DIY Cocoquantus Delay

Josh Rodriquez again gifted me two PC boards! This time they are replicas of the delay lines in the Cocoquants v1. One of the boards was partially assembled and Josh included a list of parts needed to complete it.

Board as received with most of the SMD parts soldered
Top side of the received board

My enclosure design

Naturally, I wanted to put this into a plexiglass case, the same way I’ve done my other Ciat-Lonbarde DIY projects. But this one was different. The panel parts are soldered to the top of the board instead of being fixed to the panel alone, with wires connecting the jacks, pots, etc., to the board below. But this projected called for the panel to mount over the jacks, pots, and switches soldered to the board. I had to drill the plexiglass with more precision than usual. Not really possible – Hah! But there’s always the handy round file.

Panel drill template on graph paper and drilled plexiglass

I bought two pieces of plexiglass, one for the top and one for the bottom. Both have corner holes where nylon standoff will go to connect them together. The top gets the holes that must match the PC board. I got pretty close, but plenty of filing remained before it would fit over the panel parts.

Nanajacks

The Nanajack problem with filed tab at right

I decided to use Nanajacks, because if regular banana jacks are used here, since they insert through the panel top and solder into the board, the panel cannot be removed afterward. Nanajacks looked like a simple solution. But the ones I got from Synthcube are “beta” versions. Synthcube’s description includes improvements for future versions. And they’re needed! In the photo above a yellow Nanajack is compared to an orange Johnson banana jack. The first problem encountered was that the solder tab on the Nanajack is a bit wider, too wide, in fact, to fit through the slots in the PC board. The metal jack barrel can be pulled out easily in the beta version. I had to Dremel grind 11 of these to narrow them enough to fit into the board. Since the barrel slips in the plastic sleeve, the force of inserting a banana plug pushes it out the back if it’s not soldered into a board. This is supposed to be fixed in later Nanajack versions. I was lucky the barrels could be removed easily for machining, though. One aspect of the Nanajacks is the lower insertion force than that of the Johnsons.

What are those big holes in the board?

Josh’s build

Josh made an opaque panel with nice graphics. His version includes an XLR connector, like the original, for connecting a microphone. He also used a large, round toggle switch, similar to the original ones on the sides of the Cocoquantus, with an LED inside the switch. This is the freeze switch that circulates the buffer when engaged. I took a much simpler route, omitting the XLR and putting a miniature toggle switch and an LED in those panel locations.

Project Completion

Board with all components fitted
Actual Cocoquantus v1 PC board

The board is almost identical to the original. The big holes are in the location of the quantussy oscillators on the original.

Bottom of completed unit
Detail showing power and the LED with connector
Detail showing tiny SMD parts
View showing the 1-inch nylon standoffs and feet on bottom
End view showing bumper behind ground Nanajack to hold the barrel in place

Tryout Video

2 Responses to DIY Cocoquantus Delay

  1. Joshua Rodriquez says:

    Beautiful build!!

  2. Richard says:

    Thank you, sir! Much credit to you.

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