If you love classic hi-fi gear and neat repair work, you’re probably not going to love what you’re about to see. Sorry.

Welcome to the hi-fi repair Hall of Shame. As far as I know, this is the only resource dedicated to documenting bad repair work done on hi-fi equipment. It is also uniquely presented by a technician specialising in exactly the sort of equipment seen here, but repaired with precision rather than – well, you’ll see…

Speaking with colleagues, I believe crappy work is a ‘dirty little secret’ of the electronics repair industry. It seems that many have known of these bad actors for a long time and perhaps not had the time, energy or means to do anything about them. I don’t have the time either, but I most definitely have the energy and means.

Updated, September 2021

Dirty Harry

In an ideal world, everyone would be good at what they do. We don’t live in that world and, whilst some individuals are really good at what they do, some are appallingly bad. Few have any idea of the damage that can be inflicted by the wrong electronics repairer for example, and why would they? There’s almost no way to see the sort of poor workmanship that destroys electronic equipment. No way that is, until now.

Everyone’s good at something. But, as ‘Dirty’ Harry Callahan observed in Magnum Force:

“A man’s gotta know his limitations.”

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As a warm-up exercise, try to spot everything wrong in this picture.
bad quad 405 repair
What not to do to a Quad 405-2 amplifier. At the risk of overstating the obvious, when selecting parts, one should choose correctly sized capacitors and clamps. You could make spacers for a small gap between the two, but stuffing the 10mm gap resulting from poor parts selection with beer carton cardboard, whilst amusing, is not acceptable. The capacitors will move, maybe even fall out, and the work looks absolutely horrendous. Whoever did this left the original board-mounted ERO electrolytic capacitors in place which was also a mistake. The most astonishing thing though is that they gave it back to the customer, looking like this.
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By contrast, this is my work on a customer’s Quad 405-2. Note the lab-grade filter capacitors, correctly-sized (though not yet tightened) clamps, neat wiring, solder tags, retention of the factory looming etc.

Ideally, the Digitech multimeter wielding inepts who did this stuff would accept their limitations and remove themselves from the industry. The problem is they don’t. Some have been run out of town and others may vaporise themselves, Darwin Awards style, but others stumble on, helped by the fact that potential customers don’t know any better. Let’s try to stop them.

“But Mike, if this equipment works, who cares if the work looks bad?”

Nope, none of this gear works properly and much of it has been ruined, beyond economic repair. Unsurprisingly, the owners care a lot about this.


These guys are often keen to offer ‘quotes’ without seeing equipment or identifying faults, so they can get hold of your gear. They often promise unrealistically low prices, they are usually not busy, eager to take your equipment and might promise quick turnaround times. Sounds great, doesn’t it?!

Well, a technician is only as good as his tools and these tools say a lot about how someone thinks and works. These folks rarely have anything of value in terms of hand tools, soldering equipment test and measurement equipment and so on. It’s usually the cheapest rubbish.

A good Fluke handheld multimeter is $600 – $800, vs $20 – $50 for the cheapies. I’ve got six Fluke handhelds. The calibrated Keithley bench DMM in my lab is worth $4000. Tektronix or Keysight oscilloscopes I use cost anywhere from $2000 – $10,000 new. A crappy Chinese scope might cost $300.

Even carefully staged photos of test gear may only contain crappy gear if you look closely. Contrast this with the image below for example, with about $20K+ of visible test gear and much more you cannot see.


For most, the idea that it’s worth paying just a little more for the right repairer makes sense. The people you want looking at your hi-fi gear have invested in education, equipment, calibration, parts, tools and these things are part of running a better business.

Think of it this way: Most bakers can bake a loaf of bread. Prices range anywhere from $1 to $10+ a loaf. Flavour ranges from zero to delicious. Price, effort, flavour and quality are pretty much directly correlated. The best bakers use experience, equipment and ingredients to bake the best bread and this pans out across various technical fields.

I’m not saying you should only consider the $10 loaf, but you get what you pay for, with bread and people. Ask around, find out who’s busy and who people who know a thing or two recommend, including hi-fi stores needing reliable repairs.

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My expression upon seeing work featured in the Hall of Shame…😂

You may be wondering if anyone featured here in the Hall of Shame has reached out?

  1. Trevor Lees, the vapid and deceitful retailer featured in Krell KSA-150 in case number 6, threatened legal action if I didn’t take down my video about the case. Mind you, he admitted authorising the shonky repairs, misrepresenting the condition of the equipment and fraudulently claiming he originally sold the amplifier new, so there’s that. Peter, the technician who actually did the work contacted me and tearfully apologised for the poor workmanship, apparently done under duress. That video now has over 100,000 views.
  2. The technician who destroyed the Krell KRC HR in case number 4 may have contacted me. Maybe I’m getting paranoid, but I reckon this guy called me.

Ethics & Responsibility

I’m passionate about keeping hi-fi stereo equipment alive and well. Amusingly, I’ve been accused of running a “hatchet job” on repairers featured here, you’ll see why that’s funny in a moment. If true it would of course mean:

  • I have no idea what I’m talking about
  • That the work you are about to see is actually fantastic


If you are absolutely sure you want to put your name to that assessment, be my guest. I’ll even give you a mention here if you are brave/stupid enough to do it. Just a heads-up though: someone will look stupid, and I promise it ain’t me.

Take a look around and see if you honestly think any of this is good work. No person of sound mind could assess this work as acceptable. No, the hatchet jobs were done by these bad actors on this equipment. More fool anyone who pretends otherwise.

Keep in mind that it’s often the repairers who should have initially looked at equipment like this who are left to clean up the mess. I’ve had to pass on the bad news to the owners for example and try to calm them when they realise their equipment has been destroyed, beyond economic repair.

I don’t like seeing people ripped off and equipment destroyed and I’m sticking my neck out to educate people about these issues. Before you accuse me of running a hatchet job, what are YOU doing to help the hi-fi community..?


