This is a new comer in the market, but with a lot going on for it: Audinst HUD-MX1.

I took a plunge into the unknown with this one, but has proven to be a very good choice.

Here are a few features:
- Wolfson WM8740 DAC, top of the range chip
- Tenor 7022L USB receiver chip (excellent, can support 24/96)
- accurate TXCO clock (for low jitter)
- very good choice of opamps - LME49860 (on socket, so rollable) and AD8397 (quite nice and very powerfull)
- adjustable gain for the headphone amp (can easily power even my 600 ohm AKG K240DF)
- preamp function
- optical out , galvanic isolated from USB and 24/96 (great!!!)
- power supply circuit fully regulated and separated in 6 sections
- can be powered via USB or externally (excellent!).
Comes with a wallwart PSU, but if you swap that for a high quality linear regulated PSU the sound quality will increase significantly.

I bought it manly for the USB- Toslink 24/96khz feature (for my Audio-gd DAC, which has only a crude implementation of USB input). And secondly hoping it might equal my uDAC in performance so I can use it as a portable laptop source instead.

Having listening to it, not only has it granted my two wishes, but it has also proven itself to be a high quality DAC & headphone amp.

It clearly surpasses anything uDAC can achieve on every level. Maybe except the price (unless you live in Europe, where it's 115 euro + shipping, almost matching Audinst's price).

I've only had it for a few days and it's still burning in. Therefore I won't go into describing sound in detail as I need more time with it.
So far I cannot find any obvious flaws with it. It's quite neutral and natural sounding. Detail and soundstage are very good and so is bass department (good authority and control)
It also seems to have avoided the common pitfalls of low budget DACs - sounding digitized, thin and with an artificial timbre.


-->> TWEAKS [UPDATED on 25th of April]

As the LME49860 is mounted on a socket (therefore rollable) I decided to try a few opamps I've had or bought recently based on feedback from the DIY people here.
One thing must be noted: LME49860 is a very good chip, amongst the best that National Semiconductor makes. This fact should be considered before rolling opamps in Audinst, otherwise lower grade ICs would most certainly bring no benefit.

I will start my presentation with a cheap and ubiquitous opamp:

- OPA2134PA (dual, DIP pckg. no adapter needed)
This is the same opamp that came with Matrix M-stage. After only a few minutes I found that the sound quality has degraded slightly.
Most noticeable change was the decrease of soundstage size (and ambiance information), somewhat duller dynamics and inconsistency in the high frequency detail (seem a bit grainy).
Overall the the sound is a bit restrained and closed in compared to the stock LME49860.

- AD797BRZ x 2 (SOIC pckg. on BD)
This is one of the most famous top of the range opamps. I just bought a pair and, needless to say, it came with great expectations.
First impression was a positive one. AD797 strikes me as a smooth and warm sounding opamp with more presence in the lower end of the spectrum (bass and lower mids). This makes the tonal balance of the MX1 fuller and even more natural.
It's also a more resolved and more dynamic sounding opamp.
WIth large orchestral recordings, for example, string instruments are better delineated amongst each other and their timbre is rendered in a more natural and textured fashion. Double basses and cellos are now just as present as the violins and give more solidity and power to the overall sound.
LME49860 is comparison tends to "normalize" the strings in a large mass of tone (with the lower register instruments performing a more background-role).
As pleased as I am with AD797 I must be also fair - saying that it makes a radical difference and cured all wrongs in Audinst HUD-MX1 would be an overstatement.
The improvements I hear are small compared to a better source, amp or headphone. I'd say they are similar to going from a cheap interconnect cable to a high quality one. The overall sound is preserved, but cleaned and extended in a few key areas.
In the Audinst's case that initial airy, relaxed and slightly cool sound signature is less apparent, probably enhanced in the first place by the LME opamp. With AD797 in place it feels a bit more natural and life-like (alive and kicking).

