A little information about Coherent Systems

Coherent Systems also offer a wide range of services that forum users may find helpful these include, Installation of dedicated mains supplies for audio and home cinema systems fully approved and certified. Repairing of a wide range of audio equipment and beyond we also offer a bespoke upgrade service tailored to each customers individual needs and we can demonstrate options far beyond tradition so called high end equipment.

Why not give us a call and find out why we are highly regarded within our profession

Coherent Systems Contact details


Our repair and upgrade facilities sport some of the very latest and specialist test and measurement equipment from the world's best manufacturers Teledyne LeCroy Keysight , Rohde & Schwarz, Tektronix, Kikusui, Picotech, Flir, GW Instek, Rigol, Siglent. 12bit oscilloscopes, up to 8Ghz bandwidth, Real time spectrum analyzers, ultra low noise  bench power supplies and 7.5 digit multi meters, Vector network analyzers (cable and transmission line measurements). We are very well placed to identify any issues within your problematic equipment. We strongly believe we have one of the best lab facilities for audio within the UK and that includes many manufacturers of audio equipment!

Coherent Systems have over the years acquired state of art electronics test equipment to enable us to investigate pretty much any issue that affects audio equipment. We can go in-depth into RF and EMI emission testing both conducted and radiated at a board level with real time spectrum analysis and large GHz bandwidth oscilloscopes, LISN’s impedance analyzers, power analyzers, Audio analyzers  thermal imaging camera’s etc. We have the ability to deep dive into those most interesting of problems!

From time to time those audio electronics we cherish and adore so much can run into problems.

Whether its a noisy channel, low output on your pre-amplifier, distortion issues or plain non functionality.

So, if your DAC is poorly, your valve amplifier is sounding a little off colour, or maybe your CD player has just given up the ghost. We can help with these matters.

Coherent Systems has a fully comprehensive electronics lab coupled with the expertise and knowledge of over 50 years experience in electronics and electrical engineering field. Including: fault finding and diagnostic work.

We have a very open policy when it comes to repairs. No large and unforeseen hidden expenses. We investigate first, advise you of the situation then discuss the best possible course of action for the individual circumstances, making sure you are kept in formed at all times.

We specialize in all digital electronics, CD/SACD/DVD players. Amplifiers (both solid state and valve), digital to analogue converters, power supplies too.

We also have great experience with turntables both in mechanical repairs and set up and use the very latest tools to extract the best form your vinyl playback.

Coherent Systems take pride and care in their workmanship and understand all equipment being repaired is looked after correctly.

Insured collection and delivery service also available.


An image of one of our designs power supply being thoroughly tested for CE emissions before any work commences. Looking at the incoming mains noise and how much conducted noise is being transferred to the PSU and the end result we are looking at CISPER 16 standards for DC output ripple and harmonic noise via a real time analyzer and DC LISN.




 


Here was are looking into the jitter spectra, trend RJ/DJ and histogram of a Mutec MC3 clock with our superb LeCroy Wavepro 254 12 bit scope with a Rigol MSO8000 providing damn fine conformation of the results




Here is one of our new QP-1 ultra quiet power supply being measured with a 1 amp dynamic load applied to the DUT (device under test) as you can see it clearly show dc line ripple noise below 18uv which is quite decent given its actually being measured with a genuinely working load applied! To put this into perspective our Keysight E36313A industry standard has  a ripple noise of 'only' 350uv



Some more of the instruments we have in the Lab, A 2Ghz 500Mpts MSO Oscilloscope, 150Mhz Function generator, 6.6Ghz Real time spectrum analyzer, Vector network analyzer

Morning Chaps

Thought I would update some of the images so I took some more photo's last night.

Some of the other test equipment gracing our lab.

Here we have our JBC soldering suite which can handle just about any soldering issue that may arise




Here we are testing a new regulator design with the DC power analyzer which is both a power supply, dc load, sink and data logger very useful piece of equipment for characterizing power supplies.




Lastly demonstration of an ultra clean linear audio dc power supply   happily delivering a solid 2 amps @ 12Vdc through a dynamic dc load.

Thank you Oli,

Early on we realized that if you are to get to grips with true audio fidelity you need to look at all aspects of the circuitry and beyond 20Khz Looking outside of the box is very important to designing equipment, however your ears are as important as the theory and design, modelling and creation of new ideas.

We are constantly improving our facilities all the time, however what a lot of people misunderstand is that supporting cast to the measurement instruments themselves are just as important as say the scope itself, in the same way cables/supports and mains equipment is to audio.

With RF testing you need attenuates, loads, RF probes, RF amplifiers, RF current probes, antenna, correct test cabling we use 18Ghz T-Flex 405 damn good stuff as some of the big BW stuff costs way in excess of the audio high end cable sector Factor mixers and shunts etc and it gets £££.

For example a quality 1ma resolution 50 amp 100Mhz probe for the scope is £7K on its own, if you are looking at low level power in densely pack boards then a optically isolated high BW probe is required so no change for £8K for that one. Tektronix produce an optiview probe which is a basic £24K no tips lol

The supporting equipment for confident precision measurements can and do equate to almost the cost of the test equipment itself

Anyway we have the ability to cope with pretty much any job you could mention.

Certainly some quality looking gear there, and probably the cutest little Snap-On tool box I have ever seen.

Just to let you know we are now back up and running again no thanks to a man and a JCB plus large bucket into main power line delight person

It's a proper den of Hifi investigation!

Great stuff T

Roy Gregory was a big fan I remember, and it's certainly a looker

Simon

I would characterize the casework and application of components around it as interesting and unconventional, however they did engineer in a back door ability to gain access to to the circuit boards with having to un-solder around 60+ connections.

This particular model is working as it should and still sounds engaging and incredibly listenable. Having own a few Hovland models over the year I found them be worthy of a shelf of my personal system, not many brands obtain that ability.