YAMAHA's Professional Amp 

I want to try something new. Something more live. So I’m running a 3-part live workshop that takes us on… A Time Travel Through Vintage Electronics. We’ll rewind the clock, dive into the tech of the times… (and study the very history of how things were broken and repaired has evolved) From the 1950s all the way to 2020s. It's still just an idea. The dates and times are to be confirmed. But if you're reading this, then the workshop hasn't yet taken place. So if you're interested and don't want to miss out, you can sign up here: menditmarkk.ck.page/6e8fbd9521

Is there anything that you don't look forward to more than a new Mark video? Keep them coming please!! Also, it would be great to hear how you gained your knowledge. Electronics, chemical, mechanical, you know it all!

I recognise that amp as one from Birmingham Repotory theatre. It came into where I was working at hte time for service. The initials JD belonged to John Deakin one of the service technicians. A long time ago in the seventies. He has since passed away sadly.

Let's get this man some more subscribers. There are a lot of channels that are really crap that have more subscribers than he does. Mark is the real deal when it comes to repairing electronics! This man takes so much time and effort in putting these videos together. In such great detail, next to nothing skills and when something is not available, he makes it himself. Mark is such a nice guy, great knowledge and very entertaining to watch. Every time he puts out a new video like this, you can take your popcorn and drinks and watch this from start to end like you watch a new episode from your favorite series. Keep up the good work Mark, great to hear you move to a new workshop.

Dare I say that Mark's videos are on the edge of being therapeutic to watch! Thanks so much, Mark!

Fabricating those transistor covers is just next-level refurb; not only painting, but matching the text. Awesome.

I bet if you sent Mark a shoebox and told him it was a McIntosh amp, you’d get a McIntosh amp back in 10 business days 😂

Mark exudes confidence and competence. You know he’ll sort this disaster

No surface mount items, no chips...ah the joy of components that can be examined, tested and replaced without magnification!

Can we all admire what appears to be masking tape with “nope!” written on it :D

Mark shows us a level of craftsmanship that many ‘repair shops’ don't even know exists.

The abject anxiety I get watching Mark completely dismantle these old buggers is offset by the dopamine blast I get when it comes back together and actually works.

I really like how absolutely every single thing that was done in this repair is left in the final edit. Really gives you a good idea of what's happening that a lot of other channels don't provide

Mark is one of my favorite net personalities. Straightforward with no mucking about. Can't wait to see the new digs.

The sticky residue on the cables is from the smoke, not dry ice 😁 . The smoke fluid is water and glycol, and the glycol is the thing making the smoke white. If the smoke is used in a nightclub without any ventilation, the glycol will condense on stuff. A typical fault on movingheads is the condensed glycol on the cables inside, making the dust stick on them, and making them brittle.

You won’t find anyone as professional as Mark he’s the best !

This is more than just mending. To see someone taking care to recreate missing parts from raw steel is truly a labor of love.

A sunday with Mark! Splendid

Genuine shock when Mark said he'll be moving shops, I thought he loved the clutter! Extremely organized, however the lack of space is only somewhat evident(;

A great end to a hot and sunny weekend. I like the way Mark goes the extra mile to ensure that all repairs leave in a safe condition. Best of luck moving to your new workshop.

It's better to watch you working than to watch a Hollywood action movie. Lots of love and regards from Pakistan. Stay blessed.

Mark, You've even made it to the Netherlands. I find your videos so informative and well-explained. It's just a positive therapy to watch you while doing the work you perform.

Mark, your attention to detail and general knowledge and professionalism never ceases to amaze. Good luck in your new workplace

Your cheerful confidence seems born of experience and a good attitude. Most of us would be scared to tackle the projects you take on in stride.

Good afternoon Mark! I can relax, cuppa tea, and watch your great video!

Meaning to say this for a while. Whoever designed the sound for your videos is a genious. The precision, but also calm inducing.

Not only are you extremely talented in electronics but you also understand how to make things from sheet metal and how to measure correctly. Absolutely awesome and I appreciate your RU-vid channel one of the best around.

Cover fabrication at the end was just amazing. Really rooting for this channel to grow big.

Mark, you make these repairs look so easy! The missing parts is simply amateur workmanship and unforgivable.

How many of us would take one look inside that thing, and say, "Sorry, no way this can be fixed"? Congratulations on the new shop . . . hope the cat likes it!

He’s Mend it Mark AND Bend it Mark…!!! those covers are awesome! 👏 🔥

New workshop?.......looking forward to it!

