I thought i'd share a lttle trick i came up with last week - how to get balanced audio into HV20.
In balanced XLR michrophone cables there's three pins: ground (1), plus two "hot" ones (2,3). The signal one gets from ground and either one of the two hot pins is the same, except the signal phase is opposite. Balanced input is just the difference of these two signals - which one gets by inverting one of them again, then combing them. All the buzzing etc. noise the cable gathers gets phase cancelled, and the signal gets amplified by 6dB. The result is buzz free audio. This is MUCH better than unbalanced, especially if the cables are long, if there's other electrical equipment around etc.
Enough of theory...
One can turn HV20's stereo miniplug michrophone input into a (fake) balanced mono input with a simple cable:
XLR pin 1 > 3.5mm TRS plug sleeve
XLR pin 2 > 3.5mm TRS plug ring
XLR pin 3 > 3.5mm TRS plug tip
A michrophone connected to HV20 with the above custom cable will record a stereo sound, where the signal of L and R is in opposite phase, but all the noise and buzz is in the same phase.
Here's the catch: When the channels are combined, one gets a mono signal with very little usable audio, and a lot of buzzing. But when either the left or the right channel's phase is inverted before combining the channels - TADAA!!
...clean audio without buzz and noise.