lassoharp said:
Are you planning on using outboard line amps during mixdown?
The reason I ask is that it sounds like you're just looking for a good passive outboard mixer to run straight from your converter interface? In that case you'd really only need a bridging input, so a high impedance mixer might be a more flexible choice if you're not using amps that want to see a 600 ohm load.
The 600r mixer was designed primarily for using with vintage line amps that expect to see a 600 ohm load on their output. I used mine with 8 tube line amps in front coming off an 8 track analog machine (or sometimes from DAW interface outputs). The UAD Apollo may work just fine driving 600 ohm loads, but doesn't require them like some vintage line amps do. NYDave also had a schematic for a high impedance version of his mixer up at one time too. I think he posted it a bit before the 600 ohm version. Seems like there was a thread about it way, way back there - like 2004 or 2005.
Thanks for the help and thoughts, and thanks shabtek for the schematics
The apollo has 600 ohm outs, which is why I said that. I still don't understand impedance bridging, I should research that.
My plan was to run the 8 600 ohm outs of the apollo into a simple mixing board, with some outboard in between for some channels- for instance a spring reverb, an echoplex, a plate reverb if I ever get around to building it, a compressor or two, etc.
It would be something like:
Output 1 - Bass out to 1176 into mixer channel 1
2 acoustic guitars (summed in DAW) into mixer channel 2
3 rhythm guitar (panned left) into mixer channel 3
4 lead vocal out to echoplex into mixer channel 4
5 and 6 drums (summed in DAW) into mixer channels 5 and 6
7 lead guitar with panning effects into mixer channel 7
8 reverb sends summed from DAW out to reverb unit into mixer channel 8
Then plug the stereo out of the mixer into two mic pre channels and record the mix/mixes back into the DAW
I have two spectrasonics model 101 cards I have been planning on using to build mic pres with, but I could use them as line amps for the output of this mixer - especially if I use it all the time. I could wire it in "permanently" into two line in channels in the apollo.
Would it be best to keep this balanced? in the schematic the first transformer is just converting the input to unbalanced, right? what would the input impedance of this on be?
I'm also thinking of adding another apollo at some point to get more UAD processing power, and I could use that to expand this whole rig to 16 track outs, but I think it would be best to design and build another mixer then after learning from mixer 1.
So what should I do for this?