I know sod all about electronics but I'll happily sit watching Mark carry out his repairs, a true craftsman at work! Love the intro music too! Look forward to seeing the new workshop. Thanks Mark!

Looking forward to seeing the new workshop.👍🇩🇰

I mostly have no idea what you are talking about but your style is very engaging so I keep watching

I'll miss the old workshop for sure, Mark. Quaint. Calm. Homey.

I have absolutely no clue about electronics but why do I watch every video?? Love the channel 👌👍

Excited to see the new workshop!🙂

Absolutely amazing repair! You can't admire more that these amps never get old! Thanks Mark

Always a pleasure to watch Mark. I will skip whatever I'm watching to get here. Another rescued landfill item. 👍👍👍

Good Lord!?! What a toroidal transformer! Unlike any other transformer that I’ve ever discovered in any other piece of appliance. Nice. Balanced inputs. Your workshop is always pristine. You figure any engineer with an antique transformer curve tracer has had for himself a pretty long history of experiences in electronics. Mark, I don’t know where you got it from, but your English is the real treat of your channel! Wherever you’ve been, you really have a pleasant voice!

I am a hard man to impress but you impress me very much Mark

For others watching - you have to be careful when substituting transistors in a power amplifier. It isn't always enough to make sure the replacements have the same or better specs on things like voltage and current - two important criteria Mark did not show here is Ft and Cob. You can have oscillation issues in some amplifier circuits if the outputs arent of similar speed or there is more/less Cob capacitance.

i watch his videos only for pleasure..this guy seems very humble and nice...

I don't get any of the technical stuff but somthing about Marks videos make it compeling viewing. Like many comments on here, I really look forward to the days these come out.

This is my first time coming across your channel, and what a pleasure! Your repairs are so thorough, and your positive attitude is a joy. It's always satisfying to see old equipment being repaired instead of just thrown out. Excellent work.

Those transistor covers were such a clever idea. The printer trick was clever as well.

I'm kind of sad that you're moving to another shop yours has such honest character

He’s so clever. It seems like there is always something new to learn in each video.

That looked like a right basket case, but you sorted it all out very confidently and professionally. Love these videos and the "professional" gag at the start of this one. Would love for you to feature the cat more often!

New workshop coming !!! Interesting Mark. I prefer to keep things as they are. It is difficult enough to keep track of where I put stuff 😄

It feels like Christmas! Mark has turned up!

Sunday is complete… cold beer sitting in the garden with Mark… 🎉😂

This is some serious workmanship. Mark you are amazing.

That is the sibling of the P-2200. That was a gorgeous amp with Awesome meters. Its downfall was, Yamaha made custom meter drive amp IC, an IG0.... something or other, that tended to fail and render the meters useless. It had a big Toroid transformer for mains. I never have seen a P-2201, but I can guarantee you that Yamaha would never leave their output transistors open on external heat sinks. This is a case where some lame servicer lost that stuff.

Mark, you go after these complete basket cases! Once I saw all those transistors missing, I was yelling TRASH IT! You are amazing!

Thanks Mark. Real entertainment on a sunny Sunday afternoon in North west Germany

Old school analog amp! Glad to see it brought back to life.

i admire that repair. Good work. I can't imagine explaining the repair bill to the customer. He would have thought he had the transmission replaced in his car. That Clarke brake is really a handy outfit. That 1970's glue they used on the capacitors is nasty acidic stuff. My wife's finger nail polish remover makes quick work of removal.

Happy memories of Servisol Foam Cleaner from my time in the Co-Op TV workshop in the 1990's.... I've still got a tin I "borrowed" before being made redundant in 98.😉 Just shows how little I've been fixing stuff in the last 2 decades. Slowly getting back into it now I'm on the scrap heap. Wonderful video Mark, thanks for sharing. Cheers 🍺

EVERYONE should have their 'favourite printer...' Very much a 'fab' episode

A very experienced and talented electronics engineer that's for sure

Love how they provide a switch to change whether pin 2 or 3 is hot on the XLR ins, most Euro equipment was Pin 2 hot I believe while most American (and Aussie gear like mine) was Pin 3 hot, until they standardised Pin 2 hot later on.

And now: MARK -- THE MAN OF STEEL (parts making)

Most talented technection ever

New workshop Mark! That needs a series of videos in and of itself please!

