The Dynaco ST-70 was the company’s first stereo amplifier. It utilized four EL34 output tubes, one GZ34/5AR4 rectifier tube, ...

The design is inspired by the guitar amps of the 1950s and 1960s so ... two stage double triode preamp and a single power output tube. The transformers are usually the difficult part of a build ...

Despite the oldest solid state audio circuitry now qualifying for a pension and a bus pass where this is being written, the thermionic tube retains ... a tap on the output transformer feeding ...

Like Folkvangr, the Schiit Valhalla 3 operates as a OTL/OCL design—no output transformers, no capacitors in the signal path.