I've had the G3 Arrow for about 10 days or so, and it's time to send the G1 back after comparing the two for a bit.
This was out of my transportable rig, which consists of an iMod fed into an oversize Vcap dock, using Monster MD Tribute and Ortofon e-Q7 universal IEMs, Audio-Technica AD2000 and Sennheiser HD540 RII open headphones, and Ultrasone Edition 8 closed headphones. For a/b purposes I went back and forth using the same music, sometimes listening to a single song, and sometimes listening to the entire album. The Cowboy Junkies' Whites off Earth Now is well-recorded enough to highlight the strengths of various listening systems, and it is an album that I am familiar with; most importantly I can listen to it repeatedly without growing sick of it.
My settings are typically crossfeed I, with variations in gain and bass boost according to the volume and boost requirements of the headphone. The IEMs definitely liked impedance 0; with the higher-impedance 540s the differences with the impedance settings weren't quite as noticeable but they definitely sounded better with the impedance boosted. The lower-impedance Ed8 and AD2000, like the IEMs, also sound much better to me on the 0 setting. The AD2000 ate up bass boost II on the G3, but surprisingly the 540s did as well so it's pretty clean bass even though there is more of it than on the G1. The Ed8s and the MDs sounded best with limited or no boost, respectively.
Most of the audible differences between the two amps are pretty subtle, with the bass boost being the most noticeable. With my Ed8, I was happy enough with the I setting the G1, and could go to stetting II if I wanted more. With the G3 I hear a bigger difference on the I setting, no need for II. With the MD, the result is the same between the G1 and G3, no need for any boost. With the Ortofons I preferred with the II setting, and I appreciated the extra oomph with those. Overall, bass boost setting I on the G3 sounds close to setting II on the G1. I appreciate the enhanced bass boosting ability, but if there is a single drawback to the G3 compared to the G1 it it a little less finesse when you just want to boost the bass a "tad".
The G3 does have a higher overall gain setting, as my MDs had more headroom on the I setting with the G3 than with the G1. I didn't try with orthos and don't have my K701's anymore so I didn't really compare the gain between the two Arrows at maximum gain with the high setting. My previous testing with the HE-5 and K701 out of the G1 convinced me that the Arrow had some limitations driving the higher current-demanding headphones, but I will try the G3 with the LCD-2 sometime in the relatively near future.
Overall the G3 has a slightly more dynamic, exciting sound. I think that this may have to do with more treble and midrange detail, but also to slightly more forward upper mids. The bass is about the same which is definitely not a bad thing, with the G3 having the improved bass-boosting feature. The G1 is a great amp and I could have been quite happy with it without upgrading, but for me the G3 sounds better overall no doubt about that.
The G1 overall has a delicious, slightly warm and quite smooth sound signature, which the G3 manages to improve upon but without losing these positive characteristics. There is a definite, audible difference in overall sound quality and frequency response between the two models, and that made the $25 upgrade worth it alone. Other notable differences between the two Arrows include even better battery life, a completely automatic on/off switch, and a second headphone jack on the G3.
