Recently, I had begun thinking about downsizing my system, both in an attempt to save a little bit of money, and in anticipation for moving abroad for a year. I needed a system that would be compact enough to bring with me, but also one which would work on 220 volts.
I was using a Little Dot MK-II amplifier for a while, and then purchased an Opera Consonance Cyber-10... both of which sounded great with my Sennheiser HD-600s, but neither of which were very "travel friendly", in that they were too large to pack in a bag and only worked on 110v. Enter the Keces DA-152 to the scene. It's smallish footprint and user-selectable voltage input intrigued me greatly.
Here are some of the specs, taken (and modified by me) from the Keces description found on AudioCircle:
* Updated DA-151 circuit, with 100% DC circuit and no capacitor in signal path or DC servos.
* High performance headphone amp with up to 250mA/channel capability.
* Variable output via RCA, no need for a separate pre.
* Over 26V p-p output, which is appox 9.2V RMS.
* Revised power circuit that further lowers the noise level of our DAC.
* A new and more powerful transformer, designed just for DA-152 and its headphone load.
* Updated power input module to the newer ones used by DA-131.1; you can switch between 115V and 230V.
* Dimension: 215 ×205 ×80mm (W*L*H), excluding knobs and connectors.
Before buying the DA-152, I was using a DA-151 USB DAC as my source, and was nothing short of blown away by its build and performance. It was possibly the most neutral DAC I've heard at this lower price point, and one of the physically cleanest looking DACs I've ever seen, period. This gave me confidence in purchasing the Keces combo unit even though this particular piece hasn't quite yet made it fully into the limelight, being that there are so few reviews on the internet. Hopefully, this short review will help give more people the confidence to try it, as well.
Build Quality: As with the DA-151, I continue to be thoroughly impressed with the structural and aesthetic quality of the DA-152. The feel of the unit itself is almost unheard of at this price point: there is naught a piece of thin, resonant steel to be found. The chassis is thick, very substantial, and is topped by a thick piece of smoked plexiglas. Possibly the most impressive part of the build quality is the layout itself: clean, clean, clean is the only way to describe the board, cables, and power supply inside the 152. (here's a looksee inside the unit, but please forgive the scratches... it is a used unit that I purchased from a fellow Head-Fi member)
The 1/4" singled-ended headphone input is not a locking one, but it grips firmly to the plug, and does not let go very easily once it is in. Good.
A couple of things need to be said about the volume pot. Shining a light inside, I've tried to find the make of the pot, but I can't quite see what it is. However, it is touted to be a reasonably good one, with a retail of $25, far beyond the budget allocated for volume pots in many other headphone amplifiers at this price point, let alone DAC/amp combos. That being said, however, there are some points which may be potential problems for some people. First, there is channel imbalance at lower levels (mine shifts to the right). This is not a problem with my HD-600s, since my regular listening level is at a point above this threshold. However, when listening to Alessandro MS-1 (recently sold), my preference for a lower listening level combined with the higher sensitivity of these phones led to my needing to first find this threshold and then turn the knob ever so slightly above this point. For some music, this resulted in a volume which was louder than I normally prefer (please note that I really do tend to listen to my music at lower-than-average volume levels). Second, there seems to be some sticking in the range of the knob which begins at a point above my normal listening level. The sticking is so noticeable that, at first, I thought that it was the end of the range for the pot. This does not affect the sound, though, and I'm tempted to think that the cause may be due to how the knob itself is attached, because the motion becomes smooth again after turning it past a certain point.
Sound Quality: I'm afraid that this section will be fairly short, and wanting in description. How much can one say about a sound signature that doesn't exist??
I'll begin with the first impression that was made on my ears: the attacks. Nearly every instrument sound that can have a noticeable attack (snare hits, tom hits, kick drum hit, guitar pluck, guitar strum, even hand claps and finger snaps) was much more evident on the DA-152 than my previous Little Dot. This held true for both the high-impedance Sennheisers as well as the low-impedance Alessandros. I was very impressed with how punchier the MS-1s sounded on the Keces than the Little Dot. Even at low volumes, these defined attacks lead to a much more punchy and immediate presentation to the music. Combined with a very "black" background (I mean EXTREMELY quiet!!), the Keces has a very dynamic sound, even on the Sennheisers, which some consider to be laid back and un-involving. The more immediate attacks also help give a clearly focused image, resulting in a more realistic soundstage, one in which instruments and voices are placed solidly, and can be located with near pin-point accuracy.