All images on this page belong to Mike @ Liquid Audio and Jason @ The Speaker Doctor. Observations are my own and I’ve condensed and sanitised Jason’s thoughts where necessary. I’ve avoided using real names.

PS: Get in touch if you’ve had hi-fi equipment bodged or destroyed and you’d like to share the details.

Hall of Shame Case Files

The cases listed are linked to the details. Just click and prepare to be shocked!

10 – Gryphon DM100 Class-A Power Amplifier
9 – Pioneer PDS-507 CD Player
8 – MAS Solitaire Power Amplifier #2
7 – MAS Solitaire Power Amplifier #1
6 – Krell KSA-150 Power Amplifier
5 – Marantz CD85 CD Player
4 – Krell KRC Preamplifier
3 – Harman/Kardon PM-655 Integrated Amp
2 – Perreaux PMF 3150 Power Amplifier
1 – Kenwood KA-5700 Integrated Amplifier

Case 10 – Gryphon DM100 Class-A Power Amplifier

This is another of those sad stories that force you to drop your head to your hands, Patrick Stewart style. I’m sorry to have to say this but the owners of equipment like this stunning Gryphon DM100 bear at least some responsibility for who they take their equipment to.

Note that I’m not blaming the owners for what happened, but as I mentioned, we all have to exercise discretion and in this case speak to a few people, get some perspective, talk with respected repairers who work on this sort of equipment.

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How I felt when I saw what you are about to see, and heard how it happened.

In the case of high-end equipment like this, it simply MUST go to a competent, well-regarded repairer. By that I don’t just mean someone who has a website and a few Google reviews, I mean someone who people know can tackle gear like this. Sending equipment like this to a TV repair guy or outer suburbs ‘electronics guy’ is like taking your Ferrari to the local petrol station. It’s just not a sensible idea and will only ever end badly.

To most people all of this seems obvious, so the bigger question is: how does a stunning, rare and irreplaceable piece of Danish hi-fi history end up with a repairer in the boondocks anyway? In most cases, it’s because someone was trying to save money, or a repairer misleadingly said they could fix it, no problem, it will be easy, blah, blah, blah.

How this ‘saving money’ equation makes sense to anyone is beyond me, but sadly it’s common. I’ve had customers baulk at spending a few hundred dollars on a Krell preamplifier repair. Oftentimes people just don’t want to spend money, even on a $50,000 amplifier. Yes, this is patently ridiculous, but I’m sure most of us have seen a Rolls Royce at Kmart Tyre and Auto.

People actively make these decisions. One can only educate and perhaps influence things a little, by raising awareness with pages like this. Being misled by a repairer is inexcusable though and if that happened here, that person deserves to be named and shamed.

I’m sure the guys at Gryphon aren’t amused. Sorry guys, I really tried with this one and lost money on it too.

Gryphon DM100
A plan view of the stunning Gryphon DM100 in my workshop. This is a high-resolution image, so zoom in and try to find all the missing fasteners, disconnected wires etc. I know what you’re thinking: “But Mike, surely there was a bag containing all the critical fasteners etc..?” No. There wasn’t. Why keep all the critical fasteners..?!

Speaking of Krell, Gryphon is a Danish high-end hi-fi equipment manufacturer, one of the best-regarded in my opinion and a company that produces some really stunning gear. For me, they are a Danish Krell, if that makes sense. Similar design ethos, similar build, a similar need for the right attention and maintenance.

The Gryphon DM100 is, without a doubt, one of the great class-A power amplifiers. It weighs 76kg or 168 pounds. It was Gryphon’s first power amplifier and a true statement piece. As such, it’s a rare piece of audio and Gryphon history. You can read more about it here, and here.

It’s a minimum two-man lift and, if you read my articles, you’ll know that means something. These amplifiers are a $10K seller all day long. Replacing it would set you back $50K+, and for that money, you’d likely end up with something not as good as this beautiful old girl.

I thought my old Krell KSA-150 class-A amplifier was a beast. It was, but this DM100 goes to 11. You can probably see where this is going.

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Just look at the beautiful wiring, RIFA main filter capacitors, high-current cable, Torx fasteners, bus bars etc. RIFA makes the best electrolytic capacitors you can buy. Aerospace-grade. This is how you do a power supply.

I’ll never understand what drives someone who owns hi-fi gear like this to take it to a Shitsville repairer. As I said, it’s probably a combination of ignorance and an attempt to save money, but honestly, when you own gear like this, neither are entirely acceptable excuses. As an owner, you have a responsibility to care for a piece of equipment like this.

When you see what was done to this stunning amplifier, you’ll appreciate the irony of trying to save money repairing it. Far from saving anything, this cost someone. BIGTIME. This amp is effectively a write-off and Gryphon didn’t make many of them. Not exactly a money saver, when you look at it. All that needed to happen was for it to go to a careful, skilled repairer in the first place.

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This is the right driver board from the DM100. It has been butchered. I focussed on this board initially as we needed service data, which I eventually obtained. The correct functioning of this board is critical, but having spent some time going over it, I realised that it was already probably a bridge too far.
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Sigh, where do I start..? Replaced TO-220 devices with shorted leads, how was this supposed to work? Bueller..? Mr RadioFreakinWaves told my customer that this channel had issues. You don’t say. I’m not quite sure how this driver board could run like this, or why anybody would attempt to run it, looking like this. That’s the biggest red flag here. Powering the amplifier on with a driver board in this state is like starting an engine with no oil in it. You JUST WOULDN’T DO IT if you had even the slightest inkling of what’s going on. Do you see where I’m going with this and Mr RadioFreakinWaves…?
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I’m sorry, it’s just too much.
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Sorry about the lack of focus, but COME ON – the soldering?!!! Just look at the soldering! Look at the transistor legs, top left. I’ll say it again: irreplaceable board, irreplaceable amplifier…
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I don’t know why you would place this ‘repair’ bodge on the top of the board. For those wondering, yes, the trace on the bottom was vaporised. You can still make the repair on the trace side, solid wire is good for that. Who cares about soldering properly though, when you work like this, soldering technique is obviously not something you can just tap into. Again: irreplaceable board, irreplaceable amplifier.

