Topic: Nakamichi CM-300 - how to make them shorter?

[Popmarter]

I am offered a pair of Nakamichi CM-300 (3 caps) where the batteryunit is replaced with a 48volt transformer.

I might be interested but i'd really prefer them shortened (for stealth use) as pictured here http://taperssection.com/index.php?topic=74283.0 (which are 700's but you get it).

Can this be done, without much trouble? (i am not that technical). Would like to connect it to a tascam dr-680 for the power.

[Patrick]

If you're handy with a soldering iron the mod is not terribly difficult to do.  Soldering 3 wires to the small PCB in the capsule housing and running/securing cable out the back of said housing.  Then you'll need to power the mics with phantom power adapters for use with the 680.  The mics can also be powered with a 9v battery box available from Naiant, Church Audio, Sound Professionals, etc for stealth purposes.  (Never have seen a tascam 680 but I have a feeling it's way too big for stealth!)

If you don't want to DIY, I would suggest sending a message to Chris (BusmanAudio) or email him through his website.  http://www.busmanaudio.com/contact.html

[Popmarter]

Thanks Patrick, glad to hear the mics can work with 9v aswell, that should work in stealthsituations. that solves the problem with the tascam

[Walstib62]

So it sounds like you are buying a pair that has been modified from stock already. If that is the case, then the details of the mod. must be known before any clear advice can be given in terms of RE-modifying the mic.
THe short answer is that there are several types of mods that can be done. Like a lot of things, may not be terribly difficult, but very easy to mess up.

[Popmarter]

Yeah, correct  Read about Franken Naks, Busman Naks etc.

It's nice it already works with 48v (I read something about hard to find battery's etc.), but these mics are still long...

I'd rather not mess with it myself, so have to see what it will cost me too have it done and what are the possibilities in terms of modding.

[Walstib62]

Yeah, correct  Read about Franken Naks, Busman Naks etc.

It's nice it already works with 48v (I read something about hard to find battery's etc.), but these mics are still long...

I'd rather not mess with it myself, so have to see what it will cost me too have it done and what are the possibilities in terms of modding.

Do you have any info. at all about the mod that was done?

[larrysellers]

It sounds like the mod Stephen Sank used to do. Is there a large piece of brass where the battery would be?

[Popmarter]

All I know is that it is done by a company (here in The Netherlands) that used to be the distributor for Nakamichi (Transtec - Rotterdam). The 48v transformer is placed on the spot of the battery, therefore you still need the 'bottom-part'. That is all I know sofar.

[Roger Gustavsson]

popmarter,

That modification is to run them from P48 (48 V of phantom power). You can find more information on this modification in this document: http://www.taperssection.com/reference/pdf/DIY_NakamichiCM300_P48-mod.pdf  The schematic of interest, "Ombuw CM 300 voor 48V. phantoomvoeding." I mailed Transtec of few years ago but the person doing these modifications had left the company.

If you decide to make them shorter the whole modification made by Transtec will have to go. If you remove everything after the capsule with the impedance converter, you can use BIAS supply (7-10 V). The output will be single ended (not balanced). If you are running short cables it will work fine. A suitable preamp is the Naiant Tinybox.

Some pictures of my short Nakamichis, they run on an internal battery (9 V):
http://www.twin-x.com/groupdiy/albums/userpics/chopped_Nakamichis.jpg
http://www.twin-x.com/groupdiy/albums/userpics/short_Nakamichis.jpg
http://www.twin-x.com/groupdiy/albums/userpics/Nakamichi_in_parts_4.JPG




 
 

[kirk97132]

I second everything that has been said so far.  Here is a link to the cut down mod I did to a set of Nak 300 clones (teac 120).  Designed to use a battery box or the PFA's.  It's a step by step with pictures.
http://taperssection.com/index.php?topic=143476.msg1891358#msg1891358
http://taperssection.com/index.php?topic=143476.msg1891361#msg1891361

[Popmarter]

Hi all, thanks for the pictures, very nice. I will get the mics and see what's inside