Hi all,
First, this will evolve over the course of the next few weeks into a full-blown review. However, I wanted to begin as an initial impressions thread, and edit it as time allows.
I've been interested in this amp ever since it appeared on the scene. I was always a big fan of Audio Alchemy back in the day (I still have an HP-1 amp), and was really looking forward to hearing what kind of headphone amp Mark Schifter's new company, av123, might produce. Everything I'd heard about it seemed promising - discrete circuitry, class A output - especially at the direct mail price of $200. Then, when the amp was released in October of 2008, reports of buzzing were reported in several places, including this site. Too bad, I thought at the time.
Recently, I'd heard that they had resolved this issue, and I thought I'd give it a listen. I bought my own amp - version 2 - as I didn't want to wonder whether I'd received a review sample that had been given any special going over. It arrived in mid May, well packaged, and in perfect condition.
The first thing that I did was test for buzzing or any other noise. Nothing. Two weeks later, no change. So far so good.
So far I've been listening to it in a variety of set-ups, including the following:
Sources:
Silverstone EB-01 (a nice USB DAC for the money IMHO)
Musical Fidelity V-DAC
Wadia 830
iPod 6th Gen
Headphones:
Denon D5000 (markl modded)
Sennheiser HD600
AKG K271S
AKG K501
AudioTechnica AH-A700
AudioTechnica AH-AD700
Music:
Beth Orton - Central Reservation
Chet Baker - Chet
Cowboy Junkies - Whites off the Earth Now (MFSL)
Dave Matthews Band - Crash
Dennis Wilson - Pacific Ocean Blue
Dire Straits - Love Over Gold
Elvis Costello - Imperial Bedroom
Miles Davis - Kind of Blue
Ryan Adams - Demolition
Whiskeytown - Faithless Street
While I've still got a lot of listening to do, so far I'm favorably impressed with this amp. Generally speaking, it presents as slightly forward, with emphasis in the upper midrange and upper bass. Initially, it seemed a bit rolled off in the high end. However, as it's continued to burn in and (interestingly) warm up, I find this to be less apparent. Lots of detail, and suprisingly good bass response and extension...no "one note" bass from this amp.
Perhaps not surprisingly, it reminds me somewhat of the Audio Alchemy HP-1...though it's a more "grown up" version, if you will.
BTW - I tend to listen at a low level, so it's always important to me that an amp does a respectable job at lower volumes. While I think that the amp really hits its stride at a listening level above what I typically would choose, it has sufficient bass presence and rendering of fine details that it is more than passable for low-level listening.
Listening to the X-Head paired with the Wadia 830 and AKG K501's, I noticed a sweetness in the midrange that I attribute to appropriately powered K501's. On Dire Straits' "Love Over Gold" (from the album of the same title), the guitar and vibraphone were crystal clear and lifelike. On Cowboy Junkies' "Shining Moon" (from the excellent MOFI release of the
Whites Off The Earth Now album), the K501's deftly handled both a prominent bass line and a resonant hollow body guitar (not to mention Margo Timmis' smoky vocals). Interestingly, the bass in these cans so often criticized as bass light is very much present. It's not of the skull-cracking variety to be sure, but it's certainly there..,and with little sense of "one note" that can be common to less expensive amps. On Elvis Costello's "The Long Honeymoon" (from the
Imperial Bedroom album), the bass is particularly apparent. The X-Head, when paired with the K501's and Wadia 830, presents as forward, with a slight upper midrange emphasis, and distinct, separate (if not overly emphasized) and tonally distinct bass.
I also gave it a fairly lengthy listen with the Wadia 830 and my markl modded Denon D5000's. I've concluded that this amp is not the best match for these cans. The Denon's IMHO are a bit smiley faced in their presentation, and the combination of an amp that presents in a similar way leaves insufficient emphasis on the midrange for my taste. Ah well...plenty of fish in the sea.
Then I plugged in the Sennheiser HD600's. Dave Matthews Band's "Cry Freedom" (from the
Crash album) displays detail and separation of the various instruments and vocals. The bass drum has a realistic thump, and a natural decay. The bass guitar is maintained as a distinct and separate instrument. There's also no sign of the so called Sennheiser veil, as the midrange was presented as deep and rich - it seems natural to me, which is really what we're after.
I've always maintained that the HD600's simply don't flower the way they're capable of without plenty of power. Without it, the bass sounds mushy and the so called Sennheiser veil is very much apparent. Generally, speaking, I didn't much care for them single ended...but love them with balanced termination. So, when I find an amp that presents them as open and full-throated, I can be sure that I've found a powerful amp well suited to high impedance cans. Such is the case with the av123 X-Head...I'd wager a lot of money that the Sennheiser HD600 was used to voice the amp.
WHAT IT DOES WELL:
I think it sounds best with the Sennheiser HD600's. I suspect that they were used to voice the amp, but I don't know that for sure right now. Generally speaking, it seems to handle higher impedance and/or less sensitive cans better...the AKG K501's for example, sound wonderful.
WHAT IT DOESN'T DO WELL:
Nothing much thus far, though it sounds a little bit thin with my Denon D5000's. I suspect that it's because, generally, the amp presents a bit on the smiley-faced side, and this causes the the Denon's (which are also a bit smiley-faced in their presentation) to seem a bit hollow in the midrange. It's not horrible, but it's certainly not the best match I've ever heard. Generally speaking, I don't think it's the best amp in the world with low impedance cans.
I do have one issue with the amp that may prove to be of concern to some: because it presents as more forward and with an a more pronounced upper midrange, it can be a bit fatiguing. It can also be a very fun listen too. As a disclaimer, I tend to "fatigue" easily, so consider that when making your judgment.
WHAT I LIKE:
The amp seems to scale reasonably well, as it sounds good with both the Silverstone EB-01 and the Wadia 830. I do think that there's a little something that I can't quite put my finger on that's missing when using the Wadia, but then I remind myself that it's a $200 amp and it doesn't matter so much any more.
WHAT I DON'T LIKE:
I'm not crazy about how it looks...probably because it's so different from most other amps I've had. I call that personal preference and have done with it. I suspect that there are several folks who feel just the opposite.
I also just plain don't much like the digital volume control...I really would have prefered a nice smooth rotary potentiometer. I've read that Mark Schifter has spent a lot of time considering the pros and cons of this very issue, and still made the decision to go with it as is. My biggest complaint is probably born out of habit, as I feel like I really want the feel and familiarity of a rotary volume control. I also don't like that I can never really tell just how loudly it's actually turned up. More than a few times I've rushed for the mute button upon discovering that it was louder than expected. Some sort of LED indicator (a L=>R multi-bar display, for example) would be a very welcome addition on future models. That said, I can live with it, given the value - have I mentioned that it's a $200 amp yet? - of the X-Head overall.
WHAT NEEDS FURTHER EXPLORATION?:
I've not yet had a chance to give it a listen with Grado cans. I've got an HF-2 on order, and hopefully I'll have it before too much longer so that I can report back.
I've also not yet had a chance to give it a listen with the new Sennheiser HD800's. Again, hopefully before too much longer.
OVERALL:
I like it. Nice amp. I'll probably buy another one for my computer rig - at $200, it's a very very nice value.
REVIEW (in process): av123 X-Head Headphone Amp
