EML-20A DHT Dual Mono

About the EML-20A DHT Dual Mono

The Shiny Eyes EML-20A DHT Reference Dual Mono Preamplifier is a single stage preamplifier designed for the most demanding audiophiles. It uses the Emission Labs EML20A mesh tube, known as one of the lowest distortion tubes ever built, providing a gain of 14dB (5x). The preamp delivers 10Vrms output from a 2Vrms source with a low output impedance of 375 ohms and measured total harmonic distortion (THD) of 0.02% at 10Vrms output, dominated by second harmonic distortion. The design features a separate power supply chassis with Lundahl transformers and chokes, a hybrid rectification scheme, and a screened 6-foot umbilical cord for low noise and high signal-to-noise ratio. The filament supply is on a separate board with its own transformer, and there is an additional DC supply for volume remote control and output delay. The main preamplifier uses a self-biased EML20A tube loaded on a Monolith Amorphous Core LTA 01/25mA line output transformer wired 4:1. The input is DC coupled, and the output is transformer coupled, with no coupling capacitors or negative feedback. Volume control is implemented via a Tortuga Audio ePOT V3 mini with OLED display and Apple remote, offering either LDR or discrete stepped attenuator modules. This preamplifier is noted for its simplicity, excellent sound quality, and extremely low distortion characteristics.