I've been searching for a reasonably priced DAC that would compliment my PS Audio Headphone amplifier, iMac, and RDV1040 CD/DVD player. I jumped on a Musical Fidelity M1DAC because I found a demo on sale. I haven't received it yet, but in digging further I found a Simaudio Moon 100 DAC for not much more than the sale price of the Musical Fidelity. I haven't really been able to find much comment on either DACs, so if anyone can comment or point me somewhere I'd appreciate it greatly. I've got 30 days to return the MF.
 
I suppose I probably should have waited for the Musical Fidelity M1 HPA combo headphone amp. with DAC, but I got tired of waiting for it to become available.
 
Finally, have I painted myself in the corner with the MF M1DAC and the PS Audio Headphone amplifier? I can already see I've got limited options in connection to the PS Audio and the iMac USB/Toslink.

I am also looking for some impressions on the Simaudio DAC.  I was drawn to it because it has sample rate indicators for all standard signals from 44.1-192 kHz.  This is useful as a diagnostic tool if nothing else.

I found a review of the Simaudio 300D which is the big brother of this DAC.  They both have the same Burr-Brown PCM-1793.
 
http://www.uhfmag.com/Tech/Moon300D.pdf
 

you might be interested in this thread:
 
http://www.computeraudiophile.com/content/Simaudio-DACs
 
imho, it looks like they've taken the $400 dac option from their integrateds & made them standalone products with understandably smaller power supplies...
 
not sure I'd pay $1600 for the 300d knowing that the USB isn't asynchronous, but I did like that they made the effort to explain themselves instead of just saying screw you...
 
 
 
Quote:

An important note about the USB input

The USB input on the MOON 100D accepts a digital audio signal of up to 16-bits/48kHz. This is the native specification of the USB input. However, if you require a higher sampling rate, there are ways to achieve this with the 100D. 

Rather than including a USB input for sampling rates exceeeding 48kHz, we opted to provide the best possible power supply, D/A converter and analog stage in the MOON 100D at this price level. Also, keep in mind that USB wasn’t originally intended for use with hi-resolution audio; there are latency issues which compromise sound quality (i.e. jitter and phase errors, etc.). These could be minimized through dedicated costly circuitry, but this would significantly drive up the cost of the100D without improving the sonic performance on any of the other inputs. 

If you intend to use the MOON 100D’s USB input, it’s very likely that your computer is a data source for music. Today most computers with a built-in sound card will have either an S/PDIF (RCA connector) or Toslink (optical connector) digital audio output, thus eliminating the need for a USB input on the 100D. Furthermore, if you’re committed to getting the most out of the music stored on your computer, then in all likelihood you have installed an after-market soundcard in your computer. Virtually all of these soundcards have at least one S/PDIF, Optical or AES/EBU (XLR connector) digital output. At this point, USB connectivity becomes irrelevant. The USB input is there for convenience as opposed to performance. 

In the event that you wish to use your computer’s USB connection with files greater than 48kHz, there are several relatively inexpensive after-market products; compact one-box USB-to-S/PDIF interfaces that will work with USB datastreams up to 24-bit, all the way up to 192kHz.

Click to expand...

i try both 100d and 300d at my local audio store( with the hd 800) and the 100d dac damage my ear, the 300d is so smooth and enjoyable. you cant enjoy your music on the 100d. i dont know how it works on others headphones, but the 100d on the hd 800 is a poor combo . 300d is perfect!

The Simaudio DACs are fantastic and while I haven't heard the M1 I remain skeptical of them. I haven't been impressed with a few of their items that I've heard. 
 
The one thing you need to remember about the Simaudio DACs is that if you primarily want to use USB just forget them. They say on their site that the USB is basically a throw away. More like a classic DAC than anything. If you want to get a good USB to SPDIF converter that's a whole 'nother story.
 
Also, as far as not pairing well with the HD800...What amp were you pushing them with, Minky?

i try both graham slee novo and graham slee solo ultra linear. and the 300d is just perfect for my ear . when i listen to the 100d .. is like .. knife on my ears. lol . 300d + novo or linear is very very great for me. 

Just thought I'd point out that the 300D now has a v2...
 
http://www.simaudio.com/moon300D.htm
 
Proper USB input.

i just won the 100D at a local Los Angeles & Orange County Audio Society event! Pretty cool as this unit escaped me. i always wanted to hear it/review it.
 
it makes for an excellent companion to the E.A.R HP4 - w/ my Audeze LCD-3's (and HD800's - I enjoy the DAC w/those too) Im experiecing some of the most incredible headphone listening  sessions!! its blowing my mind.
 
cant figure out how to post the pic from my freakin ipad.
love this thing, but hate this ****.
 
anywau - big thumbs up from me - and this unit offers Async, maybe a new version?