Barry French has recently build his version of the 01a Preamp Gen2. Here are a couple of pictures:
And Barry’s impressions:
“The 01a Amplifier is a stunner, personally I feel it leaves the 26 out in the cold, better top & bottom by a Country Mile, this was built using the Russian FT-3 Caps on the Output, Russian PIO Caps on the Boards with Jupiter 0.1 μf Wax/Oil Caps from B+ to Ground, the Power Supplies for both Filaments & B+ are from my original 26.”
A couple of mods I did was to remove C3 which improved the Treble Sparkle, I deliberately didn’t use screened cables on the Input & Output as I find this can flatten the Sound a little, I like the openness that the 0.5mm Silver Wire in PTFE Sleeving gives. I am going to replace the the 2 Russian Pio’s with Jantzen Superior Silvers as well as soon as they come, but generally very happy with the sound this little Amp gives.
The second mod will make You laugh, I put 2 Pringle Tubes over the Valves as the Amp is a little Microphonic, they don’t get at all Hot so no Problems with that, this somewhat tightened the sound up, giving more snap to the Sound!