[jeffrocc]

Anybody know how to identify Grado's ha-1 high gain amp vs their regular ac version?

 

[kramer5150]

Is there any kind of identification inside the battery compartment?  IIRC RA1s in general are devoid of any kind of product markings or identification of any kind on the outside.  I am not sure what the actual circuit gain is, but I think the obvious way to tell would be how high up you have to turn the volume with higher impedance loads, or conversely how low you need to turn it with 32 ohm Grado loads for comfortable listening volumes.  If you get a lot of hiss with ~16 ohm IEMs that could also be a sign of the HG model.

 

[jeffrocc]

It's the AC powered. No battery compartment. I did remove the bottom, however, and nothing to identify except a black marker number in low 4000's what ever that means. I know it's got to be 6 yrs old, that's it. Plugging in, at full volume, sr-80i's are loud but not reckless. Plugging in a higher impedance, fostex rp 50's, does not produce near adequate volumes. So... I am assuming I don't have the high gain, but is their any possibility that I actually do and their are mechanical failures?