Aux return cards... source or roll my own?

So... jumping the gun a bit here, but eventually I need to deal with aux returns...

Do you think something like these calrecs might be good to reverse (see below ebay link) or does anyone have a suggestion for a fairly simple returns module?

I'd prefer to keep the 2520/2623 thing going, so I'm not opposed to rolling my own, I just would like this thing to pass audio this year.

https://www.ebay.com/itm/aux-module-foldback-from-Calrec-recording-studio-console-2-of-2-RC1652-312/292089875410

Eesh, why these so expensive?  Edit: I guess  ~$350 a pop isn't that bad (sold as a set of 8 ).

https://www.ebay.com/itm/API-501-AUX-RTN-MODULE-MONITOR-RTN-MODULE-LINE-IN-MODULE/302773942167

looks like these use a 1731 variant?

Also I need 6 ch auxes, so one of these could serve as inspiration...

Also here's how much I know about aux... might it be more simple to use an aca card and stick a fader and pan off of it?
Allowing for program/group routing, inserts, possible VU and a DI split if needed?

Um...Is that all an aux return card is in the API vein, less a typical full-on 2520/2503 arrangement?

Of course I need to look at some API schema, which I've yet to do.  8)

Edit: Sorry for the blasting of questions, but thanks for your thoughts on any of it!

I would roll your own. The aux return is probably the simplest module to make. Basically a buffer with a volume pot. I wouldn't worry about mojo. Your going to be sending a signal, processing it with compression or verb and mixing it back into a buss. So there will be enough "sound" going on in that path not to have to add another couple discrete op amps....Heck I would use a balanced line receiver chip and a couple NE5532's with a pot in between.

I agree 100% with bluebird. Aux return is the most basic line input module. You have to think about the auxiliary sends: you probably don't want to inject echo into the echo sends  ;D, but you may want to send echo to the foldbacks.
Another thing is the Mute/Solo safe operation. Electronically, there is no use for transformers.

Depends what you want it to do. It can be as simple as a balanced buffer followed by level and pan controls. Or you might make it a stereo version with level and balance controls (you can probably fit two channels in a single module either way). After that it is just window dressing:

Do you really need to solo the return of an effect? Do you really need to be able to route it to all groups. Do you want to send reverb return to artistes foldback cans?

As other posters have said, I would recommend keeping it simple. If it needs to be really complex then you use the line input of a channel. As long as you have more channels than tracks you can so this. At Neve we rarely built special return channels.  A 32 channel mixer would, at mixdown, use 24 channels for tracks and the remaining 8 for returns.

Cheers

Ian

Cheers

Ian

For an aux return I don't see much downside in making it simple, clean,  and neutral  sounding.

A differential receiver,  level control,  buffer,  then send it wherever it needs to go.

john12ax7 said:

A differential receiver,  level control,  buffer

Click to expand...

The signal path is easy.

...  then send it wherever it needs to go.
[/quote] That is the real issue.

ruffrecords said:

Do you really need to solo the return of an effect?

Click to expand...

Well, you probably need some form of monitoring, checking the signal is correct in level and not distorted, which advocates for PFL, at least.

Do you really need to be able to route it to all groups.

Click to expand...

Some people do, some people don't. I almost never use groups when mixing, but I know current trends favour that (in particualr this trend of sending half-assed mixes to mastering in the form of stems).

Do you want to send reverb return to artistes foldback cans?

Click to expand...

I would think the overwhelming majority would favour that.

  At Neve we rarely built special return channels.  A 32 channel mixer would, at mixdown, use 24 channels for tracks and the remaining 8 for returns.

Click to expand...

Those were different times. Today, many cannot afford the bulk and cost of a 32 channel desk and do not have 24 physical "tracks" . A more typical set-up would be a 16ch interface going into a 16ch desk. There may be additional MIDI-sync'd synths using several bare-bone line ins.
Anyway, this particular set-up of using a hardware mixer in conjunction with a digital recorder is in itself an oddity, so I guess we can't base recommandations on the basis of conventional techniques. It's to the user to define his needs and wishes and decide accordingly. We can only try to break down the resulting MO in its basic elements.

Good morning gents.  Thank you kindly for your thoughts and suggestions. Those breakdowns of Ian's questions does get to right to the feature set tradeoffs.

Echo of an echo of an echo .. .. ....

One thing I might add,  is I've gotten used to,  and quite like having returns on faders (as opposed to rotary knobs). So that is partially an argument for just having a bigger frame console with extra channels, or perhaps simplified extra channels.

There is something nice about being able to grab faders for all the levels,  especially for something like a delay throw.