With regards to frequency range, the Keces is no slouch at the extremes. I was most pleased by this particularly with the low end, because I previously felt that the only drawback to the HD-600 was a rolled-off bass response. I'm glad to say that I no longer think that this is the case. Whether it be due to further bass extension on the part of the DA-152 or greater control of the headphones by a solid-state design, I can't be sure. I am sure, however, that unless you are a veritable bass freak, the headphone amplifier in the Keces combo should suit your bass needs just fine.
As far as the overall sound is concerned, I thought at first that the DA-152 was not so much "warm" as it was ever-so-slightly accentuated in the midrange, and ever-so-slightly rolled off in the treble. The more I listen now, however (I've had the unit for about 2-3 weeks), the more I've come to be convinced that this is evidence not of any flaws in the frequency response of the Keces (in particular, because I liked it!), but instead of its greatest strength: the DA-152 is extremely transparent. After listening to a couple of different headphones, it has become more and more clear to me that what I was hearing at first was not the sound signature of the Keces, but of the Sennheisers. The common description of the HD-6x0 sound was previously hidden from my ears, but was now made as clear as day. Just as the DA-151 DAC, the DA-152 combo is about as neutral as they come, which means that it will allow you to truly hear not only what your headphones are capable of, but what they truly sound like. I would recommend this DAC/amp combo to anyone who owns a pair (or multiple!) of headphones that have a sound signature that they truly adore, because the DA-152 will simply get out of the way and let you hear that sound in all of its glory. I'm not sure if component synergy has as big of a role to play with the Keces as with other amps, because it doesn't seem to be as much a matter of matching or complementing the headphones that are plugged into it as it is a matter of allowing you to hear the sound of those headphones; nothing more, nothing less.
One final note on the sound that I feel I should mention is that this is most definitely a solid-state amp. What I mean by this is that it won't wow you with its euphoric midrange, nor will it sweeten the treble of any overly-bright headphones. It may even be, to some people's ears, a tad dry. I am a tube man in the deepest reaches of my heart, and will always have a place for that special sound... however... I am thoroughly impressed with this solid state amp. This says a lot, I think. I knew when I plugged in my Sennheisers that I was listening to solid state, and for a brief moment felt the twinge of want for a liquid midrange pierce my soul, but that's when and where it ended. The control and neutrality of the DA-152 has impressed me so much that I dare say that it might be a long while before I return to tubes. At this point, I see (read: hear) no need.
I was using a Little Dot MK-II amplifier for a while, and then purchased an Opera Consonance Cyber-10... both of which sounded great with my Sennheiser HD-600s, but neither of which were very "travel friendly", in that they were too large to pack in a bag and only worked on 110v. Enter the Keces DA-152 to the scene. It's smallish footprint and user-selectable voltage input intrigued me greatly.
Here are some of the specs, taken (and modified by me) from the Keces description found on AudioCircle:
* Updated DA-151 circuit, with 100% DC circuit and no capacitor in signal path or DC servos.
* High performance headphone amp with up to 250mA/channel capability.
* Variable output via RCA, no need for a separate pre.
* Over 26V p-p output, which is appox 9.2V RMS.
* Revised power circuit that further lowers the noise level of our DAC.
* A new and more powerful transformer, designed just for DA-152 and its headphone load.
* Updated power input module to the newer ones used by DA-131.1; you can switch between 115V and 230V.
* Dimension: 215 ×205 ×80mm (W*L*H), excluding knobs and connectors.
Before buying the DA-152, I was using a DA-151 USB DAC as my source, and was nothing short of blown away by its build and performance. It was possibly the most neutral DAC I've heard at this lower price point, and one of the physically cleanest looking DACs I've ever seen, period. This gave me confidence in purchasing the Keces combo unit even though this particular piece hasn't quite yet made it fully into the limelight, being that there are so few reviews on the internet. Hopefully, this short review will help give more people the confidence to try it, as well.
Build Quality: As with the DA-151, I continue to be thoroughly impressed with the structural and aesthetic quality of the DA-152. The feel of the unit itself is almost unheard of at this price point: there is naught a piece of thin, resonant steel to be found. The chassis is thick, very substantial, and is topped by a thick piece of smoked plexiglas. Possibly the most impressive part of the build quality is the layout itself: clean, clean, clean is the only way to describe the board, cables, and power supply inside the 152. (here's a looksee inside the unit, but please forgive the scratches... it is a used unit that I purchased from a fellow Head-Fi member)
The 1/4" singled-ended headphone input is not a locking one, but it grips firmly to the plug, and does not let go very easily once it is in. Good.
