Tech Lowdown

Southport, UK – May 2020
iPhono3 Black Label
micro series
the Tech
engineering journey by building his own kits at a young age. Thorsten continued
exploration of the audiophile realm by repairing and refurbishing classic tube gear,
HiFi tubes, guitar and bass amplifiers as well as pro-audio devices. His international
fame was gained mostly through extensive publishing. Many years of personal
experience were complemented by advanced research, development and testing
at AMR/iFi putting into production acclaimed designs in both Tube and Solid-State
circuitry, analogue as well as digital.
Many inexperienced audiophiles believe that the ‘tube sound from solid-state’
focuses on emulating the characteristic distortion of tube circuits, but we have
long stressed that there is much more to just replicating the harmonic distortion of
the tube sound in solid-state. Adding distortion only ‘mimics’ of one aspect of the
‘tube sound’. The extent to which the result of this operation reaches the result of a
real tube circuitry experience varies widely, but in many cases the words ‘hilarious
dummy sound’ come to mind. We would be one of the first to admit this. The key is
not to add distortion, but to avoid certain types of distortion .
Once it is understood that specific distortions are endemic to solid-state circuitry
and are pernicious with respect to subjective sound quality, we can eliminate these
from solid-state circuitry, without adding on tube-like distortion and noise.
To enhance the audiophile experience, the iPhono3
Black Label employs a simple Class A buffer circuit. The
Class A buffer minimises the loading of the amplifier
circuit AND at the same time reliably biases the output
stage of the integrated circuit amplifier into single-
ended Class A (it normally operates in Class AB).
Incidentally, all other stages in integrated circuit amplifiers operate in Class A. This
is why biasing the output stage into single-ended Class A and adding the Class A
Buffer is so effective to improving sound quality.
Tube-state does not mean to add a lot of synthetic harmonics, but to emulate core
features of tube circuits in solid-state. The result is a sound that combines the best
features of the tube sound (lack of grain, edginess and naturalness of sound) with
the best of modern solid state (low distortion, low noise).
For the iPhono3 Black Label there is a third-generation upgraded circuit that has at
the heart top-notch op-amps & hand-matched PNP bipolar transistor Class A Tube-
state Buffer. By virtue of the J-FET component it has a very high input impedance
approaching the ‘zero loading’ a tube grid provides ever more closely, while the
increased drive ability allows the iPhono3 Black Label to drive 1V into 600 Ohm
loads with 0.005% THD, (dominated by low order harmonics, just like it is the case
with exceptional tube circuits. On top of lowering THD, these state-of-the-art op-