GerusAudio 300B Build Process, Updated 4/23/18

Here's a preview of how we build the GerusAudio 300B

The C3G/300B Amplifier is complete and for sale now. See my "Amplifiers For Sale" page.

Both amps are setup for high power. The 300B's will run at 350V and 80mA.

The Lundahl OPT's are on order.

One amp will use a C3G in Triode mode for the input/driver, the other a 6SG7.

Before I list the amplifiers for sale, I listen to the each one for 10-20 hours, re-check the voltages, power output and frequency response.


The 3rd chassis will be used for an "A3 Series" amplifier.

Some basic Wood Work!

This batch is Walnut

Cut the Radius

Route the chamfer

Transformer side covers

Chamfer the side covers

Finished top plates

Cutting, Drilling and Bending Steel

Bottom Covers

18 gage mild steel, painted with Hammered Gray

Transformer Covers

18 gage mild steel, painted with Hammered Copper

2/19/18 Update

Varnish Sides

Varnish Top Plates

Rough Idea of Parts layout

The Input/Driver Power Supply Board

The Back Plate

3/05/18 Update

The Power Transformer

The main power transformer is rated at 600mA. The amplifier draws about 250mA. So no need to worry about this bad boy being over loaded!

The input/driver power supply

This is board supplies the DC voltage for the input/driver. Zener diodes are used for the "G2" voltage.

The "Ultra Path" Capacitors

The 300B's use the "Ultra Path" configuration.

Close up of the Rectifier

This is the "Hybrid Rectifier"