C&C USB DAC with simultaneously driven XLR and RCA outputs

brj · « **on:** 6 Jun 2016, 11:05 pm »

Edit: Modifying the topic title and content of this initial post to better address my primary questions.

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Hi all.

I'm helping to spec a demonstration/simulation system at work and looking for some cheap and cheerful audio options. Think of it as a 2 seat flight simulator driven by a powerful Linux workstation to handle all of the physics calculations and graphics. The combined audio solution side of this needs to be simple, reliable, rugged enough to survive semi-regular transport, Linux compatible, and approaching full-range.

I was initially going to keep it really simple and use a Peavey USB audio interface into a pair of JBL LSR308 powered monitors for a total just over $500. (Add a bit to cover a USB cable, balanced cables, and some speaker mounts.) The total solution only required 3 cables, was insensitive to ground loops, and had no audio software drivers to worry about - dead simple.

Then I was told of a desire incorporate tactile transducers (ala "Buttkickers") into each of the 2 Recaro racing-style seats. I have no experience with these units, but it looks like Parts Express carries the most options. Unfortunately, this also means that I need to find an audio interface that can simultaneously output the signal via XLR to the speakers and RCA to the subwoofer amp that will drive the tactile transducers. (I think I can get away with a Dayton subwoofer amp as a suitably cheap and cheerful option, and it conveniently includes a variable LP filter on it, so no need for crossover capability in the DAC.)

Does anyone have any recommendations for a reliable, reasonably rugged C&C USB DAC that plays well with Linux, and might even have a decent volume control? As for price... I don't have a hard number, but $250 should be an easy sell, and I can probably push that if needed.

If anyone has any feedback on a specific tactile transducer setup, I'd happily take that as well, as I have no experience with them.

Thanks!

P.S. The Linux workstation motherboard has a Realtek chipset with your usual TOSLink and 5 analog outputs. I'm assuming that it won't add much to the equation.

brj · « **Reply #1 on:** 7 Jun 2016, 01:39 am »

As I think about this a bit more, it sounds like what I need is a C&C USB DAC, preferably with volume control, that can drive both XLR and RCA outputs simultaneously. (XLRs to the powered monitors, RCAs to the tactile feedback units, much as you would subwoofers.)

The catch is finding a half-decent one for a reasonable price, and one that will work with Linux.

Any suggestions welcome! Thanks!

brj · « **Reply #2 on:** 8 Jun 2016, 11:45 pm »

Note: I changed the initial post and thread title to focus the question a bit in the hopes of generating a few responses.

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So far, it looks like the Teac UD-301 might be an option at $400. I haven't been able to confirm whether it will drive both the XLR and RCA outputs simultaneously yet, and I only find anecdotal evidence of Linux support, but it's a start...

JohnR · « **Reply #3 on:** 9 Jun 2016, 12:08 am »

~~Won't you need a different signal for the bass shakers? i.e. low pass filtered.~~ Oh OK never mind, you said that.

You could make an adapter cable and take the positive leg to the plate amp. Or use an interface with headphone output and take the single-output from the headphone socket.

JohnR · « **Reply #4 on:** 9 Jun 2016, 12:20 am »

Or use a Crown XLS to drive the bass shakers. (And a Y-splitter). They have crossover/LPF in them. Not sure if they can still be obtained cheap. Would save the time making an enclosure for the plate amp...

Atlplasma · « **Reply #5 on:** 9 Jun 2016, 02:01 pm »

This discussion on Computer Audiophile might be helpful: http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/simultaneous-xlr-and-rca-output-28076/

Also saw a post on Head-fi that indicates a TEAC UD-H01 will drive RCA and XLR simultaneously. May be true for the UD-301 as well.

brj · « **Reply #6 on:** 9 Jun 2016, 05:40 pm »

Hadn't considered a headphone output.... I'd been trying to find units without one just for the sake of simplicity, but that could work.

Regarding the tactile transducer amp, I'd been looking at the Dayton plate amps, which are enclosed. Ala the SPA250. I'll have to talk to the guys that will install the rig to find out if a plate amp or rack amp would be easier to integrate. It may be that a small rack might be preferred, especially if I can find a rack mounted USB DAC to go with it.

That said, I like the idea of the Crown, though I may look for a version that just has simple physical controls. (I can set it, take a picture, and give it to the guys that will travel with the rig and say "make sure it's set like this".)

Good link, Atlplasma - thanks! I shot a note to Teac support to ask those questions.

Let's see what Google turns up for "rack mount USB DAC"...

