The Nagra III Portable Audio Tape Recorder
In the late 1950's Stephan Kuldelski introduced what was soon to become an icon of battery
portable audio tape recorders. Used countless times both off and on the silver screen the Nagra
III became the de-facto film industry audio recorder, as well as an object of lust for any
knowledgeable audio enthusiast with good taste.
It was designed for a maintenance free service life of 5 years and was built to near military
standards of toughness and functionality, rapidly becoming the machine of choice where self-
contained audio recording of the highest quality was needed. This ability though was not
without some significant cost, as these beautiful machines were priced way above any other
portable audio recorder of the time, at a price similar to perhaps that of a good quality small
The Nagra III employed not only 'Swiss' standards of precision engineering and fabrication but
also cutting edge technology as well. Its electronics used the new and expensive Germanium
transistors, of which there are 38 of the PNP type. Some of these devices are used in an
advanced capstan servo control system, which was probably the first example to be fitted to a
portable tape recorder, and quite posibly the first such system to be found in any audio recorder.
(I remember having earnest discussions about the audible advantages or otherwise of the Revox
A77's capstan servo, but that machine was introduced in 1967, many years after this Nagra had
been introduced). Back then the big problem with battery powered tape recorders was speed
stability and wow and flutter, for most (actually all) machines were pretty poor in this respect,
even the previous clockwork Nagra II was not without its critics. So the Nagra III with its
electronic capstan servo system, new low power, minature transistor technology and overall
high quality of mechnaical engineering can be regarded as a genuine quantum leap in portable
In this machine we have a lightweight and self-contained device able to work all day on a set of
D cells and capable of giving fully professional levels of performance and reliabilty. The
concept proved so successful that it was to last well over 30 years, and the last Nagra IVs are
instantly recognizable both inside and out as very close relatives of this seminal tape recorder.
Having spent some time with this earlier Nagra and a few later series IV versions, I have to
conclude that while the newer machines are of course more refined mechanically and
electronically, they do actually feel rather less solid and well made (!) I am sure they are
indeed actually much better made, but these older machines seem to have a certain quality of
feel, fit and finish that seems slightly diminished in the later recorders. It is also rather
disconcerting when in the presence of the Nagra III to remember just how old this machine
actually is (40+ years), but this is I suppose to do with the timeless quality of any properly
designed tool. The finely machined Aluminium does also of course echo current fashion
trends, though with this machine we do very much have the real thing, and not a silver
painted plastic horror that is what most domestic 'techno-cr...p' has become.
The image below shows a close up of the top deck of the Nagra III, notice how the surface
has been chemically 'milled' (a very new process in the 1950's) to leave the Kudelski logo
and various lands around the screw heads, this looks very impressive. Actually I wonder if
they just masked off the plate with photo resist and just dunked it in some caustic soda, but
what ever they did it looks good.
One of the most remarkable and valued aspects of Nagra equipment is the quite unique
combination of impeccable engineering and almost exuberant standards of fabrication. 'Over
engineered' might be a legitimate criticism, but in a modern world where cheap plastic moulded
parts are sprayed with silver paint to make them look like metal, people such as Nagra and
Stellavox hand built their products out of real machined-from-the-solid metal components.
Take a look at one of the two Nagra III flutter rollers below. Not only is it finished in a satin
chrome plate that would not look out of place on a classic Leica camera (as is the rest of the
machine), notice how that instead of say anodically printing the strobe marking on the end face,
these strobe markings are actually machine cut gear disks. Yes, these are the same type of
hobbed gears that one might find in a pocket watch, what level of consciousness decides that
this is how they will make a simple stroboscope?
As befits a professional tape transport, the tape head area below is very clean and open. Left
hand head; erase, next: audio record, middle head; pilot record and replay, and the Right hand
head is playback. The audio record and replay heads have Nagra's unique gearded azimuth
Click on the above image for pictures of the machine's insides