YAMAHA's Professional Amp

UPDATE:
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)
The workshop is coming soon, but if you're reading this then you're in luck (or not)...
And there's still time for you to sign up using the link below:
www.menditmark.com/mend-mark-...
The workshop dates are mentioned in the link above too.
---
Mark rebuilds a battered 1976 vintage Yamaha P2201 Amplifier. "There's a fault with one channel", they said.. But who took all of the parts out?
Special Mention to Lighthouse UK Ltd, who provide Mark with some much required support for the Label Printer (see last 5 minutes of this video for the full story). Should you contact them, make sure you mention the channel!
www.lighthouse.uk.com
For the super-fans, you are welcome to support Mark, and get behind the scenes peeks on the Patreon page:
www.patreon.com/MendItMark

[@MendItMark]

UPDATE: 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) The workshop is coming soon, but if you're reading this then you're in luck (or not)... And there's still time for you to sign up using the link below: www.menditmark.com/mend-mark-workshop The workshop dates are mentioned in the link above too.

[@MVVblog]

I signed up immediately! I didn't understand a word because I don't speak English but I'm sure it will be great!

[@haroldbekaroe4556]

? M)) p)ft

[@davidurk3229]

I signed up, can't wait. Greetings from Milan, Italy.

[@briangoldberg4439]

Is it going to be on youtube, or is this going to be somewhere else like Twitch or something?

[@FUNKLABOR_DL1LEP]

of course, for me in German 'VE99' and 'curious marc' is nr 1, than 'mr carlsons lab'..

[@Mcqlfc]

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!

[@georgedyson9754]

Absolutely - go straight there when there is a new one!

[@davidroberts3429]

Totally agree!

[@TheAmazingprd]

I'm so happy when a new video is uploaded!

[@matthewm3927]

I agree!

[@wirdy1]

I don't know if anyone else notices the superb editing & audio on Mark's videos? Just the little touches like changing the sine audio level as it's varied on the amp, sublime.

[@malcolmclenton1663]

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.

[@PaulaXism]

I knew John quite well. He did most of the large heavy audio equipment repairs in the midlands. Nice guy, always helpful. Sorry to hear of his passing.

[@bsimpson6204]

"A long time ago in the seventies. He has since passed away sadly." But his amp lives on, we should call it 'John's amp' serviced by Mark

[@shimarlie1]

Wow, that's bizarre.

[@Mnelissen1968]

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.

[@che1602]

Totally agree. I’m sure he’s a guy you could have a drink and share a laugh with too.

[@andymouse]

Yep, I can think of one with double the subs and I don't get it !

[@RegiPavan]

Spot on! Let's get him more subscribers

[@user-mv5bu2kk8b]

Like watching a whodone it on telly

[@SlartiMarvinbartfast]

I couldn't agree more - unfortunately due to the stupidity of the vast majority of the human race most are drawn to the loud, flashy dumb stuff. This of course applies to all walks of life, not only KZbin videos.

[@exiledscouser919]

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

[@wirdy1]

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

[@ZiggyAndTheSpiderFromMars]

Mark has the skills and tools for every problem. He even has a labeling machine for this very purpose that cuts out the warning labels per spec.

[@OC35]

I would have used TO-3 plastic covers!

[@prs24328]

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

[@sobolanul96]

He is such a positive guy!

[@rokkenbole]

Absolutely! I 100% agree!

[@bobgrob4]

He's in my top 3 list here on YT for sure. He should have a million subs and his channel will grow and grow if he stays with it.

[@bobgrob4]

it's approaching an addiction for me. I love this guy. Every aspect of his uploads are excellent.

[@EdmundPaddington]

Agreed - I'm working my way through all the past episodes.

[@davids2448]

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

[@alfsmith4936]

Built when amps were designed to be fixed before tomorrows gig.

[@michaelfuller34]

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 😂

[@rayofcreation3996]

😂😂😂

[@alfsmith4936]

I'll be sending him my Dumble next week then.. I don't know why it's not working. It's very light too..

[@bobgrob4]

LOL!!!!

[@bobgrob4]

I can just hear him say, " some parts were missing so I had to improvise with a bit of wood and metal work here in the workshop." LOL!

[@CasperHP1977]

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.

[@BTW...]

Imagine what it does to ya lungs.

[@app0the]

@@BTW... and yet some people are now carrying around pocket sized smoke machines to suck on them at any free moment they have

[@jpdemer5]

Glycol is in "vape" smoke. Doubt there was much of that in the '70s and '80s. I think the sticky goo is phthalate plasticizer in the clear PVC tubing, which gradually sweats out to the surface (making the tubing itself gradually become more stiff.) That's why it's only the tubing that has sticky crud on it. It's an easy-to-replace item.

[@alfsmith4936]

If it was gigged, it's probably real smoke.. I replaced the pickups in a Strat I used to use before smoking bans last month and it still stunk of cigarette smoke.

