Good value for post-fooger vol pot?

Plug in here for info tips and strategies for your Moogerfooger Analog Effects. Connect more than one for plenty of fun!
Post Reply
narrowcaster
Posts: 204
Joined: Mon Jul 09, 2007 11:57 am

Good value for post-fooger vol pot?

Post by narrowcaster » Mon Aug 20, 2007 8:43 am

Can someone tell me a good value to use for a volume pot to put after my Moogerfoogers in a passive effect loop? I'm thinking just of a box with two jacks and a pot, to let me trim the volume back. What value of pot is optimum relative to the output expectations of the MFs?

Also, if there are any other components I should add to make things more transparent, please let me know. Thanks...

User avatar
GregAE
Posts: 1590
Joined: Mon Jul 21, 2003 8:44 pm
Location: In the studio, of course

Re: Good value for post-fooger vol pot?

Post by GregAE » Mon Aug 20, 2007 12:58 pm

narrowcaster wrote:Can someone tell me a good value to use for a volume pot to put after my Moogerfoogers in a passive effect loop? I'm thinking just of a box with two jacks and a pot, to let me trim the volume back. What value of pot is optimum relative to the output expectations of the MFs?

Also, if there are any other components I should add to make things more transparent, please let me know. Thanks...
Instead of making one, you could simply buy something that would do the same job very cheaply. Take a look at the ART PowerMix passive mixer:

http://www.musiciansfriend.com/product/ ... sku=180623

Using just a single channel, it can serve as a simple outboard volume pot. Might be all you need.

narrowcaster
Posts: 204
Joined: Mon Jul 09, 2007 11:57 am

Post by narrowcaster » Mon Aug 20, 2007 1:11 pm

That's an idea to keep in mind. The problem is that I'm also trying to save a little space on the board, so I'd like to avoid unused channels if possible.

strata189
Posts: 44
Joined: Mon Mar 06, 2006 6:42 pm
Contact:

Post by strata189 » Mon Aug 20, 2007 11:07 pm

I just use one of the attenuators on my CP-251.
Works like a charm.

Randall

User avatar
GregAE
Posts: 1590
Joined: Mon Jul 21, 2003 8:44 pm
Location: In the studio, of course

Post by GregAE » Tue Aug 21, 2007 8:40 am

narrowcaster wrote:That's an idea to keep in mind. The problem is that I'm also trying to save a little space on the board, so I'd like to avoid unused channels if possible.
I understand the desire to keep things small, but the ART PowerMix box I suggested is only 3 3/4" x 3" x 1.5", and it's $30. You could use some right-angle jacks to keep the smallest possible footprint, and still have the luxury of summing four channels if you ever need to.

BTW, the ART box uses four 47K ohm pots, but you could easily get away with using a single 10K ohm pot if you decide to build something.

narrowcaster
Posts: 204
Joined: Mon Jul 09, 2007 11:57 am

Post by narrowcaster » Tue Aug 21, 2007 8:43 am

strata -- your message got me very excited! But then I tried it out, and discovered that on my rig, whenever I plug the effect loop return into any of the attenuator outs on my CP-251, there's a quiet but very noticeable high-frequency whine. The sound of this is completely independent of any knob settings, and is the same on all attenuator out jacks, whether or not there's anything patched into them. So I guess while my CP works great for mixing CV, and for mixing audio for use as CV, it's not going to work for mixing/attenuating audio for use as audio.

Thanks for the idea, though, and I may keep playing with it. But does anyone at all have an answer to the original question? If I just want a volume trim pot in series with the last MF, what value would be good? Or does it matter?

narrowcaster
Posts: 204
Joined: Mon Jul 09, 2007 11:57 am

Post by narrowcaster » Tue Aug 21, 2007 8:45 am

Greg --- Thanks again, you might be changing my mind. And thanks also for checking the pot values on the Art: that gives me a good starting point.

strata189
Posts: 44
Joined: Mon Mar 06, 2006 6:42 pm
Contact:

Post by strata189 » Tue Aug 21, 2007 10:07 pm

narrowcaster,

I just use one of the CP-251's attenutors as the last stop before my effects loop return. I don't get any whine or I wouldn't use it. :D

Randall

narrowcaster
Posts: 204
Joined: Mon Jul 09, 2007 11:57 am

Post by narrowcaster » Wed Aug 22, 2007 6:18 am

Randall -- Yeah, that's what I tried. There must be something different about the setup of our loops, or our CPs. I think I'll start another thread to ask about this...

User avatar
latigid on
Posts: 1579
Joined: Mon Jan 30, 2006 3:47 pm
Location: Auckland, New Zealand

Post by latigid on » Wed Aug 22, 2007 6:54 am

Noise problems:

If you are using a daisy chain, you could try and use a separate power supply for the CP. Maybe you're drawing too much current or another unit is interfering. Try swapping the supply anyway.

An attempt at the original question:

Larger value pots provide better attenuation. You can "reduce" the volume more
But if the value is too large, you lose resolution. I.e. you might restrict the useful range of the knob.

I would expect a value of somewhere between 10k and 100k would be the most useful. And probably go for a log pot, not linear.

narrowcaster
Posts: 204
Joined: Mon Jul 09, 2007 11:57 am

Post by narrowcaster » Wed Aug 22, 2007 8:59 am

Thanks latigid. I'll try a separate power supply and see if that helps. Right now everything's being powered from a Voodoo Labs Pedal Power II. If that doesn't clear it up, I'll start a new thread.

Thanks also for the pot explanation. I ended up using a 50k, and it works fine. All they had in the mall was linear taper, which is a little frustrating but OK for the application (no sweeps, just set and forget).

Post Reply