I had one of these built for me a while ago.
Chose the unity gain design (instead of a 'pre') because the Perreaux 100p I use it with has mountains of gain.
Also, the 12SN7's it uses, even NOS ones, are fairly cheap.
It's a single-input XLR-in/XLR-out design (using 2 valves) with Alps volume control.
"An octal?-based buffer amplifier that uses the 6SN7/5692 or 12SN7 and utilises a cathode follower. Premium components include metal film resistors and polypropylene film capacitors."
It sounds really good with the Perreaux.
However I don't have the knowledge to know what it's doing (or not doing) to the signal.
What do you guys think of the circuit?
(Circuit shown is for the single-ended version so it won't match the images.)
5Vrms output at 1 kHz: 4.5K Ohm load 0.5% THD predominantly 2nd order distortion.
Output impedance at 1 kHz: 454 Ω (908 Ohms Balanced)
Input impedance: 100 kΩ
Hum and noise at output: less than 0.1m Vrms
Phase: non?inverting
Power consumption: 4 W, 120 VAC (230 and 240 VAC) 50?60 Hz
Chose the unity gain design (instead of a 'pre') because the Perreaux 100p I use it with has mountains of gain.
Also, the 12SN7's it uses, even NOS ones, are fairly cheap.
It's a single-input XLR-in/XLR-out design (using 2 valves) with Alps volume control.
"An octal?-based buffer amplifier that uses the 6SN7/5692 or 12SN7 and utilises a cathode follower. Premium components include metal film resistors and polypropylene film capacitors."
It sounds really good with the Perreaux.
However I don't have the knowledge to know what it's doing (or not doing) to the signal.
What do you guys think of the circuit?
(Circuit shown is for the single-ended version so it won't match the images.)
5Vrms output at 1 kHz: 4.5K Ohm load 0.5% THD predominantly 2nd order distortion.
Output impedance at 1 kHz: 454 Ω (908 Ohms Balanced)
Input impedance: 100 kΩ
Hum and noise at output: less than 0.1m Vrms
Phase: non?inverting
Power consumption: 4 W, 120 VAC (230 and 240 VAC) 50?60 Hz