[@haakonness]

@@BTW... ​ it's also used in inhalers

[@ronmelanz2820]

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

[@bobgrob4]

@OldFatBubba many of these techie type people are kinda grouchy. Mark has got the best, most refreshing personality that Ive experienced. His channel should be in the millions of subs. Its money in the bank when he uploads a video. Hes the best by far. One of the main reasons I do KZbin.

[@mpmyprojects6687]

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

[@jooch_exe]

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

[@hubbsllc]

And a power amp is ready to re-enter service! Power amps are among the most useful pieces of vintage tech there is. Even a really good one from the '70s or '80s, once properly sorted, is really good even today.

[@weevie833]

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.

[@RickMahoney2013]

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

[@richards7909]

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

[@marcse7en]

"Nope!" ... We can't!

[@user-mv5bu2kk8b]

I do that at the Cooker before the wife begins

[@ps-ib6ct]

A sunday with Mark! Splendid

[@Barbarapape]

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.

[@Jacob.Zonneveld]

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(;

[@IqbalKhan-hc1hv]

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

[@TheAsrgrant]

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

[@TronicGames]

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

[@markboon341]

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

[@arieschouten1326]

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.

[@markfx12]

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

[@drummerhammar]

I think when the former repairman found out that the blown transistors were out of production, he didn't bother to look for replacement, like Mark did.

[@PaulaXism]

@@drummerhammar It was very different 25 years ago. We don't appreciate how easy it is to source parts these days. I had to basically give up on quite a few things back then because parts simply were not available.

[@edmaster3147]

Mark's a gentleman leaving out displaying his underlaying knowledge and the judgement, though he sometimes subtle hints of what he thinks about other techs' solutions. In this case one cannot know the reason behind not finishing the repair by the previous tech, I know just to well that sometimes projects of gear you don't really use gets pushed behind.

[@jpdemer5]

Also possible that the amp was cannibalized for parts (those rare transistors in particular).

[@alfsmith4936]

Back in the day, If it works for tonight's gig, it works until it needs fixing again.

[@michaelalberson126]

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 KZbin channel one of the best around.

[@neph3129]

Excited to see the new workshop!🙂

[@jeremiahchamberlin4499]

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.

[@crumplezone1]

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

[@user-mv5bu2kk8b]

I'm sure that Mark is not that wayl inclined

[@KP-nd3bx]

Looking forward to seeing the new workshop.👍🇩🇰

[@rafaeldouglas2065]

Marvel at the professionalism and attention to detail in Marks repairs. I know absolutely nothing about electronics, but know Mark is an expert. Keep up the good work.

[@rccc5806]

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

[@pantelisEVs]

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

[@liquidco2]

This channel is criminally under appreciated, when you reworked that motor a few videos ago that hooked me in.

[@ciogon]

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

[@toolsarecool]

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

[@andrewslade7867]

Mend it, Bend it and Print it Mark!

[@UNCLEBGA]

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

[@alphabeets]

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

[@Plons0Nard]

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 😄

[@fiddleywest3778]

This is some serious workmanship. Mark you are amazing.

[@jaycee1980]

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.

[@BTW...]

Yes, seemed all too simple a sub. Was there a step missing from the work - to match the amps output gain? After all, the driver and output transistors were substituted.

[@markrages]

@@BTW... Negative feedback makes the transistor gain characteristic less important -- as it is somewhat close. Gain varies more than that difference from part-to-part.

[@jaycee1980]

@@BTW... No issue with gain as negative feedback deals with that, but stability can be an issue. I might have considered replacing the transistors in both sides just to make them a matched pair, though i doubt it is really neccesary.

[@jaycee1980]

what Mark might have done off camera, is tested with a square wave into a load, and looked at the scope. You'd see potential instability as severe over/undershoot on the waveform, with ringing. You'll always get some peaking but as long as it's not excessive and there is little to no ringing, you are OK. The original 2SC1586 transistors had an Ft of 10MHz and Cob of 110pF, where as the MJ15023 has an Ft of 4MHz and Cob of 600pF. Unfortunately there's no fast/low capacitance power transistors made in the TO-3 package any more. I also noted that the working channel had a failed Zobel network resistor. That's usually a sign that the amplifier has been oscillating. Maybe that's what took out the channel that had no parts in it.

[@MrTylerStricker]

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

[@bobbicaroldavies494]

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

[@PeterHughes-ne9wz]

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!

[@weswright3187]

I didn’t have a clue what you were doing from beginning to end. But I still watched in fascination.

[@batmandestroys1978]

It feels like Christmas! Mark has turned up!

[@IanScottJohnston]

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

[@nomadben]

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.

[@NFLineast]

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

[@D.Hozzie]

Thanks for taking the time for this Mark. Hope great things in your new shop!

[@graemeyetts3465]

The making of the heat sink rail covers was great alone. Excellent video and skills in a fun presentation.

[@shaky3142]

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

[@normansuchorzewski1026]

Just loved watching thisv-Takes me back to my Royal Navy Days doing component repairs to communication and Radar Systems. What a beautiful trip down memory lane.

