Fig.1: Prototype of the phono stage. The switch at the side was added temporarily for listening tests concerning class A mode of the op amps.

Enhanced phono output stage with composite op amps and LL7902 audio transformer

Detail photo of the 1kOhm feed back resistor of the OPA 603

MK III Phonostage “La Bohème”

Star-wiring is mandatory

Symmetric inputs of the MK III Phono Stage

Connector to the external power supply

Accumulator based external power supply

Control unit for charging / operation modus

Setup for matching jFETs