As you might have read in my previous installment, I started experimenting with a relatively inexpensive Chinese mini Bluetooth receiver by modifying it and connecting its analog outputs to a vacuum tube line stage.
PCM 1794 Bluetooth Receiver
I bought this device from eBay to see if I could get a decent sound from my smartphone when used as a source connected wirelessly via Bluetooth to the audio system. This is a more direct way compared to the case where a smartphone is used only to control the playback by means of communicating with a dedicated streamer via the local network.
Tube-rectified Power Supply for Oto’s Phono Stage
I recently built a phono stage using some original Audio Note parts: a phono board featuring a 12AX7 and a 6DJ8 double triode with a passive RIAA equalization network in between, a power supply based on solid-state rectification, C-R-C-R-C filtering, and a mains transformer.
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DIY Stepped Attenuator
This project came as the logical end of a continuous process of refining the amplifier’s performance. The itch to find out how a stepped attenuator would perform against the ubiquitous volume potentiometer became increasingly acute after the surgery that transformed my Audio Note OTO Phono SE Signature integrated amplifier into a P1 SE Signature power amplifier.
Audio Note AX-Two Crossover Project
Two coils, two caps, and a resistor, arranged across two drivers with the purpose of dividing the energy between them evenly. This is what I came up with after several months of experimentation. I tried almost everything, but it was the series crossover network that brought resolution and peace to my weary soul.