The ability of amplifier to represent undistorted musical event is frequently mistaken as its continuous power output (rms). However, this specification is very useful to estimate the desired loudness of the sound at your listening chair and no more.

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 lower.

(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 compressed.

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 SE 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.

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. This also suppresses the noise and buzz originated upstream from the amplifier. The other 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 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 noise and distortion free sound transmission, leading to a spectacular improvement in three-dimensionality and resolution of detail in the music.

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 required.

We can customize this step  for your individual needs - however, prior to the amplifier assembly only.

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 (black) posts.

3. Flip the phase switch on the left channel of the amplifier  from in-phase to out-of-phase. 

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.

 

To Bi-Wire:

Repeat Step #2 for the second wire or see diagram below: