I love my Behringer K-2, an affordable copy of the legendary KORG MS-20. However, I wanted access to a feature seen on other synths: oscillator sync. This is more famously found on the Sequential Circuits Prophet and Pro-1 series synthesizers. Thankfully, this is a fairly straightforward modification. It involves connecting a specific spot on oscillator 1 to oscillator 2 with a diode and switch, allowing you to access the effect at a moment's notice or return to normal operation. I found a tidy spot on the control panel between OSC1 and OSC2 and drilled and mounted the mini toggle switch to the control panel. I soldered the diode and two very thin wires to the switch and covered them with heat shrink tubing. All that was left was to connect it up to the PCB. This was a bit tricky as the PCB was all surface-mounted components. I bought a very fine solder tip and was able to carefully solder 30 gauge wires down to the two necessary points. For the second mod, I added an additional 1/4" output to the back panel, as a duplicate of the front panel's 1/8" external signal processor output. This was more about convenience of use than increasing the capabilities of the synth. On the original 1978 version of the synth, all of the patch cable connections on the front panel are 1/4" jacks. Since then, the industry standard for modular and semi-modular synths has shifted to 1/8" jacks, which allows for a much smaller form factor, eurorack being the most popular format. This becomes a minor issue if one intends to use the external signal processor of the K-2 with non-eurorack synths, effects, or mixers, as it leaves you with only 1/8" out instead of the industry standard 1/4". to remedy this, I simply drilled the rear panel of the case for a new 1/4" jack and wired it directly to the original 1/8" jack. This allows me to use either style cable as I please without cumbersome and potentially damaging adapters.