The last repairer this went to before I saw it – Mr RadioFreakinWaves – is featured elsewhere on this page and I’ve worked on many pieces he has damaged. It apparently also went to a semi-country repairer, and/or a ‘guru’ in the Perth hills, or both. I don’t exactly know. I really tried to find out but just couldn’t get clarity on this. I asked a lot of questions about this one.

The current owner swears Mr Radiowaves didn’t do the damage and really tried to convince me of that. I’m not sure what that was about. Maybe it was the Buzztronics boondocks guys, maybe it was Mr RadioFreakinWaves, I just don’t know who to believe I’m afraid. But somebody actually did this, that we know. I want to know who, because everybody deserves to know that. Why are people so reluctant to speak the truth I wonder…?

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Sadly, this sort of thing was everywhere I looked inside this DM100. After seeing just how trashed just this driver board was and realising that the critical board-to-board and chassis fasteners inside the amp were missing, I called time on this one. These missing fasteners which carry power, the disconnected and unmarked wiring, blown-up and kludged repairs, lack of notes and lack of a full set of service data made this a war I just didn’t need to fight. I spent several hours on this and only charged the customer for an hour of my time. I felt bad for him, but cases like this take up a ton of MY time and leave me with nothing but bad news to pass on. Difficult for me to win in cases like this.


The moral of this story?

DO NOT take beautiful, high-end hi-fi gear to cheap repairers, VCR and TV guys, gurus, people who make their own ‘brand’ of homemade amplifiers, etc. It’s NEVER worth it, it only ever causes problems and in this case, it has written off yet another stunning piece of equipment. This amp carries a $50K+ replacement cost. Seriously, was it ever worth trying to save a few hundred bucks? Come on.

For reference, if a repairer seems too eager, not busy enough, not in possession of the right equipment, or unable to converse fluently on the topic of repairing your equipment, read between the lines and find someone else. There’s a reason why the people who should look at this are busy.

Nobody can quote you upfront on a job like this. Nobody who knows what they are doing would say they don’t need service data or factory support for a repair like this. Nobody competent would suggest this job should be straightforward. If someone gives you the impression that fixing an amplifier like this is easy, walk away.

AGAIN: Don’t take your Porsche to the local garage, don’t take your Rolex to a shopping centre watch booth and DON’T take your Gryphon amplifier to Buzztronics. EVER.

Is this amplifier repairable? Sure, given enough time and money, almost all gear is repairable. The key is to find someone willing to take it on despite all that’s happened to it (I’m not) and someone willing to pay for it (the current owner is not).

There’s obviously more to this story but I lost enough time and money on it, digging around, trying to help the owner, billing him a pittance and receiving little appreciation for it. Ultimately, my job is to educate and offer sensible advice. It’s more than most are doing and I can’t do much more than that!

Case 9 – Pioneer PDS-507 CD player

This is another sad case, likely perpetrated by a local tinkerer named Clifford, or Pat. Both are known in the ‘scene’ here in Perth, so local readers may know who I’m referring to here.

On the surface, we have a perfectly nice and quite classic Pioneer PDS-507 CD player. These were good machines, nice transports, but often people tinkered with them and installed clocks, regulators and other bits and pieces, usually pretty terribly. Such is the case here.

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Underneath the hood, all is revealed…

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The less said about this the better. For laughs, note the scratched off label on the integrated circuit, just so you can’t copy this amazing piece of engineering! The board was loose and needed securing to avoid the risk of shorting something out.

Quite honestly, you couldn’t build something much worse than what you see here. Well, excluding the Marantz CD player mod in case # 5, which is actually worse!

Big globs of solder, crappy little wires holding a heavy board in place, burn marks. I know some people think work like this is ‘cool’ but really it’s not. I secured the board with some decent hot glue and told my customer two things:

  1. Stop going to ‘gurus’ for work like this. This sort of nonsense wastes time, money and devalues equipment.
  2. Don’t shake this CD player around too much!

Now, for the record, I’m not against modifications and improvements. On the contrary, I support well-engineered improvements to hi-fi equipment, but if you can’t do the work neatly and safely, get someone else to do it.

Case 8 – MAS (Metaxas) Solitaire Power Amplifier #2

It’s probably best to check out the first MAS Solitaire I looked at from this pair of beautiful amplifiers before checking this story out. I won’t go through the details again, but you can read about the first Solitaire in Case 7.

This is the second amp from the pair. The owner was sure this one was OK and it looked good from the outside. Sadly, it was as bad or worse than the first one, truly diabolically butchered.

MAS Solitaire
Beautiful amplifiers from the outside aren’t they?

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Sadly not so beautiful inside, at least not this poor Solitaire. Let’s examine some of the issues.

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Try to spot the problems here first in this overview image. One thing of note that appeared in the first of these amps is the non-matching devices in each channel and the way the leads are offset with respect to the board.

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OK, so let’s start here. This was a TO-18 device, part of a complementary transistor pair. When you replace one device with, in this case, a different TO-220 device, you HAVE to replace the complementary device. These two transistors are mismatched and can never work properly together. Also, it’s necessary to use a heatsink that suits the transistor package. So, a TO-220 heatsink should have been used on this odd TO-220 device. Instead, this lazy repairer simply clamped the old TO-18 heatsink onto this new device, guaranteeing that it will overheat, short against something or fall off.

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Another view of this appalling work. Note the dead cap in the foreground. “But Mike, why didn’t you replace the dead cap..?” This cap is the least of our concerns!

Apart from the obvious butchery here, the soldering and general filth are unbelievable, aren’t they? Honestly, as I put this case together, I can hardly believe what I’m seeing, and I’ve seen it all before!

