Topic: Dutch phantom48 mod for Nakamichi CM300...original schematics included!

[J.T.L]

...just as the title says, here are the schematics for a phantom 48 mod for Nakamichi CM300s that was originally performed in Germany Rotterdam. Sorry but I am not going to open the mics for a photo shoot because I dont want to disturb the obvious fine craftsmanship that went into this particular mod (they feel rock solid). But for all that care to tinker, here are the sheets that came with the mics. The first page is page 1 of the mic spec. sheets that has hand written notes added, the second page is page 2 of the mic spec. sheets and page 3 is a copy or printout of the mod schematics with additional notes added and highlighter work. The notes are in German Dutch so any translation is highly welcome and anyone who wants higher resolution scans, ill host a zip file and post a link here. Enjoy...

EDIT: A huuuuge thank you to balou2 for getting these in my hands...really Mike, thanks!

[Patrick]

   Thanks.  Great Reference.

[RebelRebel]

thats Dutch , not Deutsch...

[J.T.L]

thats Dutch , not Deutsch...

...thank you. See I dont know this stuff and the history of these mics are kinda hazy so any info is helpful and id like to know more about them. The original owner listed them as German on ebay but...whadoIknow?!

[RebelRebel]

thats Dutch , not Deutsch...

...thank you. See I dont know this stuff and the history of these mics are kinda hazy so any info is helpful and id like to know more about them. The original owner listed them as German on ebay but...whadoIknow?!

what gives it away is the voor,(well and the rotterdam mention ) Germans would say für. Dutch and Deutsch are very similar though. So similar in fact that the Amish in the USA call their language "Pennsylvania Dutch" though it is really Pennsylvania Deutsch....common misnomer

[Brian Skalinder]

JPGs combined and printed to PDF, now in TS Reference for safekeeping:

http://www.taperssection.com/reference/pdf/DIY_NakamichiCM300_P48-mod.pdf

[audBall]

thanks for posting these and thanks for saving them.  I'm curious to see how this relates/differs from Sank's method.  I may send this to him for the helluvit.

+T's

[flipp]

.... The notes are in German Dutch so any translation is highly welcome

Paging udovdh - recently very active in the microtrack mods discussion. He is in the Netherlands and should be able to translate these for you.

[balou2]

Totally happy to provide these!  I know there are several mods that folks do to the Nak series', but I was very fortunate to run in to these, with the spec sheets in tact and viewable.  I don't know Dutch (go figure), but some of the electrical schematics make sense to me.  Looks like a fairly straightforward power mod, but I DO KNOW that the parts used were top of the line.  I made several recordings with these mics and enjoyed the sound.  I wish I still had the recording, but the guy that I bought them from had 2 pairs of 300's- a standard pair, and this mod-pair.  We ran a comp once, mics>DAT (mics on same stand, same position) and there was a difference in the recordings, with the obvious favor leaning to the modded pair.  I didn't think the mod should affect the sound, but for whatever reason, it did.

Nonetheless, glad to see these make their way in to the hands of folks who have interest.

Peace,
Mike

[balou2]

...and btw, after having these in my possession on and off for the last 10 years, I never did figure out EXACTLY what the mod is.  If someone who is technically adept can translate the schematic to English, and regular-guy-terms, I would appreciate it.
Mike

[udovdh]

Well, here I am.
Could add a few things below.

Third sheet has most text, others have just numbers which speak for themselves?
If not, let me know what I could do.

Third sheet:

Modification of CM300 for 10V phantom power (title)

The part that was striked out:

right: The rest, N times (below the block left) (what is a DT550 (MX100)?)


Then:

Modification of CM300 for 48V phantom power

Below the dummy part: gives noise sometimes
top right: FAT-amplifier (fet?)
Below: some values for standard and for: low D, higher dynamics


Then the picture with the end of the mic (?):

gaatje boren -> drill hole 1 mm diameter
1/2 PVC sock for 5/8"pipe
right: solder, small nickel cap (+)


Then at the bottom:

Signal-noise ratio measured with B&K spec calibrator
~= -77 dBA +/-2dB versus 94 dBA(1PA) = 17 dBA!


The very bottom line is harder to read. Does it say:
Gen signuip met cp2 = 2-2.5 mv/Pa  ?

[Roving Sign]

Observation: That doesnt look like any CP-4 I've ever seen...? There is no taper on the CP4...correct?

Compare to this page

http://www.nakmics.com/nak-cp4.htm

[Roving Sign]

The 10V phantom page...?

The MX-100 has a 10V output DIN...I wonder if they were trying to utilize that?

[Patrick]

Observation: That doesnt look like any CP-4 I've ever seen...? There is no taper on the CP4...correct?

Compare to this page

http://www.nakmics.com/nak-cp4.htm

Yeah, my cp4's are straight.  absolutely no taper whatsoever.  I've never seen any nak guns like that, either.   

[poorlyconditioned]

...just as the title says, here are the schematics for a phantom 48 mod for Nakamichi CM300s that was originally performed in Germany Rotterdam. Sorry but I am not going to open the mics for a photo shoot because I dont want to disturb the obvious fine craftsmanship that went into this particular mod (they feel rock solid). But for all that care to tinker, here are the sheets that came with the mics. The first page is page 1 of the mic spec. sheets that has hand written notes added, the second page is page 2 of the mic spec. sheets and page 3 is a copy or printout of the mod schematics with additional notes added and highlighter work. The notes are in German Dutch so any translation is highly welcome and anyone who wants higher resolution scans, ill host a zip file and post a link here. Enjoy...

EDIT: A huuuuge thank you to balou2 for getting these in my hands...really Mike, thanks!

Hey, do you have photos of the modded mic?

I understand the schematics, but it looks like they've added/extended the body to put a few parts right behind the cap.  I'm not sure I would do it this way though.  Why not just gut the inside and use the existing body?

Anyway, thanks for the info.  I just got some Teac ME-80 on Ebay, and I think these are the same as Nak 300.  So, I'll probably be messing with some of these mods

  Richard