• 68 Nortoft Rd
    Gerrards Cross SL9 0LD
  • Opening Time
    Mon-Sat 9.30 to 17.30
  • Send Message
    This email address is being protected from spambots. You need JavaScript enabled to view it.

Your input is important to us. Please provide your valuable feedback. Here are some testimonials from our clients:

QP-1 Power Supply update

An update: I asked Tony of Coherent to update my QP-1 for redeployment as a dual 5V power supply for my Pi-based Audiophonics streamer. I split the power inside the streamer so that the Pi is fed separately (the 'dirty' supply) from the Kali reclocker and HDMI transmit board (the 'clean' supply).

Tony replaced the transformer with a low noise custom 120VA dual 6VAC model; moved the connector around to the side for easier cable management; upgraded the quantum regulator and installed damping and RFI/EMI shielding. The supercaps remain to provide separate 5V DC feeds with large energy storage.

The QP-1 has been running for about 36 hours and has already made a substantial improvement to the performance of my streamer. Together with some rearrangement of my grounding cables, I am hearing much greater midrange body, a better tonal balance and reduction in harshness and glare. Dynamics are still impressive but there is a greater 'hear into' ability with all types of music.

A couple of examples: the excellent Vivaldi Four Seasons by the Drottningholm Baroque Ensemble: the space in the church goes way back while the tonal quality of the violin strings is much easier to hear. Meanwhile, the continuo organ pedals underpin the music with surprising potency. Water of Love by Dire Straits seems more spacious and dimensional but when his guitar plucks hard in the left channel it makes quite a physical impression, as do the enthusiastically played drums and the overall driving rhythm.

For the second time, I can wholeheartedly recommend the QP-1 power supply for very high quality low voltage DC duties, especially for streamers and DACs. Coherent will customise each one according to needs

M Taylor

Date of Posting: 22 March 2019
Posted By: Martin Taylor
Coherent RTZ grounding system, cables and service

My recent upgrades started with hearing what upgraded Coherent BD mains cables sounded like in my system - a surprising improvement.

I was surprised when Tony brought in the RTZ 2 Grounding box as I assumed Grounding boxes made little or no difference to sound quality. However if Tony was making one I had to listen
How very wrong I was.
Connecting one cable improved the sound. Each subsequent cable connected stepped up the sound quality - each and every time. Barely makes sense to me.

I previously compared the TAD CD/DAC/Pre and TAD Power amp to my Rega Isis and Belles amps but was not convinced by the improvement in sound quality for the price difference.
With the Coherent RTZ 2 in place the difference was much greater and convinced me to upgrade to an all TAD system as well.

The final upgrade was the RTZ 3. A significant improvement on the RTZ 2.
Since the upgrades to the system the sound quality has improved and only now after 3 months am I wondering if that has stopped.

The sound quality is beyond my previous imagination and wonderful to listen to.


Date of Posting: 15 March 2019
Posted By: Mike G
Coherent Systems Audio systems upgrade with RTZ grounding products

Over the years I have managed to put together a balanced system which gave me a very enjoyable and non- fatiguing sound. Finding myself in a position to be able to upgrade I emailed Tony for his advice. Then my system was Roksan Xerxes 20+,Atemiz,Shiraz, Whest PS30RDT SE phono-stage, Bel Canto Cd3T, BC 3.7Dac, Belles IA-01 Integrated amp, Focal Diablo speakers all connected with Coherent 4/5D Mains cables, 5D interconnects.
My listening room is far from ideal and I listen at 70-75db due to having to be kind to the neighbours.
A morning at home with Tony demonstrating various new bits resulted in a substantial improvement in sound quality, exactly what I had hoped for. Whilst there were several marginal gains, 3 changes in particular stood out as eyebrow raising!
1. 4D to BD mains cable into phono-stage changed the sound completely, richer and more detailed tone, clearer vocals, fuller and textured bass.
2. 5D to BD Digital interconnect from CD3T to Dac- all the above+more analogue sound
3. RTZ2 Grounding box, to CD3T,Dac,Amp,Phono and Headphone amp just for good measure-result was a more tangible 3D sound, wider and deeper sound-stage, more intonation in the vocals=much easier to follow the lyrics.
I have during the past week disconnected the RTZ from the system to see if I had been too enthusiastic about its effect. I put it straight back in, like going from fully skimmed to full fat milk.
I can only encourage others to give the RTZ a demo in their system, it may not work in all cases but when it does it is very worthwhile. You may never know how good your system is until you try it.

Dr D Allen

West Midlands
Date of Posting: 13 March 2019
Posted By: David Allen
Excellent service and would recommend highly.

I first inquired regarding purchasing a Belcanto used pre amp and power supply, however when contacting Tony he realised that one of the items had been sold, on the website have not been updated.

However he did offer me to send and demo another power supply which he made himself, so with no money exchanging hands yet he sent me my pre-amplifier and a lovely power supply.

Used for a few days and decided that it was definitely right for me so he let me keep my demo power supply while he made my new one and sent it out to me before I have to return the loan PS.

So to sum up excellent first-class service and items were excellent too, I can definitely recommend Tony’s QP-1 power supplies

G Barlow

North West
Date of Posting: 13 March 2019
Posted By: Gary Barlow
Hi Tony

Just to let you know the Spazios arrived today and in perfect condition – amazingly well wrapped!
They look and sound great too!

