Mikeb
100+ Head-Fier
- Joined
- Sep 16, 2006
- Posts
- 133
- Likes
- 10
I have a MF V3 headphone amp with a little pinkie power supply driving my AKG 701 headphones via an RME 9632 soundcard using a digital out balanced connection into a Storm Audio Pandora dac nos in asynchrous mode and have been searching for the ideal valve setup for the MF V3 amp in this combination, the stock valves ECC88/6922 are ok but when compared to the better russian valves such as the 6H23P the soundstage was lacking, more in the head images, with a less extended top end, however the russian valves did at times produce a bright sound somewhat aggravated by the brightness of the AKGs, particularly with frequencies in the cymbal range, a better russian valve I found was a 6H1N-EB, this had the soundstage of the 6H23 but was less aggressive with better bass and treble, but on some recordings was still a bit bright, I then came across someone who was using Tesla PCC88 valves in his Audio Research preamp which normally uses 6922s and how this substituion gave a less hard sound. The PCC88 is very similar to a ECC88/6922 but with a heater voltage of around 7-7.4 volts instead of the normal 6.3 volts, searches on the web suggested using the PCC88s at the reduced heater voltage did not result in any real adverse problems. After a search on Ebay I found Colomer Valves (based in UK) had nos Tesla PCC88s at £10 for a pair of valves, so I decided as the price was so cheap I would give them a try, the valves arrived a couple of days and I immediately put them into the MF V3 amp, and straight away I found these valves to be excellent, having all the detail and near as damm it the same large soundsatge of the russian valves but with a much sweeter top end and a less hard sound, the valves are also very quiet in operation and over the 20 hours or so I have listen to them don't appear to have any downsides, I would recommend with any MF V3 or similar headphone amplifier users to give these Tesla valves a shot particularly as they can be bought so cheap.
