Standard effect pedal connector/barrel size?



Asked by: Larry Johnsson

The standard size of a power jack on most commercial pedals, is 2.1 mm inside diameter and 5.5 mm outside diameter.

How do you measure a barrel connector?





I found that the easiest, but not the cheapest, way to determine the inside diameter of a ‘barrel’ connector is to use a set of “pin gages” which are hardended and ground to precise external diameter steel ‘rods’ that come in sets.

How do I know what size DC plug I need?

If you go into a shop you can compare and test the connector size, or if you are technically minded you can measure the size of the port and pin yourself. If you are measuring you need the diameter of the center pin for the (ID) and the inner diameter of the port (OD).

Are all BOSS pedals the same size?

Guitar pedal dimensions can typically be grouped by brand, with limited variation within those brands. For example, the typical Boss pedal is always 2.87 x 5 inches. While there are smaller and larger form stompboxes, this is an extremely typical size for a single effects unit with only one bypass switch.

What are the different types of DC connectors?

In the electronics industry, there are three commonly accepted configurations for DC power connectors: jack, plug, and receptacle.

How do you identify a barrel jack?





When ordering, there are three differentiating characteristics of a barrel connection- inner diameter (the diameter of the pin inside the jack), outer diameter (the diameter of the sleeve on the outside of the plug), and polarity (whether the sleeve voltage is higher or lower than the tip voltage).

What is SAE connector?

“The SAE connector is a hermaphrodite two-conductor DC connector commonly used for solar and automotive applications (also motorcycles). It is so named for the Society of Automotive Engineers who created its specifications.” —

Can I use a 12V DC power supply on a 9V DC?

If you have a 12V adapter, you might wonder whether you can use it to power your 9V guitar pedals. In most cases, you cannot use a 12V adapter to power a 9V guitar pedal. Using a 12V adapter on a pedal designed to only handle 9V can completely destroy it.

How do you use a barrel connector?


You look inside the butt splice you'll see an indentation your conductors should butt up against insert the wire making sure the insulation touches the butt splice.

Can I use 12V adapter for 15V?

Distinguished. Assuming the polarity is correct, plugging in a 12V input to a device requiring 15V won’t do any damage, however if you undervolt an amplifier, you may get clipping or other distortion.



What size barrel connector do I need?

The two most common barrel connector sizes are 5.5 mm outer sleeve diameter with 2.1 mm inner sleeve diameter and 5.5 mm outer sleeve diameter with 2.5 mm inner sleeve diameter. Convention has evolved with the outer conductor as the ground or negative voltage and the inner conductor as the positive voltage.

How do you wire a barrel connector?

This goes to the center pin inside of the barrel connector and then this connects to the to the outside so that then you have one positive one one negative terminal.

Why do DC jacks have 3 pins?

One of the other pins is negative, the third pin is switched to negative. Connect them both to circuit negative/ground. It does not matter which is which is which and for any connector the physical attachment to the board is important. That extra pin being soldered gives higher strength.



How do you measure a jack?

Keep the tape above the jack, without touching it. Look straight down at the jack, and measure to the edge (not the top) of the jack. Measurement requires strong legs, steady hands, and good eyes. It is difficult to do.

Which is positive on a barrel connector?

If the line touching the tip in the centre has a + (plus) symbol, this means the tip is positive, and the outer shell is negative. In any case, you need to research this for your particular device. There is no general rule. Usually, negative/ground is outside.

How do you check the polarity of a barrel connector?

Use a multimeter on ohms measurement. The negative terminal of the barrel connector will be shorted to ground plane on the PCB, or the chassis, and when you connect one test lead to the negative terminal of the barrel connector and the other to chassis/PCB ground, the multimeter will read 0 ohms.

How do you test a barrel connector with a multimeter?

Take the black (negative) probe from your multimeter and carefully touch it against the barrel of the plug without touching the tip or your red probe. If you make a connection, you will be creating a short circuit. On your multimeter you should see a reading of the voltage coming from your power supply.



Can I use a 12V power supply on a 19V?

Home / Blog / Can I plug in a 12V power supply for my 19V laptop? No, you can’t. The original 19V power supply has an output range of 16 to 22V and does not charge at low power.

Can too many amps damage a device?

As long as the correct voltage is used, a device will draw only the amperage it needs, meaning there will not be “too many amps”. If an incorrect voltage is used — say a higher voltage than the device is rated to accept — then yes, too many amps may be drawn and the device can be damaged.

Is it OK to use a higher amp power supply?

Yes, sure. If the connector is the same and the voltage is 12V. The ampere value of the new power adapter should be 2A or greater.