Discover why we are the best in audio repairs and upgrades.

Average Rating: 5.0 stars (based on 192 ratings)

Effortless grunt

MF A308 CD, Integrated amp and power amp bought ex-demo back in 2008 bi amping a pair of Jamo concert 11’s. In 2019 all 3 boxes were stage 2 upgraded. Now in 2024 the system just sings effortless grunt. Plays any type of music very well never recordings especially well. Time to audition bigger speakers.

Andrew Gourlay
Item Repaired/Updraded:MF A308 CD, integrated amp and power amp
June, 2024

Outstanding work

I’d had my A370.2 since new and for various reasons after our last house move my hifi didn’t come out of the boxes. The A370 sat unused since early 2005 until Covid happened and like many others at that time when stuck at home I started to pick up old hobbies. However when the A370 was connected up and turned on it didn’t work. I gave up on it and it almost got binned at that point. Until early 2023 when I started to look for anyone local in central Scotland who could repair it. People promised a lot but couldn’t deliver. After it spending months with someone who did nothing to it other than to tell me he thought one channel was blown, and another high end dealer who thought they could fix it, but after several botched attempts and more blown MOSFETs they gave up and suggested JS Audio and John.
I called and spoke to John, explained the situation and shipped the wrecked A370 to him. He’s very busy, but he had a quick look, called me to assure me that he could fix it and gave me an estimate. He warned it would be in the queue behind a number of other repairs and would be a few months before he could look at it. True to his word after a few months I had a call from him that the amplifier was repaired and given a makeover. It’s running cooler than it used to and sounds just wonderful. Connected to my Michell Gyrodec, MF 3b preamp and driving my vintage KEF 105/3s the open, spacious, almost 3D nature of the sound and smooth yet tight control has to be heard to be believed. Thank you John, you’ve breathed new life into what I thought was going to be a write off.

Norman Taylor
Item Repaired/Updraded:A370.2
June, 2024

Amazing Transformation

I have had my amplifier from new, so over 20 years. The input selector had been playing up for some time, but not only that, it had begun to sound lacklustre. Only one thing for it. I spoke to John, who explained my problems were common for the age of the amplifier.
He explained about the Stage 1 or Stage 2 upgrade he could do, and fix any other problems, such as the input selector issue.
I went for the Stage 2 upgrade option, and I have to say it is the best money I have ever spent in all the years of listening to music.
He arranged the transport for me, and I had it on it’s way within a couple of days of speaking to him.
I’ve had it back now for three weeks and it sounds amazing. Far better than it did from new. The clarity, bass and detail, combined with the power and control it has now is startling to say the least. I am hearing things which I hadn’t heard before.
I can advise anyone in a similar situation to myself that the Stage 2 upgrade is the way to go. I am indebted to John for transforming what was a great amplifier into a whole new level of sound reproduction, one that I imagined would only be found by spending north of £10,000 on a new one. Thank you John. My Nu-Vista 3D CD player will be next. Saving up already.

Peter Stead
Item Repaired/Updraded:Nu-Vista M3 Integrated Amplifier
May, 2024

Audio Magician

Bought used around 15 years ago, my amp of maybe 25 yrs had started to hiss and crackle. John took it in to look over, diagnosis worn out. Got it back this weekend, totally transformed!
Immediately sounded impressive, now after only 15 hours of the recommended 30-40 running in it sounds fantastic. Much greater depth, detail and definition – looking forward to next few weeks/months/years!

Jim Valenti
Item Repaired/Updraded:Acurus A250 power amp
May, 2024

You Work Out the Maths!

