More 5E3 Head Progress

I found some time to finish drilling the Hammond chassis for my 5E3 head. I made some more mistakes (eg. a misaligned input jack), but it didn’t turn out too bad for a hand drilled chassis.

Drilled chassis for 5E3 head.

Progression of populating chassis hardware.

The location of the power transformer’s mounting holes were not as precise as I had liked. I was able to get everything to line up in the end.

Chassis with components mounted.

It may have taken a while to get the chassis drilled, things seem to be moving quickly. I am just about to be ready to start soldering wires onto the components.

Chassis with transformer wiring.

I am using a combination of reference documents to build the amp.

• Triode Electronics 5E3 Layout - for the wiring of the Classictone 40-18017 PT, which is equivalent to the 40-18066 that I am using.
• Metropoulos 50W Plexi Instructions - for the general workflow of wiring up heaters.
• Rob Robinette's 5E3 Page - general 5E3 theory of operation and tips to optimize layout/wiring.
• Mojotone 5E3 Kit Instructions - used as a double check for all connections.
• Trinity Tweed Amp Instructions - used as a general reference for 5E3 wiring.

Edit - 11/22/21 - I finished soldering the 120VAC wiring into PT primary. The color coding of the Classictone 40-18066 primary wiring is odd: the line connection is white and white-black, while the neutral is black and black-white. I had to double check the diagrams a few times.

AC input wiring into PT.

I shortened all of the transformer wiring, too hastily. I used a forum post in regards to the Classictone 40-18022 OT phase as reference, only to later find another forum post that contradicted the information.  I traced the 5E3 schematic and looked at the Mojotone instruction manual to double check, and it does look like I botched the wiring. I mistakenly ran the Yellow lead to V3 Pin 3, Green lead to V4 Pin 3. The diagram below is my proposed fix on the speaker jack side. 

Edit - 11/23/21 - I dressed the heater wiring based on typical Marshall-style layouts. My tube socket spacing is tighter than the average Plexi layout, so it was a bit of a nuisance to get done. It’s not as neat as I would like.

Edit - 11/29/21 - I ran all of the preamp wiring off the turret board side and soldered about half of those wires in. Once I have the turret board completely soldered, I will start trimming and routing the wiring onto the various tube sockets, pots, and jacks. 

I see why most 5E3 builds have heater wires installed above the tube sockets rather than along the chassis Marshall-style. The wires for V2 are located in the middle of the typical 5E3 board, while the tube socket itself is closer to one end of the chassis. I will soon commit and hope that I don't screw up the layout of the tube socket wiring.

5E3 turret board wiring progression.

Edit - 12/2/21 - I finished making all the connections to the chassis. I quickly did a continuity check on various connections to make sure that I didn’t have any routing errors. I fired up the amp through my Suhr Reactive Load.

I still need to drill a few holes for the vented cage that will sit above the chassis to complete the amp.

All connections soldered.