“Beamer” Notes

[still looking for a better name!]

Status (updated 3/11/2020)

I’ve been using the 1st proto enough to already be planning some changes for the X20:

I need to add an indicator LED and microswitch for channel switching. I don’t tend to change channels in the middle of things very much, so why be forced to use a footswitch?

The Standby switch is probably gonna go, too, since my simulation shows the B+ getting a pretty soft start.

Current control placement (front panel) is
jack DRIVE TONE NASTY NICE BASS TREBLE MASTER lamp

I’m open to alternate naming and/or placement of the controls so suggest away! So far I’m assuming I have to fit the channel microswitch & LED between the NASTY & NICE knobs…

Schematics

Schematic Notes:
* component numbering is strictly “per page,” mainly because I’m too lazy to figure out the right way to do multi-page schematics in KiCad.

* Some of my parts aren’t in KiCad libraries, so I had to pick near equivalents or generic enough substitutes.
— The DPDT relay and diode bridge are rough equivalents to the actual parts on the Weber Relay Board.
— The “supply” page uses two generic transformer symbols to represent the filament and high voltage supplies of a Hammond 269EX (the target PT).

* I’ll post both PDF and KiCad files once I’m done tinkering with the full prototype (which will use the intended transformers, not the ones on Verberator II proto)

Layout

This is the rough layout (really general space planning) for the x20 proto, which will be in a 3x7x15″ chassis. It looks like it’s going to need a lot of long (shielded?) signal wires, which is why I’m still considering changing the control layout.

Also note that this is a “tubes up” design, but the diagram is the view looking at the bottom of the chassis (“maintenance mode”).

x20 rough layout

Those lines of 7 6 dashes represent terminal strips. The OT wires will come through behind the large circuit card. Note that this doesn’t include the channel switch & LED that I intend to add.

Here’s a look at my usual ‘freestyle’ layout, where I just make a card with lots of grommets and work my way through the schematic. Not efficient, maybe, but handy for prototyping. This is the old Verberator II chassis after becoming the Beamer x10:

rat’s nest

That’s a “tubes down” chassis, btw (a la Fender combo amps).