Right, what’s next…

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Oh, that’s right, how about this. Lifted components, damaged traces, non-complementary devices, cut leads, near shorts, dust…
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Another view. Look at the right-most (base) leg of the 2SC2344. Is it about to short to the collector, the pin next to it or is that a trick of perspective? Who cares, what even IS that thing sticking up out of the board and connected to that base? By the way, I’m sure you’ve spotted that the 2SA985 and 2SC2344 are non-complementary devices. The 2SC2344 is non-branded, it should be an NEC 2SC2275. Failing that, a different complementary pair, from a decent brand, with similar specs could be used. I have several options here in stock. You’d also hope that the collectors of the TO-220 device and the output device right next to it that are almost shorted are at the same voltage! They probably are, but if not, that’s another issue.
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Mixed resistor and transistor types, nothing really matching.
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A better view of what I noted earlier – skewed output devices, destroyed pads and traces. Honestly, it’s a disaster.

So, that’s it for another case of amplifier butchery. This is disgraceful work, there’s no other way to put it. The person who did this had no business working on an amplifier like this, pure and simple.

People ask why I don’t fix amplifiers in this condition. The amount of destruction and introduced faults make it so hard for anyone else to go in after and fix things that the pain is just too great. I could spend a week working on this, researching and locating parts, repairing damaged traces, sourcing NOS bits. Maybe it still wouldn’t work? Quite frankly, in some cases, the gear is past the point of no return.

Case 7 – MAS (Metaxas) Solitaire Power Amplifier #1

Sadly, we have another case butchered by a technician back in the heyday of hi-fi retail. Given my updated knowledge of the pedigree of this amplifier and its partner, the work appears to have been done either by Vince Ross’s old technician or by Robert Regal, another diabolical repairer from back in the day.

This amplifier came to me for repair, but my first look told me everything I needed to know about my chances of success on this otherwise stunning amplifier, designed by the legendary Kostas Metaxas.

The MAS Solitaire is an extraordinary amplifier. With a claimed slew rate of 1000V/uS and outrageous styling for the time, this is a super-fast, wide-bandwidth amplifier, with power, stunning looks and premium parts. People rave on about ME, but ME gear has back-yard build quality compared to this beauty.

BUT, when you repair a MAS Solitaire using crappy tools, crappier parts and zero care, this is the inevitable result. The mainboard is too badly damaged and too many crappy parts have been installed to make working on this one viable. Someone might like to try, but not me. It’s a real shame, a sad end to this otherwise lovely unit.

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Lovely looking amplifier, huge filter capacitors. The problem is that one of them was loose, help in by finger-tight fasteners!
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It’s a beautifully laid out amplifier. The messy component dress you see here is because the tech who worked on it pulled virtually everything out and then didn’t or couldn’t solder it all back in again properly. Many small parts have been replaced.
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What IS this? note the damaged trace on the emitter of the 2SC2238, the weird angles of the devices, bent legs, tabs nearly touching, etc. Nothing in this picture is good.
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These bodge wires are not from the factory. Whenever you see wires like this, you know someone damaged something. Factory bodge wires look different.
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These devices have all been replaced, very badly. Note how the mica thermal pads overlap – a disaster for heatsinking. Note also that there is no thermal paste or grease. Cue my previous observation. As for the misalignment of the legs, I can only assume its because he’s used devices different from the originals or he’s misaligned the mainboard and heatsinks? I really don’t know.
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When you replace transistors in a super-high-speed amplifier, why bother using closely matched parts of the same type, as the manufacturer requires..? And hey, why not just bend all the legs, misalign the circuit board and heatsinks and overlap all the thermal pads for good measure..!
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Damaged pads, untrimmed and even unsoldered legs. Yes, this is real.
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I can only shake my head. The owner was gutted to hear about this.

Luckily, the owner has another MAS Solitaire, and it is now with me for service. Let’s see what a good one should look like, stay tuned.

UPDATE: See case # 8, the second MAS Solitaire. It’s no better, could almost be worse. Whoever did this worked on both amplifiers.

Case 6 – Krell KSA-150 Power Amplifier

This classic case fully warrants its place in the Hall of Shame. I bought this amplifier many years ago from a hi-fi dealer in Australia called Trevor Lees. Trevor is unhappy about being featured in the Hall of Shame but you reap what you sow as they say.

Over the years, I’ve been contacted by numerous people in relation to this case, telling me their own stories of woe about Trevor Lees. Incredibly, the technician who did this awful work contacted me directly to apologise. I felt bad for him because he explained that he was always pushed to repair things on the cheap. That’s definitely evident here.

Case 5 – Marantz CD85 CD Player

Check out this modification abomination that rendered a wonderful old Marantz CD player unserviceable, cementing its place in the Hall of Shame.

The obvious question here is why? It’s hard to know, but I’d suggest the perpetrator read about improving the clock on a forum and failed to understand that the way you do something is actually more important than what you do. Equipment can often be improved, but not like this.

CD85 internal 1
This is how the insides of a CD85 should look. Things are neat, tidy and serviceable.

CD85 internal 3

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The insides of the modified Marantz CD85. Note the home-brewed, hardwired PCB at the bottom left, transparent additional panel and bird’s nest wiring. This is a complete disaster.
IMG 6022
Here’s a closer look at this home-brewed board. Note the extreme home-made appearance, but wait until you see how it’s attached…
IMG 6023
Even closer. I know what you are asking – “Mike, what does this do..?” In truth, I don’t know. It could be some sort of additional power supply, or maybe a new crystal oscillator.
IMG 6028
Here’s a clue – an ovenised crystal oscillator on the underside. This board is probably a clock module.
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Check out the build quality though and how it is attached to the transparent cover. Is that chewing gum holding a wall plug as we call them in Australia? Is that more chewing gum under those capacitors…?
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Chewing gum, or Blu Tac. Someone actually did this and thought it was a good job. I’m told the work was done by “an expert in CD player modification”…
IMG 6029 e1563683868397
Some sort of hot glue or epoxy perhaps, covering these resistors.
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And for safety, the voltage selector has been left hanging inside the chassis, where the pointer no longer refers to any particular position. What voltage is this set for..?

