...... If you use a 500 ohm input transformer you will likely use another transformer to drive that one. I always try to minimize the amount of transformers in an audio chain.
Joe - GMS
I agree, all other things being equal , with Joe .... transformers add distortion
You might consider letting your 500 Ohm output from the HW just as an audio source rather than the driving power for your pp 811's .... take a look at the parallel thread started by Patrick J. on how he is driving 3-500's without a transformer ... I especially liked the approach quoted from the Clegg Zeus where they dc coupled drove 811's with a 6bl7 / 6bx7 as a cathode follower .... I have heard the audio from a Zeus (a long time ago) and it was potent