Oktava MK-012 Matched pair or just BS?

E

eichler

New member
I bought a "matched pair" of Oktava MK-012s from my local Guitar Center. However, there is absolutley no indication that they are in fact matched except for the fact that there was a Guitar Center SKU tag on the outside of the shrink wrapping (which was surrounding two individually boxed MK-12s) labeled "matched pair."

I thought I read somehwre on this BBS that the matched pairs were packaged together and came with an XY clip. Did I get bullshitted or what?

Is there any way to tell other than running tests if they are indeed matched?

Thanks in advance.
 
Good question. I got my matched pair from The Sound Room and they come with documentation in form of a printed sweep response of the two mics.
 
Track Rat -

My mics came with two manuals written in Russian. On page 12 of each manual it looks like an inspector's stamp and signiture along with a hand-written serial number. Looks like one of the mics was inspected on 3/31/03 and the other 3/28/03. Hmmm.

To further complicate the issue, the second to last page of each manual has been torn out a long a dotted line. I wonder if that was from the factory or from a previous owner?

Why is this stuff so damn mysterious?

Did you get a manual in English? Did your mics come in a single box or in separate boxes?

Thanks
 
Track Rat said:
Nope. In Russian. I talked to the guy that matched mine. Taylor Johnson.
Click to expand...

"Taylor Johnson" sure doesn't sound like a russian name. Is he from the sound room?

Did your mics come in a single box or in two boxes?
 
Don’t hold me to this, because I’m just trying to make an educated guess:

From the information I gleaned off Scott Dorsey’s ‘012 article in this month’s Recording magazine, it appears that the Guitar Center and other places (are there any?) gets the normal production run of mics from Oktava. The Sound Room, on the other hand, specifies the component quality that is used in the mics and has Oktava do a separate production run just for them at an additional cost. The mics are sent to the Sound Room where they are matched and marketed. As far as the generic run of mics for GC, they would have to be matched at Oktava, and Lord only knows how well.

Scott stated that the 012s used to be all over the place as far as specs and component selection goes. He basically said that if they didn’t have the correct parts on hand, they just stuck any old thing in there as long as it fit the holes! However, he said that the more recent ones he’s seen are using better components – like higher quality caps, transistors, and resistors. I can attest to that because I just bought one from GC had a look inside. It looks fine for the most part – good transistors, electrolytic caps, etc... A couple of resistors and one cap could be changed for an improved slightly more “open” sound, but that’s about it. When I eventually get around to changing out these parts, I’ll post the improvements, along with (hopefully) sound clips.
 
This is what the "Sound Room" has posted on their website about their matched pairs...

Matched pairs are selected from the test areas of different manufacturing labs and tested in the anechoic chamber (and ancillary facilities) at a famous Moscow-based Microphone Lab. As with all of our microphones, they are chosen for assembly and finish and then tested to meet specific acoustic and electronic modeling. Mics in matched assemblies are tested individually and then as pairs. Once matching is complete, they are boxed - along with proof of frequency response analysis. From there, the mics are sent to our "sister" studio in Moscow, where they are tested and checked again in various acoustic source tests and further documentation is attached.

The mics that pass all these tests are shipped to the SOUND ROOM, where they are checked again in our studios and readied for shipment. This may include changing packing/shipping materiel, fitting to cedar boxes (from the Ozark Mountains), final cosmetic checks and repackaging of the assorted documentation and new (US made) accessories.

http://sound-room.com
 
I was thinking about picking up a pair of these at GC. I do a lot of small electronic projects so I figured I would just get two mics and replace parts if needed. It will save me about $100. Has anyone tried this? I will probably have to test the parts I put in to make sure they measure the same. Will this give me a matched pair??
 
sk8ingsnowman said:
I was thinking about picking up a pair of these at GC. I do a lot of small electronic projects so I figured I would just get two mics and replace parts if needed. It will save me about $100. Has anyone tried this? I will probably have to test the parts I put in to make sure they measure the same. Will this give me a matched pair??
Click to expand...
No, not necessarily... unless you got really lucky... and you'd never really know if the mic's were matched until you tested them in a anechoic chamber and etc... it would be much cheaper just to buy a matched pair from the Sound Room.
 
sk8ingsnowman said:
so the differences in the mics comes from imperfections in the diaphragm?
Click to expand...

