watchnerd
Grand Contributor
The thing is, the choices below 1 ohm with sufficient output should provide the sound the Fostex was shooting for with your Purplehearts. The concern might be that you do not like the Purple hearts sound as envisioned by Fostex. So, my suggestion to a good match 1st. If you do not like what you hear, then you can either choose a different amp that provides a sound closer to what you like...or choose different headphones that sound the way you like when they are driven accurately.
Tubes are fun, but the more "tubey" they sound, the more they add color and, in effect, impart their signature heavily. For me, this eventually gets old.
My philosophy now is that amps shouldn't be effects boxes.
If you want a different sound, change transducers (headphones, speakers) or use EQ/DSP effects.