User at FAS forum got one of these. Having intermittent output issues and level concerns. Turns out they missed something in the documentation that you need to do at startup:
"In order for the bias circuitry in the PowerValve to be allowed to settle as quickly as possible, we advise the following:
To avoid any start-up instability, please power on your PV200 with the input gain at maximum, headphone level at maximum, all tone controls at 12 o'clock (in the centre detent position) and the output level at zero (7 o'clock).
This allows internal voltages to stabilise quickly so that the PV200 is ready for use within a few seconds.
The online owners manual has now been updated."
Not that you asked for a replacement recommendation, but i have been using the ISP stealth and it has been great. I saw that one! I've heard good things about it. I'll have to try and find one over here in the UK. Thanks for the recommendation!
forum.fractalaudio.com
Replied there with this same sentiment but I am not doing that. Bullet dodged.