I am enjoying your headphone amplifier a lot. I’ve had the Grado SR80 headphones for several years so I decided to upgrade. I purchased the Sennheiser HD600 headphones. Surprisingly I do not like them much better than the Grados except for their comfort in use. However in both cases I am very happy with the sound, both the detail and presence, when using your amp.

Associated gear:
Preamp: Conrad Johnson PV10
Amp: Vincent SP-331
CD Player: Nakamichi MB-1
Tuner: Denon TU-767
Tape Deck: Nakamichi CR-2A
Speakers: PSB-T55