Sony C100 circuit

[AUDIO FREQ]

Great sound but it has high self noise for my liking.

Here is a pic of the circuit if anyone is curious.

EDIT: Reverse sides of circuit.

 

[kags]

Just curious as to what mics would be quieter than this? I used the C100 extensively and found its self-noise in actual use to be comparable to U87, c414s, KM84s, and other common studio mics. I didn’t compare it directly to our Schoeps or MKH mics, but the Sony isn’t meant to be in that league.

Respectfully, I’m not saying there isn’t room for improvement- just wondering what your expectations for this mic might be.

 

[AUDIO FREQ]

Just curious as to what mics would be quieter than this? I used the C100 extensively and found its self-noise in actual use to be comparable to U87, c414s, KM84s, and other common studio mics. I didn’t compare it directly to our Schoeps or MKH mics, but the Sony isn’t meant to be in that league.

Respectfully, I’m not saying there isn’t room for improvement- just wondering what your expectations for this mic might be.

Hello,

Checking out the spec sheets for other mics, there are quite a few mics that are quieter. For instance the U87AI is quieter, TLM103, NT1, NT1A, and even tube mics like the C800g is quieter by a dB...

the C100 has an equivalent 19dB self noise in cardioid. For a fet mic, it seems a tad high in my opinion. In use, I noticed when boosting gain in the Apollo preamp, the mic starts to emit a white noise-ish self noise.

But who knows, maybe I have a dud?

 

[AUDIO FREQ]

Update, found the service manual if anyone is in need.

 

[Voyager10]

That's rather a quirky circuit. Looks like they have an LDC capsule feeding XLR pin 2 and an SDC feeding pin 3 (via a high pass filter). Combining the two happens in the preamp.

I'd suspect most of the noise comes from R152 in the LDC's impedance converter, that's 4.7k's worth of thermal noise right in the signal path. Seems sloppy to me - I wonder how it ended up like that?

 

[OneRoomStudio]

Update, found the service manual if anyone is in need.

Where’d you find the service manual? It would be interesting to get ahold of the C80 service manual to see if they used a similar circuit.

 

[emrr]

In use, I noticed when boosting gain in the Apollo preamp, the mic starts to emit a white noise-ish self noise.

You have verified the noise isn't the preamp by strapping an input resistance, such as a standard mic pad? Tried a different preamp channel? Different preamp?

 

[SubSpec]

I would concur on the noise, my experience with the C100 was similar. The best single mic acoustic guitar sound I've gotten, but it does have a more noticable noise floor than most of my mics.