• 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:

Bel Canto VBS 1 power unit for CD 2 and Day 3.5/3.7.
I noticed about a month ago VBS 1 was not supplying correctly,on making inquiries with Bill of Aanvil Audio the original distributor of Bel Canto in UK was given Tony's number to hopefully repair the unit.
Phoned Coherent Systems and spoke to Tony and was advised to send unit back for assessment and hopeful repair ( please note these units are no longer in production at Bel Canto VBS 1 in the US however Tony has several modular s which are only available to him ).
Returned VBS 1 unit Thursday Tony received unit the following day, repaired Saturday and I received it back Tuesday the following week. Excellent prompt service and gave a additional advice on the way my distribution block was arranged and advised the power amps should be on a separate supply, this has proved to be invaluable.
I would suggest anyone with this Bel Canto VBS 1to have it checked to see if the particular modular is working correctly (for peace of mind and low cost).
Also check out the Coherent Systems power leads for CD2 and VBS 1 units, they are a big improvement.
Again thanks for the prompt service and advice.

Gordon H

South West
Date of Posting: 10 May 2019
Posted By: Gordon Hurden
Coherent Systems products and consultancy service

Several years back I auditioned the Quadral Chromium 8 loudspeakers, alongside others in the Quadral range. Tony Sallis spent a good number of hours letting me listen, before I decided they were the right speakers to my ears. Tony said I should contact him so he could come round to 'dial them in' correctly.
I thought that can't be difficult.
They were duly delivered and installed by me. Between extensive business travels, I tried to tweak the setup to get the perfect balance, but I just couldn't get it right. So, after several years, I decided to contact Tony, and we agreed a date for his visit
On arrival, and after a short listening session, he looked at my room (which is not a perfect shape), and adjusted the toe-in of the left speaker, to an angle I could not comprehend....but the sound was already so improved
Tony had also brought some accessories, so over an extensive period; we tried successive changes, each adding further balance, sound-stage, and listening pleasure. Black Raviolis under the valve amp and CD player, Coherent speaker cables, digital interconnect, and RCA interconnects, which knocked the socks off my TQ Ultra Blacks. A Coherent power cable into my balanced power supply also provided a big improvement. Finally I was getting the sound I hoped for, and Tony gave me the time and space to make up my own mind.

So the moral of the story is:
- I should have taken up Tony's original offer, it would have saved me much wasted experimentation
- get the right accessories, it will make your equipment come to life, and probably save unwarranted upgrades
- Tony knows what he is talking about, and is a great guide to help get the most from your equipment
Thanks Tony!

Martin Hertfordshire
Date of Posting: 09 May 2019
Posted By: Martin Trevers
Ian Russell Belcanto CD3T investigation and repair.

I can't fault the service you provided. Replies to emails were prompt, the work was carried out when you said it would be and my fixed CD transport was returned to me with minimal delay. There prices were clearly explained and seemed fair for the work being carried out.
I'd be happy to recommend you to someone requiring your services.


Central Region
Date of Posting: 07 May 2019
Posted By: Ian Russell
Coherent Systems Power Master II mains conditoner

I have known Tony for a few years but it took awhile for me to build up trust in his knowledge and expertise. This is due to some bad experiences I have experienced with other dealers.
living in area that is close to a small industrial estate. This has a knock on affect to sound quality during the working week. The sound becomes more edgy. I finally get plucked up the courage to ask for help. We talked about the issues and potential remedies. Tony said to wait as he had a Furutech e-TP80E for me to try.I liked what the unit did so I asked Tony to build me one.
I now been listening to the system for a week and what I am hearing is no sense of harshness but the added bonus is that with the better cables I am using every element of what I am heading has improved.

The best way I can describe the improvement is that it is like I was driving a car with the handbrake not fully released.

Just fantastic service Thank you Tony


West London
Date of Posting: 04 May 2019
Posted By: J Cahill
Pre Loved Oracle Delphi MK VI

Hi Tony

Thanks for all your help with the turntable…or maybe I should say, thank you for your expertise which has been forthcoming in the (very few) instances when I needed it. The turntable arrived in fine form and was soooo easy to set up (a nice difference from a Linn!).

The sound is superb as it stands. By the way, did I tell you that my wife really likes the Oracle: her first words when she saw it was “that’s funky”, and she then insisted on having a little dance!
All the best


Date of Posting: 04 May 2019
Posted By: Professor F Pedersen
Hello Anthony

Thank you for the message. The 6D mains cable I purchased from you, and connected to my dac, has made such a wonderful improvement to my system that I certainly want more. I am totally memorised listening to music at the moment, so I feel one on my power-block is an absolute must.

Thank you.

P Hudson

North West
Date of Posting: 26 April 2019
Posted By: Paul Hudson
Hello Tony

After a few false dawns, final RTZ setup is; connection to CD3T spdif; connections to Dac, spdif 1 and 2; 2 connections to Belles, pair of inputs; connection to grounding terminal of Whest; 2 connections to Questyle headphone amp, pair of inputs.
Connecting to pre inputs of Belles and Questyle resulted in delivering the most musical performance,

I reckon to achieve the SQ I have now from digital, analogue and headphone playback I would have had to spend three times the cost of RTZ in terms of new boxes!

Many thanks,

Dr D Allen

West Midlands
Date of Posting: 02 April 2019
Posted By: David Allen
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

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

Page 4 of 11

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