Speaking from the depths of my ignorance, I would say the differences come from the sum of the components, including and maybe especially the capsule/diaphragms.

Getting a matched pair by randomly buying two mics would be like flipping two coins a given number of times, and getting the same or similar pattern of heads and tails. Replacing components would be like randomly redoing some of the flips and expecting it to be closer.

However, if you flipped 100 coins that same number of times, you could find some patterns that closely matched others - just like taking 100 mics, testing for certain electrical parameters, and grouping close matches together.
 
DJL, when did you become an expert at matching mics????

Was it after 500 people explained to you that the dots on the box didn't mean factory matched?
 
crazydoc said:
Replacing components would be like randomly redoing some of the flips and expecting it to be closer.
Click to expand...

You missed the part in my post about testing the new parts. So the only difference would be the diaphragm.

But again I am not sure how big the differences are diaphragm to diaphragm.

I would think that that would be the part they would try to keep exact but who knows what goes on sometimes at the factory.
 
c7sus said:
DJL, when did you become an expert at matching mics????

Was it after 500 people explained to you that the dots on the box didn't mean factory matched?
Click to expand...
I'm not an expert. When did you learn to count? :D
 
sk8ingsnowman said:
You missed the part in my post about testing the new parts. So the only difference would be the diaphragm.

But again I am not sure how big the differences are diaphragm to diaphragm.

I would think that that would be the part they would try to keep exact but who knows what goes on sometimes at the factory.
Click to expand...

No, I didn't miss it. I agree it would be easy and cheap to test and match the caps and resistors to a few percent. I've never seen the circuit, but I imagine it has an FET and a few transistors - these would be harder and more expensive to find, test and match.

I'm sure they try to make consistent capsules, but since these are mainly mechanical in nature, and go through lots of production steps, and the diaphragm tension is probably hard to control, these probably have the greatest variation. Even if you could buy a bunch of capsules and test them, it would be easier and cheaper in the long run to just buy the matched pairs. (Though not as interesting or educational.) :)
 
That being said I think the GC stereo pairs are bogus becuase I don't think they test them in an anachoic chamber. They probably just pull pairs out of production.

I could be wrong.
 
I am working at matching a pair of Oktava 319s right now. I have chosen the easy route. I am :
1. Unsoldering the condensor element to isolate the electronics.
2. Hook up a signal generator and "sweep" the electronics to get a frequency "print"
3. Change some key components to match the freq print to each other.
This takes care of the electronics since it is not a subjective test. The electronics only job is to amplify the signal of the diaghram.

When I hook up the condensor element, I will see if the condensor elements are on or off. This is what will interest me most. Since I have all the super expensive equipment here at work, I will find out once and for all if it is easy (inexpensive) or hard (expensive) to really match a mic. This is my latest thing.
 
acorec said:
I am working at matching a pair of Oktava 319s right now. I have chosen the easy route. I am :
1. Unsoldering the condensor element to isolate the electronics.
2. Hook up a signal generator and "sweep" the electronics to get a frequency "print"
3. Change some key components to match the freq print to each other.
This takes care of the electronics since it is not a subjective test. The electronics only job is to amplify the signal of the diaghram.

When I hook up the condensor element, I will see if the condensor elements are on or off. This is what will interest me most. Since I have all the super expensive equipment here at work, I will find out once and for all if it is easy (inexpensive) or hard (expensive) to really match a mic. This is my latest thing.
Click to expand...

Be sure to let us know your results. If the capsules are way off, maybe several of us could buy 319's and send them to you - then you'd have a pool of mics to pair up and we'd all have at least pairs that are better matched than random selection.:)
 
You must log in or register to reply here.
Back
Top