MyST 1866 USB Optical Coaxial Bluetooth headphone amp/DAC for iDevice/Mac/PC

[shigzeo]

Musica told me about a pre-order for 899$ for the MyST 1866. You can check that out here.

TouchMyApps blog has been updated about this amp/DAC, too.

Dimitri from Musica Acoustics just came back from Russia and now I've got this aluminium brick plunked on my desk. Not quite a looker, unless you find ice cream sandwiches particularly beautiful or inspiring, or happen to find hard ground edges chic. I don't.

But Russia is home to some fine audio gear, mostly in the DIY arena. It's got some big names, too. The apathetic soul in me won't bother mentioning Fischer Audio for the moment, as I'm really keen on showcasing something special.

The MyST 1866 is as far as I know, MyST's flagship DAC. As briefed in this thread's title, it has four digital inputs: USB, optical toslink, coaxial, and bluetooth. Yes, bluetooth. It works seamlessly with your Mac/PC, and less seamlessly with the iPad. The internal USB DAC is powered by the bus, and the iPad, at 20mW, simply doesn't have the sizzle to get the MyST going. You'll have to use a powered USB hub for that.

The DAC
The DAC chip is AD1866, a 16 bit DAC in SOIC package. It's obviously tied to some 24/96kHz capable receiver, because ALAC and FLAC songs in 24 bit play flawlessly via any of the MyST 1866's wired inputs, while bluetooth input plays 16bit lossless files just fine. So fine in fact, that I'm tempted NOT to bugger around with cables any longer.

Indeed, there will be some output differences favouring cables, but Bluetooth has so many advantages to running even low profile line out dock cables. Now, saying that, Bluetooth has many problems, such as the connection distance seems to be limited to a maximum of about 20 centimetres from source. Dimitri assures me that the next version will have antennae that will allow longer connection distances.

Which will be great. In order to use this amp/DAC with your iDevice portably, you MUST be committed to digital output. That means carrying something large like a Fostex HP-P1, or an AlgoRythm SOLO. Both of those items will output more reliable signal via wired toslink or coax than your iPhone's naked bluetooth. But, they make the entire package much larger.

When you are at your desk, that isn't a problem. Toslink is part of almost every MAC, and coax part of most hifi setups. By the way, the MyST 1866 has a very powerful output, so it, too, can join the ranks of GoVibe Porta Tube+ and ALO National in supporting a home rig.

The one problem with this DAC is that it has NO analogue line input. If you're heavily invested in analogue cables for use with portable amps, your investment will avail you nothing but headache. Again, you have to be prepared to make the step to digital output devices and/or bluetooth.

I argue that it's not a bad step to take.

Controls
Controls are automatic for the most part: plug any input in and toggle the select button till the appropriate input lamp lights up. The MyST 1866 will do the rest, including reclocking, sampling and whatever else it is up to.

The volume pot has good control of balance at low volumes, but the overall gain to the output is a bit too high, meaning low Ω iems with crazy sensitivity ratings will feel a bit too loud for some people even at lowest balanced volumes.

The good news for bluetooth users is that bluetooth output volume can be controlled via your iPhone, meaning that no IEM will be too loud. This is very very cool information, especially for users of high end IEMs such as the FitEar To Go! 334, or Private 333, which can suck hiss from the vacuum of space. Yep.

Regarding background noise, it is low. Not Pico Slim low, but roughly equivalent to the Centrance DACPort, which is pretty much black.

Size
As you can see from the pictures, the 1866 isn't a small DAC. It is about 1cm longer than the iPhone 4s and a little less than half a centimetre narrower. When laid horizontally onto a table, its height is roughly 1,5 cm. I'm using approximations here because I don't have a ruler, and because there is NO documentation of any sort with this device. As an engineering sample, I'm not worried at all.

Weight is sort of against it, too, when used as a wired portable DAC/headphone amp, especially if you tend to use your iPhone to read books. I spend my roughly 4 hours on the train each day reading/writing. After even 30 minutes, it's cumbersome, especially tied to the likes of an AlgoRythm SOLO.

That's where bluetooth comes in. Sort of.

As mentioned above, the current working distance is just 20 centimetres. If you're a reader, that means you can't have your iPhone in your hand, transmitting to your pocket where the MyST 1866 resides. You'll have to piggypack the devices, OR use them wired.

Again, this is an engineering sample. If the final version has a working antenna that can sustain distances of half a metre or more, I'd be in hog heaven. Imagine: amp in pocket, iPhone at your fingertips, unencumbered by cables, and attracting no more attention that it usually does.

I'll be waiting to hear more about this, and I will assume that you, too, if you are a commuter audiophile, will be waiting, too.



Outputs
Output is limited to headphone and line out. Headphone output sprouts from the front like a navel, and the line out from the back, like an off-kilter arse sphincter. The volume pot is a Japanese-made alps pentameter.

Look below for output benchmarks.

Build Quality
Again, this is an engineering sample. It has a number of issues that I assume will be fixed in the final version. Dimitri assures me that the rough tooling will be fixed in the final version. Fine. I'm not worried about that. I like the look - it reminds me of Jupiter lenses, very Russian.

What I'm worried about is the back panel, which is placed too far from the Optical and USB ports. Usually, toslink connections snap into place. Same goes for USB. Not so with the MyST 1866, whose rear plate is placed too far out. Neither snap into place and are subject to disconnection even with small jolts.

This must be fixed unless the MyST's designer wants you to use only bluetooth to connect to your device. That, or stay at home for all music listening.

I'm withholding judgement until I see a final unit.

Overall sound impressions
I've mostly been listening to bluetooth simply because it is simple, and I tend to listen to amps like this portably. I'll be testing coax and optical, too, but not right now. Generally, I'm pretty gung ho about what I hear: rich, thick, powerful sound, with primary detail focused in the mids and bass. Highs are tamed similarly to the Hifiman 801, meaning there is a high frequency roll off. DT880, K701, and Grado fans, take note: this sound signature may be a great match with your headphones.

Fans of this sort of this sort of NOS sound are many. Detractors are many, too.

I'm neutral, but can say that it pleasing for relaxing listening. I suppose relaxing is a misnomer. Rich, low-frequency detailed, pumping may be better. But, with a fairly liberal high end roll off, the sound isn't peaky at all, or 'detailed' as some people consider it.

[shigzeo]

Output Quality

[shigzeo]

Output Quality

I know it's not a proper 75Ω coax, and that this impression may be buried, using a shielded RCA to 3,5 cable works wonders for the digital coax out. I'm sure it would be better with a proper 75Ω cable, but now I've heard:

bluetooth (iPhone 4S)
optical (MacBook Pro, Apple Express, FA-66, DX100)
cobbled coax (CLAS, DX100, Colorfly C4) through my 3,5 to RCA cable.
USB (MacBook Pro)

And I like it very much. Despite the low pass filter, highs' are voluptuary. I'm still waiting on Frenchbat's impressions. Highs are my favourite frequency with this DAC/amp.