preamp AC residual noise test Audio Research SP9 vs no name BL-2A all tube preamp

It's not easy to suppress AC hum noise level under 0.1mV for solid state and tube preamplifiers. I compared 2 preamps to get objective & scientific results with reliable test equipment

[@qwerty123860]

That's very good . I have a Vintage Conrad Johnson PV12 with phono. The soundstage is wide and palpable. I would love to compare it to the BL-2A. Nice work Mr Ahn! :-)

[@YoungAhn]

It's done. Thanks

[@fullblastman]

Do you offer your Fluxion preamplifers as a kit? I like the specs and tubes used but need a more conventional chassis without tubes sticking out the top.

[@YoungAhn]

No kit available sir. Thanks