So, after many years of owning the Nu Vistas, the long dormant upgrade bug was kicking in and off I went to a local respected Hi-Fi shop to see and hear the latest offerings. As soon as the store knew what I had, the staff nearly screamed at me to keep the Nu Vistas and send them to John for a service/ upgrade. So, for far less than the cost of the amps when originally purchased, John worked his magic. After first plug in, the immediate response was “Wow, that’s an improvement”. After the three weeks “burn in”, the system just came to life both in scale, depth and insight that gave me that upgrade well beyond that, that I thought that I could afford. My biggest critic….. the other half who “can’t hear the difference” suddenly could and was, herself now sitting down listening to her collection of CD’s! I dragged her along to a high-end Hi-Fi show and the first demo room we sat in and she turned to me and said… I much prefer the sound of our system. When I discovered that the hi fi we were listening to was £100,000+, will I be upgrading anything anytime soon? Well, I could buy the new Nu Vista pre and power combo at £45,000 or I can continue to sit her with a smug face knowing that I paid not even 10% of that price to have a pair of old nu vistas that blows the new ones away. So is it worth it the cost of John’s magic? Well, you work out the maths!

Item Repaired/Updraded:Nu Vista Pre and Power
May, 2024

Transformed Amp

The latest upgrade from JS Audio is to my KW750 power amp and was a Stage 1 plus WBT terminals plus 1kW Audio Grade transformers. Now that the amp has had some time to “run-in” the difference is substantial with improved dynamics, transparency and clarity. Sound stage is bigger and better defined and music just flows (even more) effortlessly. Many years ago I had a KW500 upgraded which also made a big difference and last year my KW Phono pre-amp was upgraded which was again substantially better for the work that John carried out and encouraged me back to vinyl again. One more bit of kit is waiting in the wings for the upgrade magic, hopefully I’ll be able to call John and book that later this year.

Item Repaired/Updraded:MF KW750
May, 2024

A3CR Pre and Power Amplifiers

I have owned my amps for 20 years and love the MF sound. I was considering purchasing the new M6 pre/power but after several exchanges with John, elected to get mine rebuilt and upgraded. They have been running a couple of months now, together with a new Rega P10 and all I can say is wow. I simply love them, so much so I want more. The sound is crisp, clear, detailed and so very tight. The separation is solid and allows us to pick out all the musical detail behind the vocals. Although they are not packing huge power they move my B&W 804s with ease and I never feel like they lack in punch or volume. I now listen to vinyl for 3 to 4 hours a day and it’s totally enjoyable. Great service, amazing rebuild, so very glad I took this route.

Tony Jupp
Item Repaired/Updraded:A3CR Pre and Power amps
May, 2024

Nu Vista 3D CR CD Player upgrade

JS Audio previously upgraded my MF A300 amp that still sounds fantastic so had John do a Stage 2 upgrade on my CD Player including new valves. Initially It sounded better and had greater detail but 4 months on and time to run in the improvement is another level. The separation of instruments, soundstage, detail is just superb, it constantly brings a big smile. Both of the items JS Audio have upgraded are now 20+ years old and would highly recommend them.

John H
Item Repaired/Updraded:Nu Vista 3D CR CD Player
February, 2024

Musical Fidelity P170 Power Amplifier

Knowing the other repairer like the Getitfixed which they destroyed this power amp when they returned it to me.
Thankfully AudioJSRepairs which is Mr John to the rescue! Mr John completely remodified and improved this power amp significantly.
I am listening now and to my surprised, the details, botom end to mid and highs expanded the sound further than the original state of this amp. I am listening to live sound the closest possible! It’s Wow!!!
This company deserve the highest score, 10 out of 10.
I will be sending more stuff in the near future to this company for either repair, upgrades or tuning my equipment.
Very highly recommended..
Thank you Mr John

Item Repaired/Updraded:P170
February, 2024


Great job. My vinyl has taken a farther step on the way to perfection. Highly recommended service, glad I decided to send my amplifier (musical fidelity A3.2cr dual mono) for repair and stage one upgrade.

