Topic: running standard nak 300 into a CA9100.....any potential problems?

[heyitsmejess]

seeing as the naks run off of 9v, and the 9100 supplies 9v, would it be a problem to run the mics into the 9100?

what problems may arise, if any?

thanks in advance!

[SmokinJoe]

The 9V is in the wrong place.  It's certainly not a plug and play situation, although I believe some have been modified to work that way.

With Nak CM300 there is a FET circuit in the front half with the slots in it (aka the attenuator body), then there is a non-standard 9V battery inside the main body, and there is a some other circuitry and an output transformer in the main body.

The mod is basically to use the cap and attenuator body, and toss the main body, running that into the preamp, although I expect there is a bit more to it than that.

[heyitsmejess]

its not a case of wanting to power the naks with the 9100.  more of a compatibility issue.  i recently aquired a recorder that only accepts lilne-in, and i want to try the naks with it.  however, if the 9v from the naks and the 9v from the 9100 would cause damage to any part of the configuration (naks > 9100 > recorder), i dont want to try it.

if i had the naks chopped, would that be a better way to go?  or should i be alright.

[Church-Audio]

its not a case of wanting to power the naks with the 9100.  more of a compatibility issue.  i recently aquired a recorder that only accepts lilne-in, and i want to try the naks with it.  however, if the 9v from the naks and the 9v from the 9100 would cause damage to any part of the configuration (naks > 9100 > recorder), i dont want to try it.

if i had the naks chopped, would that be a better way to go?  or should i be alright.

My preamp will power the mics if they are franken naks. If they are not you will need to convert them. I dont really do that kind of work anymore because its way to time consuming.

[heyitsmejess]

so if i dont convert them, its not a good thing to run the 300 > 9100?

i just want to be able to run line in to my recorder.

sience the nak 300s are already powered, could i run them line in?

[SmokinJoe]

Simple answer "you ain't supposed to do it that way, but you might get away with it".  I did it once as a test, for a minute, and nothing fried, although I'm not going to say it's a good idea.  I used spare CM100 bodies which I have, although that's as far as I took that little experiment.

Where I'm going with this... is that if you have a set of Nak 300's I will gladly loan you my CM100 bodies, and you can run them CM300 heads > CM100 bodies > cable > CA9100 > recorder for a test.  If anything is going to fry on the Nak end, it will be the transformer in the bodies, and if that happens I won't hold you responsible.  I'm willing to take that chance for the advancement of taper science. 

On the other hand running 9V from the CA9100 into the Nak transformer is essentially a dead short across the plug-in-power circuit of the CA9100.  I'm not sure if the preamp will stand that for very long.  Chris?

Nak CM-100 bodies look identical to CM-300 bodies except they have a little different electronics buried inside.  You can screw CM300 attenuators into CM100 bodies (they fit) and run them... I've done it, although they don't sound quite like "proper CM300s", and they have less gain than regular CM300s:  http://www.archive.org/details/raq2007-04-22.nak300.flac16f

Naks don't have much output.  I've run Naks > R-09 using mic high gain, with mediocre results.  Running line in will not have enough signal.

Another option is the cheap Nady DMP-2 preamp. 
http://www.archive.org/details/gptn2007-08-18.nak300.flac16f

[heyitsmejess]

thats exactly the answeres i was looking for!  thanks!

i thought about it some....if i use my marantz 430 as a pass through, i should be able to run mic in, use the gain from that, and run line out from that into the recorder.

thanks a ton!

[Church-Audio]

Simple answer "you ain't supposed to do it that way, but you might get away with it".  I did it once as a test, for a minute, and nothing fried, although I'm not going to say it's a good idea.  I used spare CM100 bodies which I have, although that's as far as I took that little experiment.

Where I'm going with this... is that if you have a set of Nak 300's I will gladly loan you my CM100 bodies, and you can run them CM300 heads > CM100 bodies > cable > CA9100 > recorder for a test.  If anything is going to fry on the Nak end, it will be the transformer in the bodies, and if that happens I won't hold you responsible.  I'm willing to take that chance for the advancement of taper science. 

On the other hand running 9V from the CA9100 into the Nak transformer is essentially a dead short across the plug-in-power circuit of the CA9100.  I'm not sure if the preamp will stand that for very long.  Chris?

Nak CM-100 bodies look identical to CM-300 bodies except they have a little different electronics buried inside.  You can screw CM300 attenuators into CM100 bodies (they fit) and run them... I've done it, although they don't sound quite like "proper CM300s", and they have less gain than regular CM300s:  http://www.archive.org/details/raq2007-04-22.nak300.flac16f

Naks don't have much output.  I've run Naks > R-09 using mic high gain, with mediocre results.  Running line in will not have enough signal.

Another option is the cheap Nady DMP-2 preamp. 
http://www.archive.org/details/gptn2007-08-18.nak300.flac16f

You would need to put a dc blocking cap on the front end of my preamp say 10uf to block the plug in power from getting to the mic. That should work. But my preamp will not take a dead short to the input. Short term there will be no damage long term it will blow up the power supply in my preamp.

[Roger Gustavsson]

There is nothing strange about running the Nakamichi CM-300. Just like using dynamic microphones. Do not feed them with phantom power or plug-in power. Unfortunatly, they have a very low output. The preamp need to have a very low noise floor if you are recording acoustic music with moderate soundlevels. If you are bypassing the output transformer, the output goes up 14dB and the noise floor is at circa -118dBu.  That will be more suited to real world preamps. Without the transformer, the cables should be kept short! There are no DC present at the output if the series capacitor is left. If you like to run them on outboard power (not from the internal battery), plug-in or phantom, they can be modified. I am running my CM-300 without the transformers with the Nakamichi MX-100 preamp. This is very nice combination with low noise level but the preamp is bulky.

I have attached a picture of the CM-300. From the left: the JFET impedance converter in its black plastic housing, the battery (in this case a series of 1.5V cells put in tube), the plastic housing for the output transformer/the low cut switch that can be seen in front.

[yltfan]

No expert here, but what's the issue with just running them line in as-is? I have the same mics, and with the batteries in there, going line in to my iriver works like a champ. Yes, I have to boost the levels a bit, but my tapes sound good to me.

I am also getting a 9100, so wondering about plugging them into that to boost the gain.

[Roger Gustavsson]

I my applications, they will need a lot of gain. Without modification often 54dB (500 times) to satisfy my soundcard. After bypassing the output transformers, 40dB (100 times) of gain is still needed. My soundcard needs 2500mV for a 0dBfs. 2500mV is 10dB above 0dBu (775mV). I would call 0dBu line level but I think it can be something else for nonprofessional equipment.

[SmokinJoe]

No expert here, but what's the issue with just running them line in as-is? I have the same mics, and with the batteries in there, going line in to my iriver works like a champ. Yes, I have to boost the levels a bit, but my tapes sound good to me.

If it works for you, that's great, and I stand corrected.  I would have guessed that it would have required so much boost in post that a lot of hiss would show up.

I am also getting a 9100, so wondering about plugging them into that to boost the gain.

According to Chris, don't do it (unless you modify it as he says) otherwise you will probably burn out the pre.