Oktava MK-220 switch buzz?

I've got some serious buzz when touching the switches on my MK-220s.

What are the odds it's something to do with the wiring of the switches?

There's no where else on the mics that causes this electrical buzzing.

So for whatever reason this buzzing only happens in the basement, where there are a lot of exposed pipes, and slightly noisy lights.

Up in my bedroom and the living room there's no buzzing on either mic.

The reed switches are there. Technically it's possible that they generate noise when their contacts wavering in a magnetic field. I've never experienced such a phenomenon myself, though.

dbelousov said:

The reed switches are there. Technically it's possible that they generate noise when their contacts wavering in a magnetic field. I've never experienced such a phenomenon myself, though.

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I've been thinking about removing them anyway. The pad doesn't seem to reduce the output too much, and the low cut doesn't sound like it rolls off too much, I'd rather just not have them then have them affect the signal and not do much. The pad on my interface works way better anyway.

There's a circuit breaker in my basement that may be causing the issue. There are also power transformers within 20 metres of my front and back door (row house apartments).

It's a common practice, they are not so useful.

May I ask you to check its FET when you decide to open it? Just for my statistics.

dbelousov said:

It's a common practice, they are not so useful.

May I ask you to check its FET when you decide to open it? Just for my statistics.

Click to expand...

Think I can just disconnect the switches without affecting much else? I kind of need to leave the board in because it has the pattern switch on it too (this one seems to pee some kind of rotary switch).

I know it's really common to shorten the capsule wires and bypass the switch board, but that's not really an option since I need the multiple patterns.

And yeah, I'll post what FETs they use if I actually manage to get it open. I can't for the life of me figure out how to get the headbasket off, it seems like it's welded into place or something. There's probably some sort of trick to it, I just haven't seen anything about modding the MK-220. I didn't want to mess around too much since they're under warranty, but it doesn't seem like they're defective, waiting for a definitive response from Oktava, they asked about transformers being nearby, so I'm guessing they think that causes an issue with the reed switches too.

I've also been thinking about removing the resonators, but they're already "dark" mics as they are. Mine are almost exactly like the advertised plot, but the one has a 4 dB boost at around 3K, and the other one is only 2 dB (as advertised), other than that they're pretty much exactly in line with what's advertised.

I think the headbasket and the body just glued together when their coating was fresh.

Bypassing/replacing caps may help with its darkness. Some Pana FR if you won't manage to put MKPs in.

There is the MK18 circuit, the MK220 should be fairly the same. 

I got the switches out of the first one no problem and it works great.

Repeated the same process for the second one and it's dead. No idea what went wrong. Capsule isn't picking anything up, don't think I burned anything or desoldered any wires.

Actually looks like I might've burned a few spots. Strangely the one spot I don't recall even touching the iron too.

I think I'll either have to build a new switch PCB, or get cheap Behringer B2 Pro and throw the capsule in it.

I'll post what the FET is when I get that take out that PCB.