A couple of things need to be said about the volume pot. Shining a light inside, I've tried to find the make of the pot, but I can't quite see what it is. However, it is touted to be a reasonably good one, with a retail of $25, far beyond the budget allocated for volume pots in many other headphone amplifiers at this price point, let alone DAC/amp combos. That being said, however, there are some points which may be potential problems for some people. First, there is channel imbalance at lower levels (mine shifts to the right). This is not a problem with my HD-600s, since my regular listening level is at a point above this threshold. However, when listening to Alessandro MS-1 (recently sold), my preference for a lower listening level combined with the higher sensitivity of these phones led to my needing to first find this threshold and then turn the knob ever so slightly above this point. For some music, this resulted in a volume which was louder than I normally prefer (please note that I really do tend to listen to my music at lower-than-average volume levels). Second, there seems to be some sticking in the range of the knob which begins at a point above my normal listening level. The sticking is so noticeable that, at first, I thought that it was the end of the range for the pot. This does not affect the sound, though, and I'm tempted to think that the cause may be due to how the knob itself is attached, because the motion becomes smooth again after turning it past a certain point.
Sound Quality: I'm afraid that this section will be fairly short, and wanting in description. How much can one say about a sound signature that doesn't exist??
I'll begin with the first impression that was made on my ears: the attacks. Nearly every instrument sound that can have a noticeable attack (snare hits, tom hits, kick drum hit, guitar pluck, guitar strum, even hand claps and finger snaps) was much more evident on the DA-152 than my previous Little Dot. This held true for both the high-impedance Sennheisers as well as the low-impedance Alessandros. I was very impressed with how punchier the MS-1s sounded on the Keces than the Little Dot. Even at low volumes, these defined attacks lead to a much more punchy and immediate presentation to the music. Combined with a very "black" background (I mean EXTREMELY quiet!!), the Keces has a very dynamic sound, even on the Sennheisers, which some consider to be laid back and un-involving. The more immediate attacks also help give a clearly focused image, resulting in a more realistic soundstage, one in which instruments and voices are placed solidly, and can be located with near pin-point accuracy.
With regards to frequency range, the Keces is no slouch at the extremes. I was most pleased by this particularly with the low end, because I previously felt that the only drawback to the HD-600 was a rolled-off bass response. I'm glad to say that I no longer think that this is the case. Whether it be due to further bass extension on the part of the DA-152 or greater control of the headphones by a solid-state design, I can't be sure. I am sure, however, that unless you are a veritable bass freak, the headphone amplifier in the Keces combo should suit your bass needs just fine.
As far as the overall sound is concerned, I thought at first that the DA-152 was not so much "warm" as it was ever-so-slightly accentuated in the midrange, and ever-so-slightly rolled off in the treble. The more I listen now, however (I've had the unit for about 2-3 weeks), the more I've come to be convinced that this is evidence not of any flaws in the frequency response of the Keces (in particular, because I liked it!), but instead of its greatest strength: the DA-152 is extremely transparent. After listening to a couple of different headphones, it has become more and more clear to me that what I was hearing at first was not the sound signature of the Keces, but of the Sennheisers. The common description of the HD-6x0 sound was previously hidden from my ears, but was now made as clear as day. Just as the DA-151 DAC, the DA-152 combo is about as neutral as they come, which means that it will allow you to truly hear not only what your headphones are capable of, but what they truly sound like. I would recommend this DAC/amp combo to anyone who owns a pair (or multiple!) of headphones that have a sound signature that they truly adore, because the DA-152 will simply get out of the way and let you hear that sound in all of its glory. I'm not sure if component synergy has as big of a role to play with the Keces as with other amps, because it doesn't seem to be as much a matter of matching or complementing the headphones that are plugged into it as it is a matter of allowing you to hear the sound of those headphones; nothing more, nothing less.
One final note on the sound that I feel I should mention is that this is most definitely a solid-state amp. What I mean by this is that it won't wow you with its euphoric midrange, nor will it sweeten the treble of any overly-bright headphones. It may even be, to some people's ears, a tad dry. I am a tube man in the deepest reaches of my heart, and will always have a place for that special sound... however... I am thoroughly impressed with this solid state amp. This says a lot, I think. I knew when I plugged in my Sennheisers that I was listening to solid state, and for a brief moment felt the twinge of want for a liquid midrange pierce my soul, but that's when and where it ended. The control and neutrality of the DA-152 has impressed me so much that I dare say that it might be a long while before I return to tubes. At this point, I see (read: hear) no need.
For any users concerned about the channel balance, there are methods that you can adjust them, but since this involves opening up the top. I'd prefer those who actually need to adjust it contact me for the details. 
