bareyb
500+ Head-Fier
- Joined
- Feb 7, 2013
- Posts
- 779
- Likes
- 67
I've been on a bit of a quest lately for a transportable "All-In-One" solution for my workshop and office. Something with a DAC that I can hook up to my laptop and enjoy music from iTunes, Pandora, CD Player etc. I got my hands on three models that fit my needs and I thought I'd share my findings. I've done extensive testing on all three units and I was surprised to see how much has to go into these comparisons! I've been checking notes and typing for hours! I have new respect for all you guys who write these comparisons and reviews on a regular basis.
The Project: Find an AIO (all-in-one) solution that I can break down and move easily from workshop to office to home. The less cables to plug in the better. A small footprint is a must. It must have enough power to run my HiFi Man HE500 Planar Magnetics.
The Quest: I began my journey into this hell we call "choosing an Amp" about a month or so ago. Initially I was going to use an iPod for my source and got a FiiO E17 to up the sound quality a bit (the learned folks at Amazon said it was a must have!) I loved it. So much so, that it made me wonder that thing we all wondered at some point in our addiction... "if this sounds this good, I wonder how much something better would sound???" And therein lies the crux of the problem and the reason for the gaping hole in the bottom of my wallet.
I started out with a NuForce "iDo" and an iPod... Not enough power. Deal breaker right there. Didn't even get as loud as the E17. What it DID do, is show me how good an amp can really sound. So the logical thing to do next is what? You guessed it. Spend more money! Which led me to the next "price tier" in my journey, the "almost a thousand bucks!!!" level. Which led me squarely to the....
CEntrance DACMini:
Price: $795.00
Power Output: 1.5W @ 32 ohm
I picked the DACMini for 2 reasons. One it was highly regarded and I was told it got "very loud" (not true) and secondly because it was available on Amazon PRIME. There's no price you can put on being able to return something without any fees or hassles. I do not like having to do it this way, but it's the World we live in now... Sigh...
The DACMini Arrived in a nice box with decent instructions and a USB cable for hooking up to a computer. It's a nice looking little unit, very reminiscent of the Mac Mini (hence the name DAC Mini). I like shiny stuff so it's styling worked for me. Build quality is good and it definitely has the look and feel of something upscale.
Features and Hookup: It's got a host of input options including [size=small]line-level input for your portable music player, and an S/PDIF input for your digital sources. USB for connecting a computer. One of my requirements was for variable preamp outs in case I wanted to bypass the amp in the unit and route the signals to a bigger outboard Amp.[/size][size=small]The DACMini does not come with Variable Output by default. They are fixed. [/size]
[size=small]If you want that feature you have to try and find one with it already enabled as I did, or you have to send it in to CEntrance and pay them a hundred bucks to do it for you. The same goes for increasing the GAIN. It can be increased by 10 dB, but not by the user. You would again, have to send it to the factory and pay another hundred bucks to have it done. [/size][size=small]Personally? I think that was a short sighted decision on the part of CEntrance, but I'll save the complaining for later... [/size]
Sound Quality: No complaints here! Far from it. The minute you put on your headphones you know you have hooked up to something goooood. REally good to put in CEntrace speak. I love the sound signature of the Mini. It's open, airy, full of detail and has some pretty darn respectable Bass extension. Soundstage is wide and deep.
On my HE400s it did get a little bright at times and if I had to pick a nit that probably be it. At lower volumes it was less so, and as always was source dependent. Overall not a huge problem unless you try to push it's little Amp too hard. Then it gets kind of strident and gives you the clear message "turn me down". We'll talk more about the Amp later. Where the DACmini really shines is on Vocals however. It'll send chills down your spine... Of the three units I tested I liked the Vocals on the DACMini best.