Many thanks

North West
Date of Posting: 08 March 2019
Posted By: Antonio
Used Entreq Silver Minium grounding box and Coherent RTZ C1 cables

After reading a lot about grounding boxes and getting in touch with people who have actually tried one in their systems, I have decided to take the plunge and recently bought a second hand Entreq Silver Minimus and some cables off Tony at Coherent Systems.…

Tony was really a gent as he delivered them personally to me and gave me some recommendation on the best way to use this pretty little wooden box.

I was very sceptical at first but after a few minutes of listening, my systems which was already well balanced and lovely imho was transformed ... Lower noise floor, increased soundstage, texture and depth ... The changes have even improved since ... All with 2 cables connected to my Pre.

I can honestly say that this has been one of my Best Buy to date...

Trying & listening is believing and it seems that most of the negative comments so far are from people who have not tried a well developed grounding box in their systems. If you believe that quality cables can make a difference, you might be amazed by the improvements brought by a grounding box!

I have no other connections with Entreq or Tony from Coherent Systems. Anyone in the Oxfordshire/Berkshire area (and beyond) is welcomed to have a listen to my systems (mainly analogue).

Date of Posting: 02 January 2019
Posted By: Bernard
Focal Electra 1007be speakers.


Thankyou.I receive your Focal speakers on Today.Everything fine.Nice to buy with you again.


Hong Kong
Date of Posting: 14 December 2018
Posted By: Percy Lee
Quadral Galan 9 Speakers

After a fairly long time, out of the game, I contacted Anthony.
The main reason was that he supplied a speaker I’d seen glowing reviews of.
After some correspondence, I discovered early on that he knew his stuff and was also familiar with some electronics designers that I admire.
The demonstration at his facility was relaxed, informative with no pressure.
He personally delivered the preferred speaker (not the one I initially inquired about) to my home for demonstration that same evening.
I was and am delighted with my choice.
The finish of the speaker was chosen and ordered.
Anthony duly delivered them to my property and set them up for me.
He then stated he would return again after a period of “run in” to fine tune them.

I cannot recommend Coherent -Systems highly enough.
Anthony Sallis is obviously a very knowledgeable gent and has greatly improved my listening pleasure.

Jim E Hertfordshire
Date of Posting: 27 November 2018
Posted By: James Ettridge
Belcanto Dac3 and VBS repair

Tony really does know his stuff!
I sent a unit in for repair.....it turned out to be a complex fault but his persistence was admirable. He sourced a part that the manufacturer had informed him was obsolete. I'm sitting here listening to the repaired unit and the system is sounding glorious
Excellent service. Thanks Tony


West Midlands
Date of Posting: 26 November 2018
Posted By: Matthew
The Coherent QP-1 ‘Supercap’ Power Supply

This is a review of my individual QP-1 power supply. Each one is created bespoke for the customer’s needs but the principles remain the same: ultra tight voltage regulation, ultra low noise and the ability to meet variable demands in audio circuits by use of high value supercaps for a large reservoir of storage.

Mine provides +5V via two USB sockets for powering my Raspberry Pi and DigiOne separately, and +15V via a DC connector for powering my Caiman SEG DAC. The whole black box is large and heavy and suggests an over-rated toroidal transformer inside.

Connecting it up, what this high quality PSU does is quite dramatic in outcome, more so with my DAC than the Pi but the whole comfortably outweighing just powering the DAC alone. The soundstage becomes far larger, extending left and right outside of my speakers. Depth is profound, which is not something my system has been notable for in the past. Voices jump right out of the mix and it becomes easier to distinguish vocals in general. Bass tightens up and is more tuneful. Music sounds more dimensional, more detached from the speakers and more vivid.

One important thing to note. This PSU took a good two weeks and longer to give of its best, most likely because of the length of time it took the industrial grade super-capacitors to ‘form’ and settle. Do not judge it at all within the first week of operation, just keep it powered up.

Having stepped up from the stock switched mode power supply, through a good linear power supply, then 12V lead acid batteries and now to this supercap power supply has been a progression from decent sound quality to something quite unexpectedly extraordinary. I’ve always known that power quality determines overall sound quality but this is a surprise even to me. Highly recommended, although the QP-1’s contribution is going to vary from one component to another.

- Custom 120VA transformer with electrostatic screen, RFI/EMI shield, potted and specially designed mounting system
- From 3.3V DC - 18V DC, also can be produced to deliver up to dual rail +/- 25V DC, current capability now at 18A peak, 5A continuous up to 18V DC
- Use of two independent super-caps, one @ 470kuF, the other at 68kuF, fitted after main custom rectification and first stage smoothing / storage capacitors, which can vary according to individual specification
- Two year warranty and can be reconfigured if customer changes equipment
- Price from £495
Date of Posting: 06 November 2018
Posted By: Martin Taylor Basingstoke

<< Start Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 Next Last >>

Page 7 of 13

Our Brands

The Company

We are one of the foremost digital audio specialists in the country with over 25 years of specialist experience in this area, from CD players to high resolution playback we can deliver a sound that will delight.


Read More