£25,000 Audiophile Pre-Amp repair video by Mend It Mark

[5U4GB]

But £25k?  That's exploitation, unless it was an art piece and an investment.  You know, like an unconnected tantalum cap superglued to the wall as an exhibit.

As long as you duct-tape a banana next to it you should be fine.

[themadhippy]

No idea if this is genuine, if it is ,it has a dodgy grape smell to me

Thank you kindly for your email. I am happy to provide you with the details from our perspective.
 
As you well know there are always 2 sides to every story.
 
If you watched the video you will have heard his opening line, “the unit was damaged in the post” but he fails to mention the truth.
 
It was him ( 'bodge it Mark') that posted the unit to us but as I said he fails to mention he posted an expensive amplifier with the local post office and wrapped it in a couple of sheets bubble wrap and placed it in a card box.
 
On arrival here we noticed a rattle from the card box and after opening it we could see the units acrylic box was broken into several parts and 4 of the metal corner parts had deep dents.
 
To make matters worse we could clearly see that the unit had been previously opened by Mark, this also voids the manufacturers warranty.
 
Even so we offered to rebuild the unit into a new box and provide a new set of painted metalwork and also repair the fault correctly.
 
When we ship the units out they are sent with either Fedex, DHL, or UPS and are double boxed, the outer boxes are either made from plywood or tough Pelican cases.
 
If you take a look at all the carriers terms and conditions you will note they will not cover any insurance costs on anything valuable that has not been double boxed correctly.
 
We have sent out nearly 80 units worldwide without ANY damage, there are units that have been sent as far away as N.Z, the far east and the USA.
 
The repair he did is only temporary as the IC will also be damaged, the AVX TAP series professional grade Tantalum capacitor that failed would have also damaged the IC it’s connected to internally.
 
The capacitor failed because the customer that owns the unit pulled the inputs whilst the unit was powered up, something we strongly advise all our customer against doing !
 
The IC’s are graded in a test rig before being placed into the pcb, we would have replaced the whole pcb with a new one to be certain of future reliability.
 
We remove the ident of our IC’s to stop the units being cloned and to protect our work.
 
The design is a unique ‘recipe' learned from 40 years of working in audio, the retail price is related to it’s performance, however we don't sell them at the retail asking price.
 
They are sold directly to shops and distributors worldwide, we are paid 40% of the retail figure.
 
Unlike 'bodge it Mark’ we don't work from a shed in a back garden and have overheads / wages and rent to pay so the price we charge has to cover the costs.
 
As for his repair of the unit, it will fail again in the near future because of the internal damage to the IC and the glued casework he did will have more scars than Frankenstein’s bride, a truly unsightly bodge- up !
 
You can fully understand this now from my position, he leaves me no choice other than to protect my business and reputation by taking legal action against him.
 
Other YouTuber’s should take note and think carefully before they post as they are not immune from legal action !
 
Kind regards.
 
Tom

[coppercone2]

The 30k$ for what was illustrated was a joke.

Nude virgins need to be paid. And delivery from the remote island is expensive.

laying pipe is always expensive (shielded input)

[Xena E]

No idea if this is genuine, if it is ,it has a dodgy grape smell to me

...
 
When we ship the units out they are sent with either Fedex, DHL, or UPS and are double boxed, the outer boxes are either made from plywood or tough Pelican cases.
 
...
Kind regards.
 
Tom

You could wrap that turd up and transport it how you like, but a good shake would fuck it up without internal support.

Whatever, it's a pile of crap.

X

[magic]

No idea if this is genuine, if it is ,it has a dodgy grape smell to me

If it's fake, it's written by somebody who understands the mentality of "those people" well, or at least has similar prejudices to mine

It took me 40 years to design this
you have no idea what goes into it
it's got professional grade capacitors, man
the ICs were all hand picked
I would replace the whole board to be sure


And obligatory:

The capacitor failed because the customer that owns the unit pulled the inputs whilst the unit was powered up, something we strongly advise all our customer against doing !

Actually, I wonder if this last one might be true at all. Wasn't it simply a rail bypass cap? It shouldn't be damaged by the signal path.

But he may have a point regarding the 7815 which was feeding this shorted capacitor.
Another thing I'm curious about is if this reg is actually a critical part, perhaps something depends on its voltage exactly matching the 7915?

It was him ( 'bodge it Mark') that posted the unit to us but as I said he fails to mention he posted an expensive amplifier with the local post office and wrapped it in a couple of sheets bubble wrap and placed it in a card box.

