AFI – Thermal Precision
for Audibly Better Vinyl and Shellac
Audio Fidelity
Improvement (AFI) and HiFi-Studio Wittmann are among the pioneers of
modern thermal treatment technologies for vinyl and shellac records.
AFI follows one clear objective: to treat vinyl and shellac media
with precisely controlled heat as evenly and gently as no other
system currently available on the global market.
While conventional devices with simple metal housings often suffer
from coarse heating cycles, uneven heat distribution, temperature
fluctuations, and high power consumption, AFI focuses
uncompromisingly on precision. The
AFI FLAT.SOLO and
AFI FLAT.DUO models
therefore utilize a highly insulating, recyclable housing made from
expanded polypropylene (EPP), which keeps thermal energy stable
within the system and enables exceptionally consistent temperature
control. During stationary operation, temperature deviation remains
at only ±0.15 °C – an essential prerequisite for reproducible
results.
When it comes to absolute thermal precision, however, the
AFI flat.2 sets the
benchmark. Thanks to its double-layer float glass plates and
dual-sided heating system, AFI’s flagship model distributes heat
extraordinarily evenly across the entire record surface. Its
ultra-precise PID control system maintains defined temperature
profiles with a stationary deviation of just ±0.06 °C. Temperature
fluctuations are therefore virtually eliminated – a decisive
advantage for maximum process stability and perfectly homogeneous
material treatment.
The exceptional precision of all AFI devices is crucial not only for
the gentle flattening of warped records, but also for the tempering
or “relaxing” process highly valued by audiophiles. This process is
particularly important for vinyl records: During manufacturing,
records are pressed at approximately 150 °C, while the actual
pressing cycle lasts only around 30 seconds. This is followed by
rapid and often uneven cooling. As a result, mechanical stresses
remain trapped within the material because the long molecular chains
of PVC and polyvinyl acetate cannot settle into a fully relaxed
structure. These “frozen” internal tensions affect not only the
dimensional stability of the record, but also have an audible
influence on playback quality.
During the tempering or “relaxing” process enabled by the
FLAT.DUO and
flat.2, the record is
slowly and evenly heated to a defined plateau temperature, held
there with exceptional stability over an extended period, and then
cooled down again in a controlled and extremely gradual manner. The
complete process can take up to four hours. Through this precisely
controlled thermal treatment, the molecular structures within the
vinyl can realign themselves in a more relaxed and natural order.
The result is a more homogeneous, more stable, and mechanically
calmer material.
Sonically, this often reveals itself through a more intense,
expressive, and finely nuanced musical presentation. Music appears
calmer, more natural, and at the same time more dynamic.
Particularly remarkable is the often significantly reduced
perception of surface noise and groove noise. Playback gains inner
calm, clarity, and coherence without losing vitality or energy.
However, these results are not achieved solely through optimized
temperature profiles, but through the perfect interaction of housing
construction, thermally relevant components, and intelligent heating
control. It is precisely this uncompromising coordination that makes
AFI devices so unique and enables an exceptionally even and
reproducible treatment of vinyl and shellac records.
The technical foundation behind every AFI device – which has already
resulted in three patents – was not created by chance, but through
years of intensive development work. Driven by the question of how
vinyl could be heated in the gentlest and most controlled way
possible, Dr. Ullrich Kathe, chemist and process engineer, together
with Oliver Wittmann, analog specialist and successful high-end
audio dealer for decades, examined temperature curves, holding
times, and cooling processes in meticulous detail. The result is a
unique family of devices engineered for maximum process stability
and handcrafted by AFI in Germany. |
