Tube preamps, Bluetooth preamps, line-level boosters and passive volume controllers, with tubes, inputs and features compared.
Douk Audio DAC-T1 PRO Tube Stereo Preamp — read reviewA full-featured desktop DAC and tube preamp at $169.99: ESS9028Q2M conversion, QCC5125 Bluetooth with LDAC, USB and S/PDIF inputs, JAN5654 tubes with a bypass function, and an OLED display.
Douk Audio P1 PLUS Bluetooth Tube Preamp — read reviewA do-everything desktop hub combining a Bluetooth tube preamp, USB DAC and headphone amp with pluggable VU meters and an OLED screen. The QCC5125 streams LDAC at up to 24-bit/96kHz, while the ESS9018K2M handles PCM 384kHz/32-bit and DSD256 over USB.
Douk Audio L1 Line Level Booster 20dB Preamp — read reviewA $39.99 line-level booster that lifts weak sources by up to 20dB with an adjustable gain knob, accepting 3.5mm, RCA and 5-DIN inputs and running from a wide DC 5-24V supply.
Douk Audio P2-FM Magic 6E2 Tube Preamp — read reviewA desktop preamp and headphone amp whose VFD spectrum display and 6E2 magic-eye tubes pulse with the music - it also packs an FM radio, a clock accurate to within one minute a year and a Pomodoro timer. The headphone out suits 32-200 ohm cans.
Douk Audio P2 Mini Bluetooth Tube Preamp — read reviewA tube preamp, headphone amp and U-disk/TF-card music player in one $73.99 mini chassis, with Bluetooth, RCA in, three-band tone control and a remote.
Douk Audio P6 MINI Bluetooth Tube Preamp — read reviewA palm-sized tube preamp at $49.99 with Bluetooth 5.0, USB-disk and stereo RCA inputs, a 6A2 tube stage, separate treble and bass knobs, and an input selector to end cable swapping.
Douk Audio TUBE-T5C 4-Way Tube Preamp — read reviewA mini tube preamp that doubles as a 4-way RCA source selector, splitter and headphone amp with a glowing VU meter. Its isolated tube stage runs at 180V, and the headphone output delivers up to 500mW at 32 ohms.
Douk Audio P1 Bluetooth Tube Preamp USB DAC — read reviewA mini desktop box that works as a tube preamp, a 24-bit/192kHz USB DAC and a headphone amp, with Bluetooth 5.0 aptX-HD and a bypassable treble/bass tone stage.
Nobsound TUBE-T4C Stereo Vacuum Tube Preamp — read reviewA compact Class A tube preamp with stereo RCA in and out, swappable 6J5 tubes and independent bass and treble knobs — an affordable way to add tube warmth ahead of a power amp or active speakers.
Douk Audio L1 MINI Line Level Booster 20dB Preamp — read reviewA tiny line-level booster that adds up to 20dB of gain to quiet sources - TVs, phones, MP3 players - so they can properly drive an amplifier or speakers. It runs on any USB phone charger or power bank from the included USB-to-DC cable.
Nobsound NS-10P Vacuum Tube Stereo Preamp — read reviewA mini vacuum tube stereo preamp with two 6J1 tubes, independent treble, bass and volume controls, and a pure Class A tube stage adding 1.5-2x gain to digital or hybrid systems.
Nobsound VOL-3 Passive Preamp Attenuator — read reviewA palm-size passive volume controller that sits between your DAC and powered speakers - no power, no gain, no added coloration. A smooth ALPS A50K potentiometer and 24K gold-plated oxygen-free copper RCA terminals do the work.
Nobsound VOL-3/V1-XLR Passive Volume Control — read reviewA no-power passive preamp that adds smooth volume control to a hi-fi chain without any gain or powered circuitry. Pick the RCA (VOL-3) or XLR (V1-XLR) version; a quad-gang ALPS potentiometer keeps the channels balanced.
Douk Audio VOL-4 Volume Controller — read reviewAn inline stereo RCA volume controller that adds remote control of volume, tone, power and mute to fixed-output DACs, streamers and amps, with an OLED display and 0.001% THD+N. Listed as a pre-sale item.