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View Full Version : Inexpensive introduction to Computer Audio the M2 TECH 'hi iFace'



purite audio
30-11-2009, 18:27
Purite Audio are delighted to announce the arrival of the 'hiFace' usb to s/pdif
interface, the hi face uses kernel streaming ( to bypass the OS sound kernel ) and it's own proprietary drivers to produce an extremely high quality low jitter signal from your USB port, ideal if you just want to try 'computer audio'.
I have been listening to it for a while and it is far better than I had hoped.
http://www.m2tech.biz/products.html
Keith

Themis
30-11-2009, 18:44
This is a great converter, extremely rare !

Thanks for the info.

purite audio
30-11-2009, 20:53
Thanks Dimitri, I hope it will provide a low cost ( yet high quality) introduction to computer audio, price is £100 inc vat and delivery, Keith.

The Vinyl Adventure
01-12-2009, 00:28
could this go inbetween pc and beresford... of have i got the wrong end of the stick??

John
01-12-2009, 05:51
The idea is for DACs that do not have a USB connection I use something similar I got from ebay and sound quality is pretty good I am not sure how much it will help on the Beresford

Alex_UK
01-12-2009, 07:33
The idea is for DACs that do not have a USB connection I use something similar I got from ebay and sound quality is pretty good I am not sure how much it will help on the Beresford

It would depend which Beresford - the 7510 doesn't have a USB input so this would be exactly what you would need - but of course £100 would mean you could but a Caiman instead.

Themis
01-12-2009, 08:46
It can be used also for higher than 24/48 streams... ;)

purite audio
01-12-2009, 10:41
I haven't tried the 'hi face' with a BDAC it may improve the sound quality by providing a low jitter s/pdif signal, and as Themis says you can play everything up to 24/192 if your dac is capable of those sampling rates.
Keith.

Mr. C
01-12-2009, 10:49
We have had these for a quite a few months now, for the outlay it is a great way of introducing yourself to high resolution music.
Good for you Keith

purite audio
01-12-2009, 22:10
Tony Hi, yes the superb sound quality really continues to surprise me, generally I have been hugely disappointed with USB connections, vb Keith.

Themis
01-12-2009, 22:19
A friend compared Musiland 02 with hiFace : The M2tech is a clear winner as much more detailed.

He gives several precise music examples where the differences are apparent and evident.

purite audio
02-12-2009, 16:49
I have tried a couple of usb/spdif converters including the musiland , to be honest I wasn't all that impressed, the 'hiface' is a completely different animal.
Keith.

leo
02-12-2009, 20:51
Wish I'd have known about these before:doh: currently playing about with one of those Musiland USD's, totally agree they are crappy as is, attenuation lower than it should be, dodgy looking pulse traffo's, 50R BNC instead of 75R etc, I'll do a few tweaks, if no good it'll go with the rest of the tat, in the trash:lol:

Anyway nice one Keith, USB's been limited for a while now so its good to see things are coming along, the Hiface looks a handy little device.
I presume the Hiface helps reduce the noise usually on the USB's DC supply?

purite audio
02-12-2009, 21:29
Leo Hi, thats a technical question isn't it? You know thats not my strong point, I can send you one to play with if you like, on DIY audio they have already been taking them apart!
http://www.diyaudio.com/forums/digital-source/153191-m2tech-hiface-usb-spdif-24-192khz-asynch-5.html
It does sound good though, much much better than I had anticipated, I thought they would be an inexpensive introduction to PC audio ( which they are) but the quality of the output has taken me aback somewhat.
Very Best,Keith.

leo
04-12-2009, 17:35
Thanks Keith, once I've finished faffing about with the Musiland I may give the Hiface a go, should be interesting to see how it compares once its been modded, the Musiland may or may not turn out to be a gold plaited turd:lol:

Also thanks for the link, I'll take a read through that;)

purite audio
04-12-2009, 19:46
Leo Hi, if you pm me your address I will send you one, I would value your opinion, we tried it on a Mac yesterday ( beta drivers ) and it sounded very good, especially with the Amarra software, it continues to surprise, regards Keith.

Complin
05-12-2009, 18:14
Does anyone know of a computer interface that will provide an XLR or even a balanced output? The main problems I have found with USB is one often gets background noise such as hum. I also belive there is a technical limitation regarding bit rate and frequency so its not really up to the job.
I have a DAC with an I2s input which should remove these limitations but can only find US based suppliers of computer interfaces that support this at the moment

Themis
05-12-2009, 18:19
A computer interface ? Like a Transporter, for instance ?
Or do you mean a PC soundcard with balanced analog outputs ?

purite audio
05-12-2009, 18:36
Complin Hi, the Lynx 16aes interface is highly rgarded but it is expensive £500 ish, it provides a vey low jitter signal via AES, or for £100 you could try the M2TECH 'hiFace' usb/spdif interfacewe have had excellent results with it.
Keith.

technobear
05-12-2009, 19:25
Does anyone know of a computer interface that will provide an XLR or even a balanced output? The main problems I have found with USB is one often gets background noise such as hum. I also belive there is a technical limitation regarding bit rate and frequency so its not really up to the job.
I have a DAC with an I2s input which should remove these limitations but can only find US based suppliers of computer interfaces that support this at the moment

Assuming you are talking about a digital output here, XLR digital outputs or balanced digital outputs adhere to the AES/EBU standard. This is very similar to S/P-DIF and is most certainly not I2S.

