ProjectM
...So far, the box with the most to offer - to my ears - has been the Thermionic Culture Fat Bustard. 
... I hope your experiment here will shed some light on this. Best of luck and have fun!

I've heard great things about the Fat Bustard! I was looking at dedicated summing boxes and someone on the UAD forum pointed me towards a console for all of the other benefits; I think that was great advice.
 
Fun is the name of the game! :)

OK, here's what I'm thinking of for testing methodology:
 
Disclaimer, I know it best would be to mix into the changes but that's not feasible so will just be looking for differences on an existing mix. 
 
1. Output mix as developed with no outside summing
2. Create 16 channels in DAW to send to 16 tracks on Console and route all DAW tracks to one or a pair of these 16. That way, everything goes to the Midas.
3. Bring the summed signal back into the Daw prior to any mix bus plugins - so it's the same behavior as having all tracks ITB go to the mix bus.
4. Create files for the following scenarios:
   a. Using the Inserts of the console, bypassing both the preamps and the EQ. I will send a test tone and attempt to level each channels' fader so everything is at unity.

• Using the Inserts of the console to bypass the Pres, but putting the EQ in the chain with EQ zeroed out.
• Go line in to the console through the pres at unity, EQ bypassed.
• Go line in to the console through the pres at unity and EQ in path, but zeroed out.
• Go line in to the console through the pres with the pres slightly above unity to get some of the preamp sound, EQ bypassed.

 
That should give plenty of interesting reference tracks to listen to.
 
Am I missing something? Any other ideas?
 
I have a Stam SA4000 on order and want to play with that as a bus comp, but that's the next phase. I have actually set up the board to use an Aux to feed a sidechain of the bus comp (so I can adjust which tracks feed it and EQ it); I am looking forward to that experiment! :)

I am now remembering how many cables and little details are involved with outboard - and loving it! :)
 
The board is hooked up to the UAD Apollo 16; first 16 channels of the Midas go to the Apollo 16. (They are fed to the Midas from a snake). All 16 outs of the Apollo 16 are routed to the last 16 channels of the board for summing.
 
The UAD Console recognized the Apollo 16 and did a firmware update, and everything from a software perspective seems fine. I want to test all of the ins/outs of the UAD next. Then I should be about ready to try the summing.
 

 

 

ha ha didn't look close at the two cables I bought from GC today. Thought both had male TRS, but wouldn't ya know one of them is a girl!
 
Also found I didn't have patch cables to return the sum to the Apollo.
 
Ha HA hardware rulz! :)
 
James

Keep on keeping on James.

I dreamed of cables and faders all night long. LOL
 
I'm back at it though - and I did make a lot of progress!

OK, it appears that I have everything hooked up properly and audio flowing where it needs to go. 
 
Seeing this was a real challenge! Last night late I oops and plugged the right main output from the board into the secondary outs. Problem is I have the secondary outs set to mono to feed my Avantone mix cube. So was I was properly summing the Left into the Daw, but the right was coming in as a mono signal of everything panned right. 
 
Also, the UAD Console needed to be set up to NOT monitor the in 7/8 where I was bringing the signal back into the DAW. That was also mixing with the proper left coming in and the right that was already mono. Weird phasing issues and such.
 
Then there is the DAW. I'm using my project Believe in Ableton (don't tell me to finish it Ed, my wife is already one me! LOL). I use a lot of interesting routing in Ableton for side-chaining and grouping, plus there are the Aux buses.
 
Seriously - WHEW!
 
I seem to have everything working and now need to verify that the channels are properly set to unity, and that I didn't inadvertently change the volume of something. For example, I may have set an output of a track to go through it's group when it wasn't before. If the group has a volume change on it, I would have affected the volume of the track. I'm going to open the original project and take screen shots of all routing to compare.
 
Also, I need to make sure each track being summed is at unity with the others. My thought is to send a test tone of pink noise to each channel and measure the DB going in as well as what's going out and level. I'll need to do this for all 16 tracks. FWIW, I am sending all stereo tracks to sum - nothing mono. I figured I'd eyeball the unity on the incoming gain and then adjust the fader to get level. I welcome ideas on this though!
 
EDIT: I won't use the board to send to the Avantone. Due to latency introduced by bringing the signal back into the daw and working on it, there is a latency from the mains signal. I'll go back to using the software routing.

I would not be using pink noise for level calibrations. The pink noise signal is not a totally consistent level as it tends to hover around a level.  A better alternative would be a 1kHz sine wave at the ref dbFS level. e.g. 0 dB VU = -18 dB FS etc...
 
Level calibration is going to be very important here. The 0 dB VU tones should playback at 0 dB VU in the DAW. With the faders at unity.  The level on the master buss should also be 0 dbVU.
 
The level coming out of the interface and into the mixer should also be set so each channel sets up the same 0 dB VU output level on the mixer main outs. One by one for each track, and the track faders also at unity etc...

Thanks Jeff, that makes more sense to me!
 
There is one area of calibration I'm a bit stumped on. When going in Line In or Mic In on the Midas, you still pass through the pre-amp. There are separate markings for Unity for Line and Mic ins, but no detents so there is no way to know if you are truly at unity. 
 
hmm, looking at the schematic I could use the Insert jack instead of Line In; that appears to bypass the pre-amps. I might actually like the sound of the pres but I'm thinking one thing at a time! Going through the Inserts and bypassing the EQ with the switch would leave me to leveling with just the faders. Interestingly, I could then go Line In and use the already leveled faders to figure out unity for the pre amp.
 
Thoughts?

From Sonoris website:
 
Calibration is simple, first select what channel to use for the calibrated pink noise (bandlimited 20Hz-20KHz or 500Hz-2KHz), L, R or both. You can calibrate your monitors at this level to show 83dB on a slow, C-weighted SPL meter using your monitor control. In stereo mode add 3dB. Mark the monitor control levels for each scale and you are done!
 
The 500Hz-2KHz noise signal can give a better and more stable reading on the SPL meter under some circumstances. Please try both options and see what works best for you.