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Behringer C1 cheap microphone 'update'


 

General:

Behringer Germany is well known for its cheap (semi-)professional audio and recording gear.

The C1 microphone is no exception, it cost only $20 to $30 on second hand markets.

Special futures:

Phantom 48 Volt supplied electret condensor type microphone with permanent polarized 1" diaphragm and FET type pre-amp.
The housing is rugged and suggests to be all metal, but it isn't, there are some plastic components used.

 

User Manual:

Click here to download the Behringer C1 product info in PDF format

 

Schematic:

construction

 

Modifications:

This mic is quite nice for simple recordings and has potentionally the same quality as all electret mics,
But it may be quite noisy: suffering hiss and hum and can be made dead quiet with some modification.
Most of these cheap mics are suffering grounding problems. The mic on the picture did not have serieous
housing ground and the top chrome netting cover did not have proper ground.
Also the plug in the bottom did not have serious grounding.
This kind of grounding causes hum and ie. noise from nearby switching power supplies and all kind of other problems.

The problems this mic may have are two:
1: is the grounding of the electronics and the housing, that is the main problem: 'hum'.
2: Also some C1's may have noisy smd transistors used: problem: 'hiss'.

If you have the 'hum' problem, do the modifications below:

^ Adding 4 grounding (Shield) wires: black, yellow, red-white and green. The black wire connection is shown below, the yellow wire connects by soldering to the top netting-grid, and the red-white wire is connected as shown above. The green wire is from the plug in the bottom of the mic. housing, there is also a black wire already existing and that is connected to the shield of the plug,
separate these wires if nessesary.

^ Replace the existing capacitor for a polypropylene one as on the picture: the green selection shows the cap.
Also cover the red selection with transparant paint, that dries & hardens permanently.

 

^ Make a shield of metal around the FET transistor as shown on the picture and connect it to ground with the screw in the purple selection.
Apply some glue to prevent rattling noise.

 

Make a connection on the housing of the mic: use the screw of the top part of the housing as on the picture black wire, do not forget to remove some paint to make a good connection. ^

 

Only if you have the 'hiss' problem replace T3 and T4 for low noise smd transistors.
The board has 1 FET and 3 smd transistors, thats the whole pre-amp. V

 

 

Sound:

After updating its still a cheap but quite good sounding mic.

 

 

construction

 

 

© PE1MMK Hans Hilberink last update:15-10-2016.