Valve RIAA

Submitted by patrik on Fri, 2005-11-11 11:11

The beginning: A wood box was constructed with plywood and oak.

Testmounting of the components on the back.

Some varnish made the box prettier, and I have mounted the transformer and valveholders.

The transformer sure is lethal, so I made a little wooden house for it. We also see a volume knob and a power on indicator in the front.

A wood box has no protection for disturbances as a steel box, so I covered the insides with copperfoil. Soldering of the power input has begun.

High voltage power supply.

Beginning of the amp itself, picture showing the RIAA's input stage.

Jan Lodströms schematics from Rörbyggarskolan (Elektronikvärlden).