MK 012, needs a waranty badly

[Hurmph]

I hate oktava, I hate Guitar Center.
I bought a "matched" pair of MK012 about four months ago from GC. They ran out of the unmatched mics, so I bought a pair of matched ones, I needed them right away for a project. They worked fine and everything seemed okay. Today I brought them out for another little project only to find out one the mics is dead. I didn't abuse it, I wasn't even using it for the past few months! WTF!!!!
I called GC and they said 3 months labor, 1 year parts. BUt knowing them they will probably charge a hell of alot for labor.
Did anyone elses oktava die after just a few months? What did you do?
Did you repair them? Im just a little disturbed right now. Not Only did I pay waaaaay too much for these "matched" mics, but they lasted only a few months. It is safe to say that I will be staying away from mics for a while. They may sound good, but they are built like S**T! Watch out! They may be fine when you are testing them, but there is still a chance they will crap out on you, probably right after the time you can return them.
Sorry for the venting...

 

[Marik]

Hurmph,

No need to panic. Don't forget that any mic is just a piece of stupid electronics. Have you ever seen a screwed up AKG 414 or U87? It is normal (even if we hate it). The probem might be very easy to fix, it might be even a bad contact from the capsule.
First, is it a capsule, or a pre? You can easily check it trying the capsule from the 'good' mic in the 'bad' one.
Do you have a basic knowledge of electronics--how to use tester, how to read schematics, and how to solder? If yes, I can guide you through the process of troubleshooting, if not, you can send it to me and I will fix it for you for a modest fee.

 

[DJL]

Your a cool dude Marik... we need more people like you on this BBS.

 

[Flatpicker]

I take these apart and work on them all the time - the circuit's very simple. Swap capsules with the good mic to rule that out. If the problem's in the body I'll be glad to take a look at it as long as you cover the shipping. It's probably just a loose wire or cold solder joint and if so, I'm sure I could turn it in a day or two. PM me.

 

[Flatpicker]

BTW, I hope I don’t come across like I’m trying to cut into Marik’s profits, or insinuating that he’s being a opportunist here. I’m sure he’s just leaving some lee-way for his time. I would do the same if I thought it was going to take awhile, but given that I’ve worked on mine so much, I know them inside and out and hopefully won’t have to spend very much time on it.

 

[Hurmph]

Hey Thanks for the offer!!!
I already ruled out the capsule. It works fine on the other MK012. It must be the pre? I was thinking about opening it up, but It is really so tiny I dont even know where to open it. If you think its a simple job, can you help?, otherwise what would a modest fee be? These aren't the most expensive mics in the world, but If it can be fixed easily it might be worth it.
Thanks again

 

[Marik]

Hurmth,

There are three screws on the body. With a little screwdriver screw them inside (clockwise) until they go as deep as possible. Pull the bottom side of the body (the connector side) and at the same time push the top one (in the middle, where the capsule contact is). Do it carefully. Look at the PCB if you could see any obvious defects.
To fix this thing is not a big deal job--it has a very simple circuit. And if there is something simple I would be glad to do it for free. However, if the Russian FET got burned, it should be replaced in both mics with matched 2SK170 in order to keep the mics matched. Also, if there is something wrong with another transistor in the circuit, the procedure would be the same. Still, it should take about an hour of work at the most, including transistor matching. If you have more questions just PM me.

 

[Marik]

<BTW, I hope I don’t come across like I’m trying to cut into Marik’s profits, or insinuating that he’s being a opportunist here.>

No problem Tim,

Compare to what I get for building tube stuff or converting mics into tube ones "the profit" is really negligable. Also, if there are some obvious things like loose contacts or wires, bad solder etc, I never charge for fixing it.
BTW, did you try to use Black Gates for electrolitics in these Oktavas? They cost, but make a very big improvement.

 

[Flatpicker]

No problem Tim...Also, if there are some obvious things like loose contacts or wires, bad solder etc, I never charge for fixing it...

When I went back and read my original post, I realized someone could take it the wrong way, so I just wanted to clarify things.

BTW, did you try to use Black Gates for electrolitics in these Oktavas? They cost, but make a very big improvement.

No I haven't. I've tried everything but the BGs.

Kevin at K&K Audio was telling me about those. Where did you get yours? Did you replace them all?

 

[bongolation]

There are three screws on the body. With a little screwdriver screw them inside (clockwise) until they go as deep as possible. Pull the bottom side of the body (the connector side) and at the same time push the top one (in the middle, where the capsule contact is). Do it carefully.

Emphasis on "carefully"!

Some of these are very loosely fitted into the sleeves and some feel like they're epoxied in there. If it's the latter, you probably need to push it out rather than pull it out to prevent breaking something. I've seen some of these where the PCB mounting flanges are actually broken during the assembly process due to the tightness of the fit and just being jammed in there by main force.

Use restraint and patience!