Case 4 – Krell KRC Preamplifier

This one hurts the most and is the single worst case here and the one most deserving of its place here in the Hall of Shame. My good friend Jason @ The Turntable Doctor shared this case with me and we’ve talked about the need to get the story out. Read on, because you won’t believe this one.

Krell KRC HR 1
This is the complete package – a Krell KRC-HR in this case, including separate power supply and remote control. From the outside, both KRC and KRC-HR look the same.

There’s a repairer on the east coast of Australia we’ll call William ‘Frampton’. No offence to the great Peter Frampton, but change one letter and you have this guy’s last name. Anyway, ‘Frampton’ supposedly improves hi-fi equipment, so a Perth local sent his cherished KRC-HR over to him. Here’s what happened.

First Signs of Trouble

When the customer eventually got his preamp back, neither the preamp nor the Krell remote control worked properly. He found a cheap Chinese remote control included in the package and when pressed, Frampton informed the owner that he had ‘upgraded’ the volume control and included an ‘improved’ $6 Chinese remote control to replace the clunky old machined and anodised aluminium Krell remote… Classy.

Oh boy, try to stop me writing the rest of this…

The Krell KRC is a superb preamp. If you want to see more, check out my KRC-HR restoration. Costing over $10,000 AUD in the mid-1990s, there aren’t many improvements you can make to a preamp like this and any real repairer would know enough not to try anything silly.

The KRC and KRC-HR use logic-controlled stepped resistive attenuators for volume control. This the best way to control volume. The attenuator uses an array of 0.1% precision laser-trimmed resistors, an optical encoder, CPU and switches. The signal is routed through expensive nitrogen-filled relays.

Let me be clear – you cannot upgrade this volume control – period. Krell did the engineering and it’s for us to try to learn something from it. It’s outrageous and foolish to think that you could improve the volume control implementation in this preamp.

Wanna see some REALLY bad repairs? Let’s go.

A Normal Krell KRC

This is what a Krell KRC preamp looks like. Check out this article where I completely restored one of these beauties.

IMG 6654
Note the uppermost board, with the rows of chips, precision resistors and relays. Note also the volume encoder, top left. Spinning the encoder generates a series of pulses. These pulses are read by the CPU, which instructs the IC switches to select the correct resistor string to produce the commanded volume level. This is precise volume control, it cannot technically be improved. Typical of Krell, there is very little wiring and there is NO FLUX RESIDUE!
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Standard, unmodified Krell KRC. Dusty, yes, but see how all the capacitors fit correctly and how neatly they are installed.

The Frampton Krell KRC…

Let’s take a look at the ‘improved’ KRC, after some bad repairs by Mr Frampton. We’ll start with the preamp and then look at the power supply.

IMG 6502
Yes, this is the very same model. The entire precision attenuator board is missing. In its place is a Silicon Chip remote control volume kit – that’s the smaller green board and cheap ALPS volume pot. Note also the maze of ribbon cable, the bodged in resistors and replacement caps that are too tall and poorly soldered in.
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This is not a joke, someone actually did this. Note the vaporized traces, appalling soldering, heinous flux residue and dumpster-dirty circuit board. This is an absolute disgrace, seriously, this is the worst work I have ever seen.

Frampton probably destroyed the precision Krell volume control board by accident. Nobody of sound mind would assume they could ‘upgrade’ it, let alone try to.

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With the top board vaporized, this guy had to bodge all the top row of board mounted connectors to the bottom board.
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This is, without doubt, the worst work I’ve ever seen. Sweet Jesus, this is bad.
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Note the leftmost component lead of this capacitor doesn’t go through the board as it should and is barely soldered to the top of the board. These are multi-layer, through-hole plated boards. Components need to have their leads inserted into holes on a board like this to guarantee correct connection.
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Let’s take another look at this Silicon Chip remote volume control upgrade. Again, no sane person would consider this an upgrade.
IMG 6544
This replaces a CPU, switches and network of super-precision 0.1% metal film resistors. Why use precision parts when you can use the Studio Series Control Module with Chinese low-precision capacitors and resistors..?
IMG 6511
Transistor and ribbon cable bodgery. Note the bodged blue relay. This replaces one previously on the top board.
IMG 6512
Almost everything here is ruined. This preamp was someone’s pride and joy. What you see here is the total destruction of a beautiful and irreplaceable piece of equipment.

When asked how he could possibly have produced work of this standard, Mr Frampton cheerfully replied that he “taught this stuff”. Yes, he said that. I’d ask for a different teacher, kids.

IMG 6520
These caps are too tall, the values are wrong and they are soldered in so badly, it looks like a child did it. This guy teaches soldering..?  Heaven help us.
IMG 6521
More evidence of something blowing up and nasty repairs.

The Power Supply

Let’s take a look at bad repairs in the KRC power supply.

IMG 6523
Not much to see from a distance other than a beautifully laid out symmetrical power supply.
IMG 6525
Look more closely – what is this? Well, what it isn’t is a voltage regulator, which should be there, mounted to this heatsink. Why mounted to a heatsink? Because it dissipates thermal energy, which has to be removed.
IMG 6526
Ah, here it is, with some random diodes and a Lelon cap. No need to use the heatsink, of course, Krell wasted their time with that. This component will die and I’ve never seen work this bad – ever.
IMG 6531
Nothing lines up and look again at that voltage regulator. Easily the worst workmanship I’ve ever seen.
IMG 7052
Once more, because I can’t believe it…

Mr Frampton likely blew up the power supply by shorting something in the preamp. Here’s more evidence.

IMG 7055
There isn’t meant to be an insulating sheet under this board-mounted transformer.
IMG 7063
Nor should there be residue like this.

