MARLEY MKII
HIGH PERFORMANCE HEADPHONES AMPLIFIER
REVISION P
R
A – JUNE 2019
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7.4.9. CROSSFEED: enabling/disabling cross-feed
The
Marley MkII
is provided with a cross-feed circuit which partially blend the two
channels, therefore reducing the channel separation. This can be useful when listening to
tracks recorded in the early stereo era, when audio engineers were not really acquainted
with stereo technology. Those old recordings are often affected by the so called “ping pong
effect”: instruments and vocals were pushed to one channel, rather than being panpotted
between the two channels for a realistic soundstage rendition. This effect, which is already
unpleasant when listening by loudspeakers, is even worse when listening by headphones.
To reduce the ping pong effect, a cross-feed circuit must be used.
As there’s no need for cross-feeding with more recent recordings, the cross-feed circuit
can be disabled when not needed.
7.4.10. OUTPUT IMPEDANCE: choosing the right impedance for your
headphones
Each headphones model has its characteristic impedance and works at best with a
specific driving impedance. The
Marley MkII
allows users to choose the output impedance
(therefore the driving impedance for the headphones) based on the optimal value for the
selected headphones model.
Three output impedance values are available: Lo-Z (that is virtually zero), 10 Ohms and 47
Ohms. As a general rule, the higher the headphones impedance, the higher the driving
impedance. Therefore, a 32 Ohms headphones will probably work best with 10 Ohms
driving impedance, while a 300 Ohms model will require 47 Ohms.
