Douk Audio H5 Tube MM Phono Preamp with Sub Out Review

The Douk Audio H5 is a tube MM phono preamp priced at $89.99, designed to visually and sonically complement the company's A5 amplifier while adding tube warmth, a turntable input, tone control and subwoofer integration to a compact stereo system.

For vinyl, the MM Phono input accepts moving-magnet turntables and engages a 20Hz high-pass filter that helps tame unwanted rumble from record warp or turntable vibration, keeping playback cleaner and steadier. There is no MC option - moving-coil cartridges need a step-up device. The RCA Line In covers DACs, CD players, streamers and computers, so the H5 also works as a straightforward tube line preamp when you are not playing records.

Outputs are where the H5 goes beyond a basic phono stage: two RCA outputs can feed two amplifiers or powered speaker systems at the same time (they carry the same signal simultaneously), and a dedicated SUB Out uses a single RCA connector with a 180/250Hz low-pass filter to hand low frequencies to a powered subwoofer and reduce boomy overlap with the main speakers. The volume knob controls both RCA outputs and SUB Out together, while bass and treble controls shape the main outputs only. The tube stage is tuned around GE-4BZ6 tubes with a 180V drive for a smooth, warm character, and only the same 4BZ6 type should be used for replacement. A socketed NE5532 op-amp can be swapped for OPA2604, OPA2134, LM49720 or MUSES02, and shielded tube power with a 4th-gen relay helps reduce interference and switching noise.

Douk Audio ships worldwide with free and expedited options; costs vary by country. Parcels under 2kg ship airmail (10-25 days), heavier orders by DHL, UPS or FedEx (5-8 days), and any import duties or customs fees are the customer's responsibility. The store offers a 30-day free return or full refund and a 1-year warranty on all items, excluding orders placed by mistake, man-made damage or misuse, subjective change of mind, and anything outside the warranty terms.