volume pot is 250K. With both volumes at max that's two 250K in parallel, so 125K. Other resistor and cap is tone controll when fully open. It drops volume by less than 1dB, not something you will notice. Main effect is damping resonant peak of pickups => warm HF response
Click to expand...

Gotcha.

So if I just added the 250k resistor and 47nF capacitor in series, it would give the same tone as it would if I added the 125k, but with higher output?
 
#7
Electricblue said:
So if I just added the 250k resistor and 47nF capacitor in series, it would give the same tone as it would if I added the 125k, but with higher output?
Click to expand...


No. Just 250K in series with 47nF will give you ton of Jazz bass with just tone control and no volumu controls. 250K+47nF in paralel with 120K will give you tone of stock Jazz bass with both volume controls at max.
...
Threshold for perceptable level difference is around 1dB. However, human aural system is lying bitch. If you expect to hear difference after flipping some switch, you will hear it even if you cant actually hear it in propper ABX test (there is that famous joke about "Producer" switch on mixing desk). 120K ll (47n+250K) will not drop volume by any significant amount, it will alter HF response.
 
#12
Recnsci beat me to it.:hyper:

Two 250k volumes in parallel is 125k, so use a resistor around that value.
Then a tone pot is 250k in series with a 0.047uF cap.

Here is a diagram I have on hand of the setup, but don't mind the 250k resistor value, this was drawn up for a P bass player.
3396717485_cba593dc91_o.png
 

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