Help with DC power connectors please

It's called an Aviation connector and that looks like a GX12 2 pin.  Might be easier and cheaper just to buy the whole cable from Ghent Audio

Thank you - that's it!

The GX12-2 (9mm) and GX-16-2 (12.5mm) look the same but barrel diameter is different. Also note that pin 1 location is reversed compared to each other.

https://www.ghentaudio.com/part/dc28.html

Thank you @agisthos 

Good source for the connectors and really good information about them.  The preamp manufacturer had actually added this connector to a very cheap wall-wart that came with the preamp, and I wanted to try using a linear power supply that I have here but I only had cables with barrel connectors attached.  

Since I didn't have that type of connector, I removed the connector from the wall wart that came with the preamp and connected it to a cable that I cut off of an old computer charger that had the right sized barrel connector to go with my LPS.  I checked polarity on the wall wart before removing the connector so that I would be sure of the polarity wrt the orientation of the two connectors and, after verifying the polarity of the power coming out of my LPS, I wired the new cable to deliver the DC from the LPS in the same polarity.  The wall wart had a parallel very thin gauge wire/cable and the computer cable I used was a heavier gauge (18 awg) coaxial type.  I figured the main issue would be to have at least the same gauge wire as the wall wart for the relatively low current (5V/1A) and since the computer charger cable carried a higher amperage and was of a larger gauge, I assumed it would work fine.  I do not know whether the coaxial cable design has any other noise reduction benefits. 

The linear PS works fine with the preamp and it sounds great but it would be almost impossible to determine whether there is a sonic improvement over the wall wart.  There wasn't noise before and there isn't now.  The power is solely for a display and switching to accommodate remote control in a moderately expensive AVC passive preamplifier.  The manufacturer says there should be no improvement from using a LPS but one reviewer said he thought using a LPS improved sonics slightly.  While I am skeptical about sonic improvements, I decided it couldn't hurt since the SMPS wall wart, if noisy, could possibly induce noise to the inside of the preamp.  In addition, I don't like having a SMPS wall wart near my other electronics. 

Thanks all who replied.

While we're on this topic, what have folks found to be the best two conductor DC bulk cable for this application? I'm guessing shielded would be preferable to unshielded. Thanks.