- ADA4627-1ARZ x2 (SOIC pckg. on BD)
This is a new opamp made by Analog Devices and has already created a bit of a fan base. The opamps I have are the more common ARZ type (not the top spec BRZ), because they're quite a bit cheaper and I still had a few doubts regarding its' performance.
I've installed them after AD797 (which have already become my reference). First impressions were that I've went back to the stock LME. The richness and fullness I got used to was not apparent anymore.
Comparing it to LME49860 was very difficult as I've tried long and hard to pin-point differences. On some tracks ADA4627 seems more energetic with stronger bass lines, smoother highs and livelier mid-highs. On other tracks there's barely any change to talk about at all.
For now ADA4627 has failed to convince me that it's a better performer than LME49860. It's possible that it may require more burn in or simply that the circuit design is better suited for the LME opamp. I'll return to this comparison at a later time to see if my findings change.

- AD8066ARZ (dual, SOIC pckg. on BD.) xxx
This is a nice and affordable opamp.
I'd rate it half way between the stock LME and AD797. It's has a warmer, bassier sound to it and feels quite musical and nice on the ear. The highs are smoother than stock LME and maybe a bit less extended, which affects a bit ambiance cues and ultimate size of soundstage.
All in all a very likeable opamp, worthwhile using if you feel the stock LME is a bit to cool for your taste, or you have brighter or bass-shy headphones.

***MORE DETAILED INFORMATION ABOUT THE AUDINST HUD-MX1, THE SOUND AND SOME TWEAKS WILL SOON FOLLOW AND THE INTRO SECTION WILL BE UPDATED.



[size=small]COMPARISONS WITH AUDIO-GD FUN, AMB GAMMA2, Nuforce uDAC[/size]



Gear used for evaluation: AKG K701 and K240DF, Superlux HD668B headphones, Matrix M-stage amplifier, AMB Mini M3 portable amp, Neotech cables (UPOCC copper or silver with Teflon dielectric) and DIY power conditioner.
On all comparisons I've powered the Audinst HUD-MX1 with a TREAD linear regulated PSU (15V)

Music used - large variety of different genres, from large orchestral to solo blues guitarist or hard rock albums (RATM and AC/DC).
Software used - Foobar2000 ver.1.02.1 using WASAPI output (no DSP, album gain, etc).



Audinst HUD-MX1 vs. Audio-gd FUN (ver. A)

This was a comparison I've been keen on doing ever since I've bought the Audinst.
Having completed it in less time than I would have wanted, because I do not own the Fun (it was lent to me), it turned out to be a difficult comparison to do.
Is that because they sound the same? - Absolutely not! It's because they're both very good DAC/amps but in their own ways.
To cut a long story short: should you immediately sell your Audio-gd Fun and run off to buy the HUD-MX1 at half the price? - That won't be the case.
For this comparison I've used two distinct configurations in order to asses the performance of the entire units but also the DAC and amp sections apart. Because the Mx1 is a USB-only DAC, I used that input on both.
Note: The Audio-gd FUN I reviewed is version A (w/ AD1852 dac chip, ACSS gain modules and diamond output modules). The stock OPA2134 was replaced with OPA Earth by the owner and I reviewed it in this form.


1. Audio-gd Fun vs. Audinst HUD-MX1 (dac/amp mode)

At first listen both appear dead neutral and similar at the beginning. But it didn't take long and differences started to flesh out.
In tonality the FUN was slightly darker and meatier sounding than Audinst MX1. The FUN is warmer and fuller, punchier with good bass lines and softer high end.
The Audinst's main quality was actually in the highs where it seemed a bit airier.
Both units are quite neutral and natural in presentation without any obvious coloration. But when put side by side, each shows it's own interpretation of neutrality. The Fun is on the warm and punchy side, while Audinst on the cool and relaxed side.
The midrange of both is clean, grain free and quite detailed. Audinst renders female voices a bit better, while FUN does so with male voices.
Bass has more extension and impact with FUN. Audinst is still very tuneful and detailed, but lacks the power of the FUN.
The highs are better extended with Audinst, giving the sensation of more air and ambiance in the recording. It may also seem to be more detail in the music. While this is not really the case, Audinst does present it's extra perceived detail in a more obvious fashion than FUN does.

PRAT and dynamics are a strong-suit for the FUN. Rhythm and sheer drive are more obvious, large changes in dynamics are executed with power and poise. Audinst takes a more polite approach at this, that favors micro-dynamics and moderation, although it must be noted - it does not sound constrained or dull.