This would imply that there was more to the story than Mark said.

[tszaboo]

No idea if this is genuine, if it is ,it has a dodgy grape smell to me

'bodge it Mark'
Kind regards.
 
Tom

Yes, kindergarten level name calling is real classy, it will make sure that everyone will side with you, because you don't come off as a total douchebag. /s

Also, professional grade tantalums... As opposed to what, consumer tantalums?
And magical remote debugging of ICs? You can tell that it's faulty, because what, you have a statistics on your total 80 units sold that it always happens. 

[armandine2]

--- hope this doesn't go Wagatha Christie on us 

https://en.wikipedia.org/wiki/Wagatha_Christie

[DenCraw]

Wow! 40 years reading the same application note from BurrBrown!.
https://archive.org/details/manuallib-id-2650324/page/8/mode/2up?q=OPA111

BTW; it seems that somebody wants this video forever!.
https://archive.org/details/the-gbp-25-000-pre-amp-that-went-wrong-tom-evans-mastergroove-sr-mk-iii-rjbp-fsfzi-i

[BrianHG]

But he may have a point regarding the 7815 which was feeding this shorted capacitor.
Another thing I'm curious about is if this reg is actually a critical part, perhaps something depends on its voltage exactly matching the 7915?

After 40 years of engineering, if you truly need a matched negative supply, aren't you supposed to design a tracking regulator from a single reference, not use cheaply binned 7815s and 7915s which may temp drift and age differently?

[Xena E]

Also, professional grade tantalums... As opposed to what, consumer tantalums?

What I'd say are professional grade are the tubular metal cased variety, not those resin dipped leftovers from the 1970s. They were a joke even then.

X

[squadchannel]

tough cap.

[madires]

No idea if this is genuine, if it is ,it has a dodgy grape smell to me

...
Other YouTuber’s should take note and think carefully before they post as they are not immune from legal action !
 
Kind regards.
 
Tom

Looks like Tom booked the super deluxe Streisand effect experience package. He didn't refute asking 6k for the repair and told us that he gets 10k per unit. Also considering the build quality, it's clear that his side of the story is just a smoke screen to hide what he is selling for 10k. Mark's video simply revealed the reality, i.e. what's inside the box.

[coppice]

Also, professional grade tantalums... As opposed to what, consumer tantalums?

Consumer grade (bead type) and professional/military grade (sealed cylindrical) tantalum capacitors are very different. The tubular ones are truly sealed, rarely suffer corrosion issues, and will operate for decades at 125C in military applications. We used to use them in telecoms systems, like telephone exchanges, too. Their problem in occasionally a whisker grows between the plates, and shorts the thing out. In supply decoupling applications the power supply normally fuses this whisker, and everything seems OK afterwards. However, the momentary short makes most digital systems crash. So, telephone exchanges hiccuped every now and then, which lead to the discovery of this phenomenon. Around this time Philips and a couple of others launched the first dry electrolytics, and we migrated to those for telecoms. I was out of defence work by then, so I don't know if they followed the same path.

[EEVblog]

[timeandfrequency]

Thanks Dave. This new video from Louis brings interesting information.

Louis reads Marks' email. At 1:57 we can hear : "The preamp was originally sent to the manufacturer by its owner but it got damaged in the post. They quoted the owner some ridiculous repair price. I think it may have been around £6,000 but I can't find any evidence but it was certainly several thousand Pounds. The owner was not happy to pay that so instructed the manufacturer to ship it to me for repair despite warning the owner I would not be able to fix it. So the preamp was shipped to me from the manufacturer but not that they needed me to do the work".


Some takeaways about that :

1) The buzzing (electronic circuit failure) and the broken enclosure happened independently of each other.

2) The explanation that @themadhippy could find earlier and that might (or not) be the manufacturer's point of view, plainly contains some inexact information, like : "It was him ( 'bodge it Mark') that posted the unit to us".

Thank you kindly for your email. I am happy to provide you with the details from our perspective.
 
As you well know there are always 2 sides to every story.
 
If you watched the video you will have heard his opening line, “the unit was damaged in the post” but he fails to mention the truth.
 
It was him ( 'bodge it Mark') that posted the unit to us but as I said he fails to mention he posted an expensive amplifier with the local post office and wrapped it in a couple of sheets bubble wrap and placed it in a card box.
 
On arrival here we noticed a rattle from the card box and after opening it we could see the units acrylic box was broken into several parts and 4 of the metal corner parts had deep dents.
 