IMG 7064

IMG 7085
The mains wiring isn’t meant to be tacked onto this point here under the transformer. He’s done this because he vaporized more traces in this power supply.
IMG 7086
Bodgy wiring
IMG 7071
Another bodge
IMG 7075
And finally this. What is this? Again note the woeful soldering and what appears to be a shorted pair of legs on this device.


After the unit was assessed here in Perth, the owner contacted Mr Frampton. Frampton was unapologetic, explaining that he ‘improved’ the volume control (yes, he said that). Helpfully, he explained that the attenuator board ‘broke’. He also explained that parts were no longer available from Krell (they were, we checked).

I guess that by saying the volume board ‘broke’, he meant like when you spill petrol on your hot lawnmower and it ignites, ‘breaking’ it. Perhaps it’s like when you drive your car into a wall because you are looking at your phone and ‘break’ the car…

Anyway, Frampton offered to fix the preamp (it cannot be fixed). Against the strongest advice, the owner sent it back. He’s not seen it since. The moral of the story, don’t EVER take hi-fi equipment to this repairer.

Case 3 – Harman/Kardon PM-655 Integrated Amplifier

This case of bad repairs came to me in February 2018. My customer bought this new from Vince Ross Audio, back in the day.  It worked well for years until it developed a fault.

img 8859
Nice amp the PM-655. From the outside, all looks normal.

Vince used a repairer called Klaus, you may know of him. He worked on a lot of gear, sometimes successfully, other times not. This case falls into the not category. I should point out that Vince is a lovely guy and used this repairer in good faith. This repairer likely did good work at some point, I don’t know how it came to this.

Anyway, this repairer destroyed several boards in his attempt to repair a volume control. He used the lowest quality Jaycar volume pot and ribbon cable and destroyed traces associated with the front panel controls, many of which no longer work. I found horrible flux residue everywhere due the lowest-quality solder and failure to clean up. Needless to say, the volume control never worked properly after this.

It does now, I had a look and did my best to rectify this appalling mess and make the amp reliable for my customer. I serviced the unit and fixed the volume problem. Needless to say, the owner was horrified to see these images. He confirmed for me that it had only ever been to Klaus.

Bad Repairs…

img 8860
A closer look after removing the lid reveals this mess. Flux residue everywhere and this is just the beginning.
img 8862
This is the bodged volume control repair. Note the cut quality factory wiring loom, and the shitty, bodged in ribbon cable, just tacked onto the underside of the board. One question – WHY??
img 8864
This is an abomination. My soldering at 16 years of age was ten times better. Who would leave a job like this??
img 8865
Look closely at the joints
img 8866
This is appalling, note the unsoldered joints and mass of flux residue. This job should never have gone back to a customer like this.
img 8867
Note the cut trace ‘bodges’ here and general mess. This I think was in an effort to fix the mess he’d made of the front panel controls.
img 8868
More shoddy work
img 8872
This is how the boards should look. You’ll note I’ve cleaned away as much of the mess and re-worked many of the joints.

Case 2 – Perreaux PMF 3150 Power Amplifier

This addition to the Hall of Shame is another case from my friend Jason (Speaker Doctor and Turntable Doctor).

img 9584

This amplifier came to Jason for repair. The owner bought it for $900, from a guy who ‘upgraded’ it. You be the judge on whether these are upgrades…

Bad Repairs

img 9574
Interesting… What does this do?
img 9575
Panasonic FC caps in the foreground, but what the hell is that behind them?? It looks like an attempt at a soft-start circuit, you can be sure it didn’t leave the factory looking like this.
img 9576
We couldn’t fathom the logic of installing a 40 Amp poly switch in series with the outputs. It will sound really bad and it trips at 40 Amps. What sort of speakers did this guy think needed protection, only once the output current reached 40 Amps? 40 Amps!!! So 30 Amps to the speakers was OK, just not 40 Amps..?!
img 9577
It’s surprising this amp ever even turned on. What a mess.
IMG 1736 e1527298654571
For reference, this is what SHOULD be there in the image above. This is a power distribution board, with factory Perreaux caps, small diodes, bleeder resistors and wiring. I guess the idiot who removed this knew better than Perreaux’s own highly regarded engineer Peter Perreaux! If only Peter had asked this guy how to improve the 3150… NOTE – the factory Hitachi MOSFETs in this standard image on a non-destroyed 3150.
IMG 1768
Now look again at this mess. Note the missing factory power distribution board, the bird’s nest of crappy wiring and the non-factory MOSFETs. This last point is critical. The amp has non-standard and unmatched replacement output devices. These are different from the factory Hitachi devices and, whilst they will work in this role and they are MOSFETs, when you add up all the work needed to rectify what you see here, this once great amplifier is now technically a write-off.
img 9578
Nothing about this wiring is OK.
img 9580
Ummm, what IS this??
img 9582
A recipe for poor sound quality

Case 1 – Kenwood KA-5700 Integrated Amplifier

This lovely little amplifier came to me via a very nice customer. She’d taken this otherwise good amp to a local repairer. You can see from the images below that the repairer has ‘upgraded’ this circuit board to include a special short-circuit that prevented the amp from working properly.

img 9473

My customer took the amplifier back to Mr Radio Waves. He had the audacity to say that the unit is too old and damaged to be repaired! But he did the damage!!

Thankfully, this lovely customer brought the unit into me and I’ve repaired it. The KA-5700 is now working perfectly, though a little worse for wear after its near-death experience at the hands of Mr Radio Waves.

Bad Repairs…
img 9460
Everywhere this guy removed capacitors, he damaged the board. He didn’t even clean away the flux, nor did he properly repair the parts of the board he damaged.
img 9467
Here, you can see the same area after I re-worked it. Given the damage, its a solid, reliable repair.
img 9461
What on earth is going on here..?
img 9462
Lifted traces…
img 9464
General bad repairs bodgery caused by poor soldering and desoldering tools and technique, leading to bad repairs.
img 9465 1
This image is most alarming. It shows repair work this guy did to rectify the damage he caused but this caused a short, where this wire jumper sits right next to these two other pads. Note that the destroyed pad is floating on the board, shorting a line next to it.

