I've had a Go-Vibe for about a week now. That's a portable Vibe in a Hammond case, with the Burr Brown OPA2227 opamp, and powered by a single 9v battery. I'm using Plainview rechargeables, and getting about 23 hours per Plainview. I also own a Cmoy, from which I get about 14 hours per Plainview. Norm mentions getting about 50 hours with an alkaline 9v with the Go-Vibe. I also own a PPA. In giving my impressions of the Go-Vibe, I'm more likely to compare it to the PPA than the Cmoy, because in listening to the Vibe, the overall experience is more like listening to my PPA than my Cmoy. Overall, listening to the Vibe compared to listening to the PPA is very much like the audio equivalent of looking at a really nice digital image (PPA), and then looking at another version of the same image at the same pixel resolution, but at a lower bit depth (maxinum number of colors in the pallette) (Vibe). The Vibe very much seems to have the time resolution of the PPA, but not its dynamic range. For one-seventh the price of the PPA, its bang-for-the-buck is tremendous. THAT listening to the Vibe gives so much of the ENJOYMENT of listening to the PPA as it does still amazes me. No, I'm not saying that the Vibe is as good as a PPA. I'm saying that its quality is sufficient to allow me to ENJOY listening to it in most of the ways, and to a substantial fraction of the amounts that I ENJOY listening to my PPA.
I was very pleased that there is a sliding door into the Vibe's battery compartment. Since it comes in a Hammond case, I was wondering if I would have to open the back of the case with a screwdriver to put the battery in. Nope, tool-less battery changing.
The first thing I noticed about the Vibe is the bass: its visceral - you feel it in your bones and gut, but it's not boomy and it doesn't step on other parts of the acoustic spectrum. It's there fully and feely. The mids and highs are very nicely balanced and the upper mids and highs have some very nice air around them.
The next thing I noticed about the Vibe is that it's fast. When a quick transient hits, it hits, and its over. For some of the Techno that I listen to (such as The Crystal Method, "Vegas" CD) when a rapid rhythmic run closely spaced transients hits, each hits, and there's space before the next hits - you feel like your viscera are being run over a small washboard - I like it.
The Vibe is quite detailed: the sounds in all of my favorite music are spread out by the Vibe in spectral range, timbre and space and laid out nicely for my ear to savor, but not separated - the sounds are spread out by the Vibe for easier access but they maintain organic coherence (musicality). In techno, even sounds that can only be described as boinks or urghns are clearly presented by the Vibe as pitched melodic elements of the musical stream, rather than, say, as pitchless rhythm-only elements. The OPA2227 in the Vibe gives a nice space between musical voices, while leaving each musical voice sounding nicely solid.
The Vibe gives a very intimate sound. Because of its laying out of detail, while leaving the basic sonic qualities intact, the Vibe gives the listener the feel of having an intimate sonic connection with the performers. Its soundstage is not as large as that of the PPA, but it is coherent. It presents a unified space within which all of the musical voices exist and to which each voice contributes. The actual size of the soundstage presented by the Vibe can vary from small to fairly large, depending on the information on the recording. The soundstage that the Vibe presents is very much like a smaller version of the soundstage presented by my PPA.
The main difference that I hear between my Vibe and my PPA is that the PPA has a substantially larger dynamic range than the Vibe. In Margaret Far's "Sing Me To Sleep" from her "DayTrip" CD, there are a lot of very soft, subtle, soothing electronic sounds behind her soft-to-lower-mid volume singing of a lullaby. With the PPA, with the loudest sound in the song coming through in the lower-mid volume range (still soft and soothing), I can distinctly hear the soft, subtle and soothing electronica. With the Vibe, I need to turn up the input to the Vibe and/or the Vibe pot to hear the soft, subtle electronica so that the loudest sound in the song is too loud to be a lullaby. In my collection of 300 CD's, I don't have very many tracks for which the entire song needs to fit in the really-soft to mid-soft range, not even Classical. And besides, I HAD to have paid seven times the amount for the PPA for SOMETHING, I mean, DIDN'T I? It is this difference in dynamic range which causes me to say that the Vibe presents the sonic picture of the PPA at a lower bit depth.
The Vibe has a cleaner background than my Cmoy. The Cmoy has a background aura in the upper range which interferes with hearing information in that range that helps to form spatial impressions. Hence, the Cmoy's soundstage is not nearly as well-formed as that of the Vibe. The Cmoy's bass is not nearly as full or solid as that of the Vibe. The Cmoy is a pleasant-sounding amp, which I like. Until I got the Vibe, I used the Cmoy at work to spectrally enrich the sound and to provide a little more separation of voices from a headphone jack on a work-issue computer with nothing but a SoundMax chip on a motherboard behind it - and it did that. The Vibe produces a sound which is fuller, cleaner, more musical, involving and enjoyable in every category, for a comparable price (Cmoy $50, Vibe $65). When I listen to the Vibe and my mind is not on what I am listening to, my big picture impression is that I am listening to my PPA (the same picture at a lower bit depth), rather than my Cmoy (which portrays a different sonic picture).
I've tried the Vibe with three headphones: all low-impedance:
iRiver Silver (SlimX 350) earbuds, Grado SR60, AKG K240S.
With the stock BB OPA2227, the Vibe sounds great with all three headphones. All of my sources: Pioneer 563-> AOS DAC, Terratec EWX 2496 -> AOS DAC, Work Computer HP Jack have their sound very nicely improved by the Vibe for these headphones as described above.
I've done some opamp rolling for fun.
It's built really well in there, everything very solidly held in place.
AD823: It emphasizes the upper mids and highs the most.
I like the AKG K240S the BEST with this opamp.
The AKG K240S have recessed mids and more recessed highs, so the K240S and the AD823 are complementary - a good match.
When I go on vacation, and take my AKGK240S and my Vibe, it'll be with the AD823 installed.
It's NOT a good match for either the Grados or the iRiver earbuds - where both the opamp AND the phones are emphasizing the same range.
AD8620: It emphasizes the upper mids and highs less than AD823
Good bass, but less than OPA2227
This is my second choice opamp for the AKG K240S.
It's also my second choice opamp for the Grados.
For spectrally balanced passages, this is my favorite opamp for the earbuds.
For treble-heavy passages, I think the earbuds sound a bit tinny.
This is overall the best opamp for ALL the headphones.
This is my favorite opamp for the Grados.
Overall, this is my favorite opamp for the earbuds. It doesn't make them
sound their best, nor do they ever sound tinny depending on the spectral characteristics of the musical passage.
It sounds really good with all of them.
I'm REALLY HAPPY with the Vibe.
For just a little more than a Cmoy, Norm's providing us with a portable, well-built headamp that gives VERY enjoyable, musical and involving listening for all genres of music.
BTW, I'm not a soft touch for headphone amps. The very first portable headphone amp I ever bought, which cost me about twice as much as the Vibe, I sent back for a refund. I burned it in for about a week. Then I spent about a week listening to a variety of music carefully with and without it. I then decided that it didn't pull its own weight and sent it back. So, I don't say what I say about the Vibe about all headamps. But, the only place the Vibe is going is to my desk at work where I'll be listening to it on my work rig.