Yes, as far as I know the only headphone amps suitable for use with the Stax "Pro" phones, which would provide the right bias voltage (580 volts), the right signal characteristics, etc., are those specifically designed for them. As I mentioned, though, Woo Audio and one or two others manufacture such amps, as well as Stax.
Here are links to the currently produced Stax models.
Links to the Woo models are near the bottom of this page.
Here are links to a couple of others.
I have no first hand knowledge of how using the SRD7 vs. one of these amps may compare sonically. I can say, however, that I doubt that anyone's sonic perceptions can be counted on to be more reliable than Frogman's.
Also, member Larryi, whose perceptions are also top notch, provided comments about some of these amps here.
Regards,
-- Al
Here are links to the currently produced Stax models.
Links to the Woo models are near the bottom of this page.
Here are links to a couple of others.
I have no first hand knowledge of how using the SRD7 vs. one of these amps may compare sonically. I can say, however, that I doubt that anyone's sonic perceptions can be counted on to be more reliable than Frogman's.
Also, member Larryi, whose perceptions are also top notch, provided comments about some of these amps here.
Regards,
-- Al