simple volume control

[burningman]

Problem: I was wondering if anyone could explain how to create a simple volume control that does not degrade the tone. Right now I am using a 10k audio pot wired CW-GND, SL-Input, CCW-Ouput. It seems that the tone is very muddied when connected to the pot. Any suggestions would be appreciated, thanks.

[John Lyons]

I depends what you are using it in and where.
The wiper/lug 2 should be the output for a typical volume pot.

John

[burningman]

The volume control(s) would be placed on the input of an A/B box I am creating. The box would switch between two inputs (not a mixer) with only one output. Because I might plugging different kinds of instruments with this box, I would like to match volume levels, buffer and have the ability to boost the output. My idea was this
Input 1 - vol.pot
Input 2 - vol.pot
into 3pdt (for switching between inputs
into buffer
into booster
out to amp

If you have any recommendations, I would much appreciate them.
Thanks. ian

[John Lyons]

Ah, ok.. For an input volume control from a guitar PUyou want to use a 1m volume pot.
With a 10K you are loading down the impedance or the guitar PUs.

John

[Elektrojänis]

In that kind of setup you might get better results with buffers straight after each input, then volume pots (10k is fine after most buffers) and then the switching. This especially if the instruments are guitars with passive electronics.

[burningman]

Thank you very much for the recommendations guys ! I'm eager to build this now
Cheers,Ian

[Elektrojänis]

One more thing... John Lyons actually said something about this, but just in case... In the first post of this thread you seem to have the input and the output of the volume pot wrong way around (compared to how it is usually done and how it usually works best).

[burningman]

Would using 10klog pots after the buffer work if it was being fed into an amz booster? Would you recommend keeping the pots at 1meg? Thanks.

[Elektrojänis]

Would using 10klog pots after the buffer work if it was being fed into an amz booster? Would you recommend keeping the pots at 1meg? Thanks.

10k should be fine after the buffer in most cases. I'm not sure which booster you mean as AMZ has at leas two online:

http://www.muzique.com/amz/mini.htm#history
http://www.muzique.com/schem/mosfet.htm

Both of them should be ok with the 10k anyway if there is a buffer in front of the pot. Actually even the 1meg pots would probably work just fine, but I'd use something between 10k and 100k for that kind of setup.

There are some buffers too on AMZ that could be used for this (in case you didn't find them yet):

http://www.muzique.com/schem/eagle.htm
http://www.muzique.com/lab/buffers.htm

The fet and mosfet based ones should be fine for the setup you are planning. The ones that use Bipolar transistors might have a bit low input impedance.

Log means logarithmic taper and it should be good too as they are usually better for volume controls than linear. Log will spread the different volume levels more evenly (when compared with ears) than linear. With linear taper most of the usefull control range tends to "pack" to the start of the rotation.