New miniDSP 2x8 / 4x10 card

JohnR · « **on:** 10 Apr 2011, 11:48 pm »

The miniDSP folks dropped a surprise one in their store a few days ago:

http://minidsp.com/products/minidspkits/2-x-in-8-x-out

It has two analog ins and 8 outs, all balanced. The matching plugin is "4 in 10 out" with the two extra ins and outs obtained by using the S/PDIF interface card.

It also runs at 96 kHz.

Best source of information is the PDFs linked on the page above.

Tyson · « **Reply #1 on:** 12 Apr 2011, 12:02 am »

I wonder what the sound quality is compared to a DCX2496, which is what I have.

JohnR · « **Reply #2 on:** 12 Apr 2011, 01:37 am »

Hard to say. One thing I like about the small 2x4 board is that it's very minimal, everything happens on one chip. This one is more complex and it looks like there are buffers on inputs and outputs. There may be some mods that could be done to it although a lot of it is SMD. Regardless, it looks like a pretty good fit for my "big rig" - which was evolving to having three boards, with this I can do it all with one (I think).

mgalusha · « **Reply #3 on:** 12 Apr 2011, 02:03 am »

Since it's designed for consumer audio, the voltage levels are much lower than a DCX, so it would likely use more of the available bits since the DCX performs best when the internal digital levels are fairly high.

Lots 'o electrolytic coupling caps on the outputs, same as the DCX. They might be just a safety measure, you would have to measure the dc offset to know for sure. Looks like it may have some DC-DC switching converters on board as the data sheet shows +/- 15V rails. Almost certainly one could provide the needed power externally.

Looks pretty darn cool tho.

JohnR · « **Reply #4 on:** 12 Apr 2011, 02:17 am »

Quote from: mgalusha on 12 Apr 2011, 02:03 am

Looks like it may have some DC-DC switching converters on board as the data sheet shows +/- 15V rails.

Oh yeah - so it does! Didn't notice that. Must be for the opamps. So you'd hope the outputs could be DC-coupled then. Anyway, thinking it through...

roscoeiii · « **Reply #5 on:** 12 Apr 2011, 02:35 am »

From the looks of things, no option for digital in and digital out. Too bad (if I am reading this right)

Tyson · « **Reply #6 on:** 12 Apr 2011, 02:37 am »

I think they have a separate module called the miniDIGI that does just that.

JohnR · « **Reply #7 on:** 12 Apr 2011, 02:40 am »

Yes, the miniDIGI is an extra $40.

roscoeiii · « **Reply #8 on:** 12 Apr 2011, 02:52 am »

Well, well. That does put it on the radar.

Any advantages of using this for DSP instead of a software solution since I just send a digital signal from my Mac Mini to my DAC for the vast majority of my listening?

JohnR · « **Reply #9 on:** 12 Apr 2011, 03:42 am »

Depends on what you mean by "DSP"

For active crossovers, this is a good solution for 3-5 way and various .1/2/4 configurations. The smaller boards are good for 2-way and 2.1, or you can use two for a 4-way. If you're just doing eq and can do it on the Mac, I'd do that. I believe Pure Music can also do active crossovers although you then need a multichannel DAC, someone mentioned one recently although I don't recall what it was.

roscoeiii · « **Reply #10 on:** 12 Apr 2011, 03:48 am »

Hmm, I will have to think this one through.

NHT X2 subwoofer crossover does seem to have some competition all of a sudden, even if I need to do ADC and then DAC steps...

JohnR · « **Reply #11 on:** 12 Apr 2011, 10:08 am »

Quote from: roscoeiii on 12 Apr 2011, 03:48 am

NHT X2 subwoofer crossover does seem to have some competition

At a quick glance you can probably do all of that with the miniDSP 2x4. None of the miniDSP solutions have more than two inputs though, so if you really need the extra LFE input then it might not work for you. This article I wrote may help you get an idea of whether the miniDSP 2x4 box would work for you.

Tyson · « **Reply #12 on:** 19 Apr 2011, 08:25 pm »

Reading through the user manual of the new 2x8 miniDSP - there is a provision on the board for a master analog volume to be hooked up so a single pot can control output of all channels simultaneously. Very cool!

Also, you don't need the mini-DIGI for this unit, it can be configured to have up to 2 digital inputs.

It's also set up so it can be run off an external 12V power supply, including batteries. Nice.

Russtafarian · « **Reply #13 on:** 19 Apr 2011, 08:45 pm »

All I can say is WOW, WOW, WOW! What a cool toy. I'm finally getting a handle on my 2x4 miniDSP board. This one opens up a whole new range of possibilities.

JohnR · « **Reply #14 on:** 21 Apr 2011, 02:36 am »

Quote from: Tyson on 19 Apr 2011, 08:25 pm

Also, you don't need the mini-DIGI for this unit, it can be configured to have up to 2 digital inputs.

The miniDIGI is still needed, to provide the SPDIF input. The digital in/out selection is to the I2S signals on the expansion connector, which the miniDIGI interfaces to. I suspect the miniStreamer could be used for USB input (with custom wiring) but upsampling to 24/96 would be needed on the source computer. I think. I need to look into that a bit.

JohnR · « **Reply #15 on:** 21 Apr 2011, 03:32 am »

BTW the miniDSP people mentioned on their forum that an 8x8 version is in the works. Probably not of interest for 2-channel audio but very interesting for HT or MC.

Tyson · « **Reply #16 on:** 21 Apr 2011, 04:59 am »

John, one thing not clear to me - do you have to choose between 2 analog inputs OR 2 digital inputs? Or can you use 2 analog inputs AND 2 digital inputs?

JohnR · « **Reply #17 on:** 21 Apr 2011, 08:27 am »

My reading of it is that they are both active all the time (unless muted in the input pane). So whichever inputs are selected for an output in the matrix mixer are summed to that output. In my case, I'll use this as an easy way to have both analog and digital inputs (and just play only one at a time...). Then there'll be a switch to select which analog input, and one to select which digital input (done in the miniDIGI). I think I'm going to just skip the USB input, and use an external convertor for that.

JohnR · « **Reply #18 on:** 23 May 2011, 11:27 am »

I got my 2x8 board today. Haven't had a chance to connect the hardware yet, although I've had the plugin for a couple of days and copied over my OB 4-way settings. Hopefully I can get it running in the next few days.

nwboater · « **Reply #19 on:** 23 May 2011, 02:20 pm »

Quote from: JohnR on 23 May 2011, 11:27 am

I got my 2x8 board today. Haven't had a chance to connect the hardware yet, although I've had the plugin for a couple of days and copied over my OB 4-way settings. Hopefully I can get it running in the next few days.

I'll be anxiously awaiting your reports on the 2x8, especially on SQ. There have been almost no SQ reports on this unit.

I am going active with my 3 fronts in our HT. At the same time we are converting our Klipschorn L & Rs and LaScala clone center to 2 way, but want to keep the option open of going back to 3 way. With our Danley DTS-10 sub that's 4 inputs and up to 10 outputs.

We presently have a DCX2496 for the sub. I have considered doing some output stage mods to it and also getting a 2x8. Between the two units there would be enough I/O. I would really love to have 2 2x8s but that is getting really pricey.

Do you still have a 2x4 MiniDSP? It would be especially interesting and helpful for many of us to get a SQ comparison between the 2x4 and 2x8.

Looking forward to your reports.

Rod