Crawls Backward (When Alarmed)

IconProjects, musings about guitar builds, guitar repairs, vintage tube amplifiers, old radios, travel, home renovation, and other stuff.

Wiring the '42 Amp

Hardware is all on the amp so I can start wiring.  Hopefully this is where all the planning will pay off, and I won't find out I forgot something.

The main part of the wiring is the filter section, which I had done as a  subassembly.  All the crazy wires you see sprouting are either from the power transformer or the filter section.

Now I start wiring.

This looks a bit tidier, doesn't it?

At this stage, the power supply wiring is done and the input wiring is started.  The red lead going through the grommet is the main B+ going to the output transfomer and back to the plate of the 42 (center tube socket).

The other long red lead is the B+ going to the 6J5 plate.  At this point, I had also wired the input socket (lower left) to the volume control (center left), and the input ground. 

The main input ground is on the terminal strip on the left (green arrow).  All the power supply grounds go to the ground on the terminal strip of the filter section.  So we have 2 star grounds which should keep noise and hum to a minimum.

The picture on the left is the completed wiring.  The filament leads are the green wires - I ran them above the chassis on this build.  There aren't many components so it's fairly tidy.

The volume pot is the Alps one I removed from the Dyna PAS.  The schematic called for a 500K pot and this is the only one I had.  It's a stereo pot, but I'm just using one section here.

The big orange cap is a .22uF Sprague/SBE 716P Orange Drop.  It's the lone coupling cap (between the 6J5 and the 42).  I have some PIO caps I'll experiment with in that position in the future, but for now, I want to get it working first.

Next...let's fire it up and see if we get any smoke!


Post a Comment 0 comments:

Post a Comment