Seeking Advice for a Monitor Volume Control

I'm interested in putting some kind of monitor volume knob in place between my sound card and my (active) monitors.  One option is to build a simple passive attenuator assembly.  But a little research suggests this isn't as simple as it one might initially think.  A number of sources I've found via web searches have cautioned that even a "quality" volume potentiometer can be less than accurate with respect to balance.  So for mixing, maybe this is not a good thing.  The preferred solution is a stepped attenuator control, but these cost several hundred bucks.  A nice compromise would be to build a circuit using a two channel rotary switch and quality discreet resistors.  You could supply settings for a half dozen typical listening levels, but it wouldn't be continuously adjustable like a volume control.  The result (in theory at least) would be a reasonably priced solution with high balance accuracy at all levels.
 
OK, that's the background.  Now a couple of really simple questions.  Assume for the moment that I really do want to use an inexpensive stereo potentiometer (if only as a starting point from which to design the final solution with the rotary switch).  My monitors have an input impedance of 20K.  What kind of pot to use?  Volume control pots seem to be routinely 100K.  But is that the right value for monitors?  Also (I'm truly embarrassed to have to ask) does the pot go in series with the load (i.e., the monitor) or in parallel?  In series, higher resistance would decrease volume; in parallel, higher resistance should increase it.  I'm guessing the correct way is parallel, but an expert confirmation would be greatly appreciated.

I think the TC volume control is pretty cheap these days, a friend at a pro studio was using one (it is in his B studio but his SSL was down for a while).  He liked it.

I've got a TC 48, and it has a remote, and it is sounds great, too.

@

craigsound


How about one of these :http://www.griffintechnology.com/products/powermate
I have one and it works great, I also have 2 more in the pkg if you would like to buy one.

First of all, Batsbrew and AT, thanks.  The problem with what you suggest is that both have balanced cable connections.  I'm a just a hobbiest with not a single balanced cable in the house.  Plus, I don't want to spend 3 figures for a solution.
 
Craig, thanks for this suggestion.  I was already aware of this but I don't think I can get it to work with my sound card (M-Audio 2496) in XP because it requires a keyboard shortcut for whatever you're trying to control. I've got another thead started in Computers asking about USB solutions in this area.  I haven't check that yet, so maybe there's a reply that'll shed some light on the subject.
 
I'm probably just going to experiment with a cheap radio shack pot to get a circuit design.  I'll report back if I come up with anything that might be of general interest.
 

I use this the M-Patch 2. http://pro-audio.musiciansfriend.com/product/SM-Pro-Audio-MPatch-2-Passive-Volume-ControlSwitch-Box?sku=180067&src=3WWRWXMB&ZYXSEM=0

Frank, not having that problem here but the mono/stereo switch broke and they sent me a replacement for free. That switch is so useful for mixing. I run two pairs of speakers and not a glitch.

They have a new unit with a talkback switch which I saw at NAMM. I may upgrade to that.