But before we get started. A quick overview. MP3's, m4a's, etc. of today are all digital files which require the digital signal to be converted to analog via a DAC (Digital to Analog Converter) and then that signal is amplified for output to headphones or speakers. Many digital audio players do not allow you to bypass their internal circuitry at all (e.g. the iPod). However, you can boost these signals with a separate amplifier (a few of which we've seen reviewed by Peter). Only a very few provide a digital output (usually in the form of Coaxial or Toslink) that will bypass the internal DAC, allowing them to be used with a separate DAC.
So, for the most part, the Music Hall DAC 25.2 is solely aimed at users looking to listen to their huge libraries of digital music from home. Especially for those of you who've already thrown down the cash on a decent set of loudspeakers and are looking for the next big upgrade to improve your sound, adding in a DAC would greatly improve many aspects of your listening experience.
Now, the moment you've all been waiting for: the sound. Setting up a side-by-side comparison with our Macbook Pro plugged in via RCA (to the receiver) and our desktop PC via optical Toslink (to the Music Hall DAC and then receiver), we found a significant improvement in clarity, sound separation, and sound stage when going through the DAC. Even throwing sound sources like online radio (Pandora) and lower bitrate MP3s, we could instantly tell something interesting was going on with our sound output.
But the biggest jump in quality was when we threw on our lossless FLAC files and high bit rate MP3s (320kbps and up). From the Fiery Furnaces "I'm Going Away" to Diana Krall's "Girl in the Other Room" to Morcheeba's sweet vocals on "Summertime," each string strum and piano accompaniment felt extracted and placed in just the right spot. It was simply amazing to hear pieces of songs we've never heard before even though they were from the same file.
Now, we realized it wouldn't be fair comparing watermelons to oranges, so we took it upon ourselves to remove our amplifier, unplug our power conditioner, and re-cable our entire A/V setup to match that of an average-Joe home theater. This meant the Music Hall DAC would be going directly to an Onkyo A/V receiver routed to a pair of stereo loudspeakers. Now, how does it sound without all that extra fluff?
We tossed the same 20-song test at rearranged setup and still found ourselves still pretty darn impressed. Even though the fulfilling highs were partially gone and seemed to be a little more compressed without the extra gear, the same breathtaking clarity remained downright amazing compared to the output of our built-in DACs on our Macbook Pro or PC sound card. Now, having fully broken in the unit for 3-4 weeks, it continues to sound better every time we run it, not that it sounded anything but fine from the outset.
Modding culture. There also seems to be an audiophile sub-culture out there who are willing to plunk down $30 to upwards of up to $225 on new tubes to replace with the included Electro-harmonix 6922 one. We've read that certain tubes such as the EAT and NOS 6922 Mullard have been claimed to allow the Music Hall 25.2's performance to match match DACs at 3-4 times its price. While we're skeptical of this, it's nice to know that there's room for modding for those who are interesting in doing so. We should also note that the tube is only used for the single ended RCA outputs.Other tidbits include the thoughtfully included headphone jack, which performed just fine aside from the fact that it was just fine. Compared to everything else we've heard from the 25.2, we were slightly disappointed. However, when running an interconnect from the RCA audio-out and into our headphone amp, we instantly found ourselves in audio heaven.
Perhaps if we had the opportunity to hold onto the unit a little longer, we'd swap out a tube or two, but there's no rush. The Music Hall 25.2 is still probably one of the best things we've seen done for digital playback in our systems since the introduction of the CD player in 1984. At $600 bones a pop, it's in no way cheap for casual home audio consumers, but if you've already got everything else in place (an amp, good speakers, fancy headphones), you'd be shortchanging yourself if you didn't place the Music Hall 25.2 DAC at the top of your Christmas wish list this year.
The Music Hall DAC 25.2 is available now for $595 at a local audio store near you.
Oh, and big thanks to Eugene for letting us utilize his mad photography skills while we await the arrival of our Lumix GF1!