Originally Posted by dfkt
Not sure if the gain level makes the most difference concerning the power drain, since the amp matches output power on its own already, to provide the best amount of voltage for the attached phone.
To answer your question, yes, basically anything up to 150 Ohm from my stash runs well on the lowest gain setting. The HD650 runs already fine on the middle gain setting, and on the highest it can be driven already too loud for my taste.
I'd like to see some more discussion regarding the gain and impedance settings on the Arrow. For example, I have found that setting the gain so you can drive headphones a little "too loud" doesn't mean that you have to turn the volume up that far, but setting the gain this way does have a positive impact on SQ and frequency extension, to my ears at least. There is some interplay between the gain and impedance settings obviously, and it would be nice to have some set guidelines regarding adjustment of them, which aren't as "subjective" as the bass boost and crossfeed features.
PS; I posted my initial impressions of the Arrow in the wrong thread (upon request) a couple of days ago; I have now moved it to this one instead of linking to it, and have linked to this copy from there:
Originally Posted by cn11
How are you liking the sound on first listen?
I am really digging it, thank you Robert for such a fine little product!
I am not a huge fan of any signal modification, but when it is of the well-executed hardware variety I don't mind it so much. The crossfeed is noticeable right off the bat and I can detect it at both settings, an experience I did not have with a Bithead I returned. I am leaving it off for now however.
Thanks to the combination of the custom tips I just got and the bass boost of the Arrow, I am in love with my 8? year old ER-6is more than ever, all over again. The way they sound anyways, they are a royal pain to get in and out and set up with the new tips and earguides, but comfortable and secure enough in between, with fantastic isolation, which important with these "isolators". The bass improved with the customs slightly compared to the old Shure foams, but with the Arrow's bass boost on level II, it brought out a beast of a bass not I did not think the ER-6is could reproduce. The detail and extension I am hearing from them on both ends of the spectrum, along with a bigger soundstage and the always perfect mids are mind blowing. I have never heard a better Etytomic like the ER4, but I think I am in a way now.
Now I am doing the A/B thing with my RE0/Hybrids, and while there is decent treble extension, the RE0s on first listen just don't seem to stand up to the "new and improved" ER-6is at all. Their overall clarity makes the RE0s sound if not muddy, then perhaps veiled by comparison, and the RE0s seem to have much less soundstage as well, which can lead to a congested sound during more complex passages. I am using the 1st gain boost on both, and it makes a big difference in SQ as well as volume to use the right gain setting I have noticed. I have settled on the 1st bass boost setting for the RE0s; they definitely sound warmer than the ER-6is.
I am currently resisting grabbing my RE1s, as I am very curious to A/B them with the RE0s (which I have to admit are not fully burnt in yet), and I am saving what I am hoping to be the best-sounding IEM in my possession at the moment for last, my Tripl.fi 5 Pros. I have noticed that they have been sensitive to hiss with certain types of amplification, but so were the ER-6is and none was heard through the Arrow; it is very quiet.
I sold my iBasso D4 a while ago so I only have my Simpl A1 to compare the Arrow with, and while I love the A1 I know what it is and what it is not, and the comparison is not worth making as the Arrow is a completely different beast. This is a killer amp by any measure, and while the iBasso was very clean sounding, it simply was a different type of creature as well; I actually didn't use it that much in 9v amp-only mode, I mostly used it like a uDac, which replaced it.
To my ears, upon first impression the Arrow sounds very transparent, and I am looking forward to taking this little racecar of an amplifier it up the impedance onramp and onto the audiophile superhighway with my full-size cans on to see what's really under the hood of this baby! But I want to break the "engine" in carefully, so I will cycle through my IEMs slowly first
note: the RE0s are already sounding better, but still, what a difference right off the bat
edit: my experience with the Tf5 Pros was OK, I would put them right up there with the RE0s for sure, but they didn't blow me away as I had hoped. They have the same kind of dynamics as the Tf.10s, a little thin-sounding in between well-extended high and lows, with slightly recessed mids. Out of the four (non top-tier) IEMs I tried, I would say the SQ is a tie between the RE1s with no bass boost, which are very smooth and well balanced, and the ER-6i customs at bass boost II, which have great transparency and soundstage. The RE0s annd Tf5 Pros are not far behind, however. The nod goes to the RE1s at this point, as they are easier to use and therefore the first IEMs I grab for at this time for use with the Arrow.