All right, here's my short review.
I call this a short review because I am not really temperamentally (or, probably, auditorally) equipped to write a review matching the
depth and detail of the
really good ones on this site. I'm not those guys. I'm just going to tell you what I hear with ears that are less practiced (and to be honest less patient) than theirs.
The goal: to see which of these portables comes closest to my home Gilmore Lite, an amp whose sound, to me, is that of Truth. My target earphone for this is Ety ER-4S. I want to make this goal very clear because it literally is the only thing I'm aiming for and the only thing I'm writing about. I'm not trying to drive some other headphone or obtain a warm tubey sound or anything else, and I don't think I will have much useful to offer here to those who are.
Test rig: Squeezebox III through 3-way split to Gilmore Lite, GV5, and, in turns, each of the other amps, subjectively volume-matched as best I could. Once I had the best volume match I could attain among the amps, I used the Squeezebox master volume to choose a listening level for each track. I don't have an AB or ABX headphone cable so I just swapped my Ety cable around as efficiently as I could. If you're about to point out that this is a highly imperfect test procedure, believe me, I already know that. (Oh, re burn-in: the GV5 has about 25 hours on it at this point, and each of the others is at 100 or more.)
That said, here are the contenders. Having re-listened to each this evening, I want to state up front that
all are fine amps, and if you are buying your first amp you could choose any one of these and enjoy really outstanding sound. The differences I'm listening for are incremental and will likely be difficult, perhaps impossible, for brand-new listeners to discern.
1. Pimeta w/8620 running on single 9V, built by JMT.
This was my main amp for quite a while, and my main portable still longer. I was quite happy with it. Compared with the others, though, it was easiest to choose as the first to be voted off the island. I find it a little emphasized in the treble, giving a slightly light and splashy sound to cymbals and other hard attacks, while being a little un-weighty in the lower mids and the lows.
2. Ray Samuels Audio SR-71.
This is a terrific-sounding amp which provides the depth and emotional weight that the 8620 Pimeta lacked. I really love it. The only thing wrong with it is that it has a bit of high-frequency rolloff that, to me, robs percussion of some of the hard leading edges that I'm looking for and sacrifices some detail. With most other headphones you'd barely hear that rolloff (if you could detect it at all), but with the ER-4S you can. Now,
to some people that adjustment to the ER-4S's highs counts as a real benefit, and I have full respect for that point of view. But me, I like hearing those really sharp corners that the ER-4S is capable of delivering. SR-71, wonderful as it is, is the second amp set aside tonight.
3. Pimeta w/627 running on 18V, built by JMT
My desktop amp at work until I bought my HeadFive. I like its tone very much: the treble's neither excessive nor rolled off, and the mids and lows have weight and texture. IMO this is a very nice-sounding amp. But compared to the Gilmore it's missing some transparency. Simple arrangements don't have the 'live,' 'you-are-there' feeling that a better amp gives them, and busy, complex passages are congested-sounding with this amp, whereas the Gilmore makes the layers easy to peel apart.
(I should add that this amp is equipped to run from 18V (dual 9Vs) or from a 24V Elpac. Since I'm auditioning for portable use I mainly listened with 18V, but I also gave it a chance with the 24V. 24V had an effect but nothing that would make a difference to my choices.)
4. Go-Vibe V5
This is no Gilmore Lite, but I do prefer it to the Pimeta 627. It is more transparent than the latter, though it is still capable of being congested-sounding in tricky passages. It is more forward-sounding than the 627, which I won't characterize as good or bad, just different.
The GV5 exhibits both fantastic detail and terrific bass power. "Since the Last Time" from Lyle Lovett's
Joshua Judges Ruth album includes a crowd/chorus attending a funeral, and there's a lot of 'business' going on on the periphery of the song - a little chuckle here, a bit of modulation there, that kind of thing. Listening with the GV5 gave me some of those "I never noticed
that before" moments which you won't get on material like this with an amp that's at all murky-sounding. And my bassiest tracks (things like "Blanche Neige" by Axelle Red) were well-rendered with all the power and texture I was looking for.
Detail and bass are rendered so prominently that lead vocals lose some of their prominence, and this is my least favorite thing about the GV5's sound. I love hearing all these other things so well, but the trade-off is that subjectively the main vocals seem a little diminished in the mix compared to what I'm used to. Still the sound overall is extremely satisfying and it's easy to get lost in it. My first evening with the GV5 turned into one of those extended I-need-to-listen-to-all-my-favorites-all-over-again-it-sounds-so-good-I-can't-stop sessions.
Note on power: for this audition I ran the GV5 from a single Duracell Coppertop.
A 9.6V NiMH is supposed to be better. I also experimented with running it from 18V (dual 9V batteries) and from a 24V Elpac. The higher voltages do not change the overall character of the sound, but do give it more substance. It's not a huge thing, more subliminal. On "The Ubiquitous Mr. Lovegrove" from Dead Can Dance's
Into the Labyrinth, there's a slow drum that starts at the beginning of the track and continues through the song. Ultimately it's behind many other layers, but it's still there. With the Coppertop, you can hear that it's there. With the Elpac, and to a lesser extent with 18V, you
feel that it's there - it's like the slow tread of a giant in the distance. It's not strong or overblown, it's just a little more substantive and visceral. I liked the effect of the higher voltages, but ordinary 9V is so good that it didn't leave me feeling like I had to remain tethered to an Elpac to stay happy.
The GV5 is not the "portable Gilmore Lite" that I want to have one day, but it's my current favorite of the portable amps I do have, at least with my Etys. I think it's a remarkably great-sounding amp at a prepostrously reasonable price.
