Why we use terminals instead of DC jacks

Optimal connection for your power source.

We are often asked, why we use terminals for input and output connections, instead of using a DC jack. We would like to summarize our reasons here:

Typical use case:

In nearly all use cases the HPULN power supplies are implemented in a chassis - the HPULN module is inside of an existing enclosure. Often even in the enclosure of the device / circuit, that has to be powered. With a HPULN power supply one shall reach the final power supply solution, so there's no need for a "faster" kind of a connector, than a terminal offers.

- Chassis space:

A terminal needs less PCB area, further no connector is needed, which usually would need around another 5 centimeters in front of the HPULN power supply. That can be a showstopper for many projects, which have only a little space left in a chassis. A cable is flexible, bend it how you need it - directly out of the terminal without wasting area.

- Flexibility:

A decision of the used cable can be a very subjective thing - use the cable you prefer, with more wire diameter than possible using a DC jack. And when a DC jack is really needed, the DC jack connector is usually connected to the DC jack socket on the enclosure, so it's easy to connect it with a few centimeters to the HPULN's terminal.

- Resistance

We use terminals with cage clamps only. That ensures the most surface contact between the wire and the terminal, resulting in a minimum of resistance. DC jacks have a small clamp, which in addition to the low contact pressure is the only contact to the round shape of the male DC jack - resulting in a small contact area only. That's why DC jacks are often rated with <60mOhm of contact resistance, which is by far more, then is reachable with a pure wire. Contamination (i.e. because of touching the (male) DC jack) can cause oxidation and so influence resistance once more.

Additionally we avoid one step of contact-transformation:

Terminal: PCB - terminal - wire

DC jack: PCB - DC jack - clamp - wire

- Power rating:

DC jacks are usually rated to 3, a couple of them to 5 ampere and low voltages only. Our terminals are rated to 300V / 13,5A.

- Costs:

We use high quality terminals, which are cheaper than usual DC jacks (male and female), though. We mirror that in our prices.

So is a DC jack generally a bad type of connection? No. But we see many advantages to use a terminal instead - especially for that kind of device, that is itself optimized and designed to bring your audio setup to the next level.

Our general recommendation:

Keep wires short, use as as less connections / connectors as possible. In some cases it can even make sense to remove the terminals to solder wires directly on the PCB.