miniStreamer USB to S/PDIF interface

strider

Just ordered a miniStreamer USB to S/PDIF interface that I'm planning on integrating into my DIY DAC. Currently using a Hagerman HagUSB interface that's limited to 16/44.1, the S/PDIF input of the DAC does 24/96 so I'm looking forward to having something that outputs those rates. The DAC is based off of the Burr Brown evaluation board that Fred was kind enough to karma a while back. Will probably power the board off of the 5V power supply that the digital and D/A portions of the DAC use already. I'm also looking into sending the signal between the USB interface and DAC via I2S. Some of the stuff I've read about I2S seems intimidating, anybody have an idea what to expect?

FTGV

Cool,I have spent some time on miniDSP's site regarding their active DSP crossover but did'nt realize they had a USB interface.That looks like a very cost effective way to add 24/96 USB capability.(It would be even nicer if it were async. instead of isochronous).As for the I2S,this should be easily implemented on the eval board.Since I2S signal transmits the clock and data signals separately(parallel instead of SPDIF's serial)you will bypass the CS8414 input reciever on the eval board.I believe there is an area on the board to facilitate such an external input that effectively bypass's the CS8414 and will likely require some switch toggling.

strider

Attached is a picture with the hood off. Not the best looking thing, it's in an old 5 disc changer chassis for the moment, but it sounds pretty good.

The only available real estate is at the front of the box, since I don't have a faceplate I think I might just run the USB cable in through the front and right to the board. The connector on the DAC board for I2S is on the right, toggle switch right next to it to select that connector as input. Unfortunately because of the toggle on the board, I don't think I can run any other input without having to access the DAC board to switch between I2S and S/PDIF.

It shipped on 5/2, hopefully it'll be here soon, along with the 2X4 crossover board I also picked up.

FTGV

Kinda looks familiar.Thats a serious looking regulator circuit your using for the analog supplies.

strider

The regulator is a bi-polar Placid from Twisted Pear.

The miniStreamer board is really small so finding space for it isn't a problem. What is kind of annoying with it's design is the fact that there aren't holes in the board that would allow the use of standoffs to mount it to the chassis. The only option for mounting is a threaded insert on either side of the USB jack that takes a thread a step or maybe two above a 4/40.

Should be able to finish mounting it in the case tomorrow, hopefully

headrott

Keep the I2S wires as short as you can and perpendicular to any power (especially AC) lines. I2S can be heavily susceptible to noise, so the shorter the better. Looks pretty good. Enjoy your work.

Greg

strider

The board is installed in the case, it's playing music, but not hooked up in the way I anticipated going in. Any hook ups on the board, aside from the USB input and S/PDIF input and output, are via pins on an expansion connnector. Rather then wading through my Mouser catalog for a female connector I decided to try and solder the wires for I2S and power directly to the pins. It didn't work out as I'd hoped. The pin for the 5V power supply into the board pulled out when heat was applied. A screw connection terminal strip for the expansion connector would have been much easier to work with.

For the time being it is outputting to the DAC board via S/PDIF with the power being provided by the USB. Not ideal, but it's a starting point. Eventually I think I'll remove all the pins and solder directly to the board. Probably won't happen 'til I re-case the thing, at that time I'll probably upgrade to seperate power supplies for the 5V digital and DAC portions, as well as the USB interface.

For now, I'll just enjoy the 24bit/96kHz material I've found and dream about this USB to S/PDIF convertor I came across on a diyAudio banner ad: http://www.exadevices.com/exaU2I/Overview.aspx
Does 32 bit and 384kHz asynchonously, multichannel, and has a terminal strip for connections. All for the very reasonable cost of $430.

headrott

I have also been looking for a USB to I2S/SPDIF converter PCB to put into my DAC. What do you think of the ministreamer sounbd wise? I have read some say they were not impressed with it too much. I don't know what they were comparing it to though. That exadevices board looks to be phenominal. I will have to save up $430.00 to but it though.:eek: Kind of expensive for doing USB, but it will do everything I want it to. Seems to be the most forward reaching board I have seen. There are a few others out there that cost a little less, but also do not have the specs that the exadevice's board does. If you know of any USB to I2S and SPDIF conversion PCB's that could be incorperated into a Twsted Pear Buffalo II DAC and do at least 24bit/192kHz please let me know.

Greg

strider

At this point I'm not completely taken by the sound. Noise floor is noticeably higher then when I use the optical input in the DAC. Sounds a bit grainy as well. I'm not throwing in the towel on it yet; I anticipate that it'll improve quite a bit when I have it powered by it's own supply, rather then the USB bus.

I'd love to have the exadevices board, it does everything I've dreamed of and more. That price tag is a bit steep for me right now, though. I used the HagUSB previously, but it was limited to 16/44.1. I was surprised that the Twisted Pear USB board was also limited to redbook resolution and powered only by USB. From what I've seen on the market currently, I'd stick with the miniStreamer if I was integrating it into the chassis of a DAC. May not be the end all/be all, but the price to feature ratio is right there.