First up - I am unabashed fan of this tiny amplifier. I think that it's features are quite simply amazing given the form factor.
Sadly - I'm actually moving on from it - as I find that I'm using it less with my harder to drive cans now (for most of my portable use - I now simply use my IEMs). However I wouldn't hesitate to recommend this little amp to anyone.
Preamble - a bit about me
At the time of writing, I'm a 46 year old music lover. I don't say audiophile - just love my music. Over the last couple of years, I have slowly changed from cheaper listening set-ups to my current entry/mid-fi set-up. I vary my listening from portable (i-devices + amp) to my desk-top's set-up (PC > optical > NFB-12 (or NFB+LD MK IV) > HP). My main full sized headphones at the time of writing are the Sennheiser HD600s, AKG K701, Beyer DT880 and Shure SRH840. I also own the Asian Shure SE535 Special Edition IEMs. My previously owned gear is in my profile.. I have auditioned quite a few entry and mid-tier cans, but have yet to hear any flagships (at current time of writing this review). I have very eclectic music tastes listening to a variety from classical and opera to grunge and hard-rock. I listen to a lot of blues, jazz, folk music, classic rock, and alternative rock. I am particularly fond of female vocals. I tend toward cans that are relatively neutral/balanced - with a slight emphasis on the mid-range. I prefer a little warmth in the overall signature. I am neither a bass or treble head. Previous portable amps = GoVibe PortaTube, Fiio E11, Fiio E7.
Packaging & Accessories
I purchased the Arrow direct from Robert at Headphonia. Packaging was minimal - just the amp a mini USB charger, and a 3.5 - 3.5mm interconnect..
From the Headphonia website:
• Ultra Thin Case Design
• 30-40 Hours Battery Play Time
• Three Selectable Gain Settings
• Bass Boost
• Treble Boost Switch
• Modified Öhmann Crossfeed
• Automatic ON/OFF Switch
• High-Capacity 1200mAh/4.2V Lithium-Ion Battery
• Two Input Jacks & Two Headphone Jacks
• ALPS Analog Volume Potentiometer
• Low-Battery Indication (Slow and Fast LED Blinking)
• 4-Layer Circuit Board with two Ground Planes for Low Noise
• Aluminium Case with Laser Engraving
• Size: 8.5mm x 56mm x 98mm (0.33'' x 2.20'' x 3.86'')
• Weight: 75g
There are no real technical specs published - but in correspondence with Robert, he has informed me (by email) that the headphone out impedance is ~ 3-5 ohms.
Build / Form Factor
The Arrow is very slim, and almost exactly suited to pair with an iDevice like the Touch. It is a very solid build - and appears really well mode. On my unit, everything fits exactly - no sign of any imperfections. The Alps pot is very smooth and tracks well. The switched (whilst small) are easy to use, and appear firm. The inputs and outputs (even after well over a year) are still firm.
I'll keep this pretty brief. To my ears (and they are not perfect) the Arrow 4G sounds very flat - a wire with gain scenario. What you put into it is what you get out of it - just with very clean and powerful amplification. The hardware EQ is subtle but (IMO) very good. The bass boost is in 3 parts (off +1 +2) and definitely gives the bass (and only the bass) a small lift at each setting. It's not exaggerated. Similar with the treble switch. These have been very handy when I can't be bothered with a preset software EQ - and just wanted a quick boost in either the upper or lower end. I've tried the crossfeed - and to my ears it doesn't really do much. Perhaps it's too subtle for these old ears. Anyway - I've left it off.
It's a pity the specs aren't listed - because the amplification on this tiny device is impressive. It has 3 gain settings - and there is a noticeable boost in volume with each. Even at the lowest gain setting it was able to drive my 600 ohm Beyers to pretty loud levels. More impressive was that there was no sign of bass flabbiness (ie being under-driven). It also drove the K701 well - but without a doubt my favourite headphone with the Arrow was the HD600. Call it synergy perhaps - but I really enjoyed the combo.
Did it drive the Beyers as good as my NFB-12 or Little Dot MKIV ..... no. But it did a pretty good job - and one that I was perfectly satisfied with if I was travelling.
Yep - nothing is really perfect. My only real gripe was the sensitivity of the pot - but I can't really complain - because this is normal with most Alps pots. For really sensitive IEMs (eg my SE535 'specials'), I had to go so low on the pot that I often had issues with channel imbalance. One way to solve this (on iDevices) was to use a third party EQ app that allowed a lowering of the preamp. Using this, I could then bring the volume back enough to be able to turn up the Arrow and avoid the imbalance.
For me - besides the excellent amplification & massive battery life - the best feature is the automatic on/off switch. When music plays - it is on. When it's not, after about a minute - it switches itself off. No more flat batteries because I forgot to turn something off. It's a feature that I wish was on all portables.
I'm really sorry to be letting this little "dynamo" go - but it needs an owner who is using it more than I have been. If my circumstances change again, I wouldn't hesitate to purchase it again. Despite the cost - for the form factor and features it just 'kills' the previous amps I've owned.