Back in the 1960s Philips invented a truly awful (even worse than mp3!!) system for reproducing sound ….. The Compact Cassette, which rapidly became hugely popular with the great unwashed, undiscerning, record-copying masses! Originally designed for low-grade speech applications it was left to the genius of Japanese manufacturers to develop it into a more-or-less acceptable means of reproducing music!
The most successful of these Japanese manufacturers (in terms of quality) was undoubtedly Nakamichi, who produced a range of cassette decks which came very close to the technical specifications of up-market reel-to-reel recorders. Needless to say the Nakamichi models were not cheap. (I paid £850 for mine in 1989) However, because these machines were fairly portable they attracted a following amongst both amateur and professional sound engineers for stereo location recording.
Because the Nakamichi recorders did not supply phantom power they produced a number of high quality, small diaphragm, electret condenser mics, including the excellent CM-300, that ran on a 9v battery. See cm300user manual PROBLEM………. THE RECOMMENDED BATTERIES ARE NOW OBSOLETE! I have seen it suggested that an ordinary AA ( 1 ½v ) battery will do the job. That is fine if you don’t mind a greatly reduced output, increased noise, and a mangled frequency response ! (Though, if you are still recording on to cassette maybe it doesn’t matter!!!) This mic does need 8 to 9volts to function properly! A trip down your local photographic store or electronic shop will solve the problem with a couple of camera batteries. A 4LR44 lithium 6volt and a CR2 3volt lithium . Together these turn out to be the right length and wrapped with a bit of insulating tape or rubber bands can be made to fit perfectly in the battery compartment. These are nice sounding mics and well worth the trouble!
My Nakamichi CM-300 with omni and cardioid capsules, pop shield and 2 new batteries.
15th October 2012 NEWS FLASH UPDATE ON THIS POST Just had an email to say………….. THE SMALL BATTERY COMPANY IS NOW RE-STOCKING THE ORIGINAL 9volt BATTERIES. http://www.smallbattery.company.org.uk/sbc_a1611.htm
Martin Mitchell's Microphones 
Clever and creative solution. Do you know anything about whether or not overheating could occur due to using lithium batteries? I wouldn’t want to damage the mic if it isn’t properly designed to manage the heat generation – might only be a problem if sensitive components are in close proximity to the battery compartment, though.
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Hi Travis,
Thanks for your comment. I have not noticed any problem with heat generation.The batteries have always seemed to be cool when I have come to take them out after use. However, I am not an expert on battery technology.
All the Best
Martin
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thanks for this! saves me some trouble getting my mikes going 😀
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Thank you. Via Amazon (I’m in the USA) I purchased an Exell 206A that is supposed to replace the Eveready 206/NEDA 1611. The Nakamichi owner (our symphony chairman – I record radio ads for the Brockton Symphony Orchestra in Massachusetts) had trouble getting out the dead original battery, it was so tight. The replacement battery would not go in by any means, until I peeled off the plastic outer wrapper, and then a couple of layers of the cardboard wrapper. I hope this unwinding has not compromised the safety of the battery – I would hate to damage a borrowed microphone – but this gave me a quality microphone with much better performance than when I tested it with a 1.5 volt AA battery. Thanks again for sharing your insights. “Harry The Librarian”
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Good to hear that you got it working ok.
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martin, i just came across your article and have a trio of cm300’s i’ve wanting to use(especially since i seem to have misplaced my matched pair of schoeps MK-2s mics and have some recording gigs coming up).
specifically want to know how u install the 2 different sized lithium batteries? how did u wrap/package them?
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Hi Erick,
The physically larger of the 2 batteries I wrapped around with electrical tape until it was the right diameter to slot easily into the battery compartment without jamming. For the smaller one I used an elastic band twisted several times around it, which performed the same function. I put the larger one in first with the + terminal upper most and then posted the small one in on top of it, once again with the + terminal uppermost and then screwed on the capsule holder.The 2 batteries I used were exactly the right length. The other option is to buy a single battery from The Small Battery Company, which also works just fine.
Good Luck
Martin
P.S.
I hope you find those missing Shoeps!
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thanku martin, that gives me a much visual on how to configure this. i hope i find them as
well as i am getting nervous.