Item Repaired/Updraded:Musical Fidelity A3.2 dual mono amp
February, 2024

Transformed Goldmund

John has just completed a startlingly successful repair and upgrade on my classic and much sought-after Goldmund Mimesis 9. It is now able once more to run rings around current power amp references. I have nothing but praise for his work and technical insight; you can safely leave your beloved high-end gear in his hands, confident that it will come out sound better than ever. – Jon Bower, January 2023

Jon Bower
Item Repaired/Updraded:Goldmund Mimesis 9
January, 2023

Nu Vista 800

It’s been a year now since getting my NV 08 repaired and upgraded to stage two. I’ve deliberately given the amp plenty of time to settle in as I did now want to give a “false” report.
My initial impressions were not that great to be honest . Yes , the amp certainly was better but not as much as I thought it would be .
But after giving it more time to allow the replaced components to settle in it now is certainly much much better than an original NV 08. A change of cabling (speakers & interconnects) has also contributed to the new quality.
The amp really does sing now . Still smooth but with an openess that did not exist before . Bass is deep/ strong and effortless. The slightly recessed mid band is gone and is replaced with a vivid fleshy version.
Of course it would be very interesting to compare an upgraded and standard version as relying on our memories alone may not be as accurate as we would like. Even so , I’m confident the upgraded version punches above its weight . How much above it’s weight I don’t know as I have no idea what the other integrated amps sound like in the above £10k category

Item Repaired/Updraded:Nu Vista 800
December, 2022

Musical Fidelity M6Si

Just want to share my opinion with the upgrade of my amp – Musical Fidelity M6Si.
First of all – John Sampson is a brilliant tech-guy, he knows the MF products in details and knows their weakness.
After contacting John we clarified the upgrade – 10-15 emails and I decide to make upgrade Stage 3.
It took a little bit more time but it was worth the wait.
Now my amp sounds brilliant – more natural, more powerful, the sound is amazing!
It’s a keeper for a long time!

Petar Karageorgiev
Item Repaired/Updraded:Upgraded Stage 3
October, 2022

More musical

I got in touch with John for repair of my CD player which had stopped providing an audio output and decided to go for the Stage 1 upgrade at the same time. I’m very pleased with the improvement in sound quality. Although I’ve long appreciated the Musical Fidelity sound, the combination with my PMC speakers and M6i amplifier, (which had a Stage 1 upgrade before I acquired it) sometimes lacked emotion. Following the CD player upgrade the whole system now sounds a lot more musical and involving, it’s really unleashed the potential of my amplifier and speakers.

Kevin Stephens
Item Repaired/Updraded:Musical Fidelity A5 CD player
September, 2022

Bought back to life

John is an ex MF service engineer, I worked for the company during the latter years and I’ve always been a fan of MF kit. With the sale of the company I was unsure how legacy products could be serviced and repaired.
I knew of John’s work and how highly regarded his work is seen.
I picked up an A1 from ebay, I always wanted one and found one in great condition. The volume control became noisy and the input switch became very intermittent. I contacted John and his his advise was to upgrade and service.
I said to John I wanted to retain the amplifiers warmth and musicality, the upgrade is absolutely worth the investment, I feel I now have a brand new amplifier with the Tim de P designed circuit, what a transformation. Music has come to life, organic, musically and transparent.
I can’t recommend John highly enough, he has done a fantastic job from drop off to being sent to me.
He is a genuinely nice guy who absolutely knows his stuff.

Thanks John.

Dave Waters
Item Repaired/Updraded:MF A1
September, 2022

Musical Fidelity NuVista 800

Upgrade done in an extremely professional manner. All Capacitors replaced op-amps internal cabling and speaker binding posts replaced.

The first thing I noticed was that the sound is so much smoother; sounding much more like a single ended amplifier.
The smoother sound is not at the expense of information; far from it.

I can now hear when woodblock percussion is being used; the structure of the sound is quite clear.

When listening to solo male singers, there used to be an artificial zing associated with the male voice. Now the voice sounds natural as I would expect it to sound in a live performance without amplification.
Orff: Carmina Burana the dying swan is an example of this.
Imaging is great, and dynamics have improved. The Amp also seems to work better at a lower volume quite a surprise!
This amp now punches way above its weight a very relaxing detailed sound worth every penny.