 

[Hurmph]

MARIK, You are Awesome!!!!!
Thanks for the step through, I was scared at first, but managed to pry the sucka open. And since I had one that was working and one that wasn't it was pretty easy to figure out what was wrong, A wire had come loose connecting the capsule part(?). Anyway a little soldering iron and it was back to working again.
Thanks again. i was under the impression that microphones were more complex things, Im glad I got over the fear.
On another note, What would you say were the neccesary tools if someone wanted to do this on a regular basis. I had only a radioshack iron, which took forever to heat up.
What's a good iron? What type of"solder" is good to use. What other wrenches or what not is good to have around for little electonic jobs like these.
I think you have inspired me to try and fix my dvd player that bee dead for over a year!
Thanks again Marik.

 

[Flatpicker]

Hurmth,

There are three screws on the body. With a little screwdriver screw them inside (clockwise) until they go as deep as possible.

I just caught this when bongolation posted the quote. I wouldn't screw them all the way down because they'll come out the bottom and fall inside the mic. This doesn't hurt anything but those little devils are easy to loose and a pain to thread back in. You just have to screw them down past the outside sleeve, which isn't far because the sleeve's pretty thin.

 

[Hurmph]

Also what would be the minimum equipment I would need in order to make my own cables, I was scared at first, but now that Marik has liberated me I am eager to give cable buliding a try since those darn things are so expensive now. I know about the mogami wire and neutrik plugs, but what about the solder, the iron , the flux?. Everything. I totally forgot everything I learned in electronics 101. If you guys could refresh my memory, That would be awesome. I am still excited about the mic, thanks again everybody, marik, Flat and the bong.

 

[bongolation]

I wouldn't screw them all the way down because they'll come out the bottom and fall inside the mic. This doesn't hurt anything but those little devils are easy to loose and a pain to thread back in.

"Been there, done that."

It's stuff like this that a real pro knows about so he can turn a fifteen-minute job into three hours of cursing and crawling around on his hands and knees.

 

[Flatpicker]

"Been there, done that."

It's stuff like this that a real pro knows about so he can turn a fifteen-minute job into three hours of cursing and crawling around on his hands and knees.

ROTFL!! Aint it the truth!

Hurmph, glad to see you're back in business!

 

[Marik]

<Where did you get yours? Did you replace them all?>

Flatpicker, you can find them at:

http://www.referenceaudiomods.com/Merchant2/merchant.mvc?store_code=RAM

and of course, replace all these chipo Russian caps esp in the signal path. However, I did not touch the PSU ceramic ones, probably it would be also worth to change.
BTW, did you see Kevins phono pre on his website? It would be just absolutely awsome mic pre. I am working on it right now--4 channels.

Hurmth, I am glad we were of help. I think that DVD player will be little more challenging thing, but again, at least 80% of faults is something obvious.

<What's a good iron? What type of "solder" is good to use. What other wrenches or what not is good to have around for little electonic jobs like these.>

I use grounded Weller 60W station with temperature control and replacable tips. As a solder I use "Welbornelabs silver solder". It is more expensive, but much better quality then Radio Shack one. I have a zillion of different tools, but sometimes still feel that I am short of something. Good quality little wire cutters, long nose
little pliers, tweezers, exacto knifes, wire strippers, all kinds of screwdrivers, little wrenches would be helpfull here. And of course, a good quality multimeter.

<i was under the impression that microphones were more complex things>

Have you ever seen AKG414, or Sennheiser MKH40 guts?

 

[Flatpicker]

...but what about the solder, the iron , the flux?.

As far as irons go, I'd get something where the iron plugs directly into a station rather then stright into the wall. The Weller iron are good, but a little expensive. Be sure and get one you can control the temp on. Some are temp controlled by the tip you use (the tips have different temp ratings, depending on your needs), and some have a variable temp control.

For solder, I use Kester 331 organic water soluble flux, cause you can clean the flux off with water (DigiKey #KE1299-ND thru KE1303-ND, depending on the gauge).

 

[Flatpicker]

[BFlatpicker, you can find them at:

http://www.referenceaudiomods.com/Merchant2/merchant.mvc?store_code=RAM

and of course, replace all these chipo Russian caps esp in the signal path. However, I did not touch the PSU ceramic ones, probably it would be also worth to change.
BTW, did you see Kevins phono pre on his website? It would be just absolutely awsome mic pre. I am working on it right now--4 channels.[/B]

Thanks, Marik. Yeah Kevin told me about the pre and I went to the site and looked it over. I hope I can find time to build at least a 2 channel version of that before I die!

 

[bongolation]

Re: the Black Gates, I took one of the MK-012s apart and took a look and I see what appears to be two 68mfd@63V and one 33mfd@63V capacitors. I don't see anything quite like that on that site. Am I looking in the wrong page?

 

[Flatpicker]

Re: the Black Gates, I took one of the MK-012s apart and took a look and I see what appears to be two 68mfd@63V and one 33mfd@63V capacitors. I don't see anything quite like that on that site. Am I looking in the wrong page?

I don't see any 68/63s either. Mine all had 47/40s instead of 33/63s though. There's also a tiny 1uF that needs to be changed to a 4.7uF or even 10uF. It needs to be 35V.