Soundstage is a tad deeper on Fun but wider on Audinst. The differences are however slight.
In terms of imaging Audinst has a better apparent focus to the images it renders. The FUN is slightly more diffused and creates slightly more compressed images in space (dunno if it makes sense).

All-in-all both are quite close, but the FUN shows a more mature character. While it's not technically superior to Audinst, it does have a better amplifier section that puts more muscle and drive on the table.
When using K701 I noticed a better drive from the FUN, closer to what I'm used to hearing from them. This is not to say that Audinst can't drive K701, it can, but not as good as the Fun.
When using K240DF the gap between the two became smaller, but the Fun still kept its edge.
As a preliminary conclusion - if I'd have a warmer/bassier headphone and/or an easy to drive one, then I'd have very little reasons to pay double for an Audio-gd Fun. But if you have a more demanding headphone and want a one box solution, the FUN cannot be bettered for the price (IMO)

2. Audio-gd Fun vs Audinst HUD-MX1 & Matrix M-stage.

As it became clear that the FUN's amp section is superior, I wanted to see just how much better it is by using a separate amp with Audinst.
I started off with AMB Mini3 (just completed and burning in). This is a wonderful and great sounding little amp.
Connecting it to Audinst brought a few benefits, although nothing big. For one the character slightly changed towards warm and smooth. Some of the airiness that differentiated Audinst from FUN went away and was replaced by a smoother and more even top end.
The bass lines became deeper and stronger, but still not as good as FUN.
Overall I'd say that adding a Mini3 to the Audinst is worthwhile and makes for a smoother and fuller sound with improved bass performance.

Next was the Matrix M-stage. This is an excellent amplifier of superior pedigree (Lehmann Black Cube Linear).
The difference it made while connected to Audinst was immediately obvious. There's no doubt in my mind that these two blow the FUN out of the water, hands down. The neutral and relaxed character of the HUD-MX1 is preserved, but everything else is transformed to the better. The bass in particular has greater impact and texture. The sound is richer and more vivid (better dynamics) and the soundstage extends quite a bit (especially in depth).
Audio-gd FUN sounds a bit duller in comparison and more closed in.
Now, it's debatable if buying the M-stage to complement the Audinst MX1 is worthwhile.
Together they cost 450$ (W/ free international shipping for both), which is significantly more than the FUN (330$ + shipping). The sound is well worth it but at this price point there are other options that might be better for some users.

Just out of curiosity I've connected the M-Stage to the FUN's DAC output to evaluate both the amp section but also the DAC section.
As good as the integrated amplifier section is, the M-stage made a clear improvement.
It's hard to say which of the two (FUN + M-stage vs. Audinst + M-stage) is better.
In a way this comparison has brought me back to my initial findings when testing the units as a whole, in dac/amp mode. The differences however are not so distinct now, but I tend to favor the Audinst which feels more natural and spacious in presentation. Your millage may vary.

Initially I intended to swap opamps on both units and see how they change/improve in that direction. Unfortunately my time with Audio-gd Fun ran out a bit to soon, as I had to return it this afternoon. The owner is a friend and colleague and I'm sure I'll have another shot at this again.
So, the comparison is pretty much done. I hope I've covered at lest the essential bits that differentiates them and might help you in your future decisions .



Audinst HUD-MX1 vs AMB Gamma2 + AMB Mini3

Unfortunately my Gamma2 has died on me (probably because a cold joint) so I cannot finish the scheduled comparison this week.
I won't be able to get it back up and running sonner than the weekend.
I'll update the review some time after that.

I did however spend two evenings comparing the two, and what I've listened so far favors the Gamma2 by some margin, depending on power.

Gamma2 has a smoother and more refined character which indicates a more mature sounding DAC than Audinst (probably because of it's upsampling and ASRC circuit). Gamma2 is improving the already very good HUD-MX1 in just about every department.
Sound signature is slightly warmer and fuller on Gamma-2. Also more engaging (timing and rhythm is very nicely executed).
Overall Gamma-2 feels and sounds like an expensive source, while Audinst like a very good budget source (honest, plenty resolute, but not as refined)


Differences aren't big and the PSU has actually the last word here:

- Gamma2 fed by TREAD PSU is superior in just about anything to Audinst fed by USB or wallwart. Both fed by TREAD the gap is not as large and Audinst can hold its' own.