Volume and Power and Slam! (oh my): I like my music loud sometimes, so anything I buy has to have some muscle. If it doesn't sound good LOUD that's a deal breaker. The problem with the darn Mini is that it comes without a user adjustable gain!!! WHY??? I'll never understand their decision to make it a one hundred dollar add-on that would require being without the Amp for however many weeks while they do the "upgrade". I was lucky enough to find one with the Variable output already enabled for free, but that's rare.
Needless to say I didn't pop for the upgrade(s) because I wasn't sure if I was going to keep the Amp! I'd suggest a user adjustable gain for future models... In the end, I honestly don't think it would have made much difference, because the Mini was already beginning to clip at the Volume Knob's extreme position so upping the gain would probably not have gotten me much more useable volume anyway. Would simply have reached the distortion level earlier on the knob.
I'm not saying the Amp isn't adequate because it is. It's gets somewhat loud with my less than efficient HE500s and would probably be fine for most folks with less "need for speed" or easier to drive headphones.
Pros: Smallest Footprint, best vocals, great price.
Cons: No user adjustable gain. No user adjustable "variable or fixed" pre-outs. Each "option" will cost you a hundred bucks and shipping charges to send it back to CEntrance. Amp is powerful enough for fairly loud listening levels, but be advised. If you are a rock monster or have inefficient headphones, it may not have enough grunt for you.
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Up Next:
Benchmark DAC1:
Price: $1,595.00
Power Output: 1.1W @ 32 Ohm
This one came about for two reasons as well. One, it has a remote control. For my situation that would solve a host of problems for me. Secondly because the Mfr. publishes the Power Output Specs in Voltage output rather than rating it at 32, 50, 300, and 600 ohm like almost everyone else out there. The GRACE didn't have normal specs either... Between the two I misinterpreted the specs and thought the Benchmark was the more powerful of the two, it turns out it wasn't.... more on that later... Of the three units, I thought the DAC1 was the best looking. It's got a well thought out front Panel and the styling is cool.
Features and Hookup: If you thought the DACMini had a lot of input output options, this one takes the cake. It's pretty much got them all. You can tell this was designed to be used in a studio environment and the solid construction and solid steel remote control bely that fact.
It's got a standard removable plug (nice) and a large controls and LEDS up front to let you know what input you are on etc. This unit does have adjustable gain, but it is accomplished via jumpers inside the box. Not ideal for me as I did NOT want to scratch anything and it made me nervous to 'crack the case' as I wasn't sure if I was going to keep it. My fears were allayed by Benchmarks' Sales Rep who was kind enough to give me the go ahead via email. So on to the next most important section...
Sound Quality: If I had to characterize this unit in one word I couldn't, It would take two, and those words would be "extreme clarity". The DAC in this thing is amazing. I see why it's the reference for magazines like Stereophile. It is very accurate and is often described as "organic". It's obvious this was made for the studio environment and the priority in this unit is clearly to "have no sound at all". I think for the most part it accomplishes that, except for in one area...
The Bass. The folks at Benchmark pride themselves on their low impedance design (less than 1 ohm output) and the very high dampening factor that is a result of that. Unfortunately, all that control is at the expense of some Bass texture and extension. The Bass is there, but it's not as musical as it is on either of the other offerings. The midrange and high end are very detailed and it is those areas that this little AIO really shines.
You can hear every instrument separately and distinctly. Vocals are ever so slightly forward and you can hear the singer's breathing. The realism on voices is literally startling at times. It's a beautiful thing all that clarity and detail, but it does so at the expense of sounding a little bit "sterile" and thin. I have seen other reviewers describe the DAC1 as "analytical" and I think that's probably a fair characterization. Of course, for the purpose this product was intended, (studio work) that is exactly what you want. I would never describe this Amp's sound signature as "warm and toasty", but if clarity and detail is your thing, along with pristine highs, the DAC1 could very well make you cry.
Volume, Power and Slam: The unit ships from the factory with the -10 dB jumpers installed. With this setup on my HE500s I was able to turn the volume control all the way up with no distortion. Unfortunately, it didn't reach the kind of volume levels I require so that prompted an email to Benchmarks' Sales Rep asking him if they had a problem with me cracking the case. He not only didn't have a problem with it, he insisted!
Well that made a huge difference I'm happy to say. The unit SCREAMS now. Not all of that glorious 10 dB's of gain is useable however. You can crank up the volume to about 3 o'clock without distortion, but beyond that, it starts getting pretty ragged and starts clipping on heavy Bass passages. This unit had the least power of the three and it showed.
I began to wonder if the sound signature of this unit was because of the Amp or the DAC. I bypassed the Amp in the Benchmark and ran the DAC in it into the Amp on the m903 and it sounded a lot better and it became difficult to distinguish the differences. The DAC in the DAC1 is the true star. If you are looking primarily to use your AIO as a dedicated headphone amp this may not be the best choice of the three. If you are looking for a remote controllable preamp/DAC to use as a link to a bigger system this unit would perfect for that. The DAC in it is amazing and reportedly the DAC in the new DAC2 is better than the one in this unit in every regard. Unfortunately at the time of this writing they were not available for purchase and they are going to cost you $300.00 more than the DAC1. Which puts it squarely in the same price category as the m903.
Pros: Clarity, detail, accuracy. One of the most highly regarded DACs in the industry (Sabre). Lots of connection options.
Cons: If Bass is your thing, this may be a bit lacking. Has lowest power output of it's 2 rivals. Must crack the case to adjust the gain and the only option is to raise it by a full 10 dB (which is too much). A more adjustable gain would be a nice option.
_____________________________________________________________________________
Up Next:
Grace Designs m903
Price: $1895.00
Power Output: 2.1W @ 32 Ohms
This is another unit with remote control and by now I'd decided if I could make that work that's what I was going for. Even if it meant using one of these handy AIO's as a remote controlled preamp to a more powerful amp. I was beginning to think I was simply not going to be able to find an all-in-one with enough intestinal fortitude to satisfy my lust for Power. That is until I had the opportunity to make the acquaintance of the Grace Designs m903...
Features and Hookup: The m903 makes a very nice initial impression. For one thing, the m903 is much better looking in person than on the Internet. Kind of the opposite of what is normally true... It's a little larger than it appears in picture. It's very solidly built and weighs the most of any of the contenders. It looks very expensive when you see it in person. Very nice materials all the way around. Upscale looking connectors and very nice fit and finish. Lots of connection options on this unit as well. XLR's RCAs, Coax, S/PDIF, you name it. It's got 'em all.
Beyond the vast array of hookup options, this one has a really extensive feature set. The most extensive of all three units tested. You can adjust almost everything on this. You can have different output levels on every output and even have a different listening levels on the two headphone jacks on the front (nice touch). You can gang the outputs or leave them separate, and you can choose to have variable output or fixed, all accessible through the Menu system.
The Menu system gets some guff out there in the world wide web, but I didn't really have much trouble with it myself. Once you learn the abbreviations they use it's pretty straight forward and intuitive. It's not much different from any other Menu you would see on a high end Printer. Just pick the heading, press the button, and scroll the options and confirm. Easy pea-sey (at least for me-sey) I was adjusting things and turning on and off the Crossfeed Circuit (more on that later) at will the very first night.
It has the best GAIN implementation that I've seen on any amp. It is fully adjustable in .5 dB steps in either direction, up or down (up to 9.5 dB gain or cut) and each output can have it's level adjusted separately! That's cool (and useful). In other words you can level match all your components with ease. There's too many options to list them all, but suffice to say, there's something in there for everyone. It's got a numerical volume readout which is very nice, and easy to see from across the room. I like a numerical readout so that really worked for me. It's got an array of LEDs on the front panel to let you know what input you are on and if the Corssfeed circuit is enabled or not. It's got a nice BIG retro looking on/off button and the volume knob accelerates the faster you spin it. You can have it power up to any volume level you wish and can even have the lights dim for night use. If you forget to turn it off, it will turn itself off after 15 minutes of non use.
