cad m179 mic

[chessrock]

I bet it's the mic. I have some older CAD E-100s, I have to keep the -20 pad on almost all the time, or they clip very easily even with only moderately loud sources. The SPL rating is with the pad engaged, it seems.

Boingoboy, I'll try to explain this really simple: If your mic is clipping -- which is nearly imossible to do unless you're recording nuclear blasts or jet engines -- then engaging the pad isn't going to do anything about that. It will just make your clipping mic quieter. The pad merely attenuates the strength of the signal the mic is sending to your pre and the rest of your signal chain. If engaging the pad makes the clipping go away, then it means the signal coming from the mic was too hot for your mic pre or something else in your signal chain after the mic.
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[RandyM49]

I own 2 179"s and they are very nice however they they do need 8 milliamps of current from the 48 volt supply to run correctly , if they don't have this it will lower the operating point of the f.e.t inside the capsule and this will let the f.e.t distort at a very low level of input signal. Most 48v power supplies only have around 2 ma of current. So you need to look at the specs for your supplies and find out if your supply can handle that much current. I found an old neumann unit that had enough current to run 2 of these at the same time (16ma) and can hear a big difference between that and one plugged into a mackie 48v supply. This is also how the cad e 100 worked only they put a battery in to supply the additional current.
Randy LaMora
Waconia Mn.

 

[travelin travis]

a man with some good info

 

[PhilGood]

To both Chessrock and RandyM49, this is some food to chew on.

The M177 and M179 are different than most mics in 2 respects.

A. They do not use a capacitive pad. Normal pads are nothing more than a capacitor from the capsule positive lead to ground. This lowers the output of the capsule to the amp, which reduces the output. It also can degrade the sound. From what I have read CAD uses a different method for the pad that does not allow the sound to degrade. This might, in effect, mean that the amp can be clipped by the capsule on a loud enough signal.

B. The M177 and M179 do not use an FET as the amp. They use Op Amps.

I don't know if this really means anything regarding the clipping, I just know these mics are different in those respects than most SS mics.

 

[travelin travis]

more good info.

 

[boingoman]

Boingoboy, I'll try to explain this really simple: If your mic is clipping -- which is nearly imossible to do unless you're recording nuclear blasts or jet engines -- then engaging the pad isn't going to do anything about that. It will just make your clipping mic quieter. The pad merely attenuates the strength of the signal the mic is sending to your pre and the rest of your signal chain. If engaging the pad makes the clipping go away, then it means the signal coming from the mic was too hot for your mic pre or something else in your signal chain after the mic.
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The pad is to keep the internal circuitry from clipping due to loud sources. A quick look at the block diagram of an SM81 for example shows the pad is between the capsule and the output circuitry. It pads the capsule output before it hits the mic's circuitry. It's not the capsule that's clipping, it's the internal electronics of the mic.

When I say "the mic clips", I mean it's internal electronics, not the capsule. Applying the pad takes care of the problem, as the capsule's output is reduced 10db, and no longer clips the impedance converter in the mic.

It is not my pre, or anything else, the clipped signal is from the mic.

 

[cannabis]

Boingoboy, I'll try to explain this really simple: If your mic is clipping -- which is nearly imossible to do unless you're recording nuclear blasts or jet engines -- then engaging the pad isn't going to do anything about that. It will just make your clipping mic quieter. The pad merely attenuates the strength of the signal the mic is sending to your pre and the rest of your signal chain. If engaging the pad makes the clipping go away, then it means the signal coming from the mic was too hot for your mic pre or something else in your signal chain after the mic.
.

wrong wrong wrong

what boingoman said is correct

chessnurtz, "i'll try to explain this really simple"



if the mic's output signal is too hot

the pre's attenuator reduces the signal strength

(you turn down the gain)



if the capsule's signal is too hot

you engage the pad

to attenuate the signal

to the mic's headamp