Discontinued product. It is replaced by the Minion pre-amplifier. The Minion pre turns out to be even better than the DHT pre and is absolutely silent, no microphonics, hum or any noise, this is why we decided to discontinue the DHT pre.

The DHT pre is our top of the line pre amplifier, made specially to fit our 300B and Fet SE monoblocks, or any other high input power amplifier (3V up is recommended). It uses the mesh globe PX4 made by TJ as driver tube. It is capable of delivering up to 20Vrms output with 30 mA, this power never will be used, but it ensures a lot of overhead and thus easy dynamics and low distortion.

The power supply is rectified with the EZ81 tube for slow startup rectification. The chassis is a brushed stainless steel cover over a 2 to 4 mm thick black poader coated steel frame. The amplifier has three compartments, one for the power transformer and rectifiers, one for the power supply smoothing and stabilisations and one for the signal part, to reduce hum and noise to a minimum. The tubes are mounted on birch plywood subchassis decoupled by rubber dampers from the steel frame.

The signal part is hardwired point-to-point and power supplies and controls are build on special high Hf rejection design double sided PCBs. High voltage power is choke loaded. The amplifier uses two specially designed low core saturation shielded torroidal power transformers, one for the heaters and controls, and one for the high voltage signal power supply, mounted on rubbers for low noise. The PX4 have VCCS stabilisation on heaters and CCS load. The parts are specially choosen for optimal sound, like Allen Bradley and other mil spec resistors, Sprague paper-oil output capacitor, low esr power supply capacitors, tin plated copper/teflon wire, NOS teflon and ceramic tube sockets. Volume control is a ladder type stepped attenuator with Vishay/Dale resistors.

Click here to download the DHT PRE pre amplifier owner's manual.