The ML19 ribbon microphone from Oktava is still a little underrated and I think this is one of the best sounding end-address cardioid ribbon mics.

Based loosely on the RCA BK5, the ML19 has a wider ribbon and is a little warmer in tone with a good bass response, without being overly dark or woolly. It is great for upright bass and horns and any source where you need rear end rejection. It also sounds rather nice on acoustic guitar.

Here is a short acoustic guitar recording I made with a spaced pair of Oktava ML19 cardioid ribbon microphones.

The tune was played (by me!) on an old Levin flat top acoustic with silk-and-steel strings, and recorded into a UA Apollo 8 preamp with 57 dB of gain, using Logic Pro. There was no processing aside from normalising the file. I pointed one mic at the 12th fret and the other at the lower body. However I suspect a crossed pair might sound really good here.

These mics don’t age well and it is worthwhile getting them serviced if that not been done. Generally they need new cables, new ribbon and perhaps most importantly the internal foam should be cleaned out and replaced.