Item Repaired/Updraded:Level 2 upgrade
July, 2022

A5 CD and A5CR pre

John completed a Stage 2 upgrade on my A5 CR Pre, I was using a Croft Micro 25R pre, sounded good but presented a vague and inconsistent soundstage. John assured my that the upgraded pre would bring everything into focus.. he was SO right. Next stage was to upgrade my aging A5 CD to Stage 2, what a revelation. I also have an Akurate spec LP12 and am really not sure if I prefer listening to CD of Vinyl now. In all my years of upgrading and listening to music I have never ever said that. The A5 CD is now simply staggering. John’s advice and guidance has been invaluable through my upgrade journey (he also did a Stage 2 to my 550k power amps a couple of years ago)
Costs have gone up, but the value far out weighs the money I have spend so I am a very happy man…

Item Repaired/Updraded:Upgraded
June, 2022

Musical Fidelity Fully Balanced Pre

You switch on the amp you’ve cherished for 11 years and after a moment it turns off and you have that sinking feeling. You take it to the local highly respected repairers and you are told that the main transformer has failed and they cannot get a replacement.
You then dredge from the back of your mind JS Audio and give John a call and with a reassurance born of experience John tells you he can fix and it can be upgraded as well.
So I’ve delayed writing this review for a month or so to let it settle in now that my Musical Fidelity A1 FB Pre is repaired and upgraded. All I can say is wow….
An example of the improvement is one particular piece where the singer is singing about a gypsy market previously I could hear there was the sounds of a market hiding in the mix, but now if I focus on the market I can hear what they are selling the clarity is so clear no mush. Doesn’t stop there though
Bass more tuneful more texture more bounce.
Treble is sweeter
It’s like every part of my system has been upgraded
so a big thank you to John, he is a magician.

Alan Webb
Item Repaired/Updraded:A1 FB Pre
April, 2022

Repair and Upgrades

If like me you are wanting the right person to repair your HiFi separates you have come to the right place, John is excellent. My Quad 405-2 amp went bang so I looked at Quad service reviews, they were a bit hit and miss. My Musical fidelity A3CD player was skipping so I searched for Musical Fidelity repair and found John with 100% 5 star reviews. I phoned John up and just talked about my requirements, there was no hard sell or pressure at all. I then decided to get John to fix the amp and CD player but also to do a stage 1 upgrade on my A3CD, Quad 34 control unit and Quad 405-2 amp. The amp had blown one of the mid/bass drive unit voice coils on my Spendor SP1 speakers and John recommended Wilmslow Audio who replaced the voice coils on both mid/bass units, recapped the crossovers and rewired the speakers with new binding posts. So, how does the system sound? In a word, unbelievable. Everything is richer, deeper and more detailed, it really is like having a brand new CD collection. On great recordings I feel like I’m in the room with the musicians, the sound is so life like. Thank you John for doing a brilliant job on my separates, the sound is high end, just as you said it would be!

Robin Taylor
Item Repaired/Updraded:Musical Fidelity A3CD, Quad 34, Quad 405-2
March, 2022

Stage 3 – Is there no limit?

So had to take my kW500 for a check as I had clumsily shorted an input terminal (with the volume still up!) Asked John if he could do the stage three upgrade which includes a new Alps pot and upgraded capacitors, well it just gets better and better!! The sound stage is even more defined, the separation is phenomenal. If you’ve got a kW500 then let John at it and be prepared for a very pleasing outcome! As ever Genius!!

Kevin Wood
Item Repaired/Updraded:KW500
March, 2022

Spectacular Delivered

Having had my MF A3 Dual Mono Pre amplifier upgraded in 2019 by John the difference in sound quality was immediately noticeable and improved even more over time. In the search of sound perfection John had also suggested at the time of upgrading my MF A3 power amp to increase the quality even more. The word “spectacular” was sown and stuck with me… move on and 2 years later… I bit the bullet and went for the stage 2 upgrade. Coupled with Monitor Audio Gold reference speakers I just cannot believe the depth of sound, the bass and tone across all the ranges is incredible, I have purposely waited three months before writing and again over time the sound just continues to improve, and is way beyond my expectations. .JS Audio truly have delivered “Spectacular” in every way. Thank you so much.