Outstanding work Mark, just outstanding. A master of many, many talents. I think I'll miss the current/old workshop, it has such a one man in a shed vibe, a bit of a cosy warm feel to it. However, I can't wait to see the new workshop, you might even have enough space to swing a cat and have a bit of elbow room.

15:36 ... The cat being scared by the desoldering pump! 🤣

Never fails to disappoint. Always worth the wait. Looking forward to seeing the new workshop Mark, thanks for the effort you put into these videos!

This is a work of art. Been watching for a while and this channel is the best! When MendItMark meets MakeItMark, I feel a sense of serenity. Mark, get that second channel registered.

They're beautiful brutes of amplifiers. Many years ago I repaired one of these that had suffered a "thermal event" that blew up one of the sides. It has a very nice safe operating area limit circuit that limits the output current near zero volts. This will prevent the amplifier overheating during normal operation with a blower passing considerable air over the cooling fins. The amplifier in question was being used in a practice room and the fans were turned off since they were noisy. This would have been OK, as the power out was probably around 10 watts instead of its usual flat-out front of house duty. The speaker wire was a bit dodgy and shorted out. The safe operating area circuit would have prevented any damage, had the blowers been running but... The thermal switch on the heat sink only lights up the over-temp indicator and doesn't shut the amplifier down. The output stage and the output drivers were all blown up. After the repair, I installed thermal switch buttons on the heat sinks to prevent this recurring.

Mark you have done another sound job I could site and watch you all day and night mate 👍🏼👍🏼👍🏼

Dedicated to the cause, awesome video Mark

What a thrill to watch your vids. Someone also called Mark who still uses an analog 'scope and has a copy of Towers. Though I'm now retired (semi) I love watching someone else work; especially with the talk that accompanies it.

I hope we see us from your new Workshop Mark. Greetz from Germany

You know when someone is making transistor cover plates from scratch that look factory made you are watching a master at work.

Goodbye old workshop, you will be missed. Also, I’m sure the last guy that worked on this had good intent at least 💪😁

When I was making artwork the early 80s (for 35mm slides) we used a solvent called CLEANART. It worked very well on any sticky mess or SprayMount residue. However it also contained Benzine, so it was banned for being carcinogenic. We used tons of it. Your cat must think your de-soldering tool is hissing at him.

Another great job, Mark - and I can only echo Mcqlfc's sentiments about keeping the videos coming. If only every other serviceman took his job as seriously as you do. In my experience many of them don't give a toss!

I have been following you for a while now Mark. It's great to see a teck take pride in his work . Well done !!. I love these Yamaha amplifiers, built to last. I have a Yamaha P3500 in my lounge room, followed by a Yamaha graphic equilizer Q2031 and a Nad tuner preamplifier 917. Old school , yes but still sounds good and plenty of head room !!!. Keep up the good work and looking forward to your next post and in your new workshop.

Thorough job Mark as always, you didn't cut any corners...fake parts are a real problem...came across it when trying to source some 2SC2922 and 2SC1905 Sanken devices....The real problem is not finding modern equivalent devices that can deliver the power, but can match the Early Voltage characteristics as well.

A far simpler solution would have been to use T03 plastic caps instead of fabricating covers, Farnel part number 170031. Though your attention to detail and tenacity in approaching a repair is top shelf.

your confident positive attitude always put a smile on my face, makes my day 🙂

That’s one hell of a skill set , very impressive

what an absolute delight watching you work Mark. your expertise is amazing and going all the way of doing the covers and labels wow..thanks for your great content and time to put it all together

I am really happy for you. Well equipped, well knowledged. And I am gone miss your work bench. Work safe my friend.

MIM videos are the very few I watch from start to finish..

I love watching a genius at work.

One of the best content for any electronics, electromechanical devices troubleshooting, repairs, upgrades and RESTORATION to better than OEM, period

It's not my habit to watch YT-videos longer than 15 min. MiM is a very rare exception.

High quality soldering - Kudos!

Excellent work Doctor Mark - another item off the critical list!!!!

Amazing work Mark. Love watching you in action.

Hope your new workshop is everything you want it to be. Your skills as a teacher and a tech are first-rate.

I am always blown away by your attention to detail Mark. And this Vid even more. Not only the electronics! Transistor covers gave an “Out of the Park” look of professionalism. Wow)

Proper job there Mark, cant wait to see the new workshop.

Mark's fab always blows me away AFTER his electrical work - no one like him!

Fantastic work as always, hope your cat got over the trauma of the desoldering

Wow that was on another level. Cant wait for the new workshop.

A surprise "how to" at the end, excellent!