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Which headphone amp is "better"?
- Thread starter Bop
- Start date
The Go-Vibe V6 uses the AD8620/10 opamps, the same as the upgraded opamps I had Norm put in my V5, and they pair quite well with brighter phones like Audio-Technicas and Grados.
Norm specializes more on sound than ANYTHING else. Notice how there is no gimmicky crossfeed, no high-low gain switch, and it took him 6 iterations to make a satisfying recharging circuit . His amps are 100% focused on sound. While the ibasso P1 (correct me if im wrong, memory tells me this is the smaller, ipod nano size one correct?) focuses on portability and small-size factor.
I would go with the Go-Vibe.
Norm specializes more on sound than ANYTHING else. Notice how there is no gimmicky crossfeed, no high-low gain switch, and it took him 6 iterations to make a satisfying recharging circuit . His amps are 100% focused on sound. While the ibasso P1 (correct me if im wrong, memory tells me this is the smaller, ipod nano size one correct?) focuses on portability and small-size factor.
I would go with the Go-Vibe.
AD8620/10 for driving Grados? Really? You must really like it intensely bright. The 8620 isn't exactly a low impedance, reactive load driving champ (hooray distortion). It's probably the worst sounding chip of the 35 or so AD op-amps I've used, in my opinion anyhow. I think Norm was better off sticking with the AD8397 or using some other chips actually designed to drive this type of load. The 8397 has a common emitter _buffer_ stage for its output that is capable of driving a headphone considerably better than a normal op-amp. I guess he could try something like AD9631 to split and source/sink the output ground, although the PSRR may be too low...nice chip, though. Could try the ADA4899-1 instead; open loop response still goes out to near the edge of the audio band and PSRR is considerably better. I don't know how it sounds, though, and the nature of this topology is such that it can matter substantially what you use to drive the output ground.
There are a few op-amps that can drive headphones with good linearity, but it's a pretty rare trait, relatively speaking. If anything, I've been surprised at some of the op-amps Norm has used. At one point, he wanted to use the OPA277 which is something designed to work at DC and has very high distortion past around 4KHz, especially driving something like headphones.
The charging circuit just looks like a basic LM317-based design, like that of the PINT amplifier. Is there something special about it that I'm not noticing?
The IBasso uses on of the Maxim headphone driver chips. They sound alright. I'd probably take that over the AD8620, anyhow. Maybe you can get Norm to use other chips, though.
There are a few op-amps that can drive headphones with good linearity, but it's a pretty rare trait, relatively speaking. If anything, I've been surprised at some of the op-amps Norm has used. At one point, he wanted to use the OPA277 which is something designed to work at DC and has very high distortion past around 4KHz, especially driving something like headphones.
The charging circuit just looks like a basic LM317-based design, like that of the PINT amplifier. Is there something special about it that I'm not noticing?
The IBasso uses on of the Maxim headphone driver chips. They sound alright. I'd probably take that over the AD8620, anyhow. Maybe you can get Norm to use other chips, though.
Maybe its just my ears, but I've found that the govibe 6 with the 8620 sounds great with my grado sr225s, although i do have flats on them, which lessens the brightness to a degree. I also increased the resistance with an impedance cable, gives the bass some more body and punch.
Out of my price range.
I've narrowed it down to either the Go-Vibe 5 or 6. My headphones have an impedance of 40 Ohms so I don't know which amp would be better suited. I don't know much about audio equipment.
I think I might get the GV 5 and save $50.
you know that it is largely a waste of money going from an X-Fi to an amp for the A900s right? They don't really benefit much from an amp bro. Maaaaybe just a little better response all around but you would have to really listen to hear it.
If you're going with a Go-Vibe, I'd have Norm install the AD8397 and a suitable 'ground channel' op-amp. I was thinking maybe the ADA4899-1YRDZ (that's the model 'number'; I'm giving the full one so that way the right chip is chosen) might do a decent job since it has good performance characteristics and can supply a lot of current.
Honestly, you could just have someone build you a so-called CMoy (which is essentially a non-inverting amplifier with negative global feedback) but use the AD8397, properly implemented (e.g. bypassing, balancing of bias currents, etc.), and it would probably do a fine job for you.
Honestly, you could just have someone build you a so-called CMoy (which is essentially a non-inverting amplifier with negative global feedback) but use the AD8397, properly implemented (e.g. bypassing, balancing of bias currents, etc.), and it would probably do a fine job for you.