This is why we use a recessed DC Power Connector on our pedals

The DC Power Connectors we use are a common standard choice among pedal makers globally. They typically require a DC Power Plug with an outer diameter of Ø 5.1mm and an inner diameter of Ø 2.1mm. With an internal depth of 10mm, they can easily accommodate DC Power Plugs with barrels longer than 10mm.

It’s worth mentioning that the “BOSS standard” DC plugs have shorter 10mm barrels, which was a subjective standard imposed because their pedals had exposed DC power connectors through the enclosure, making longer barrel plugs unnecessary.

In our case, for a reliable electrical connection, we’ve chosen to solder these connectors on the main circuit board, recessed behind the 2mm thick enclosure wall. This is why a DC Power Plug with a 12mm long barrel is required for a good electrical connection. Read on to understand our reasoning for this decision.

Why do we mount the DC Power Connector recessed on the main board?

The main reason for recessing the DC Power Connector on the main board is to ensure a strong physical and electrical connection. However, using Hammond enclosures with 2mm thick, tapered walls creates an issue. These thick walls prevent a 10mm short-barrel plug from fully entering the DC Power Connector.

Several factors influence this decision. Firstly, we aim to avoid using wires in our builds, and space constraints within our pedals are another consideration. Also, having connectors protrude outside the enclosure affects the appearance, which is more critical in MINI-sized pedals.

Unfortunately, we can’t create square holes through CNC machining to pass the DC power connectors through the enclosure instead of recessing them 2mm behind the wall. Even if we could, it would not work due to the other parts orientation and available physical space for maneuvering the assembly.

We’ve also chosen not to drill big holes in front of the DC power connectors, as some other manufacturers do, just to fit the plug’s plastic cover through the enclosure wall. These large holes would not only make the connector visible and less attractive but also raise the risk of dust getting inside.

Here’s another consideration. Our Hammond enclosures come with a nice black powder coating. After we print white markings, we use CNC machine to drill on the enclosure. If we were to drill bigger holes just for the plug’s plastic cover, it would expose the aluminum surface, possibly causing electrical issues. Unfortunately, we can’t add a new coating inside these holes. And if we made the holes even larger for a bigger plastic ring, they’d look even less appealing, especially on the MINI pedals.

The aluminum enclosure is electrically connected to the circuit’s ground and negative power polarity for electromagnetic shielding. To ensure safety and prevent shorts, we drill small holes and insert plastic rings. We do this because the plugs have positive polarity on the outer surface. These rings not only prevent shorts but also make the connection sturdy.

This approach is practical, even though it increases the assembly effort and time. However, we’ve decided to implement it. It provides protection to the internal connector if you accidentally step on the plug, thanks to the enclosure’s strength. We believe it’s a good choice that combines functionality with the smaller holes and their colored isolation ring.

Is a 10mm short-barrel DC Power Plug completely unusable?

No, a 10mm short-barrel DC Power Plug can still be used effectively with the snug-fitting plastic isolation ring that we use, also depending on the barrel tip’s design. However, due to the enclosure’s thickness, it may not be fully inserted onto the recessed DC Power Connector. This can make the electrical contact between the barrel’s outer side and the connector’s contact blade less secure, leading to potential power interruptions, especially with mechanical shocks. Hence, for a reliable connection, a 12mm long barrel DC Power Plug is needed.

How do we notify users on the requirement for DC Power Plugs with 12mm long barrel?

In product presentations, manuals, and technical specifications present in product pages, we do advise to power our pedals with center negative DC Power Plugs having Ø 5.1mm external diameter, Ø 2.1mm inner diameter, 12mm long barrel. Manuals also advise users on using only good filtered and regulated power supplies and highlight the need of keeping the DC power voltage within specified limits. Additionally, we have compiled a set of relevant technical information in the CompIQ 101 present in every compressor’s presentation page and as a blog post.

Where to get power leads with DC Power Plugs with a 12mm long barrel?

Some high-quality power sources such as those made by Voodoo Labs or Cioks already come with power leads having longer barrel plugs. There are many replacement options for DC power cables fitted with longer barrel DC Power Plug e.g., Voodoo Labs, Cioks, MXR, EBS, etc. eBay is a rich source for very cheap such leads – just look for the ones with a longer barrel. Tech and music shops near your location may offer such leads or separate plugs as well.

If you don’t want to purchase a new power cable you can trim 2 mm from the plastic jacket of a DC Power Plug with a 10mm short barrel.

Since the DC Power Plug’s isolation jacket is usually made from a rubbery plastic, it is very easy to trim a couple of millimeters out of it to expose a longer barrel. We recommend this simple adjustment which works just fine and it takes less than a minute to do it. This way, the 12mm long barrel passes through the 2mm thick enclosure wall and can be fully inserted into the recessed DC Power Connector.