Pimeta vs. Go-Vibe

[dk123]

Is a portable pimeta, such as the one from Rockhopper for $100 a significant step up from the Go-Vibe, either for high or low impendence cans?

 

[gtp]

BUMP, I'm interested if anyone has opinions on this, especially for lower impedance 'phones.

THANKS!

 

[MisterX]

Yes a Pimeta is a significant step above a CMoy.

 

[fewtch]

Depends... some people think the buffers used in the Pimeta sound crappy.

 

[Andrea]

Quote:

Originally Posted by fewtch Depends... some people think the buffers used in the Pimeta sound crappy.

If so, could it just be their implementation, since they're the same buffers used in all of the Corda (non portable) amps. Or not, just an idea.

 

[Sinbios]

You can tweak the buffer settings like bandwidth and stacking, sure, but I don't see how they can be implemented differently...

Anyway, a PIMETA is a superior design to any commercial cMoy-based design. You're looking at a buffers + ground channel design vs. a plain unbuffered, common ground design.

 

[plainsong]

So has the common forum logic evolved back to equating the Go-vibe with a cmoy? I remember a while back the forum logic had it that the go-vibe was Norm's design and not a cmoy.

 

[episiarch]

I haven't heard the Go-Vibe, but I have owned two Home-Vibes (wallwart-powered Vibe amp from Norm, but based on an earlier circuit board) and two MINTs (one wallwart-powered and one powered by dual 9V batteries), plus a 9V-powered 86x0 Pimeta, a Porta Corda II, and a couple early Xin amps. So while I can't speak directly to the Go-Vibe, I have heard a variety of other arguably similar amps in that price class or the next price class upward.

In each case the Pimeta outshone the other contenders, often after only brief listening. None of the others sounds "wrong" per se -- they're all good amps, and give both better definition and better bass response than my unamped source*. But over the course of a listening session, the Pimeta was much more satisfying: the music was just more alive and real, in a way that is difficult to describe but was very clear to me during listening. It was the difference between a big smile (Pimeta) and a vague feeling of somehow wanting it to be better (the Vibes and MINTs).

The best sensory analogy I can give you is that the Vibes and MINTs were as satisfying as very good coffee brewed 30 minutes ago, while the Pimeta was as satisfying as very good coffee brewed 5 minutes ago. You can't exactly fault the 30-minute coffee, but when you're used to having it fresh, the 30-minute coffee lacks a bit of the life, aroma and smile-factor you were expecting.

All this is by way of saying that I would unhesitatingly recommend a Pimeta. It is a fine, fine amp. To my ears it sounds not just better than the Vibes and MINTs I've heard, but a little better than the Porta Corda II and as good as a tricked-out SuperMacro.

It is a real shame that as newer amps are introduced and become topics of much discussion on this board, the Pimeta has been eclipsed in peoples' awareness. It is out of fashion as a discussion topic, but on the basis of sound quality it is competitive with much more expensive and newer proprietary amps. In a way it is a pity that it is not more expensive to build, because its moderate price may mislead some into thinking it is some kind of poor relation, when really it is not.

As to the design (AKA is-Vibe-a-CMoy) discussions that have arisen above, let me echo what Sinbios said. Please remember that the Pimeta is not just an amp with buffers, it is an amp with an active ground channel -- that is, there is active circuitry making sure that the currents being returned into ground from the headphones do not disturb the voltage level of that ground. I believe this is a key element of the sonic difference between the Pimeta and the Vibes and MINTs I've heard: the MINT is buffered just like the Pimeta but without an active ground channel, and to me the MINT is clearly sonically inferior (even when driven with a higher-voltage or higher-current-capacity power supply).

[size=xx-small]
*FWIW my normal listening tests are with Ety 4S's and an iPod, but I also listened with HD25's, HD25-SP's, and various others.[/size]

 

[Andrea]

Thanks on my side, episiarch, for the account. You've tickled my curiosity bout the Pimeta.

May I ask you if the (cheaper) portable version of the Pimeta from JMT or Rockhoper is supposed to be as good as the home one, and, if you know whether it can be tweaked to work with an external supply ?

