iBasso Audio was nice enough to send me a D1 to review and compare to the Meier Audio Corda Move. There is a 55+ page thread about the iBasso D1, and as such I am not going to describe what it is or what it does, look there for that information. I think the build quality seems very good, but the D1 is big and heavy compared to most portable headphone amps. It certainly is bigger and heavier than the Move. The D1 does have an internal, rechargeable battery which lasted me more than 30 hours at a charge! Nice.
I broke the D1 in for 300 hours before doing the review listening. I use mostly Sennheiser HD25-1 and Denon D5000 for the review. I used my SPL meter to match levels within 1db. I listened to a wide variety of music. For the analog test, I used my iMod iPod. To test USB I used my Dell XPS M1210 and used WM11 playing WAV files. Also, I did not (and will not) try anything other than the stock op-amps. If you want to know about that, read the mega-thread
Further, I strongly recommend that iBasso fans read this ENTIRE review carefully, hint hint.
Taken on its own and JUST a headphone amp, and fed from its analog input, the D1 sounds very good. The treble is just very slightly bright, but it has good extension and detail, lacking just the very top bit of sparkle and air. The mids are fairly clean and tidy, with just a slight haze or grain. They are not lush, but they are neutral and engaging. The bass is decent, but lacks some weight, depth, and speed. But it’s fairly pleasant nonetheless. Soundstage is reasonable wide, and instrumental separation is pretty good, but it lacks a little depth.
Compared to the Move, however, the D1 as ja stand-alone headphone amp is not nearly as good, the Move bettering it in almost every possible dimension. The Move has MUCH lusher, more open, transparent and nuanced mids; deeper and weightier bass; deeper and wider soundstage with better instrumental separation; and better treble detail. It’s a complete runaway – driven from only the analog inputs, the D1 is not as good as the Move. Playing Dead Can Dance’s “The Ubiquitous Mr. Lovegrove”, the texture of the various instruments was so much easier to discern via the MOVE.
So, overall, the D1 is a good sounding headphone amp. It’s competitive with headphone amps costing between $100-150. HOWEVER, this is not the purpose of the D1. The D1 is designed to be a DAC with integrated headphone amp. So…
Next I compared the Move and the D1 driven by their USB DACs. This changed the situation completely, to a degree I wasn’t prepared for. Quite simply, the D1 playing through its DAC slaughters the Move. The Move does not sound as good via USB as it does via its analog input. Via USB, its less transparent, less engaging, has a smaller soundstage, less extended treble, and weaker bass than it does when fed from its analog input. The Move is also somewhat noisy via USB.
On the other hand, the iBasso D1 jumps to life when using the internal DAC. It has dynamics, bass impact, treble detail and extension, and depth of soundstage that is only hinted at when used from the analog input. Playing Tristania’s “Sirene”, I was just enthralled by the experience through the D1, which had left me flat via the Move. It was kind of shocking, to be honest. The D1 was SO much better sounding than it had been from the analog input when playing WAV files via USB, and the Move was notably worse sounding. I expected the Move to sound worse from the USB DAC; what I did not expect was for the iBasso to sound so much better. The iBasso has a very good DAC, indeed! Playing “Silent Spring” by Bettie Serveert, the reverb behind the vocals was very evident (in fact you could tell that way too much was used!). The string plucks on the guitar were far more realistic than anything heard via the D1 in analog, or the Move via USB.
I them went in for the ridiculous – I compared the Meier Opera from its USB input versus the D1. This was also no contest, but in this case for the Opera. The Opera was head and shoulders above the D1. This too came as no surprise either – the Opera is a world-class headphone amp with a very advanced DAC compared to the D1. So there is no shame there.
So in the end, the D1 accomplishes its goal in spades – it’s very good as a portable DAC/Headphone amp; in fact, in that category, it’s the best I have heard. As I type this, I am sitting in a hotel room, playing music from my laptop via the D1, and it sounds terrific. If your application is primarily listening from an analog source, the D1 doesn’t make sense. But if your primary application calls for listening from a portable with a digital out, or a from a laptop, the D1 is a TERRIFIC product. Well done, iBasso!
UPDATE 10-5-07: I received from Mrarroyo a D1 with better op-amps, as follows:
AD8656 in the DAC (replacing the AD8616)
LM4562 (2) as a buffer in the Amp (replacing the NE5532)
OPA2111 in the Amp (replacing the AD823)
Well, the D1 sounds MUCH better in this configuration, which will come as no surprise to anyone who has been following the gargantuan D1 thread. It's better in EVERY conceivable way. And I mean EVERY way. It's almost enough to convince me to roll op-amps. iBasso itself is coming out with a version of the D1 with better op-amps, and it will be interesting to see which ones they choose. There are SO many configurations. But in this config, the D1 is very good even just as a headphone amp from the analog input. It sounds great. I still slightly prefer the sound of the Move, for the D1 is still a little more aggressive and the Move slightly smoother while being just as detailed, but it's now very close.
And in USB DAC mode, the already very good sound of the D1 just gets better. It sounds terrific in this mode - highly enjoyable. It's now smoother and more transparent than the sound I described above using it as a DAC.
I'm not sure what the total cost is now with these upgrades, but the D1 is quite good. The Meier Move's USB DAC is just not it's strong suit, as the below will show...
ENTER: the Leckerton Audio UHA-3.
Well, this does complicate things a bit. The UHA-3, which I have just added to my portable amp review, is an excellent sounding amp, and it contains an excellent USB DAC. As an amp, it's better than the stock D1 by a WIDE margin (although not as good as the Move). It's very close to the modded D1 used just as an amp. The UHA-3 is noticably warmer sounding, which will appeal more to some listeners than others, but I loved it, and many will prefer it's sound over the D1, even modded, although I think overall the modded D1 as an amp only is slightly better.
But as a USB DAC, it's still very competitive with the D1. Again, different sonic signature. VERY different from the stock D1, which seems cold and aggressive compared to the UHA-3. The Modded D1 as a DAC is better sounding than the UHA-3, but only by a fairly small margin. The UHA-3 again is warmer and smoother, while offering just a little less detail and treble extension, and being just a tiny bit less transparent.
But the UHA-3 is quite a bit less money than even the stock D1, and certainly less that with a bunch of new op-amps. So it's quite a toss up - the UHA-3 is the better bargain in my mind for someone who wants a battery powered USB AMP/DAC combo. It's also FAR smaller and lighter than the D1, but of course the D1 also has optical and coax digital inputs.
Decisions, decisions, for the potential buyer. It's nice to have choices! My opinion is, though:
STAND ALONE AMP: Move > Modded D1 > UHA-3 > Stock D1
USB DAC/AMP: Modded D1 > UHA-3 > Stock D1 > Move.
And there you go.
REVIEW: iBasso D1, Leckerton Audio UHA-3, and Meier Corda Move compared.
