MXL V67g Capacitor Mods
Replacing the capacitors that are involved in the signal path is a fairly straightforward mod. The MXL V67g has two circuit boards - one for the preamp section, and one on the other side for the power supply. Below is a picture of the preamp section. Basically, we replaced all of the capacitors on this board, as they are all involved with the signal path. There is also one capacitor on the backside of this board which is critical. It is between the capsule and the gate of the FET, and we want a high quality cap here. There are differing opinions on what to use for these, but there seems to be a general consensus that WIMA caps work well for all of the preamp caps.
The capacitor on the backside of the preamp board is shown below. This may be the most important capacitor to replace.
Below is a picture of the power supply board. The three yellow blobs on the left end of the board are actually electrolytics, which can be replaced with higher quality Panasonic eletrolytics. These are less critical, as they are in the power supply, but, or course, clean power is important.
We have replaced the signal path capacitors with WIMA caps of the same values as the originals. In the picture below, we can see the red rectangular WIMA caps in place on the preamp board.
Below we can see the WIMA cap that is replacing the cap between the capsule and the FET gate.
This capacitor mod, along with the headbasket mod (see previous section), go a long way towards improving this mic. The next step would be to replace the somewhat bright original capsule. The original capsule is modeled after a K67 type capsule, which is somewhat bright on its own. The original Neumann U67 uses a capsule like this, but has internal eq to flatten it down, resulting is reduced self noise at the upper frequencies. The V67g has no such eq, so an additional good mod would be to replace the capsule with a K47 or K12 type capsule. At this point, we have replaced the capsules in a number of my other mics, includeing some MXL 990s and 770s, using capsules from microphone-parts.com. We are hoping to eventually replace the capsules in these V-67g mics as well.