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Kev, this may be one for you.. you seem like an electronicsy type guy.

I'm building a monitor switch so a can choose between input from a CD player or DAW, and output to either Monitors (powered) or headphone amp...

Problem is, the CD player I want to use has RCA outs, henced unbalanced and more than likely -10db. I need a schematic to build a simple "unbalanced -10db signal to balanced +4db signal"... any suggestions? I know you can buy these types of transformers etc, but I need a custom solution so I can build it into my monitor switch.

Thanks!
Jon

Comments

Kev Sun, 08/28/2005 - 17:29

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.

anonymous Sun, 08/28/2005 - 19:11

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?

Kev Sun, 08/28/2005 - 20:17

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)