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btw, my beloved Schoeps omnis have been found. waiting for the CR3 lithiums to come in. very curious to see how they compare to some of my other mini condensors.
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Phew! Good to hear the Scheops have been found. Be interested to hear how the Nakamichis compare with your other mics.
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just got around a moment ago to installing the batteries as u suggested and they sound quite nice. the omni sounds to my ears quite a bit more natural and accurate to the source. cardiod caps are quite sensitive to wind noise and proximity effect but i’m sure the included wind screens will ameliorate this.
what do u suggest in regards to storing the batteries? in addition to turning them off, do u remove them after usage and store in the 3 mic case or just leave them installed in the mic barrel?
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I would agree with your observations comparing the capsules, As far as the batteries go, I always remove them from mine as I don;t use it very often. In theory it should be fine to leave the batteries in and just make sure the mics are turned off before packing away…… but its an easy switch to knock on!
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thanku for the advice on storage. i’ve done some recording gigs with these the past couple of weeks and am pleased with the results. might upload some samples to soundcloud and post here.
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Please do.
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Not sure if you saw this, but another blogger did some basic component upgrades which he says greatly improved this mic: http://datsunzgarage.com/nak/ Looks convincing. For field recordings, when the qualities of a condenser are required, electrets are a good choice due to their light power requirements. I use LIne Audio OM1’s and CM3’s which will run on 12-48 VDC, and work perfectly on my portable recorder’s low phantom setting (16VDC), which can run all day on one battery pack. They are nice flat, small, and affordable modern mics, but I wonder how they would compare with the vintage Naks. Of course the Nak runs on (hard to find) internal batteries, which is another option. I think portability must explain the otherwise hard-to-phantom (pun!) popularity of the long-standing AKG C1000, which has great potential when modded, but is not, in my opinion a great mic without modifications…
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Looks like an interesting post. Thanks for that.
The Line Audio mics do sound very good, and are an excellent choice for field recording. May well sound better than the old Nakamichis!
To be honest I do like the C1000 on HiHats and also for close micing some guitar amps but I have never used them on battery power.
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I can see how the C1000 would be good on hats, as that they do have a mid-high peakiness to them. Just not my choice for an all-rounder, like the Nakamichi presumably is.
PS: I used to dream of owning a Nak tape deck, but never did come up with the cash… Fortunately, the need has long since passed!
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Thanks for the updated link to that battery company, helped me again haha
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Another battery option for powering the CM-300 is two 6-volt 4LR44 “dog collar” batteries secured end to end. You can find these all over Amazon and eBay; they’re pretty cheap. Stephen Sank, an expert on modifying and repairing Nakamichi microphones, has confirmed that these mics can safely handle up to around 13.5-14 volts. The 12v of the two batteries are fine and I’ve been running them in my CM-300s without any issues.
As an added tip, pick up some clear vinyl tubing [5/8″ O.D. x 1/2″ I.D.] at Home Depot or another hardware/pool-marine supply store, cut it down to 1-1/4 inch lengths and it will make nice, reusable sleeves to connect the two 4LR44 batteries together.
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Thanks for this Johnny. Sounds like an excellent idea.
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Hi everybody , this microphone is manufactured by Primo and sell on diverse brand ( Nakamichi , LEM …. ) . This is a great microphone and you can use it with phantom power with a small modification . LEM produce a short scale of this mic without battery space inside and this 4520 sound close to an AKG 451 with CK 1 or Neuman KM 84 … Really ! I own 5 pieces for 30 years and they still working very well .
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Thanks for that Dominique.
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Do you know of a source for the internal schematic of the CM-700 microphone? I want to develop a way to operate them from phantom power.
Joe
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Hi Joe, That would be an excellent idea. Unfortunately I have no idea where you might obtain an internal schematic for this mic. There are a few people online who have modded CM-100 and 300 mics. I’ll make some enquiries and let you know if I find anything. Sorry not to have been more useful.
All the Best
Martin
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Martin;
Thanks for your quick response. I suspect that the internal circuitry is very similar to that of the CM-300, however it may be different. A different FET might be used and different resistors and capacitors may be used. Is there any marketing material that describes the design in enough technical detail to provide some hints as to differences from the CM-100 and CM-300?
Joe
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If there is I have never seen any. Sorry. Will keep looking.
Martin
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