you can't get passive gain quite in that way

-10 at 20k up to +4 at 600 will require an active circuit

see my site for a balancing box
Peter C also has one
Jensen for more circuit ideas

please do a search
I can give direct links if you don't find

you are already looking a at a DIY DAW monitor switcher ?
have you seen my page at the DIY Factory ?

You could use an RCA switcher ... then balance the output and then into your pro stuff.
rather than
balance ALL RCA gear

There are Pro's and Con's to all methods and I'd need to know more about your set-up and intentions.

Thanks Kev,

I've actually looked around the web, couldn't find a lot on my specific needs... there's a couple of links on the Jensen site but that's about all. I'm looking through your site now, there's a couple of things that may suit me there I think.

Basically I'm just making a monitor switch.. I'll attempt a diagram below...

CD player-->bal-circuit->--.................................../-->hedphn amp
.......................................Tog.Switch>-->Tog.Switch...................
DAW output->--------------/....................................-->monitors

All ins and outs are balanced +4db except for CD player which is -10db unbalanced. I know I'll need 6 pole DT for each toggle switch, but I don't know the simplest solution for the balancing circuit for signal coming outta the CD player.

Hope my explanation/bad diagram is clear enough! Any ideas on a simple effective way to create the balancing/level circuit I need?

have you seen
http://www.diyfactory.com/projects/dawmonswitch/dawmonswitch_1.htm
basic discusion paper

http://www.diyfactory.com/projects/dawmonswitch/dawmonswitch_2.htm
with VCA volume control

http://www.diyfactory.com/projects/talkback/talkback.htm
Stereo Talkback Unit

http://www.diyfactory.com/projects/headphoneamp/headphoneamp_1.htm
a work in progress

simple 4 switched pairs of RCA's to balanced stereo output.
DAW output to trimable multiple balanced drives.
This is known as a DA (distribution amp)

Thanks for the head-start, given me a bit of info to base on! Nice site by the way, some useful stuff on there

By the way I ended up getting the TMP-8 and I'm glad I did, great little pre with a big sound... And by little, I mean little, probably only 70-80mm deep!

yes, Joe does very nice work

!!
I've just noticed
you are in Australia

Yup, just across the Bass Strait from you at the moment (unfortunately, can't wait to get back to Perth).

The lack of availability of gear here is pretty bad...

And because I'm in Tasmania right now if I'm recording a 4 piece band live, it means I need to have 8 pairs of headphones to track with