Battery-Powered Tube Preamp from Siltech

Siltech's Edwin van der Kley handed me his new preamp. There were no wires attached, but the four tubes were glowing. "It's battery-powered, and I could use a low 25V voltage rail for the tubes because they are ECC86 dual-triodes, which were developed for car-audio and microphone use." Edwin went to explain that as this tube uses a 6.3V heater, he could run the heaters of the four tubes in series from the same 25V supply. It also offers very low 1/f noise for a small-signal tube, he told me. Siltech has a plentiful supply of the tubes and the preamp wil sell for $28,000.