| Paul S wrote:|
Looks like a serious effort that has been kicking around for a while.
What tubes are used? Are they twin triode, like 12AX7 or - more likely - 6922? Both types offer a lot of options in terms of sound via tube swapping, and also via adjusting operating points.
Labels on transformers might be Lundahl?
Is initial gain passive (transformer), or...?
Is this RIAA-only?
A few details - the easy stuff ..:
Phono specs for OmniGon s/n 10 (ALF's):
RIAA accuracy (20 Hz to 20 kHz): better than +/- 0.1 dB.
Phono linear phase derivation (DLP) 20 Hz to 20 kHz phono MM: less than + 0.2°
Phono linear phase derivation (DLP) 20 Hz to 20 kHz phono MC (3-6 Ohms): less than + 1.5 °
Frequency response Phono MC1: -3 dB at 0.4 Hz and 210 kHz
Phono Overload MM: 400 mV
Phono Overload MC 1: 38 mV
Phono MM IMD RIAA de-emp. 20 Hz to 20 kHz: less than 0.019%
Phono MM THD RIAA de-emp. 20 Hz to 20 kHz: less than 0.02%
Phono MC1 IMD RIAA de-emp. 20 Hz to 20 kHz: less than 0.03%
Phono MC1 THD RIAA de-emp. 20 Hz to 20 kHz: less than 0.03%
Channel separation Phono: 92 dB
Output impedance: 120 Ohms
Tube complement: VT229 (2x), VT231 (2x), E80cc (4x), CV135 (4x)
And .... Lundahl cokes only inside power supply .... Syntax' pictures do only show the part of the iceberg which is above water line ...