CAPI SumBus ACA Summing Mixer

This is exactly right.  The Burl experiment I referenced was essentially - a.) 32 channels summed thru the Burl; b.) everything summed ITB then 2 channels "processed" thru the Burl with the same settings in the DAW and on the box; and c.) everything summed ITB then two channels processed thru the Silver Bullet.

Spoiler Alert :

FYI, the 32 channel wide version (a.) got the least amount of love.

IMO - when summing OTB, the magic is not in the summing - it's in the associated circuitry that surrounds the summing - the channel electronics, the back end amplification, etc..  So unless workflow demands it, I'd prefer to sum ITB and add outboard as needed.  Many disagree with me.  That's fine.  I've done my due diligence and formed my own opinions.  I get FURTHER in the direction I want to go with ITB summing, 2 Buss processing, and a FREAKING TON of outboard inserted on almost all channels ITB via hardware inserts.  Then, plugins picking up the slack.  That's putting the specific mojo where it's needed, and custom tweaking to allow different OTB processing where I want it as opposed to a "console approach" of "everything gets the same flavor" - which can be interesting as well, but doesn't really suit my esthetic.  Complicated stems mixes and routings can easily be recalled 100% in seconds vs. OTB routing.

Man, I would no problem, but as my setup is wired up now with a fixed mixbus and monitoring flow (and none of that easy to get to - mastering style desk), it would take hours for me to satisfy the all-to-two-track request and then rewire it all back up.

Were you not hearing the differences in the Burl example others pointed you to?

Edit: and drbill's comment above is another perspective, so maybe just consider the broader question: do you think working through a console would be beneficial, or can/are you getting the sound you want now ITB? There is no right or wrong, as drbill said, that's his setup and it's exactly how he wants to work.

I could easily ditch the SumBus and go ITB summing to my mixbus and try to make all that happen, but I'm getting our sounds with what I have and I like those sounds. Hybrid blend of outboard summing, hardware inserts and plug-ins. I've bought and sold a lot of gear over a decade+, because usually there's no demo unit, etc., and I just had to buy something I thought would get me closer.

Clarifying further (my opinion only) :

For those considering summing - figure out what you're looking for so that you can test appropriately (ala Otis's search) : the bottom line for me based on my listening tests..... Unless your summer has discrete class A electronics, tubes, transformers, etc. in some form or another on every channel, then the benefits are going to get exponentially smaller. A simple summing resistor network with uber clean makeup gain is not going to net you what Jeff's box or a Silver Bullet does.

Then....to be fully informed, you should try to compare that OTB summed sound, a quality 2 Buss solution, and ITB and see which you like better esthetically. I know for me, adding 32 channels of summing (and honestly, I'd need 48+ to really get going) and it would cost me several thousand dollars in cabling and patch bays (bays currently full, and long cable runs), cost me the flexibility that I have with an ITB sum (complicated stems / bussing / etc.), and for me, there's no net gain in the workflow. That's ME!

To achieve the CAPI sound, I'd rather add more VC528's or more vp28's and insert them where needed. Or a host of other super cool outboard like the AudioScape stuff which oozes tube / class a goodness.

When considering whether to sum / mix OTB, ITB, or move Hybrid - I think the workflow should be what should be of primary concern vs. the sonics. You can achieve the sonics with a hybrid approach. You CANNOT achieve the workflow of a console or SumBus style summer workflow with an ITB approach. Different strokes..... <thumbsup>

Totally get what you're saying and where you're at with this. And, for sure zero problem that the Burl test wasn't something drastic. I was only asking as a reference. I haven't heard the files myself.

So, as an attempt to be helpful, I ran into the same kinda decision you seem to be up against years ago. And there is no right or wrong answer. And keep in mind, our music is guitar/keys driven, some live drums, some TR-707 and samples. It's rock sometimes, it's modern sometimes. Just depends on the vibe.

I am not talented enough to get an ITB mix to sound like a record. So I journeyed to where I am now with a hybrid setup. I guess the point that might help is that maybe think about where you get your best sounds. A SumBus is NOT going to take you lightyears into the future. It is going to be special and do some amazing things sonically. That doesn't mean you can't achieve them ITB or via other hardware, that's just where my journey led me and Jeff's presentation of what he was building for the rest of us resonated with me. And, delivered, helping me get the sounds out of my head and into the computer.

Shit. I'm not sure much of that is helpful, LOL.

Were I using a simple passive summing mixer or doing the large scale hardware insert thing like DrBill, my solution would be to use a preamp (with a line in option like the VP28), in addition to whatever other comps and eqs you might use, on each channel.

That way you get all of those extra transformers and opamps in the signal path of each individual channel. That essentially recreates the same thing as mixing through a bunch of channels on a console. If you have a bunch of the same type of preamp, even better.

well..go listen to something from the 70s or 80s..or 90s...or 2000s..

Major label stuff was all done with tape and a console. was 4-120ch of the same thing. Seemed to work pretty damn good! 





I realize this reply is a bit stupid but just had to say it haha

Taking 32 tracks and adding a slight bottom boost, top shelf, and a soft low pass filter will be significantly different than doing that same treatment to the stereo mix.

I imagine the sum bus is like this (but to a much smaller degree). Does that make sense?

What kind of outputs are on the SumBus? Can't you route some of the channels outputs through another converter back into the DAW?

I see so you can't split the outputs through a snake cable of some sort? Or is that only DB25

One thing I never got with summing mixers is people saying they have greater separation.

To my mind (and ears) nothing can be more separate than the DATA streams of a DAW as there is zero cross talk.
Sure you might like the corss talk of a desk - but it's not greater separation it's less.

I've done a fair bit of testing and to my ears greater separation with a summing mixing is something I simply
cannot hear in a double blind ABX.

Personally, I don't find it anymore "3D" than mixing ITB with hardware EQ and compression on the stereo mix bus.

If you have a pair of preamps, you can simulate what you're looking for.  For one trial send the whole mix through these preamps.  For the next trial run 4 busses through these preamps one at a time.  Sum ITB, and you could run the mid through the preamp again to simulate the master bus circuitry.  Repeat, but use 8 buses, etc.

You'll be able to hear a difference, but whether or not it's significant enough will be up to you.  I'm guessing the test will resemble the SumBus if your preamps are CAPI.

I would second the Silver Bullet vote. #0008 popped up on the interwebs used and I grabbed it in 2014 (I think?). Lots of changes since, but now I still think of it in drbill 's angle where you "use it like a console". So, the SumBus driving that unit gives a lot of options. The SB has been on N for a couple of years now that I've had the SumBus. Drive the SumBus, let that drive the SB, faders in the middle of the exchange... working well for where I try to get stuff. YMMV.