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Stereo Amplifiers


Marantz and Denon

A range of stereo amplifiers are available from Denon and Marantz.

Marantz and Denon stereo amplifiers

Quasimodo Amplifiers

The Quasimodo amplifier is the result of some 15 years of development to make a stereo amplifier that sounds as musically enjoyable as possible.

With no circuit boards whatsoever, all the components are hard- wired on tag strips, which really does help the sonics!

The 40 watt model, for instance, is rated at 40 watts per channel into 8 ohms and around 70 into 4. There are also 25 watt and 80 watt models. They have been" voiced" to closely emulate that of a good valve amp. This has been done by ensuring that any distortion artefacts are primarily even - order, with 2nd order dominating, followed by a very tiny amount of 3rd, after which 4th order is higher in level than the 3rd- and so on in gradually reducing order.

According to the SPICE program, the distortion at normal levels is about 0.063% with the "nice" sounding 2nd order artefact dominating- just like a good valve amp! A transistor amp that has been designed with a perfectly symmetrical circuit configuration will ALWAYS generate primarily odd order distortion artefacts and will sound, well, "transistor- ey" The Quasimodo deliberately uses a somewhat asymmetrical transistor / mosfet output stage to ensure that any small distortion artefacts are going to be the harmonious even order types. Subjectively, an amp that has a distortion figure of say, 0.5% 2nd order dominant , will always sound far more "musical" than one rated at 0.03% 5th order dominant! 5th order distortion is subjectively quite nasty sounding, so it is good practice, I have found, to ensure that even order dominates, thus "masking out" the nasties!

The Quasimodo amp is inherently safe, and even in the highly unlikely event of an output stage failure, no harm can be done to your precious speakers!

This amp sounds so good, I have now stopped building valve amps, of which I have four now just gathering dust! After hearing the Quasimodo, I think no other amp will quite sound as "right" - at least that's what I have found!

Richard McDonald.

Quasimodo amplifier
Quasimodo mini amplifier