Stuart Duff
Item Repaired/Updraded:Musical Fidelity A3 Dual mono power amp
March, 2022

XA -200R repair & upgrade

Musical Fidelity XA-200R upgrade

It’s been roughly 3 weeks since I delivered by beloved but aged XA-200R down to JS Audio. I traveled back down to collect my amplifier, on the day after the very strong winds, that caused so much destruction around various parts of the uk. Little did I know my XA-200R was brewing up a storm of its own. When I got home and reconnected my amplifier I thought I would leave it fired up and go and make myself a coffee while it warmed up. The first few things I noticed while listening was a faster, deeper bass underpinning the other parts of the frequency range. Drums and bass guitar had another level of grip, speed and power that was not there before. All this was done while still sounding smooth and detailed. Instruments have taken on another level of clarity and separation. The image depth has now become so deep and wide, I am finding myself looking around the room to see how the percussionist, has some how managed to sneak into my house. The mid to high end has also emerged with a new lease of life, seeming to sound louder and more enriched with musical detail. I am not sure what John has done with my old amplifier, but the new addition is far better than the old. It’s almost like he’s given my amp a big sprinkling of magic fairy dust. My biggest problem now is what to upgrade next. X-Ray CD or my XA-200 power amps. Any help will be much appreciated.

This is the first of two upgrade reviews I am going to do. This one has been a next day review. My next will be either two or three months from now to see if the improvements continue.

John, thanks for the fantastic work you’ve done regarding my XA-200R amplifier.

Item Repaired/Updraded:XA-200R upgrade
February, 2022

Wow – Musicality discovered

It was by complete chance that I discovered John. I didn’t own MF gear, but heard of John through my brother. My Cyrus pre/power amps just weren’t doing it for me. I didn’t have any gear to upgrade, but instead called John for advice on how to proceed. John was absolutely fantastic and advised on the best way forward for my budget.

After some searching I now have an XP100 pre amp and an a3cr power amp. Both have been expertly upgraded by John and are a mind-blowingly good combination. The upgraded MF pre/power combo cost half as much as my old Cyrus pre/power and completely embarrasses the Cyrus. It’s frankly not even close – the JS upgraded MF amps have introduced me to a quality of music that far surpasses the Cyrus kit.

It’s fair to say the the XP100/a3cr improve every aspect of sound quality… Big, wide and deep soundstage and a realism I never thought possible with my budget. The music is so organic and natural. I’ve been into music and hifi for nearly 30 years and I can honestly say these MF amps are the first time I’ve stopped listening to my HIFI! The musicality is incredibly good and I just find myself getting lost in the music! That is some achievement – Thank you John!

Jason Darke
Item Repaired/Updraded:MF XP100 Pre/a3cr Power
January, 2022

MF A100 – upgrade MAGIC!

As I wrote to John soon after getting my refurbished & upgraded Musical Fidelity A100 back earlier in the year, it was magical, but now it is exceptionally so! It runs quietly & so much cooler. It was hot & noisy 32 years ago, so a huge improvement! The sound is incredible & I have never bothered to turn my REL subwoofer back on. It is like reviewing a new collection of music with everything sounding more musical & exciting. Friends are dumbfounded at the sound coming out of my small but trusty Quad 77-11L speakers set on custom wall brackets. I could always drag my transmission line TDLs out of the loft, but quite unnecessary. Happy times are here! Thanks John.

Chris Tween
Item Repaired/Updraded:Musical Fidelity A100
October, 2021

Musical Fidelity Amp Upgrade

V Old , but much loved Amp & Pre amp. When the Phono Chanel went , I knew it was a time for repair or replace.
I chose repair / Upgrade and am very glad I did.
Amazing Clarity – smooth smooth sound with loads of definition.
I am now re-listening to my entire music collection to pick up on all the bits I was missing before. Txs Andy

Andy Burdon
Item Repaired/Updraded:3A & P140
September, 2021