[dwchin]

At the time I placed my order with Norm, I had him give me the standard OPA2227, and he was kind enough to put the gain at 6 because I also have some high impedence headphones which I wanted to be able to drive with an inexpensive portable amp in addition to the Etys. Other than that, no other customizations. I later ordered the AD8620 from Norm, along with several other opamps I got from digikey on my own, including the OPA2107 and OPA2132. I run mine with standard alkalines so I didn't bother with rechargeable batteries.

 

[iancraig10]

Quote:

Originally Posted by aseltzer144 What opamps did you order and did you request any customizations?

AD8066 and the OPA2227. Norm recommended AD8066 to power Beyers. From what I hear, they will use more power. However, Norm seems to be a plain talking, straight guy and if he says AD8066, then I'll go with that. He is going to adjust gain for the Beyers too.

 

[jamiep]

please forgive my ignorance...but what does a pocket/portable amp do? does it just make the player louder?

 

[nikongod]

Quote:

Originally Posted by fewtch Unless you really want to annoy people who know better, stop comparing the Go-Vibe to a Cmoy. One is a newer, proprietary design/build, the other is an older DIY design that can use random parts and have random build quality, depending on who builds it. The two are nothing alike, except for the fact that they're relatively simple circuits.

what makes a headsave govibe better than a cmoy that was well built with parts that are of better quality by a detail oriented builder?

 

[Pappucho]

Quote:

Originally Posted by jamiep please forgive my ignorance...but what does a pocket/portable amp do? does it just make the player louder?

If your player has a dedicated line out than you can bypass your players compromised internal amplifier and run this signal to a better designed/better built external amplifier that is designed to drive your headphones better than what the internal amplifier ever could. The sound isn't always louder, it's just a much better (read accurate) reproduction of what was originally recorded.

 

[aseltzer144]

Quote:

Originally Posted by Pappucho If your player has a dedicated line out than you can bypass your players compromised internal amplifier and run this signal to a better designed/better built external amplifier that is designed to drive your headphones better than what the internal amplifier ever could.

Perhaps the lack of lineouts is why some report marginal benefit using an amp with an iPod. The Shuffle, for example has no dedicated line out and a fairly respectable output section and I don't hear much difference with the PA2. This is based on about 10 minutes of A/B'ing so I'll have to revisit this, but with lineout sources there general is an immediate audible improvement with an amp.

 

[nikongod]

amplification stages are GENERALLY clearer at lower output power output. so you make the junk amp stage built into the portable player clearer by using it less. simple.

not as good as running the amp off of a line out, but its a step in the right direction.

 

[atx]

Quote:

Perhaps the lack of lineouts is why some report marginal benefit using an amp with an iPod

The ipod does have a line-out. You just need to buy the adapter that plugs into the docking port.

 

[fewtch]

Quote:

Originally Posted by nikongod what makes a headsave govibe better than a cmoy that was well built with parts that are of better quality by a detail oriented builder?

Buy both and listen.

 

[sbulack]

Quote:

Originally Posted by fewtch Buy both and listen.

I did just that. When I try to describe the sound of the Go-Vibe (which I have done to the point where folks must have become weary of it) I compare it to my PPA rather than to my cmoy, because the sonic portrait of the music it portrays is more similar to that of the PPA than to that of the cmoy.

I got my cmoy from a fellow Head-Fier with good feedback, and I am happy with it for what it is and sounds like. It provides a nice improvement to sound quality from a modest source for modest phones. In fact, a colleague at work is using it and enjoying it very much every day from a the headphone jack of a work-issue PC with a pair of iRiver silver earbuds.

My Go-Vibe, by way of comparisson, is the beating heart of a listening station that I set up at home for very discerning listeners who I don't want to share my main rig with (because they aren't all that careful with equipment). To their picky ears and mine, a Sony D-321 PCDP, MagWires Original IC, Go-Vibe with AD823, and AKG K240S provide a deep, satisfying hi-fi sound for everything from the harshest rock to the most refined classical. When I listen to this rig, it reminds me far more of listening to my main rig with PPA than it reminds me of listening using the cmoy (in the same secondary rig).

The sonic differences: the Go-Vibe is better at portraying
a) dynamic range - with a blacker background, the subtler sounds get a better representation - and enable them to coexist well with much louder voices - giving an effectively wider and more enjoyable dynamic range.
b) crystal clarity and immediacy of sound - the Go-Vibe is better able to provide the voltage & current needed by the phones without the safety net of a current buffer. This direct-from-the-opamp sound path gives a crystal clarity to the sound and downright visceral (well, from the ears down to the bottom of the chest viscera) textures to sounds throughout the acoustic spectrum, but strikingly noticeable (and enjoyable) in the bass.
c) richer acoustic spectral mix - this shows up as both a richer, fuller, more ear-satisfying sound to all music, AND (because a lot of the spatial information is in the upper end, where the wavelengths are short and spatial localization is greater) better sense of the overall space in which the musical voices co-exist and the placement of the voices within that space.
d) depth of sound and its translucency - the Go-Vibe gives a significantly deeper sound and its subjective quality is that the sound has a greater translucency than the cmoy - both of which my ears love.

But the real test is overall enjoyment and the awe-in-listening factor, which are consistently higher for me with the Go-Vibe than with the cmoy. Overall, the Go-Vibe gives a portrayal of the sound that is very similar to, but at a lower resolution than, that of a stock PPA. To my ear, the portrayal of the sound from the cmoy is very different, and less enjoyable for its differences. In the comparisson to a stock PPA, the Go-Vibe beats the PPA in crystal clarity and visceral texture. The PPA provides superior SQ in sufficiently many other categories to make it well worth the price difference, though. In fact, it wasn't until I recently installed a Larocco Dyno-Biased Diamond Buffer into my PPA that its clarity and visceral texture match those of my Go-Vibe.

So, FWIW, that's my SQ comparisson between a cmoy (which I enjoy) from a well-regarded builder on Head-Fi and the Go-Vibe. In My Rig(s), To My Ears, YMMV.

 

[atx]

Quote:

In fact, it wasn't until I recently installed a Larocco Dyno-Biased Diamond Buffer into my PPA that its clarity and visceral texture match those of my Go-Vibe.

Wow.

Thanks for the comparison!

 

[NeoteriX]

Quote:

Originally Posted by jamiep please forgive my ignorance...but what does a pocket/portable amp do? does it just make the player louder?

Read this thread:
http://www6.head-fi.org/forums/showthread.php?t=115701

My post there:
Quote:

Originally Posted by NeoteriX I think it's that the use of an amp for say, a car stereo system and an amp for headphones are quite different. When people use a headphone amp, it's often under the pretense that the portable player or whatever has a crappy amp that has been castrated as a compromise between size, power consumption, and cost. Essentially, the amp cannot faithfully reproduce the original sound signal, and so on nice headphones, you lose audio quality -- things like base hits are duller, sloppier, highs are not as pronounced and sharp, etc. even at normal (not uber loud) listening volumes. A headphone amp is a dedicated unit, usually with audiophile grade components that has it's own power so it can consume as much as it needs for amplification. At regular listening volumes, all parts of the sound signal can be faithfully powered and maintained just as the recorders and producers intended. Also it sits outside of your music player, avoiding the interference from the complex components which is also important in reducing the hiss and ambient noise. Also, some headphones are rated for a high impedance which means they need more power to drive them effectively.