This is a like new condition Unico uPower amplifier in Satin Silver finish. This unit comes with all its original accessories and packaging.
The unit will be shipped double boxed to its destination.
Price includes free shipping to anywhere in the Continental USA or Canada.
Feel free to contact seller if you have any further questions.
Not to be confused with so-called `turbo boosters` offered by some manufacturers, the uPower is a properly designed high-level amplifier having separate current and voltage amplifying stages designed in such a way as to maintain unaltered the sonic nature and character of the original sound. Added to the output of a low-powered but sweet-sounding all-tube amplifier, the improvements to dynamics, driving ability, grip and control of the loudspeaker can make for a more convincing and realistic listening experience. uPower multiplies current and voltage by a factor of 4 x, and can be used with any integrated or power-amplifer.
Description of the operation of Upower:
In the normal operation of an amplifier at the output terminals of the latter is connected to the
speaker. The speaker absorbs a certain current depending upon the impedance of the speaker
himself. This absorption of power modifies the real voltage output of the amplifier ad this
phenomenon is usually measured by the "damping factor" of an amplifier.
The fact that the amplifier output is sensitive to the impedance load is that the impedance of the
speaker characterizes the sound. This is even more evident if it is noted that the impedance of the
speaker is not constant but varies with frequency.
In conclusion, the coupling between amplifier & speaker becomes a significant feature. We know
that an amplifier in Class A has a sound quality superior compared to B or AB, but suffers from a
limitation in the maximum achievable power at limited cost . The limitation of power derives from
the maximum values of voltage and current that the amplifier is able to send to the speaker.
The role of uPower is to accompany the amplifier helping to provide power to a speaker with a
capacity of providing value exactly proportional to that which already provides the amplifier. In
particular, in the current version of Upower, the increase of power is equal to a factor 3. So if the
tube amplifier is providing 15W, the Upower will add more 45 (3 x 15) for a total of 60 W on the
There are already some "boosters" on the market but they use the amplifier with a dummy load
(typically a fixed amount of resistance) to produce only an amplified voltage output. In this way,
however, the characterization of sound due the interface between the amplifier and speaker is
completely lost and depends only on the damping factor of the "booster".
The Upower in contrast, does not use a dummy load but the amplifier is always loaded on the real
impedance of the speaker and the tension and the current that provides the amplifier are
simultaneously amplified. The sensitivity of the amplifier to the impedance of the speaker remains
unchanged as if the speakers were directly connected to the amplifier, an operational condition
that, as already stated above, strongly characterizes listening.
To achieve this goal the Upower is connected in series to the speaker. So its input is connected to
the output terminals on the amplifier and its output is connected to the speakers. The power supplied
from the amplifier "goes" through the Upower which adds further power obtaining a total power on
the load which is four times that of from the amplifier. This behaviour is similar to the amplifier
when it is connected directly to the speaker, but the latter receive, in fact, much greater power.
In its internal structure the Upower, consists of two stages of amplification side by side. The first
stage generates a voltage equal to the output of the amplifier input. This tension is added to tension
already produced by the amplifier doubling the voltage available for the speaker. Alongside this
stage there is a second one which helps to provide an additional contribution of current doubling.
The simultaneous doubling of voltage and current produces the above-mentioned increase in power
load by a factor of 4.
The structure of power amplifiers inside the Upower are the same as the Dynamic Class A you will find in the Unico series. Compared with the models of the Unico series, here we only use the
MosFET power stage without the valve input stage. This task is left directly to the amplifier which
is connected to the Upower.
For each channel the Upower uses two independent stages of amplification. One for the
amplification of tension and an amplification for the power supply.
The structure is totally dual-mono and the two channels are completely independent. The power
systems consists of three power supplies for each channel and are completely independent
Questions for the seller
No questions have been asked about this item.
You must sign in to ask a question.