Archive for M7

Neumann CMV-563 Recap

Posted in Repaired with tags , , , , , , , , , , , on December 3, 2013 by AnalogAudioRepair

The Neumann CMV-563 microphone body can be used with different capsules including the famous M7 (cardioid) and M8 (figure eight).  This unit was getting noisy and swapping the tube did not entirely solve the problem. The two critical capacitors are a polystyrene cap which couples the capsule to the tube, and a film cap connecting the tube to the output transformer.  We decided to replace the third cap as well, although it was not original (green chicklet cap in the Before photos). The polystyrene cap requires extra care. A heat sink during soldering prevents damage to the component, then everything in this high impedance area must be carefully cleaned.  Any flux or oils from fingers can cause noise.  The other two caps were replaced with Wima film caps, increasing the size of the output cap to 1mfd. This was a really tight fit, but worth it. In the end, with a fresh NOS tube (not shown) the mic sounds great and the noise floor is much lower.

Before - cheap replacement cap

Before – cheap replacement cap

original Neumann CMV 563 polystyrene capsule coupling capacitor

Original polystyrene cap

 

Heatsink for Neumann CMV 563 tube microphone capacitor replacement

Heatsink on the new polystyrene capacitor

Neumann CMV 563 vintage tube condenser microphone output coupling capacitor

Original output coupling capacitor

Neumann CMV 563 vintage tube condenser microphone Wima output coupling capacitor

Wima 1.0uf output coupling capacitor

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