Telefunken U47 Operator's Manual page 5

U47 History
In production since 2004, the TELEFUNKEN Elektroakustik recreation of the
U47 was developed fresh off the success of the re-release of the ELA M 251. As
with the 251, this microphone was designed to be as true to the original design
as possible. The Telefunken U47 utilizes significant cosmetic elements of the
earliest iterations of the original "long body" design, including a nickel plated
headgrille and classic Telefunken Diamond badge, as well as the use of vintage-
correct Tuchel connectors and "NG" style power supply.
Electronically, the Telefunken U47 features a Mylar M7 capsule, the original
circuit with VF14K vacuum tube, and a BV8 transformer, as this combination
has been determined to provide the absolute best version of the classic mid-
forward frequency response associated with the U47. Originally M7 capsules
were tensioned with PVC, which is now known to crack and fail over time. With
longevity in mind, the non-historic change from PVC to Mylar was an easy
decision to make. Mylar is the industry standard tensioning material and can be
found in most other highly regarded capsule designs including the K47, K67,
and CK12. While TELEFUNKEN Elektroakustik M7 capsules have always been
made in North America, as of 2022 they are now made in South Windsor by the
same small team that makes the CK12 capsule, which is found in the ELA M
251E and C12.
The major obstacle to releasing a microphone based on this classic design
is related to the tube selection. With virtually no VF14/VF14M's available for
purchase and no exact replacement tube types known to exist, most settle
on modifying the circuit to accept different tubes; usually tubes that look like
VF14s but do not operate the same. Telefunken developed the VF14K to solve
this problem for new customers and old purists alike. The VF14K consists of
a NOS military grade glass vacuum tube and a passive circuit housed in an
enclosure designed to fit the original VF14 tube socket. As there is no circuit
modification necessary, this is the best solution both for those with vintage
microphone models that need new tubes and those purchasing new U47 or U48
microphones with the intention of installing a NOS VF14. The Telefunken U47
operates on a single 105-volt line, same as the original design.
8 TELEFUNKEN Elektroakustik
Soon after the U47, the U48 was also released. With its defining red polar
pattern logo, the U48 features Figure-8 instead of Omnidirectional as it's
secondary polar pattern. The two microphone models are otherwise identical.
Both models are point to point wired with premium components including
precision metal film resistors and polystyrene capacitors. Almost all metalwork
and mechanical parts are interchangeable with original examples and serve as
replacements in vintage restoration projects and repairs. Now in production
for two decades, this design has been honed and perfected and is the best
example of the U47 currently being manufactured.
Diamond Series 9