Thanks!

uncola · « **Reply #7 on:** 9 Jun 2016, 05:56 pm »

there's this one http://www.amazon.com/Teac-UDH01-S-Digital-Converter-Interface/dp/B00647H30S?ie=UTF8&keywords=dacmagic%20plus&qid=1465494968&ref_=sr_1_7&sr=8-7

mcgsxr · « **Reply #8 on:** 9 Jun 2016, 05:56 pm »

I have an older generation Crown XLS1500 (the new version is S I think).

The Xover settings are buried - ie you click through to set them, and then anytime you boot the amp it remembers all the settings. So there should be no issue with people needing to reset anything - in fact the lack of physical ability to obviously do so might help!

The amp is excellent.

I also own a 500w Dayton sub amp (enclosed plate style) that I use for my HT subs. Works great too. Probably weighs more than the XLS Crown!

brj · « **Reply #9 on:** 10 Jun 2016, 01:16 am »

Good point, mcgsxr, and I appreciate your reinforcing John's recommendation!

The more I think about this, the more I like the idea of a rack mounted solution. It saves a bunch of integration work, and simplifies shipping. Mount the server, surge protectors, Crown or similar subwoofer amp, and maybe the audio interface in something like this Gator Case and you'd have a single convenient package that would even let us keep many of the cables installed.

I'm not finding as much as I'd expected in the audio interface department, however. Surprisingly, The Teac UD-301 or UDH01 that uncola found (thanks!) still seem to be the most likely option, though I'd have to find a way to kludge a rack mount for it.

srb · « **Reply #10 on:** 10 Jun 2016, 02:29 am »

I think the Emotiva Stealth DC-1 half-rack 1U DAC meets your requirements, and there is an an available RK-1 Rack Mount Kit for it.

Steve

brj · « **Reply #11 on:** 10 Jun 2016, 08:08 am »

That could work - thanks, srb! No explicit mention of Linux support, but it looks like the USB chip is the cm-6331a, which is commonly supported. Price is is likely to be an issue, but I'll keep it on the list. Too bad the XDA 2 is discontinued... that looks like it would have been perfect.

Unfortunate that the UD-301 is taller than 1U (1.75")...

srb · « **Reply #12 on:** 10 Jun 2016, 08:28 am »

Quote from: brj on 10 Jun 2016, 08:08 am

No explicit mention of Linux support, but it looks like the USB chip is the cm-6331a, which is commonly supported.

I do recall a user on a forum talking about using it with Linux and foobar.

Volume display might also be nice for easily repeatable preset volume setting.

Steve

JohnR · « **Reply #13 on:** 10 Jun 2016, 01:35 pm »

There is this:

https://www.amazon.com/TASCAM-US-1200-USB-Audio-Interface/dp/B00IMN8U72

The price seems to good to be true... however the reviews are generally positive.

As above, you would need to check Linux compatibility.

There are others but the rack mount units are generally more I/O, therefore more expensive and more likely to need drivers.

JohnR · « **Reply #14 on:** 10 Jun 2016, 01:45 pm »

Quote from: brj on 6 Jun 2016, 11:05 pm

P.S. The Linux workstation motherboard has a Realtek chipset with your usual TOSLink and 5 analog outputs.

I am actually wondering why you don't use that...

srb · « **Reply #15 on:** 10 Jun 2016, 01:48 pm »

The Tascam US-1200 is inexpensive (Amazon has it discounted $0.01!), however I'm only seeing a single pair of TRS balanced outputs.

Steve

JohnR · « **Reply #16 on:** 10 Jun 2016, 02:51 pm »

If he did get a crown, he can use the Link out connectors. Otherwise, Y-splitters. (I'm assuming brj has moved on to a rack mount amp.)

JohnR · « **Reply #17 on:** 10 Jun 2016, 03:00 pm »

Oh, there's a problem with the rack mount amp idea, which is that it (the Crown anyway) won't sum left and right.

brj · « **Reply #18 on:** 10 Jun 2016, 03:03 pm »

Yes, I'm sold on the rack-mount idea. Good catch on the summing - I do need each of the 2 subwoofer outputs to the tactile transducers to be summed. I'll take a look at similar amps, though the performance of the Crown was appealing.

Funny - I found the Tascam about 10 minutes after I posted last night, but was too tired to read about it in detail. (Didn't know Tascan was the professional side of Teac.)

mcgsxr · « **Reply #19 on:** 10 Jun 2016, 04:00 pm »

Can you bridge the "tactile" things? What is their resistance?

The Crown can do a 4 ohm bridged load. I believe that effectively sum the inputs would it not?