Two Class-A, mono power amplifiers and two mono pre amplifiers. The OPLO-1 integrates all four independent amplifiers into one simple stylish cabinet. It has the single objective of amplifying the small, sensitive source signals to a high power signal capable of driving any loudspeaker. The detailed, natural, solid and open soundstage makes you forget that you are listening to a reproduction.
Both pre-amplifiers and power amplifiers are designed using open loop circuits without negative feedback, hence the name OPLO-1, the first Open Loop amplifier of TIESSENS AUDIO.
Open loop, Class-A amplification requires ultra-stable, noise free, low impedance power supplies. Therefore all 4 amplifiers are powered by their own, dedicated oversized transformers, power supply stabilisers and filters.
All amplifiers use, double sided circuit boards with ultra thick copper. The power amplifiers are additionally silver hardwired over the thick copper tracks. Solid silver internal wiring and audio grade components are used throughout the amplifier, it all adds to the sound, details matter.
To minimise internal wiring the 4 inputs are selected by 4 relais located close to the terminals. The input is separated from the pre-amplifier by a buffer amplifier with it’s own power supply stabiliser and filters. To further minimise interference of the source signal the buffer amplifier has additional shield covers directly placed over the electronics on the circuit board.
Class-A amplifiers generate heat and oversized power supplies require space. The amplifier has been completely designed in 3D CAD software to optimise the space. The Class-A power amp is cooled by a horizontal heat pipe which contributes to the simple and relative compact design without the traditional bulky, external heatsinks.
The input circuit and pre-amplifiers are built into their own cabinet within the overall cabinet preventing influence of the high power amplifier currents on the sensitive low power electronics. Just like with separate preamps and power amplifiers..
The front, back, sides and top panels are CNC milled from solid aluminum and built on a strong stainless steel base. An additional solid cherry wood cover is used to visually emphasize the independent preamp. It creates, in combination with the sandblasted aluminum, a timeless design. The CNC machined cherrywood feet are the finishing touch to the amplifier.