Sound Quality: The best way to characterize the sound signature of the m903 is "warm and robust". No lack of Bass on this bad boy. It's got some power too, and that manifests itself in the Bass response as well. The DAC in this unit is a Burr Brown model and it is also very accurate, but it achieves that accuracy in a different way. The Burr is a warmer, more musical sounding DAC than the Sabre, but it does so at the expense of some of the Sabres' clarity and detail. It's a trade off all Amp Mfrs. have to make and in the case of the m903, I think the designers made all the right choices. The midrange is soaring and there is no sign of Sibilance or Tizz.
It's got a smooth presentation that is never bright or fatiguing, and the vocals are natural sounding with a nice timbre to the voices. The best part of m903 is the Bass. Of the three units tested this not only had the hardest hitting Bass, it also had the most texture and layering of any of them. If you love to hear the fingers pluck the bass strings and hear that DEEP Bass roll off into oblivion then this is the AIO for you. The bass is tight, punchy, deep and detailed.
Crossfeed Circuit: A part of me wanted to hate it to be honest, so I could write it off as a "gimmick" and never mess with it ever again. After hearing it though, I'm quickly becoming a believer. It definitely fills in the "hole" in the middle of the sound image, but you do lose a little bit of separation in the process.The best part is that when the circuit is activated, you get a nice little "Bass Boost" to go with it. It's quite a neat little deal. It adds a nice bit of low end grunt that I found quite pleasing and it put a big fat smile on my face more than once. I kept going back and forth with it, and found there are advantages to both having it on, and having it off. You can toggle the option on or off with the remote or through the Menu system so it's easy to A/B the effect and see for yourself.
Volume, Power, and Slam: To be fair to the DACMini and the DAC1, this unit has more than double the power of the DAC1 and the DACMini has no user adjustable gain. So let's just get to the point shall we? The m903 just trounced everyone in the Power and Slam categories. Not to put too fine a point on it, but this thing is a BEAST. It had the highest clean output of all three (by far) from the factory. It's plenty loud stock, and at full volume there is no distortion. It was the first Amp I've had that was "loud enough" for me, but I raised the gain by 4 dB anyway just because I could. I like to have a little knob left at the end the dial. Makes me feel better somehow that I'm not "maxing it out"... The m903 is the Power and Slam Champion. It's got a nice liquid presentation with plenty of detailed Bass ad smooth highs. If you like a warm amp with a bit honey drizzled on top, this just might be the AIO for you. It was for me.
Pros: Power for days. Deep, detailed Bass, smooth highs, Honey dipped Mids. Large feature set, virtually everything is adjustable. Numerical volume readout. Excellent Crossfeed circuit with Bass enhancement. Plenty of ins and outs.
Cons: Not as detailed in the midrange as the others. Remote control is an extra charge. Most expensive of the three.
Conclusions: All three AIOs are very good products. The DACMini is a great deal for the money and would probably satisfy most people. especially if you have easy to drive cans (well easier than the HE500s anyway) and don't need GAIN control or Variable outs. Those mean a trip to the factory and a hundred bucks for each change...
The Benchmark is a clean machine. If clarity and detail is your thing and lots of Bass isn't, this might just be the AIO for you. The DAC is first rate (no glitches) and the mids and highs are very clean. It's got an included remote control and would make a nice building block for a larger system.
The Grace Designs m903 is my favorite of the bunch. If I were designing an AIO for myself this is close to what I'd design. It seems clear from talking to the company founder, Michael Grace (he answered all my email questions personally, even late at night) he is very passionate about what they do and he clearly puts in all the little details that he wants for himself. One of the perks of being the boss I guess. Once you start comparing features and power, the price starts to look like a bargain. It's also got a fantastic Burr Brown DAC and a beast of an internal Amp that would make this an awesome investment as a stand alone listening station, or as a remote controlled preamp for a larger system.
