Oh, dear. Wish I'd seen this thread sooner. Your PS-2 has been modified so that it converts the signals from your balanced microphones to unbalanced signals, via a wiring scheme that works in many cases but not all--because balanced output circuits can have many possible configurations. No one adaptation scheme works with all of them.
A balanced output has two modulation leads which are independent of shield and/or ground. In many modern microphones, one of those leads is actively driven and the other one has a matching impedance (to create the balance) but is not actively driven. That's perfectly OK when the microphone is connected to a balanced input. But it sounds to me as if the modification on your PS-2 takes the signal from one modulation lead, grounds the other one, and the lead that's being grounded happens to be the one that the microphone is actively driving! So you probably need to connect the wires that go to the tip (left) and ring (right) of the stereo miniplug to the modulation leads for each channel that aren't currently connected, instead of the leads to which they're connected now.
That's only a guess, however. The best procedure is to ask the microphone manufacturer how to unbalance the signals from that particular model of microphone, and follow their instructions carefully. And you should understand that even if you do that and it works, the PS-2 will no longer work with many other types of microphones that have balanced outputs. That's just the way it goes.
For many decades (say, from the 1920s until the mid-1970s) there was pretty strict separation between professional and consumer audio equipment. Any interconnections between the two realms were special-case, one-off situations. There are well-established standards for how to connect balanced equipment such as your Oktava microphones to other balanced equipment, and there are well-established standards for how to connect unbalanced equipment like Sony's consumer microphones to other unbalanced equipment such as your Sony consumer recorder. But there is no standard way to connect a balanced microphone (or other balanced signal source) to an unbalanced input, and because balanced output circuits vary so much, there can never be one. There is no such thing as an "adapter from balanced to unbalanced" (e.g. from a pair of XLRs to a stereo mini-plug) that can possibly work given all the various kinds of balanced output circuits that exist. People shouldn't buy or sell adapters that supposedly do that--it's deceptive, unethical, and can lead to things just not working, or even being damaged.
You can convert an unbalanced input into a balanced input by putting an input transformer in front of it, but that can get expensive if you want the transformer to be really good at passing wide-range audio signals, and it can also be a little awkward logistically. Or you could use a preamp with phantom powered, balanced inputs and unbalanced "aux" outputs--there are plenty of those around.
--best regards
Topic: Modded PS-2 won't work with Oktava MK-012's. Grounding issue? (Read 15254 times)