[Audiophile1946]

I want to use a new Stax SR-407 (580 volts) with an old SR-D6 (230 volts) . What difference in the sound with a new dedicated Stax amplifier in comparison...Thanks.

 

[Michgelsen]

I remember using pro bias headphones out of a normal bias socket, when I had a SRM-T1, making the sound a bit softer and 'rounded off'. When you go back to pro bias, everything is clearer and better defined and controlled, but normal bias also works and the general identity of the headphones is mostly the same.

 

[edstrelow]

I would say the dynamics is the big issue.   The pro bias stators are spaced further apart than the low bias, so that they could be driven harder.  The bias was then increased to propel this greater excursion.  You won't be getting this with the SRD-6 ( have one as well as some SRM1Mk2 amps with low and high bias sockets).  The one Stax that I have found sounds most the same under high and low bias is the SR003.