To sum up, I'm grateful to have found the AIO I've been looking for and I'm happy to be able to share my findings with the community. You guys have been so much help to me and It's nice to have a chance to contribute. I hope this is helpful to future seekers of AIOs.
Cheers and happy listening!
The Project: Find an AIO (all-in-one) solution that I can break down and move easily from workshop to office to home. The less cables to plug in the better. A small footprint is a must. It must have enough power to run my HiFi Man HE500 Planar Magnetics.
The Quest: I began my journey into this hell we call "choosing an Amp" about a month or so ago. Initially I was going to use an iPod for my source and got a FiiO E17 to up the sound quality a bit (the learned folks at Amazon said it was a must have!) I loved it. So much so, that it made me wonder that thing we all wondered at some point in our addiction... "if this sounds this good, I wonder how much something better would sound???" And therein lies the crux of the problem and the reason for the gaping hole in the bottom of my wallet.
I started out with a NuForce "iDo" and an iPod... Not enough power. Deal breaker right there. Didn't even get as loud as the E17. What it DID do, is show me how good an amp can really sound. So the logical thing to do next is what? You guessed it. Spend more money! Which led me to the next "price tier" in my journey, the "almost a thousand bucks!!!" level. Which led me squarely to the....
CEntrance DACMini:
Price: $795.00
Power Output: 1.5W @ 32 ohm
I picked the DACMini for 2 reasons. One it was highly regarded and I was told it got "very loud" (not true) and secondly because it was available on Amazon PRIME. There's no price you can put on being able to return something without any fees or hassles. I do not like having to do it this way, but it's the World we live in now... Sigh...
The DACMini Arrived in a nice box with decent instructions and a USB cable for hooking up to a computer. It's a nice looking little unit, very reminiscent of the Mac Mini (hence the name DAC Mini). I like shiny stuff so it's styling worked for me. Build quality is good and it definitely has the look and feel of something upscale.
Features and Hookup: It's got a host of input options including [size=small]line-level input for your portable music player, and an S/PDIF input for your digital sources. USB for connecting a computer. One of my requirements was for variable preamp outs in case I wanted to bypass the amp in the unit and route the signals to a bigger outboard Amp.[/size][size=small]The DACMini does not come with Variable Output by default. They are fixed. [/size]
[size=small]If you want that feature you have to try and find one with it already enabled as I did, or you have to send it in to CEntrance and pay them a hundred bucks to do it for you. The same goes for increasing the GAIN. It can be increased by 10 dB, but not by the user. You would again, have to send it to the factory and pay another hundred bucks to have it done. [/size][size=small]Personally? I think that was a short sighted decision on the part of CEntrance, but I'll save the complaining for later... [/size]
Sound Quality: No complaints here! Far from it. The minute you put on your headphones you know you have hooked up to something goooood. REally good to put in CEntrace speak. I love the sound signature of the Mini. It's open, airy, full of detail and has some pretty darn respectable Bass extension. Soundstage is wide and deep.
On my HE400s it did get a little bright at times and if I had to pick a nit that probably be it. At lower volumes it was less so, and as always was source dependent. Overall not a huge problem unless you try to push it's little Amp too hard. Then it gets kind of strident and gives you the clear message "turn me down". We'll talk more about the Amp later. Where the DACmini really shines is on Vocals however. It'll send chills down your spine... Of the three units I tested I liked the Vocals on the DACMini best.
Volume and Power and Slam! (oh my): I like my music loud sometimes, so anything I buy has to have some muscle. If it doesn't sound good LOUD that's a deal breaker. The problem with the darn Mini is that it comes without a user adjustable gain!!! WHY??? I'll never understand their decision to make it a one hundred dollar add-on that would require being without the Amp for however many weeks while they do the "upgrade". I was lucky enough to find one with the Variable output already enabled for free, but that's rare.