This Post Has 23 Comments

  1. More Anon

    OMG, that Perreaux. Shocking.

  2. Mike

    I didn’t think my amateur work was that great but after seeing these horror stories I don’t feel so bad !
    I think I might cry if some of my work looked like these examples.

    1. Liquid Mike

      Thanks for commenting, Mike. I guarantee that your work is 100% better than anything in the Hall of Shame! It’s truly staggering to me that work like this is seen as acceptable by the perpetrators.

  3. Brian fisher

    Yep. Cowboys who ride a 3 legged horse, claiming it has 4! It`s a wonder they didn`t perish in the stampede.

  4. Nicki

    I have worked in both pro and high-end consumer audio manufacturing. Those ‘repairs’ make me want to weep!!! Where is the care and love for these lovely bits of kit? Disgraceful!

    1. Liquid Mike

      Hi Nicki, thanks for your comment and I couldn’t agree more. The work I highlighted here is truly disgraceful. It would almost be acceptable if it was the result of backyard tinkering, but these are the results of so-called specialist repairers. It’s mind-boggling!

  5. Connor

    Wow, absolutely atrocious work by self proclaimed “techs” – I see this all too common too, especially when it’s the equipment owners trying to repair their own gear. Even someone with no experience and a cheap dollar store soldering iron is almost guaranteed to do better work than the work on this thread. This is absolutely appalling. Thanks for sharing!

    1. Liquid Mike

      Hi Connor, yeah, this sort of work might almost be excusable if was owner-induced. The really sad part is that it was all done by so-called “experts”. I’ll never understand how people like this operate and stay in business?!

  6. Brian Fisher

    I totally agree, Mike. I have chosen my repair techs carefully over the last 40 years. Sadly in my city they have all retired and now there is no one. Fortunately, my stereo components are near new. Only the Akai GXC-760D Tape Deck is over 40 years old, and still performs like new. Akai originally guaranteed these Glass Heads to last @ 24hours -non stop play. for 16 years . That`s over 41000 hours. More than a lifetime. I estimated since 1977 when I purchased this machine, new $CDN 1000:00 it has less than 1000 hours of use. Best sound ever for a cassette deck. love your columns. Take care.

  7. Michael Peter

    There is a crooked repair shop here in the USA that specializes in Carver equipment and does nationwide business that does crummy work and charges top top dollar. He has special resources to promote his crooked business. How can I alert people to stay away from him??

    1. Liquid Mike

      Hi Michael, you can alert people via the usual forums and places people commonly visit, that’s probably the best way to start.

  8. Ralf Dudat

    I totally support shaming dodgy technicians and in particular the unscrupulous bosses who bully their techs to spend as little time and money on a repair job as possible. Likewise the owners handing in their gear for repairs should be prepared to allow the time and money to do the optimal job and not push for quick and cheap repairs.

    1. Liquid Mike

      Thanks Ralf, and you make a very good point about business owners forcing technicians to do cheap work. Almost everyone featured on this page runs/ran their own repair business, goodness knows how, but case number 6 featuring my old Krell KSA-150 is a classic example illustrating your point. Owners wanting cheap work are thankfully not something I see often due to the way I run my business, but I do occasionally see them and try to steer them elsewhere.

  9. Trevor Wilson

    ME has a “backyard build quality”? Really? Compared to MAS? In what sense? I have an old MAS amp on my bench right now and it reeks. Big time. I’ll post some photos in due course. Later models are better for sure, but MAS attention to heat is appallingly poorly implemented. When I see/measure TO5 devices operating at 80 degrees C, I sense big problems. The stuff looks great from the outside though.

    As for Krell, well, I had one on the bench awhile back. The drivers were bolted to their heat sinks using plastic bolts. Saves the effort of using proper mounting procedures, but when those plastic bolts let go (and they all do), there are big problems. The old Krells (fan cooled models) were better. Except for the ones where the fan was arranged to blow air DOWN through the heat sink tunnel. Sheesh!

    So, tell us, what PRECISELY is wrong with ME design and construction techniques?

    And yes, as you may have guessed, I do have a horse in this race.

    1. Liquid Mike

      Hi Trevor, my name is Mike, thanks for commenting. My apologies for the delayed reply, I’ve just returned from a two-week camping break.

      A quick note that I’m happy to grant permission to comment on my site, as long as interactions are polite and respectful. I have a name for example and greetings are normal. I see that you’ve emailed and commented elsewhere, I’ll reply as/where appropriate, once I sort through the several hundred emails in my inbox!

      I’m not interested in debating the obvious, especially not where one party has a conflict of interest as you admit to. I’m only interested in facts, my work is not influenced by any brand affiliation. This is rare and something I’m especially proud of, along with the work I do to educate people about hi-fi equipment and expose dodgy repairers. We all benefit from this, of course!

      PRECISELY what’s wrong with the ME gear I’ve worked on is that it is very crudely built, as I already mentioned, and absolutely awful to work on. Parts, construction and serviceability range from poor to terrible. I know that there are religious followers of this brand and some may be afraid to speak the truth but these are facts and any assertion to the contrary is factually and technically incorrect at best, dishonest at worst.

      The Krell gear I’ve worked on has been in a different universe in terms of construction, build quality and serviceability, so much so that your comments suggest a lack of familiarity with such equipment. My comments about MAS refer specifically to the amplifiers here, no others. I work on lots of Krell gear and I haven’t found plastic bolts anywhere BTW. Nylon and other plastic fasteners are used sometimes for electrical isolation, though I’ve not seen any in Krell gear I’ve worked on.

      Anyway, on these points, we may have to politely agree to disagree, and that’s OK. Again, thanks for visiting and commenting.

  10. Mike

    I am sorry for asking a stupid question but what is ME gear? What brand is that? I didn’t see it anywhere on this page

    1. Liquid Mike

      Hi Mike, no problem and not a stupid at all, ME is/was a small Australian brand, it’s short for Modular Electronics.

