Back to the Go-Vibe V6 .....A few weeks ago, I received the Go-Vibe V5 I ordered with AD8397/AD825. I'm a big fan of the Go-Vibe V5 with LM6172/1 (I bought two of them, and they get regular use). The sound of the Go-Vibe V5 with AD8397/825 has a substantially more spacious, and cleaner, more coherent soundstage than with LM6172/1, a substantially fuller, riper spectral balance and more lifelike mids, timbre, textures, and more control in the highs - which are more natural and lovely. My OTHER amps are a PPA with Discrete Buffer and a high-bias M^3. The V5 with AD8397/825 takes another very nice step toward the authority and finer points of what those amps do really well. For one thing, I am far more impressed with how the V5/LM6172 drives my lower Z phones (Grado SR225, KSC75, Ety ER4S) than with how it drives my higher Z phones (HD580). I am substantially more impressed with how the V5/AD8397 drives them all, and especially so the HD580. With the ER4S, I'm getting an appreciably fuller, richer sound with more finesse/control in the highs - the most beautiful I've heard the ER4S sound (regular gain version, BTW). For the portably-minded, the sound of the V5/8397 running from a 9V battery is quite a bit closer to its higher voltage sound than it was with the LM6172 - based on the operational capabilities of the different opamps AND that the voltage difference is lower as well (max V is 12V instead of 24V). In an email to me during my purchase of the V5 with AD8397/AD825, Norm wrote that the V5 in this configuration has a current draw of 28mA at 10V, giving an alkaline battery a usable runtime of less than 20 hours, and about 8 hours for a 230 mAh NiMH rechargable battery.
So, the Go-Vibe circuit uses the AD8397 in a way which harnesses its power to produce a really beautiful sound across a variety of phones. I'd anticipate that, the V6, using the same opamps, will be at least as good as the V5/AD8397, which is a noteworthy improvement over the V5/LM6172. My educated GUESS (knowing Norm) is that he'll find some way to improve the SQ of the V6 over the V5/8397 he's already released (maybe some supporting component settings more optimized for the new opamps - along the lines of the mini^3-ification of the PINT) - again, only my guess. The only downside to the V5/AD8397 is that, having taken care of all of my 24V needs, I've recently built a 12V battery pack and purchased a 12V wall wart for this newer V5. Given the added SQ and listening enjoyment this amp delivers every time I hear my music through it, I find it to be worth it. YMMV, as usual (and expected).
For you gals and guys who have not had a chance to hear the Go-Vibe V5 with the AD8397/AD825, I'm anticipating that you've got a real treat to look forward to with the upcoming V6.