MC QP-1 Linear Power Supplies

Coherent Systems QP-1 linear power supply is an ultra-quiet and incredibly stable high quality linear power supply with much less ripple noise lower than Keysight linear test bench equipment power supplies which are typically around 350uv (micro-volts)



For over Twenty Two  years Coherent Systems have been associated with highest quality cabling, which among many traits demonstrates high electrical noise rejection characteristics and a low noise floor.

Our cables can deliver sounds that allow more information to be clearly and repeatably detected in a great many audio systems.

Our passion for making top quality power supplies started some twenty years ago while working on a measurement test bed for an aerospace client (previous workplace!) and how when finished we used the premise of the design architecture to install in a personal piece of audio equipment.

From that point onwards our perspective of how to obtain a quality sound from pretty much all audio equipment was irrevocably changed.

We feel that over 90% of the performance from a great deal of ALL audio equipment comes solely from the quality of power supplies that feed said piece of equipment.

Introducing the Coherent Systems QP-1 linear power supply, having spent many years designing and testing all forms of power supplies from a basic single rail to multiple complex PFC units up to three phase supply level.

We feel that our QP-1 which stands for Quiet Power is one of the most stable and quiet supplies currently available in the audio industry and beyond.

Our design for the QP range of power supplies uses some innovative design criteria that keep both the conducted and radiated electrical noise and electromagnetic emissions not just to CE testing standards (CISPER 16 + 20 both AC & DC measurements all parts for conducted, radiated and immunity ratings) but way below this threshold.

Custom designed ‘power packs’ capable of 20 amps peak and 14 amps nominal are fitted to the QP-1 (single rail) QP-2 (dual rail can be either two positive or a +/- outputs) with voltages up 28Vdc in this configuration.

We also use bespoke toroidal transformers with ratings from 120va to 5Kva. Each transformer has a dedicated EMC screen which sits between the primary and secondary windings.

This screen is grounded to earth which greatly assists with preventing any interference between the pair of windings plus is known to improve leakage current.

Also we in place a high silicone content grain orientated band which surrounds the transformers, lastly the unit is fully potted.

Also, in the pre bridge rectifier section a specially designed line filter to remove a great amount of the incoming common mode noise and harmonic content.

Further filtration stages are implement along the way before entering the ultra-accurate regulation stage where fine voltage trimming and filtering take place.

The internal; enclosure is also screened with EMC materials and Furutech IEC inlet devices are used as standard.

This all adds up to one very stable and superbly accurate DC power supply capable of delivering quite potent uplifts in your audio systems performance.

We have several options available including further super capacitor regulated stage, different wiring and DC connecting hardware, O.E. Black Ravioli supports.

We have some loan units available on 12 and 5Vdc versions, delivery time is 14 working days from receipt of order



  • Can feature two independent totally isolated DC outputs, each capable of delivery up to 5A load each rail.
  • Designed to produce ultra-high quality DC power to a wide range of low voltage DC power equipment from Streamers/Dac’s/Routers/Network bridges etc.
  • QP-1 can be configured from 1.8Vdc and 50ma to 50Vdc and over 30 amps
  • Ultra-quiet fully linear design, no switching power supplies secreted inside, just real linear goodness
  • Bespoke toroidal transformer starting from 120VA transformer with electromagnetic interference and electrical shielding, potted for the task of powering the QP-1.
  • Bespoke Coherent Systems design ‘power packs’ ultra-compact format with ultra-low noise full bridge rectification and the best selected capacitors for the PSU
  • Ultra-low noise linear voltage regulators designed by ourselves for not just quietness but ultra-stability.
  • Noise figures of PSU :- example 12Vdc + 1 amp load measured after the supplying cable @ the device actually drawing said power generating a mere 18uv of ripple noise.
  • Enclosure made of top-quality non-magnetic materials, further enhanced by vibration and EMC control used throughout the inside.
  • Top quality fittings used (Furutech, Oyaide, Harwin, Lemo etc)
  • Safety features: case fuse, current limit and thermal overload protection, transient over voltage protection on each rail.
  • Manufactured in UK using around 85% of UK produced components 230Vac / 115Vac voltage versions no problem.
  • Dimensions 280 mm L x 180 mm W x 80 mm H
  • Weight single rail 2.85 Kg dual single rail 3.25 Kg

Prices start from £895 for a QP-1 single rail

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