I had a HP 100 for a year without any problems. I used the stock tubes (Sovteks). I remember the manual stating not to roll the tubes in the Hovland as it would not improved the sound. The Sovteks are known to be very durable tubes and hearty tubes. Maybe the circuit is tough on the Mullards?
If it wasn't for the lack of a remote, I would still have this pre.
If it wasn't for the lack of a remote, I would still have this pre.