- Gamma2 fed by USB is hardly different or superior to Audinst fed by the TREAD.

- Both fed by USB, there are a few differences, but nowhere near as big as discrete.
I think feeding the Gamma2 by USB is a crime.
It's such a good sounding DAC, but it doesn't show it's full colors and bloom until fed by clean power.

..........................................
UPDATES TO FOLLOW






Further resources:
- The official product webpage
- project86's excellent review on Head-fi
- Headfonia review and comparative review.






..... (to be continued)

man. i'd love to hear this guy.
right now i'm using an ibasso d4 dac into a hifiman ef2a as my work rig. and it's pretty good, but this might simplify or improve on that...

i mean, don't we always wonder??

I've got one as well, full review to be finished tomorrow (hopefully). I've been using it for a few weeks now and I must say it is very impressive.

I was hoping to have a scoop on it, but my review is taking so long that a few people seem to have beaten me to the punch. I'll have to check out the Headfonia review when mine is completely done (don't want to know what they think until I've already posted mine).

I'll post a link here to my review when it is done.

EDIT it is done, link in my sig.

PS with all these USB DACs with built in HP amps (and some are even portable), how do we know which section to post in? Computer audio? Source? Portable amps? Desktop amps? Some of these things fit in seveal catergories....

I would personally post in Computer Audio because the MX1 has the unique option of USB-in. However, simply by looking at it, I can tell it is a very versatile product. Seeing as it fits my needs, I might very well get one myself in the near future.

By the way, Project86, which cables did you use in your review?

Quote:



I'm not a cable voodoo believer (apologies if that offends anyone!) so I mostly use Impact Acoustics SonicWave cables. Specifically for this review I used THESE for interconnects, THESE from the amp to the speakers when using the mx1 as pre-amp, and THIS when using the mx1 as a USB to SPDIF converter with another DAC. I used some silver USB cable that I had laying around, nothing high end.

Hope that doesn't make my findings worthless for some people. Although I guess with "better" cables things could only improve right?

How would this compare to an Auzen Forte or Xonar STX? They're similar in price and all function as dac+amp.

It's a much better DAC/amp than any of those.

I see from your profile that you have an audio-gd dac19. While I know the two are in different price ranges, any thoughts on how they compare for use as dacs?

There is very little to compare actually.
DAC-19 is a better performer in just about any category. But it's logical to be so, given the price difference and technologies involved.
DAC19 is one of the very best DACs you can buy in the 1000$ range, while Audinst is a really good budget DAC with a nice amp section to boot.

Audinst performs closer to Audio-gd Fun.
I have it on loan at the moment and I have a hard time comparing them (because they're really close)

As DAC only both units are very very close, but with different presentations.
As DAC/amp the FUN takes advantage of it's excellent amplifier section and looks like a definite winner.

I'll add my final thoughts on the matter after I'll experiment with different opamps on both units.(AD797, ADA4627, OPA2107 and OPA Moon and Earth).

Quote:



I'm looking forward to your comments.

I'll update the first post with my finding later on tonight.
I've compared the MX1 to Audio-gd FUN, Gamma2, uDAC and Audiotrak HD2 Advance using different configurations (amps).

Some quick thoughts (not criticisms): It would be better off having coax output instead of optical for best results, IMO. Also, the Tenor USB chip I suggested to Kingwa to use, but he was told, IIRC, by Tenor themselves that it isn't very reliable, which is funny considering I had the Audiotrack Prodigy Cube which died on me. However, if it gives you an improvement, then all well and good. I look forward to your impressions.

-->> UPDATED first post with Audio-gd FUN comparison review!

Quote:



You are right, coax would have been better.
For Audinst HUD-MX1 Toslink makes sense as it is by nature insulated from USB. They would have needed a Pulse transformer and appropriate circuit design to obtain that.
Given the low price of the unit I'd say it's a fair trade.

Quote:



I have no knowledge about the reliability of this chip, but let's hope for the best
I've added my impressions ( MX1 vs. FUN) in my first post.
More impressions and comparisons will come soon.

very nice! if you have the FUN version that comes w/ a stock OPA2604, it would benefit greatly from an opamp roll as well: