Topic: Disassembling the Nak 300/Primo preamp capsule

[Roving Sign]

Finally getting around to trying to make an active set. I dont have any power supplies yet. And to be honest I'm a little foggy as the specifics. I'll bump this as this project progresses. Feel free to advise - paticularly if you have made a set of these...!!!

Here's a few photos that might help others pondering this mod...this is a TEAC ME-80 - but it should be the same for all the Primo OEMs...

The first thing you want to do is remove the ring that holds the preamp assembly in place. There's probably a special tool for those things but - a small stiff screwdriver will do the trick - but be careful - the ring is springy and can go flying. Once its removed you can push the little plastic housing out of the metal casing. You will then have the little pile of parts shown in the second image. I'll try to get some good pics of the little circuit board next.

[Roving Sign]

I got a little further - but wanted to get better photos...

The little plastic capsule just pulls apart in the center. I used the side contact to push it along...

[CHURCH-AUDIO]

You know funny enough that is the same capsule used in the crown c4 headset I use alot of primo capsules that one is one of there best I also like the em-63 that one is used by AT in some of the older mics that they made. Just thought I would add my two cents is there a J102 fet inside the mic pre and a 1 giga ohm resistor if not you can change around alot of the cheaper parts like the carbon resistors for metal film should make it a bit more quiet.

Chris Church

Finally getting around to trying to make an active set. I dont have any power supplies yet. And to be honest I'm a little foggy as the specifics. I'll bump this as this project progresses. Feel free to advise - paticularly if you have made a set of these...!!!

Here's a few photos that might help others pondering this mod...this is a TEAC ME-80 - but it should be the same for all the Primo OEMs...

The first thing you want to do is remove the ring that holds the preamp assembly in place. There's probably a special tool for those things but - a small stiff screwdriver will do the trick - but be careful - the ring is springy and can go flying. Once its removed you can push the little plastic housing out of the metal casing. You will then have the little pile of parts shown in the second image. I'll try to get some good pics of the little circuit board next.

[Roving Sign]

Chris - the person who originally did this mod used Audio Technica AT8533 power supplies to run the capsules.

http://taperssection.com/index.php?topic=24624.0

Is there another option? I'd like to still be able to run the power supply off batteries - or phantom...There are other AT power supplies that run off phantom or 9Vs...are they an option?

[larrysellers]

Chris - the person who originally did this mod used Audio Technica AT8533 power supplies to run the capsules.

http://taperssection.com/index.php?topic=24624.0

Is there another option? I'd like to still be able to run the power supply off batteries - or phantom...There are other AT power supplies that run off phantom or 9Vs...are they an option?

A 3 wire battery box seems to do the trick. One guy on here runs active ck93 caps to bb and has had success. Pretty much the same design between the mod procedures (active nak vs active akg), so it should work.

Edit to add: the old at adapters worked off of either aa batts or 48v phantom but they are friggin' huge.

[CHURCH-AUDIO]

Yes there is an option there is a circuit used by crown that is a j102 and a 1 giga ohm resistor i will see if I can find it. That will work with a 9 volt battery. Not very sensitive perfect for live recording .

Chris Church

Chris - the person who originally did this mod used Audio Technica AT8533 power supplies to run the capsules.

http://taperssection.com/index.php?topic=24624.0

Is there another option? I'd like to still be able to run the power supply off batteries - or phantom...There are other AT power supplies that run off phantom or 9Vs...are they an option?

[bdasilva]

pagong poolyconditioned... Rich this is right up yo alley.

[Scooter]

i got some me-80's, and modded them ala the Franken Nak circuit.  Turned out good.  i'm not interested in stealthing them, i just wanted to power them from phantom instead of the batts.  i clipped the three wires that go from the XLR to the circuit board (where the switch is located) ran the three wires from the modded capsule assembly all the way down the tube to the XLR connector.  a channel has to be cut in the plastic just below the spring on the switch/circuit board assembly to allow the wires to reach the  XLR.  everything can now be reassembled and appears stock.  now i can use the samson pm4's for power, and whalla, no more batts!!  they can also be returned to stock without a huge effort.  you can see the clipped wires and the cut channel below.

[bluegrass_brad]

Ever thought about gutting the PM4's and putting that in the Teac body? Shouldnt take a whole lot of effort.

[Scooter]

there's def room in there if you get rid of the circuit board/switch assembly.  i'll have to see how the guts of the pm4 look like when i get em (gotta raise some cash).

[bluegrass_brad]

Cool, I was just curious more than anything as it could be a clean solution for folks like yourself who arent worried about getting rid of the bodies.  Im gonna pick up a pair after we move to do the active mod on. 

[Roving Sign]

I have actually had my ME-80s cut down so they are about 4 inches long...

Not wired up yet - still need power supplies...

And my digi-cam is BROKEN!!!! &^)#&)#@_#*@$ - so cant put any pix up...but they look cool...

[poorlyconditioned]

pagong poolyconditioned... Rich this is right up yo alley.

Hey Brian,

Yep.  I'm all over it!  I just bought some Naks (Teac ME80), so I'll be doing this within the next few weeks or so.

Yes, a 3-wire battery box would work great, and that's what I'll do.  I just terminate every mic I have (CK91/93, AT853, AT831) with a 3-pin miniXLR(f) and run off the same battery boxes.  (pin1=ground, pin2=audio, pin3=bias voltage, 9v).

I'll post here if I get anything working...

  Richard

[poorlyconditioned]

You know funny enough that is the same capsule used in the crown c4 headset I use alot of primo capsules that one is one of there best I also like the em-63 that one is used by AT in some of the older mics that they made. Just thought I would add my two cents is there a J102 fet inside the mic pre and a 1 giga ohm resistor if not you can change around alot of the cheaper parts like the carbon resistors for metal film should make it a bit more quiet.

Chris Church

Hey Chris,

+T for the info.

I'm always curious to know what is used in commercial mics.   Do you remember what AT mic used the Primo caps (and what types)?  I've taken apart some AT mics, but can't find any useful markings on them.

Also, do you know anything about the Primo caps used in the Naks?  Are they back electret?  They are Nickel plated (not gold), right?  Do you know the diaphram thickness?  I heard rumours about someone "reskinning" these with better diaphrams too, but I don't know who or when.

  Richard

[Roving Sign]

http://www.primomic.com/

Cardioid
http://www.primomic.com/products/em-21.htm

Omni
http://www.primomic.com/products/em-23.htm