    2. Trevor+Wilson

      Please understand that I readily accept and acknowledge any criticism levelled at ME gear. Peter Stein (the creator) is somewhat less accepting of criticism though. I will address your points in order:

      Parts. Yes, you won’t see $5.00 Dale resistors in an ME product. You will see high quality, $0.05 resistors, which, in specific areas, are matched. Some to within 0.05% tolerance (RIAA stages). Electrolytic capacitors are manufactured to ME specifications in Taiwan, using foil from Germany and electrolyte from Italy (or the other way ’round – I forget). And those caps last a very long time. I’ve pulled caps from amps built in the mid-1980s (convection cooled) and they still meet spec (ESR, ESL and capacitance). And that was for convection cooled amps. By comparison, I’ve had three Mark Levinson amps in over the past year or so. The main filter caps could be used as a baby’s rattle. Emitter resistors in ME amps are standard, low inductance types, matched to within 1%. Semiconductors are standard TO3 Motorola types, US sourced low signal types, or Japanese drivers and outputs, depending on the model. All semiconductors are matched to within 1% tolerance for hFE and Vbe. Switches are gold plated, Lorlin or C&K. Pots are Alps ‘Blue Velvet’. Trouble with ME products is the stuff you DON’T see. Like the extreme level of matching used for EVERY semiconductor (except for control ones) in the amps. As you would be well aware, to match 8 TO3 output devices to within 1% tolerance requires a substantial stock holding and a great deal of labour.

      Crudely built. I guess that is a matter of opinion. When I worked on the Levinson amps, it took the best part of a day to remove ONE output stage. It was impossible to test the output stage on the bench. By comparison, I can remove BOTH output stages from an ME1400/1500, ME850, ME750, ME550 in less than 30 minutes. I can connect it to my bench power supply and operate on the module as required. Dismantling the module, itself, takes another 5 minutes, when any faulty parts can be replaced. Simple, quick and easy. The Krell I have out back is waiting on some unobtainable FETs. Don’t get me started. Don’t get me wrong, the Krells I’ve seen are decent enough to work on (except those KAV things) and they do use quality components. Easier to work on than any Levinson? Yep. Easier than an ME? Nup. I readily acknowledge that the most polite comment about ME STYLING would be: Industrial. They ain’t pretty. But they are exceptionally well engineered. The fan cooled models draw air through the main filter capacitor banks and then through the heat sinks. Output stage temperatures are kept with 5 degrees C by a continuously variable speed fan. Great design and part of the reason why the main electros last so long. In fact, I would call the design (of the cooling system) borderline genius. And I’ve seen an awful lot of amps in my 50+ years in the biz (i started when I was still in school, servicing for the local music store). FWIW: I refuse to accept Mark Levinson amps for repair anymore. I have more to do with my life. Krells are fine.

      Seviceability. Sorry Mike. You are flat out wrong. I’ve been servicing audio equipment for more than 50 years. Those 1970s Marantz receivers were a little easier than an ME, when I was national service manager in Brookvale, but I’ve not seen much else that is easier than an ME. Certainly nothing in the high end arena anyway. Not Mark Levinson, nor Krell, ARC, Rowland, whatever.

      I am reasonably familiar with Krells. I’ve worked on a few, ranging from their ancient stuff (KSA50 and KSA100), to the KSA250 (I think) and the one I mentioned with plastic bolts. I can’t recall the model number, but I’d guess it was a late 1990s product and the plastic bolts were factory fresh. Generally, Krells are well built and reasonable to service. That said, they ain’t perfect either (no amp is), but they are certainly decent enough. Cosmetics are second-to-none. WAY nicer than any ME amp.

      As for your honesty, I expect nothing less. Which model/s of ME amps have you worked, BTW? I should add that there are a couple of really good reasons why there are so many ME fan bois around:

      1) Sound quality. NOTHING sounds quite like an ME.
      2) Price. ME amps were typically way less than half the price of an equivalent foreign product. Listen to an ME850 sometime and tell that it is not a world class amp.

      Now if you want to see rubbish design, look at Musical Fidelity, Sim Audio and others.

      Anyway, sorry for the rant and thanks for responding.

      1. Liquid Mike

        Hi Trevor, no worries, good discussion, though this does read like an advertisement for ME and as you represent the brand, we might finish this particular discussion here. Appreciate your thoughts though and people can make up their own minds.

        Briefly, as I am inundated at the moment:

        Regarding engineering, to say the ME gear is exceptionally well-engineered to me is like saying a Lada is exceptionally well-engineered. You are way off here IMHO! In terms of build, the ME I’ve seen has been solid, but again, crude. Parts are disappointing, no matter how well-matched they may be. Five cent resistors and re-badged Taiwanese caps are not good enough in high-end gear. I’ve said this about MF, Redgum and others.

        In terms of serviceability, almost everything I’ve worked on has been more serviceable than the ME gear I’ve looked at. Perhaps I’ve been spoiled but even basic Japanese gear has been easier to service. I’m willing to be persuaded but I need to see some nicely made, serviceable ME gear.

        I’ve found sonics to be disappointing, though reflective of the design decisions made. Appearance I don’t really care about. An amplifier could be the ugliest thing in the world but if it sounds good and is well-made I’ll like it!

        At the end of the day, if people like the stuff, no problem. I’ve found it disappointing but I work on a huge range of gear that most never see in a lifetime. No disrespect intended towards Peter Stein either, good on him for successfully creating the brand, I take my hat off to him for that.

        I’m always open to being surprised, so rest assured, if I find and work on a really nice piece of ME gear, I’ll write about it!


        1. Trevor Wilson

          Fair point, Mike. I did not want it to sound like an advertisement. I seek only to correct misconceptions about the product. As discussed. please give me a call sometime. I do have some things I’d like to discuss with you that may be beneficial to both of us.

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