Disassemble an Oktava MK-012

Hi !

I can't open my Oktava's MK-012 :roll:

i turn the three screws inward and the body
move lightly, but there's a strong resistance
and i don't think it's the good way to open the mic

what the trick to open this mic ?

:thumb:

Force

Sometimes there seems to be some kind of a coating on the end that has the XLR bonding the body to the end.

I twist the XLR end against the body and pull after some time it does come apart. I had one that took about a 1/2 hour of work.

You could try heating the body(with the capsule removed) with say a hair dryer warm to the touch not to hot and then cooling the XLR end in ice water to help break the bond. I have not done this but it should be OK to do.

thanks you Gus

so i must rotate the base from left to right ?
and pull the base...

i'll try with my hands only first!

(It's ok the body is opened :thumb: )


Anybody have the schematic of this mic ?

it's probably already on the Lab, but i can't find it
by myself. :?

Zebra had my hand drawn one at omnipressor.

now about this microphone and changing parts

As it is stock try it on the strings and body of a acoustic

Change just the input cap to a different type like a polystyrene

Try it again on the acoustic

What is better? Hard to say seems to depend on the source.

Next the tant or electro 1uf change that to a film 1uf or bigger that fits

test again

I like to change the output RF filter caps

I leave the BC electros they have good forming voltage.

I do not believe the input Rs need to be changed. I don't like the bigger Tant mod.

All the ones I played with the stock FETS are fine and just changing the fet might not work because of operating points.

I am not a fan of the SD mod.

I believe it has its use stock or with just the Al or tant replaced, change the other caps starting with the input for taste.

I don't want to post what I hear as not to effect what others might find.

Wasn't there a thread here, or somewhere else, that went through some modifications... was that you Gus? My memory is failing me right now.

EDIT: We must have been posting at the same time... my memory held up, it was you !

thanks you very much !

i'll try this and tell about my experience
on that mod

:thumb:


PS :
i can't find the schematic on http://www.omnipressor.com/ :roll:

A scan from SD article: schemo

Slightly larger scan: schemo

I did the SD mod on my 012s with SilverMica input caps. I like em, but I liked them before the mod as well. My unmodded were better for acoustic, but the modded are better as overheads, toms, electric guitar. Someday I'll buy a few more and play with different caps. I bought 1000pf polyprops and meant to try those too, just never have time.

thanks !!!

From the microphone META: http://www.groupdiy.com/index.php?topic=3435

Slightly larger scan: schemo

My 012s were extremely hard to take apart as well. I think I almost broke the circuit boards pulling them out of the bodies.

On the SD mod,

the two 680M leak resistors are changed.

But it seems that Gus don't recommend to do that.

If we don't talk about subjectiv sound that we hear.

What is in theory the effect of this resistor modification ?


- Gus : when you say RF filter cap, you talk about
the two small "103" cap at the back ?

About the 680megs

If you read the fet app notes at vishay you will see that about 1gig is about the lowest noise spot for a fet.

Two 2 gigs will give about 1 gig total for the fet.

Now with a 1000pf instead of the the RC filter is lower than stock

with the 2gigs and the 680pf the filter is lower than stock

Yes the noise could be lower with the two 2gigs but I have not noted a change to the ear. Yes maybe the two 2 gigs and a film 680 to 1000pf should be the best but is it worth the time for something that might not realy make a difference and that part of the circuit board with the coating etc can be a pain to work with and keep clean.



RF caps yes the two at the back

thanks :thumb:

[quote author="Jazzy_Pidjay"]On the SD mod[/quote]

I think SD was going for best possible specs, lowest noise, flattest response, etc. We all know that doesn't equate to most pleasing sound. The decrease in noise was barely noticable, if at all, to my ears. I do think that the mod has its place, making the sound more true to the source.

Last night I wrote a short paper on Existentialism, and I can't help but think about this discussion, human experience is purely subjective. As with all mods, you gotta try it and see if you like it. Oh, the angst! :wink:

it's the road i'll take !

and tell you what i think about the modifications :wink:

looks like you got it open, but in case someone else with the same problem reads this thread, I personally spent an hour trying to unscrew the body before realizing that one must screw the screws *in* (clockwise, "righty-tighty") to get it open.

anyway, good luck with the modding.... I'm hoping to do the same to mine at some point. But they sound pretty good as is, capsules are from the sound room.

billy

[quote author="skipwave"]The decrease in noise was barely noticable, if at all, to my ears... [/quote]For a couple of drum tracks, you?d never know the difference, but if you?re recording several tracks of acoustic instruments, it could become noticeable. I found a stash of 1/2W 2Gs that I?ve been using with 1000pFs, but according to Gus?s figures (great info, btw), 1G w/1000pF is a-plenty, so I?d go with that.

The modifications I?ve done are pretty darn quiet. I don?t know how many times I?ve powered one up in the cans and thought it wasn?t working, only to bust my eardrums by snapping my fingers in front of it, realizing that I was fooled by how quiet it was!

Modified, these are very good little mics, but I don?t even own them any more. I guess I?m starting to share Gus?s opinion about SDs. Seems like I always end up using an LD because it just sounds better to me. But then again, I haven?t tried a Schoeps or Neumann. :wink:

[quote author="Flatpicker"][quote author="skipwave"]The decrease in noise was barely noticable, if at all, to my ears... [/quote]For a couple of drum tracks, you?d never know the difference, but if you?re recording several tracks of acoustic instruments, it could become noticeable. [/quote]

I hear ya! :wink: Noise certainly does become compounded with overdubbing. I went with 2G and 1000pf in mine as well.