As for the bit-rate/frequency limitation of USB, the new M2Tech hiFace appears to do away with this limitation.

purite audio
05-12-2009, 19:29
Chris Hi, yes it does play everything up to 24/192, which I think might be unique at the moment.
Keith.

Themis
05-12-2009, 19:41
And, I would add, that XLR digital output is inferior to coaxial, due to limitations of connectors and cables used for XLR.
In this aspect, too, the hi iFace is perfect. ;)

technobear
05-12-2009, 20:00
And, I would add, that XLR digital output is inferior to coaxial, due to limitations of connectors and cables used for XLR.

Would you care to quote a reference for that assertion?

What limitations of the connectors are you talking about?

XLR's have a characteristic impedance of 110 ohms which is more than can be said for most phonos.

What limitations of the cables are you talking about?

You just need a 110 ohm cable in order to construct a balanced digital interconnect. There are plenty of good ones to choose from.

As far as I am currently aware, your above assertion is simply not true. On what is it based?

Themis
05-12-2009, 20:54
Would you care to quote a reference for that assertion?
Sure, mate : http://forums.slimdevices.com/showthread.php?t=71262


Best parts:


AES/EBU is a defective technology, use coax S/PDIF instead.



AES/EBU doesn't fix anything in s/pdif, it makes it worse. It uses wiring and connectors that lack the bandwidth and impedance matching for RF signaling. Just because XLRs are suitable for analog audio doesn't make them good for high frequencies. It's included on Transporter frankly because of legacy expectations, and perhaps in a pro environment you might need it for one reason or another (got the cable handy, used up all the other inputs, etc) but I don't recommend it.


Its nice to know someone else agrees with me about AES EBU, I always thought I was the lone voice in the wilderness.

Anyway I see two main reasons for the inferiority of AES/EBU.

1. XLRs are horrible RF connectors. In order to send a square wave fairly faithfully the interface must support a bandwidth many times higher than the frequency of the square wave. For the signals in question that is getting well up into the RF spectrum where the XLRs are terrible. The impedance varies radically with frequency which will cause all kinds of bizarre reflections. The choice of XLR was a very poor choice.

2. Output voltage. The S/PDIF electrical spec is 0.5V into 75ohms, but the AES/EBU is 3-5V into 110 ohms. Think about that for a second, what happens when you put 5volts across 110 ohms? You get almost 50mA of current flowing. This means the driver sitting in the source box has to be able to dump between 30-50ma into the cable. That causes huge current spikes in the power and ground pins of the driver chip which is going to cause big noise spikes in the power and ground planes of the board. If you are not extremely careful that is going to cause significant jitter in the output signal.

All modern high speed interfaces use less than 0.5V signal.

As far as I can tell the XLRs were chosen because studios had lots of microphone cables and wanted to use them. Because they are such lousy RF transmission lines they had to go with high voltages to make sure there was some signal left at the end.

I wouldn't really discuss Sean's or John's views... I guess they know quite a bit more than me on digital transports...

technobear
05-12-2009, 21:57
Sure, mate : http://forums.slimdevices.com/showthread.php?t=71262
etc.

Thanks Dimitri. This is news to me.

I was aware that RCA phono plugs and sockets are not ideal for the job and that BNCs are much more suitable but I had not heard any of this stuff regarding XLRs.

Themis
05-12-2009, 22:04
Thanks Dimitri. This is news to me.

I was aware that RCA phono plugs and sockets are not ideal for the job and that BNCs are much more suitable but I had not heard any of this stuff regarding XLRs.
Yes, I used to think the same, because of the balanced stages etc. Because of the analog interconnections, in fact. XLR are better, for several reasons.

But, it seems that for digital, it's the contrary ! RCA/BNC connectors have got their revenge ! :eyebrows:

purite audio
07-12-2009, 12:19
Interesting article T, John Swenson certainly knows his stuff as does Sean Adams!
Keith.

Maximum
07-12-2009, 22:49
I really don't know whether to go for this or just get a squeezebox touch. The hiface is quite a bit cheaper but doesn't offer the disconnection like the touch will, which may mean less noise problems from the pc and the further option of using a better power supply, and the option of optical. The touch can give a mobile music without switching the pc on, but hiface will give directsound support for games and videos and give more choice of playback software. Then I could use my netbook to give mobility too but it's probably not as elegant a solution as the touch.

Themis
07-12-2009, 22:55
I really don't know whether to go for this or just get a squeezebox touch. The hiface is quite a bit cheaper but doesn't offer the disconnection like the touch will, which may mean less noise problems from the pc and the further option of using a better power supply, and the option of optical. The touch can give a mobile music without switching the pc on, but hiface will give directsound support for games and videos and give more choice of playback software. Then I could use my netbook to give mobility too but it's probably not as elegant a solution as the touch.
Hi Rob,

What is the rest of your system ?

Maximum
07-12-2009, 23:10
My most common route of listening is currently, X-fi XtemeMusic soundcard > Beresford 7520 > Grado SR125. This is using a Blue Jeans Belden 3.5mm jack (that's Creative for you) to RCA cable. The 7520 has the MLC 5/6 mod and AD826 opamps.