Needless to say I didn't pop for the upgrade(s) because I wasn't sure if I was going to keep the Amp! I'd suggest a user adjustable gain for future models... In the end, I honestly don't think it would have made much difference, because the Mini was already beginning to clip at the Volume Knob's extreme position so upping the gain would probably not have gotten me much more useable volume anyway. Would simply have reached the distortion level earlier on the knob.
I'm not saying the Amp isn't adequate because it is. It's gets somewhat loud with my less than efficient HE500s and would probably be fine for most folks with less "need for speed" or easier to drive headphones.
Pros: Smallest Footprint, best vocals, great price.
Cons: No user adjustable gain. No user adjustable "variable or fixed" pre-outs. Each "option" will cost you a hundred bucks and shipping charges to send it back to CEntrance. Amp is powerful enough for fairly loud listening levels, but be advised. If you are a rock monster or have inefficient headphones, it may not have enough grunt for you.
---------------------------------------------------------------------------------------------------------------------------------------------------------
Up Next:
Benchmark DAC1:
Price: $1,595.00
Power Output: 1.1W @ 32 Ohm
This one came about for two reasons as well. One, it has a remote control. For my situation that would solve a host of problems for me. Secondly because the Mfr. publishes the Power Output Specs in Voltage output rather than rating it at 32, 50, 300, and 600 ohm like almost everyone else out there. The GRACE didn't have normal specs either... Between the two I misinterpreted the specs and thought the Benchmark was the more powerful of the two, it turns out it wasn't.... more on that later... Of the three units, I thought the DAC1 was the best looking. It's got a well thought out front Panel and the styling is cool.
Features and Hookup: If you thought the DACMini had a lot of input output options, this one takes the cake. It's pretty much got them all. You can tell this was designed to be used in a studio environment and the solid construction and solid steel remote control bely that fact.
It's got a standard removable plug (nice) and a large controls and LEDS up front to let you know what input you are on etc. This unit does have adjustable gain, but it is accomplished via jumpers inside the box. Not ideal for me as I did NOT want to scratch anything and it made me nervous to 'crack the case' as I wasn't sure if I was going to keep it. My fears were allayed by Benchmarks' Sales Rep who was kind enough to give me the go ahead via email. So on to the next most important section...
Sound Quality: If I had to characterize this unit in one word I couldn't, It would take two, and those words would be "extreme clarity". The DAC in this thing is amazing. I see why it's the reference for magazines like Stereophile. It is very accurate and is often described as "organic". It's obvious this was made for the studio environment and the priority in this unit is clearly to "have no sound at all". I think for the most part it accomplishes that, except for in one area...
The Bass. The folks at Benchmark pride themselves on their low impedance design (less than 1 ohm output) and the very high dampening factor that is a result of that. Unfortunately, all that control is at the expense of some Bass texture and extension. The Bass is there, but it's not as musical as it is on either of the other offerings. The midrange and high end are very detailed and it is those areas that this little AIO really shines.
You can hear every instrument separately and distinctly. Vocals are ever so slightly forward and you can hear the singer's breathing. The realism on voices is literally startling at times. It's a beautiful thing all that clarity and detail, but it does so at the expense of sounding a little bit "sterile" and thin. I have seen other reviewers describe the DAC1 as "analytical" and I think that's probably a fair characterization. Of course, for the purpose this product was intended, (studio work) that is exactly what you want. I would never describe this Amp's sound signature as "warm and toasty", but if clarity and detail is your thing, along with pristine highs, the DAC1 could very well make you cry.
Volume, Power and Slam: The unit ships from the factory with the -10 dB jumpers installed. With this setup on my HE500s I was able to turn the volume control all the way up with no distortion. Unfortunately, it didn't reach the kind of volume levels I require so that prompted an email to Benchmarks' Sales Rep asking him if they had a problem with me cracking the case. He not only didn't have a problem with it, he insisted!