Thank you in advance.

 

[episiarch]

Hi, Andrea,

I have two Pimetas, both built by JMT. One is his standard Portable model, 8620 and stacked buffers. That's the one that I keep referring to as better than the Vibes, MINTs, etc., because I've tested them head-to-head specifically looking for a good portable sound for myself. So that's how good the "cheaper" Pimeta is: very very good, and to my ears much better than the Vibes and MINTs. I believe JMT (and probably other builders) will happily build you one with an AC input if you want it.

I can't really tell you what a true "Home" Pimeta sounds like. My other Pimeta is a desktop version with an Elpac wallwart and OPA627 opamps, but a little less than "Home" specs. I custom-commissioned this amp from JMT for use at work, and because it's just for office "background music" use I did not max it out to the fullest. (He described it as "an AC-powered Portable in a Hammond case," meaning he didn't use all of the premium components he would use in a true Home amp.) This Pimeta has, unsurprisingly, a 627-ish sound signature rather than an 86x0-ish sound signature, but is otherwise substantially similar to my Portable in overall quality. It is very, very good, but compared to my Gilmore Lite or SR-71 it does not quite have their superb transparency.

Does that more or less answer your question?

 

[DJGeorgeT]

I have the rockhopper pimeta portable and I love this amp. It has quality components and it is very well built. I only wished the gain was higher than 5 and that it could drive some headphones like the HD600 or DT880.

 

[gtp]

DJGeorgeT, (great name BTW)
Can you tell me a bit about the battery life of the Pimeta with rechargeables?


episiarch,
Thanks for the great comparo/reviews. You explain audio intangilbles very well!


THANKS!
George

 

[Andrea]

Quote:

Originally Posted by episiarch Hi, Andrea, I have two Pimetas, both built by JMT. One is his standard Portable model, 8620 and stacked buffers. That's the one that I keep referring to as better than the Vibes, MINTs, etc., because I've tested them head-to-head specifically looking for a good portable sound for myself. So that's how good the "cheaper" Pimeta is: very very good, and to my ears much better than the Vibes and MINTs. I believe JMT (and probably other builders) will happily build you one with an AC input if you want it. I can't really tell you what a true "Home" Pimeta sounds like. My other Pimeta is a desktop version with an Elpac wallwart and OPA627 opamps, but a little less than "Home" specs. I custom-commissioned this amp from JMT for use at work, and because it's just for office "background music" use I did not max it out to the fullest. (He described it as "an AC-powered Portable in a Hammond case," meaning he didn't use all of the premium components he would use in a true Home amp.) This Pimeta has, unsurprisingly, a 627-ish sound signature rather than an 86x0-ish sound signature, but is otherwise substantially similar to my Portable in overall quality. It is very, very good, but compared to my Gilmore Lite or SR-71 it does not quite have their superb transparency. Does that more or less answer your question?

Sure, thank you!

My Xenos 3HA is on its way to me. Just in case I wasn't entirely blown away...

But no, I'm pretty confident.

And gtp said it well, by "You explain audio intangibles very well" !

 

[meat01]

Quote:

It is very, very good, but compared to my Gilmore Lite or SR-71 it does not quite have their superb transparency.

I am surprised by this, because I believe the SR-71 does not have an active ground channel.

 

[episiarch]

meat01, I'm sorry if I've inadvertently suggested that I think an active ground rules all. That's not the impression I'm trying to give. I'm not trying to say that the Pimeta beats anything without an active ground channel. I don't think the evidence would support such a contention. Other amp designers may have their own ways of keeping the ground voltage stable despite the incoming currents, or it may simply be that other designs don't suffer from this problem in the first place or beat out the Pimeta in other respects sufficiently to outweigh the active-ground advantage.

I am only saying that:

1. the Pimeta differs from a "CMoy-type" amp in more than just the use of buffers
2. compared to its close relative the MINT (buffered but no active ground) I feel the Pimeta demonstrates genuine audio quality improvement.

.