Eurorack DIY Prototyping Cards Rethink

Post updated 3rd July 2018

The Synovatron Eurorack DIY Kits have now been discontinued. Because many of the kit components are easily available from online retailers it made sense that Synovatron just provides the unique (e.g. PCBs) and harder to source parts (e.g. pot brackets). This provided a great opportunity to reassess the PCB designs rather than just reorder more of the same.

What has emerged is a revised and rebranded Eurorack prototyping solution that is more usable and more elegant than before. The revised product revolves around three PCBs in the Synovatron Proto series: ProtoPotz, ProtoJax and ProtoXp. 

The new Proto PCBs' holes line up with each other to allow each board to be stacked one on the other using header plugs and sockets; allowing power and signals to be routed between boards without resorting to linking ribbon cables. Here is an example board stack-up:

ProtoJax, ProtoPotz and ProtoXp boards stacked together

Examples of headers and sockets used to stack the boards

ProtoPotz

ProtoPotz is the direct replacement for DIY1 PCB (as used in DIY Kit 1 and DIY Kit 2). It is designed to hold up to five 16mm P160KN series pots using brackets. What's new about it?

• Plated-through holes for robustness and convenience, essentially it's a double-sided PCB. 
• Better supports the A-100 bus with dedicated positions for 10 or 16-way open or boxed headers, small electrolytic capacitors and protection diodes (to protect against reverse power connection.

ProtoPotz pot breadboard PCB

Here is the range of pots available from Mouser that Synovatron recommends for use with ProtoPotz:-

ProtoJax

ProtoJax is an evolution of DIY2 and DIY3 PCBs. It is designed to hold up to five Cliff CL1384 3.5mm mono jacks. It is almost identical to ProtoPotz except it has footprints for jacks instead of pots and another two rows of breadboard holes. What makes it more advanced than DIY2 and DIY3 pcbs?

• Larger breadboarding area. 
• Supports the A-100 bus similar to ProtoPotz.

ProtoJax jack breadboard PCB

ProtoXp

ProtoXp is a completely new PCB. It is an eXpansion board designed to add more breadboarding area to ProtoPotz or ProtoJax boards. It's features are:-

• It has a cutout that allows the A-100 bus ribbon cable connector to fit without fouling on the ProtoXp board. 
• The same ±12V power bus structure as the ProtoPotz or ProtoJax boards.

ProtoXp expansion breadboard PCB

DIY2 jack breadboard PCB

 

DIY3 jack breadboard PCB

Cliff CL1384 (S6) 3.5mm Jack Sockets - Rumours vs Facts

Following a really useful blog post by PatchPierre about dealing with poor connections on jack sockets I started to wonder if the jack sockets that I have used on my kits and intend using on my forthcoming CV Tools and Diode modules may have quality issues. I read through a few forums (fora?) and blogs on the subject and it does leave you with the impression that there could still be issues with Cliff sockets unless you get the right ones. So I approached Cliff directly who have clarified the situation as follows:-

• Synovatron: "I've been using CL1384 jacks for several years now without any issues but am aware that there have been poor contact issues in the past. Your website refers to type C contacts for far-eastern jack plugs and also to be aware of counterfeit types. I read that Doepfer now use CL13841 sockets due to earlier problems (are CL13841 and C contacts the same thing?). Can you please clarify the situation for me?"

• Cliff: "Thank you for your mail. I can clear any confusion up very clearly by saying that we use the C contacts on all S6 jack sockets. The CL13841 part is no longer sold but CL1384 is now exactly the same as we are using the C contacts as standard."

So in summary you should get no problems with current standard Cliff jacks but older ones can be fixed using PatchPierre's advice.