To make matters worse we could clearly see that the unit had been previously opened by Mark, this also voids the manufacturers warranty.
 
Even so we offered to rebuild the unit into a new box and provide a new set of painted metalwork and also repair the fault correctly.
 
[...]
 
Tom

3) Louis is ready for a huge legal fight
Stay tuned!

[tszaboo]

Also, professional grade tantalums... As opposed to what, consumer tantalums?

Consumer grade (bead type) and professional/military grade (sealed cylindrical) tantalum capacitors are very different. The tubular ones are truly sealed, rarely suffer corrosion issues, and will operate for decades at 125C in military applications. We used to use them in telecoms systems, like telephone exchanges, too. Their problem in occasionally a whisker grows between the plates, and shorts the thing out. In supply decoupling applications the power supply normally fuses this whisker, and everything seems OK afterwards. However, the momentary short makes most digital systems crash. So, telephone exchanges hiccuped every now and then, which lead to the discovery of this phenomenon. Around this time Philips and a couple of others launched the first dry electrolytics, and we migrated to those for telecoms. I was out of defence work by then, so I don't know if they followed the same path.

Well the point is that in the past 15 years, consumer products moved away from tantalum capacitors for multitude of reasons. It's a conflict material, more expensive, performance is outclassed. The consumer grade tantalum capacitor market is all but dead.
Saying that "I used professional grade tantalum" is a statement that's empty. It's the equivalent that you used automotive grade transistors. So it's the same transistor, but it goes to 125C and the supply chain is checked regularly, congratulations. It goes into a consumer equipment, and it's not used at high temperature anyway. Lifetime is not correlated with the grade. It's not better or worse QC wise, and likely to come from the same production line with different marking.
There will be actually better tantalums, wet with extra small leakage or hermetically sealed or whatever. But it's the same through hole green frog from the 80s, that's a fire hazard with a exothermic failure rate orders of magnitude more often than an elco. Quite embarrassing in a new design to be honest.

[EEVblog]

2) The explanation that @themadhippy could find earlier and that might (or not) be the manufacturer's point of view, plainly contains some inexact information, like : "It was him ( 'bodge it Mark') that posted the unit to us".

Thank you kindly for your email. I am happy to provide you with the details from our perspective.
 
As you well know there are always 2 sides to every story.
 
If you watched the video you will have heard his opening line, “the unit was damaged in the post” but he fails to mention the truth.
 
It was him ( 'bodge it Mark') that posted the unit to us but as I said he fails to mention he posted an expensive amplifier with the local post office and wrapped it in a couple of sheets bubble wrap and placed it in a card box.
 
On arrival here we noticed a rattle from the card box and after opening it we could see the units acrylic box was broken into several parts and 4 of the metal corner parts had deep dents.
 
To make matters worse we could clearly see that the unit had been previously opened by Mark, this also voids the manufacturers warranty.
 
Even so we offered to rebuild the unit into a new box and provide a new set of painted metalwork and also repair the fault correctly.
 
[...]
 
Tom

Details irrelevant when it comes to the copyright takedown.

[Kleinstein]

For the copyright question they could claim that the amplifier is a 3D work of art. In this case pictures of the object could still be copyrighted by the maker.
Still I think this is a bit far fetched and stetching the rules.

[EEVblog]

For the copyright question they could claim that the amplifier is a 3D work of art. In this case pictures of the object could still be copyrighted by the maker.

Not a chance. Fair Use case law alone makes this not a thing.

[andy3055]

So, Mark's video is back on line. However, it is on a channel by NickT6630

[EEVblog]

Video is up on Trevor's Bench channel. Louis hasn't uploaded on his channel yet.

[timeandfrequency]

The video can also be found on the 'Twobob Club' channel.
It duplicates itself 
At the beginning one channel was buzzing, now the whole preamp creates buzz.

[EEVblog]

More uploads! 

[Xena E]

The video can also be found on the 'twobob[/member]/videos]Twobob Club' channel.
It duplicates itself 
At the beginning one channel was buzzing, now the whole preamp creates buzz.

Certainly has.

The Mend it Mark Channel has had quite a number of extra subscribers over this too.

X

[timeandfrequency]

And two more uploads on channels 'Brettbob Brettbob' and '84johnhead' 
Maybe CNN will broadcast it soon

The Mend it Mark Channel has had quite a number of extra subscribers over this too.

Yes, about 20 k more since he published the first video of the broken preamp.