811A tube amp



811A Parallel single ended amp

This 811A tube amp DIY project designed by George Filippou and Giannis Spathopoulos and me. It is the first attempt to work with 811A direct heated triode audiophile tube in parallel single ended topology .
It is based on Shishido 811A tube amp,and the whole project is still in progress.Power output stage uses 2 X 811A tubes in a parallel single ended connection. Plate voltage is 450 Volts. The driver stage uses the 6L6GC tube and the voltage stage the EF86 tube.
We are working on the PSU boards performing measurements and adjustments.
You can find the Shishido schematics in amp schematics pages and 811A tube data in tube data pages.

click here for the SV811-3 DHT similar project

After six months of testing and fine tuning the amp, we decided to rebuild the amp using a dual mono design. The reason for doing this, is to eliminate the weight of the amp, and to improve the power supply unit.

This project is still in progress. We will upload more data soon.


The prototype Parallel Single Ended 811A :


The dual mono version of the amplifier :

assembling the amp using new chassis :