Neumann (Vintage) Tube Microphones
M49, M50, M249, M250 (show me a Neumann M49 !)
The Neumann M49 was built as a
standard studio condenser microphone. The M49 has a remote
switching to select three different directional characteristics,
so it can be used in various situations. The M50 is a pressure
transducer with omni-directional characteristic only and was
originally used for recording orchestras in accousically
favourable conditions by the one-mike (mono) technique.
Both microphones are of the same shape and size and belong to Neumann's standard microphone range.
They can be distinguished from one another by means of a red or white dot respectively above the NEUMANN sign. They are both of extremely robust construction.
The microphone capsule is underneath
the removable wire mesh housing and is rubber mounted on a
perspex cover. Due to this construction, the microphones are
relative insensitive to low frequency disturbances such as floor
vibration due to walking.
(Today, after some decades of M49 life, the rubber mounting often creates problems as the rubber gets either very hard and breaks or gets extremely soft and is so unable to hold the weight of the capsule. Original replacement is not available and it needs some skilled hands to make a suitable mounting...)
Read more about the M7 capsule (in my Neumann U47 information file)
The supply voltage input and the signal output connections to the microphones were made on the M49 and M50 via an 8-pin Tuchel plug with bayonet locking or on the M249 and M250 via an 7-pin Tuchel "standard" coupling, as also used on U67 microphones.
Neumann built various versions over the years. The first M49 was built 1949 and used the M7 capsule, which was also used in the U47.
In 1951 the omni version M50 came in production, first with a similar goldplated PVC capsule as the M7, (KK50).
Both microphones used a tube called MSC2. Neumann replaced this tube after 1954 with the low noise Telefunken triode AC701k for the M50 and after 1960 also for the M49.
With the change to the new AC701k tube, Neumann also changed the capsule in the M49 to the PE/goldplated diaphragm and in the M50 to a rather unusual aluminium diaphragm capsule (KK53) and than later, in 1965 also to the PE/Gold diaphragm (KK83).
From 1961 Neumann also produced the M249 and M250 version with the smaller 7-pin Tuchel standard connector as used in the U67.
The M249 was produced until 1974.
diagram NEUMANN M249c
try this link for more M49 technical information: G PRIME
if your M49 is sick and you need technical help, i.e. a
new AC701 or new original diaphragms,
Sydney, April 1999