At your risk.
Va is 1.3V, Vb is 48V.
One channel has been built so far with Wago connectors.
It works and sounds very nice.
Signal path:
Africa - Toto - Sony CD Walkman line out - Lipshitz inverse RIAA network - Pleiades 3 DC90 - Sennheiser HD580
It consists for an input transformer, 1 DC90 with grid at space potential (only a capacitor is connected to control grid), 1 DC90 with 10MOhm grid leak bias, 1 DC90 with 1MOhm grid leak bias, and the output transformer. Signal transformers are Sowter ones on octal bases.
As there is no chassis it picks up RF and FM radio can be heard!.
So there is some hiss which should almost be gone when it is built on a Hammond diecast aluminum enclosure.
A rough preliminary frequency response test with anti RIAA (inverse RIAA Lipshitz) network gave -5dB at 20Hz and 20KHz.
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