Well that made a huge difference I'm happy to say. The unit SCREAMS now. Not all of that glorious 10 dB's of gain is useable however. You can crank up the volume to about 3 o'clock without distortion, but beyond that, it starts getting pretty ragged and starts clipping on heavy Bass passages. This unit had the least power of the three and it showed.
I began to wonder if the sound signature of this unit was because of the Amp or the DAC. I bypassed the Amp in the Benchmark and ran the DAC in it into the Amp on the m903 and it sounded a lot better and it became difficult to distinguish the differences. The DAC in the DAC1 is the true star. If you are looking primarily to use your AIO as a dedicated headphone amp this may not be the best choice of the three. If you are looking for a remote controllable preamp/DAC to use as a link to a bigger system this unit would perfect for that. The DAC in it is amazing and reportedly the DAC in the new DAC2 is better than the one in this unit in every regard. Unfortunately at the time of this writing they were not available for purchase and they are going to cost you $300.00 more than the DAC1. Which puts it squarely in the same price category as the m903.
Pros: Clarity, detail, accuracy. One of the most highly regarded DACs in the industry (Sabre). Lots of connection options.
Cons: If Bass is your thing, this may be a bit lacking. Has lowest power output of it's 2 rivals. Must crack the case to adjust the gain and the only option is to raise it by a full 10 dB (which is too much). A more adjustable gain would be a nice option.
_____________________________________________________________________________
Up Next:
Grace Designs m903
Price: $1895.00
Power Output: 2.1W @ 32 Ohms
This is another unit with remote control and by now I'd decided if I could make that work that's what I was going for. Even if it meant using one of these handy AIO's as a remote controlled preamp to a more powerful amp. I was beginning to think I was simply not going to be able to find an all-in-one with enough intestinal fortitude to satisfy my lust for Power. That is until I had the opportunity to make the acquaintance of the Grace Designs m903...
Features and Hookup: The m903 makes a very nice initial impression. For one thing, the m903 is much better looking in person than on the Internet. Kind of the opposite of what is normally true... It's a little larger than it appears in picture. It's very solidly built and weighs the most of any of the contenders. It looks very expensive when you see it in person. Very nice materials all the way around. Upscale looking connectors and very nice fit and finish. Lots of connection options on this unit as well. XLR's RCAs, Coax, S/PDIF, you name it. It's got 'em all.
Beyond the vast array of hookup options, this one has a really extensive feature set. The most extensive of all three units tested. You can adjust almost everything on this. You can have different output levels on every output and even have a different listening levels on the two headphone jacks on the front (nice touch). You can gang the outputs or leave them separate, and you can choose to have variable output or fixed, all accessible through the Menu system.
The Menu system gets some guff out there in the world wide web, but I didn't really have much trouble with it myself. Once you learn the abbreviations they use it's pretty straight forward and intuitive. It's not much different from any other Menu you would see on a high end Printer. Just pick the heading, press the button, and scroll the options and confirm. Easy pea-sey (at least for me-sey) I was adjusting things and turning on and off the Crossfeed Circuit (more on that later) at will the very first night.
It has the best GAIN implementation that I've seen on any amp. It is fully adjustable in .5 dB steps in either direction, up or down (up to 9.5 dB gain or cut) and each output can have it's level adjusted separately! That's cool (and useful). In other words you can level match all your components with ease. There's too many options to list them all, but suffice to say, there's something in there for everyone. It's got a numerical volume readout which is very nice, and easy to see from across the room. I like a numerical readout so that really worked for me. It's got an array of LEDs on the front panel to let you know what input you are on and if the Corssfeed circuit is enabled or not. It's got a nice BIG retro looking on/off button and the volume knob accelerates the faster you spin it. You can have it power up to any volume level you wish and can even have the lights dim for night use. If you forget to turn it off, it will turn itself off after 15 minutes of non use.
