Musician III Mk2 -
Fully Balanced Monoblocks
Musician III Mk2 is capable to operate both in stereo and fully balanced monoblock configuration. This is, basically, user-selectable feature (see below Part III). To better understand potential advantages of fully balanced monoblocks, lets look at the nature of faithful reproduction of musical peaks like symphonic crescendos as well as relation between amplifier’s distortions and fully balanced signal processing.
Part I: Power
The ability of amplifier to represent undistorted musical peak is frequently mistaken as its continuous power output (rms). However, this specification is very useful to estimate the desired average loudness of the sound at your listening chair and no more. The real life music, however, behaves very differently from continuous test signal in the lab.Its not continuous to begin with, has many pauses, plays sometimes very quietly and sometimes simply “explode” – particularly so jazz and classical music.
The headroom is a true measure of the
amplifier's ability to reproduce large transients (e.g., the
cannons in the 1812 Overture, or more often in piano music,
or the rim strike of a snare drum often found in jazz). It's
correct that power is the product of the voltage times the
current. However, in reality an amplifier's voltage headroom
is limited by the power supply voltage, which limits the
peak voltage. Spectron's amplifiers are the highest voltage
we know of in the audiophile world, using a plus and minus
supply of 120V. By comparison most amplifiers use power
supply voltages on the order of plus and minus 65V or even
(Additionally, most other amplifiers,
particularly tube amplifiers, increase their distortions
dramatically, sometimes immensely, at full output - making
experience of listening loud passages highly unpleasant.
On other hand, Spectron's distortion level almost does
not increases with output - see the specifications).
What does the limitation in peak voltage
mean? To illustrate, lets take example of a CD player with
typical output of 2.2V rms (i.e. peak 3V), and if you
use XLR balanced output then its peak voltage is 6 volts.
Lets for simplicity assume that you are using passive preamp
with gain set at this experiment to the unity i.e. 1.0, and
finally, lets take typical amplifier which has usually gain
of 26 dB or x20. Thus, you must expect your amplifier to
have output peak voltage: 6V x 1.0 x 20 = 120V. This means
that when listening to the same music with most other
amplifiers, particularly those without output transformers,
the signal would be "clipped". These amplifiers would be
unable to deliver the transient voltage to the speaker. The
effect is that the music loses some of its lifelike
qualities i.e. signal is distorted and dynamics is clearly
Above example represents situation when your preamplifier
gain is unity i.e. with relatively efficient speakers.
When your speakers (or music) demand your preamplifier to
have gain more then 1.0 then even Spectron amplifiers might
clip! Fortunately, Musician III MK2 is capable of operating
both in stereo and mono (fully balanced) modes. While not
necessarily an advantage for highly efficient speakers as
described above, less efficient loads will benefit from the
fully balanced operation that triples the power and doubles
the headroom to + 240 volts as well as
staggering 7000 watts of peak power (and hold it for an
extraordinary 500 msec) assuring that no matter what
the speaker load, the amplifier will deliver the full
dynamics of the original recording undistorted. Number of
reviewers observed that Spectron monoblock's sound creates
noticeably deeper bass, effortless presentation
and powerful slam.
Part II: Finesse
Regardless of the efficiency of the speakers,
balanced mode of operation doubles the slew rate and
bandwidth by virtue of the out of phase transmission. The effective bandwidth of the Musician IIImonoblock is 200 kHz.Wider bandwidth translates into faster transients and greater detail, better preserving phase information. This results in a bigger soundstage, sharper image and more holographic representation.
The balanced mode of operation
also suppresses the noise and buzz originated upstream from
the amplifier. The other and probably the most important advantage of fully balanced
mode in Spectron amplifiers is that transmission of both
positive and negative signals (in each amplifier) is
maintained separately from the amplifier's input to the
speakers binding posts. Assuming that the signal path
electronics are absolutely matched, all of the intrinsic amplifier
distortions arrive at the speakers with practically
identical amplitude but with opposed polarity and
essentially cancel each other. The result is a largely reduced noise
and distortion-free sound transmission, leading to the
spectacular improvement in three-dimensionality, finesse and
resolution of detail in the music. Please note that advantages of fully balanced amplifations described above are not uniquie to Spectron! All amplifiers in the world can be used in the identical fashion, provided that their part tolerance is extremely high; otherwise your level of distortions may actually increase!
Part III: How to use your
Stereo Musician III in Balanced Monoblock Mode
1. Connect the right channel output of the Pre-amp to both
inputs of the right channel amplifier. Do the same for
the left channel amplifier i.e. connect Pre-amp left channel
output to both inputs of left channel amplifier. If the
preamp has two output jacks in parallel, run two cables,
either RCA or XLR. If the preamp only has one output, a
cable with a “Y” connection at the amplifier's end will be
We can customize this step for your
individual needs - however, prior to the amplifier assembly
2. Connect the speaker to the two high (red)
amplifier's binding posts. By convention, use the right
channel of each amplifier for the speaker high (red) binding
post. There are no connections to either of the two low
3. Flip the phase switch on the left
channel of the amplifier from in-phase to
4. Repeat steps 1 - 3 for the second
(left channel) amplifier.
5. Reduce volume control to adjust for
substantially increased sound pressure
The system is now ready for operation in
the balanced monoblock mode.
Repeat Step #2 for the second wire or see diagram below:
The most important major advantage of fully balanced mode in Spectron amplifiers is that transmission of both positive and negative signals (in each amplifier) is maintained separately from the amplifier's input to the speakers binding posts. Assuming that the signal path electronics are absolutely matched, all of the intrinsic amplifier distortions arrive at the speakers with practically identical amplitude but with opposed polarity and thus cancel each other. The result is a largely reduced noise and distortion-free sound transmission, leading to the spectacular improvement in three-dimensionality, finesse and resolution of detail in the music. Please note that advantages of fully balanced amplifations described above are not uniquie to Spectron! All amplifiers in the world can be used in the identical fashion, provided that their part tolerance is very, very high; otherwise your level of distortions will only increase!