[@kenp9073]

Woot woot!!! New repair video. Can't wait to see what you have in store for us at your new location!! Congratulations, Mark. Thank you for sharing your knowledge with us.

[@Ribbitmefoot]

Congrats on the new workshop.. looking forward to seeing it .

[@wheelyman81]

Talk about going above and beyond!! I must admit to having very little clue about the technical stuff - but I look forward to every video! Thanks Mark.

[@WayniKlaru14344]

Wow, I enjoyed watching every video you have, Mark. I am glad to find your channel. I wish I had those instruments you have there. I am eager to see the true sound of that amp next time for a sound test, Mark. This is a complete repair. Many thanks! Keep doing what you do.

[@hnatyshyn]

This is the most impressive one I've seen from you so far. It is really inspiring to see all the steps, including the making of custom parts. Makes me also dream of having a bigger shop and some more testing equipment and specialized tools. Looking forward for your Time Travel live workshop

[@billvakras8272]

I really admire the methodical way you work, your patience and your perfectionism. Your love of bringing back to life packages that no one else would repair. I don't think there are many like you. Even the videos are well taken. Thanks for what you do.

[@rayofcreation3996]

What a job! Good luck and best wishes Mark. Looking forward to the next excitement from the new workshop. Cheers! 🎉

[@GeoffSeeley]

Thanks for the hearing test @46:30 ! Nice work. Congratulations on the new workshop!

[@AreTwo2]

Love your work Mark. Best wishes in your new workshop.

[@VK5IR]

Amazing work Mark. Love watching you in action.

[@vkuolema79]

So nice to see vintage lab equipment. I used to fix amplifiers and build tube amps and this gives me memories. Replacing power and driver transistors can be problematic sometimes with old amps but you made it look easy!

[@johnburns5783]

Excellent work Mark. Love your attention to detail 👍👍

[@nomada7029]

This amp brings back memories of lugging that big heavy thing around with no rack case, banana adapter on the speaker terminals dangling around and all those injury-causing heat sink extrusions clipping me in the shins. Good times.

[@iantyler4045]

Once again you have gone over and above on this rebuild. That amp will last for many more hours now. Very nicely done.

[@Jammerk40]

Nice restoration and I knew the covers would fit! Your work is so precise! Love those video's please keep them coming!

[@mortjoer]

Hope you will feel right at home in the new workshop, best wishes and thank you😊

[@imnjs]

Hey Mark really enjoying your videos. Always cool to see the contrast of modern and vintage tech and how they work. Thanks for the great content!

[@DarrenBoss1984]

Love watching your videos. Even though i know nothing about electronics or amps, it's still a joy to watch you fix old equipment. Goo luck moving to your new workshop.

[@Reflectiveness]

Your videos are not only educational but also a delight to watch.

[@synthsandstuff]

Very impressive work Mark! Thank you for making these videos, looking forward to your new workshop.

[@drewdemien481]

Very very nice. Fun to watch you walk through components. Those were nice amps

[@bigthamal]

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

[@billsmith5166]

Beautiful job! Thanks for the video. Looking forward to the new shop!

[@javierboughton5386]

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

[@rcetvg11n72]

poetry in motion watching you resolve the problems congrats for the new workshop .

[@thijsvanexel]

Such rewarding fun to watch your videos. Looking forward to seeing your new workshop soon!

[@rankenfile]

Well done!! Love the details, and showing us how you got there.

[@ussul6524]

wow, brilliant work. Also thank you for showing all the searching for components.

[@GreyRockOne]

Very intriguing! Not only impressed with your electronic skills, your design and fabrication skills also! Thank You Mark!

[@DavidGilden]

Amazing attention to detail, well done ❤

[@JonDoe-zi3mh]

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!

[@bsimpson6204]

Well done fixing that amp Mark, you went above and beyond. Subscribed,

[@sarkarbroadband]

Congratulations on your new workshop. 🎉

[@spyderman1964]

Looking forward to the new shop. Well done as always.

[@WieEiPiehGuy]

Thank you for the new video. It's always very entertaining watching you repair equipment! Cheers.

[@renaldonormani6646]

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)

[@user-lt7ne9mv9b]

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.

[@worldpeace1977]

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!

[@gustaw937]

Wspaniałe filmy . Mark jest rewelacyjny.Wszechstronne umiejętności i wiedza . Nie mogę się doczekać kolejnych filmów z napraw.

[@geekbot5000]

I'm American and I love your accent. You are my current favorite KZbinr. Awesome job, I was mesmerized.

[@pezz38]

Congrats with the new workshop, looking forward to c it, great job as always.

[@vwsculler]

Love watching you work champ!

[@markfx12]

Good luck with the new workshop. I know I can speak for many that a tour would be splendid!

[@432b86ed]

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

[@marjon1703]

Yet another superb electronic rescue. Joy to watch, thank you. Good fortune with the new workshop move! In my experience it takes weeks to find everything again :)

[@christianboddum8783]

High quality soldering - Kudos!

[@robjw66111]

oooh new workshop!! Can't wait to see it Mark! Great job on the amp, great video as usual