Sound Quality: The best way to characterize the sound signature of the m903 is "warm and robust". No lack of Bass on this bad boy. It's got some power too, and that manifests itself in the Bass response as well. The DAC in this unit is a Burr Brown model and it is also very accurate, but it achieves that accuracy in a different way. The Burr is a warmer, more musical sounding DAC than the Sabre, but it does so at the expense of some of the Sabres' clarity and detail. It's a trade off all Amp Mfrs. have to make and in the case of the m903, I think the designers made all the right choices. The midrange is soaring and there is no sign of Sibilance or Tizz.
It's got a smooth presentation that is never bright or fatiguing, and the vocals are natural sounding with a nice timbre to the voices. The best part of m903 is the Bass. Of the three units tested this not only had the hardest hitting Bass, it also had the most texture and layering of any of them. If you love to hear the fingers pluck the bass strings and hear that DEEP Bass roll off into oblivion then this is the AIO for you. The bass is tight, punchy, deep and detailed.
Crossfeed Circuit: A part of me wanted to hate it to be honest, so I could write it off as a "gimmick" and never mess with it ever again. After hearing it though, I'm quickly becoming a believer. It definitely fills in the "hole" in the middle of the sound image, but you do lose a little bit of separation in the process.The best part is that when the circuit is activated, you get a nice little "Bass Boost" to go with it. It's quite a neat little deal. It adds a nice bit of low end grunt that I found quite pleasing and it put a big fat smile on my face more than once. I kept going back and forth with it, and found there are advantages to both having it on, and having it off. You can toggle the option on or off with the remote or through the Menu system so it's easy to A/B the effect and see for yourself.
Volume, Power, and Slam: To be fair to the DACMini and the DAC1, this unit has more than double the power of the DAC1 and the DACMini has no user adjustable gain. So let's just get to the point shall we? The m903 just trounced everyone in the Power and Slam categories. Not to put too fine a point on it, but this thing is a BEAST. It had the highest clean output of all three (by far) from the factory. It's plenty loud stock, and at full volume there is no distortion. It was the first Amp I've had that was "loud enough" for me, but I raised the gain by 4 dB anyway just because I could. I like to have a little knob left at the end the dial. Makes me feel better somehow that I'm not "maxing it out"... The m903 is the Power and Slam Champion. It's got a nice liquid presentation with plenty of detailed Bass ad smooth highs. If you like a warm amp with a bit honey drizzled on top, this just might be the AIO for you. It was for me.
Pros: Power for days. Deep, detailed Bass, smooth highs, Honey dipped Mids. Large feature set, virtually everything is adjustable. Numerical volume readout. Excellent Crossfeed circuit with Bass enhancement. Plenty of ins and outs.
Cons: Not as detailed in the midrange as the others. Remote control is an extra charge. Most expensive of the three.
Conclusions: All three AIOs are very good products. The DACMini is a great deal for the money and would probably satisfy most people. especially if you have easy to drive cans (well easier than the HE500s anyway) and don't need GAIN control or Variable outs. Those mean a trip to the factory and a hundred bucks for each change...
The Benchmark is a clean machine. If clarity and detail is your thing and lots of Bass isn't, this might just be the AIO for you. The DAC is first rate (no glitches) and the mids and highs are very clean. It's got an included remote control and would make a nice building block for a larger system.
The Grace Designs m903 is my favorite of the bunch. If I were designing an AIO for myself this is close to what I'd design. It seems clear from talking to the company founder, Michael Grace (he answered all my email questions personally, even late at night) he is very passionate about what they do and he clearly puts in all the little details that he wants for himself. One of the perks of being the boss I guess. Once you start comparing features and power, the price starts to look like a bargain. It's also got a fantastic Burr Brown DAC and a beast of an internal Amp that would make this an awesome investment as a stand alone listening station, or as a remote controlled preamp for a larger system.
To sum up, I'm grateful to have found the AIO I've been looking for and I'm happy to be able to share my findings with the community. You guys have been so much help to me and It's nice to have a chance to contribute. I hope this is helpful to future seekers of AIOs.
Cheers and happy listening!
