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.
@@OC35That was my initial thought as well…. Until you realise that the transistors could get quite hot in operation, particularly at high output powers, possibly leading to the plastic covers partially melting.. Also, since the plastic TO-3 covers just clip on, they could easily be removed by a “curious” owner leading potentially to electric shock if touched.
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.
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.
If it’s the same John I knew him too, I was an AV tech at Gear House in Birmigham and he would come in and service the broken equipment. I think his sons name was Ziggy.
WOW ! 100 years ago I picked up a P2200 (same amp only with VU meters) in my last year of high school. I lugged that beast and a pair of Klipsch LaScallas around for years. All through college, got married moved into a brand new home they were with me every step of the way. Fantastic amp, never had a single problem. Makes me sad to see the condition of that old girl that you were working on but you brought her back to life good for another 50years. Great job, respect. I'm in Phoenix, Arizona and enjoy your accent and even temper. Thank You for posting.
Do the meters still work? We rebuild these often but the meter drive circuitry is encapsulated in epoxy, and so, no repair there. I'm going to build/design a replacement board next year hopefully
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 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.
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.
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 TH-cam videos.
@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 TH-cam.
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.
Great job fixing this amp. These old Yamaha's perform extremely well and are of much higher build quality than what you'll find today. I actually have the model P2250, which is very similar to this one. Thanks for saving this one from the junk heap!
We did some blind shoot outs with amps for a JBL 4435 monitor system at a studio I worked at, we ended up with P2200s over some much more esoteric offerings. The bean counters were thrilled too!
I agree, the old stuff had much better quality compoents in it, and you can hear that. Look how chunky the induktor is, how solid the psu is, maybe not 100 percent efficient in power consumption vs heat. I would also love my old Technics Amp back.
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.
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.
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.
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.
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.
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 TH-cam channel one of the best around.
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've worked in nightclubs for a couple years (yes, I have hearing damage) and that sticky residue you mention at 8:49 is most likely from the hazers they use, as opposed to dry ice as you say. Depending on how long this particular unit has been in service, it may have seen both oil-cracker and water/glycol haze in its lifetime. Excellent video. :)
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.
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.
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
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.
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.
@@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.
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.
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!
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(;
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!
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.
Had a Yamaha C-40/M-40 combination bought in 1984, a beautiful amp combination and well constructed. Sold them when I was in a 1 bedroom unit and there wasn't a lot of space.
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!
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.
Hi Mark, I have this exact same amp and have had it from new when I bought it in the 80's. It still works brilliantly, it is built like a battleship! Thank you so much for uploading this video, I have learned so much from it.
I aquired a P2201 in 1986. Legendary. Indestructable. Great sound at home in the HiFi and kicked ass in school gymnasiums, weddings and hockey arenas. That and the P2200 are some of Yamaha's best work.
Having worked with that model in the early 1980s, I can't agree with your assessment at all. Yamaha makes some excellent drums, great brass instruments, very good motorcycles, and they make amps. Not great, not good, but adequate. Yamaha's amps have rather a lot of negative feedback which gives them decent harmonic distortion specifications, but they are an unpleasant source of phase distortion. Cheers, Alan Tomlinson
@@diegorhoenisch62 _Phase distortion?_ What? I mean, with the undegenerated BJT input stage it's not going to be a slew rate king, though relatively high gain ought to help with that, pulling off an amplifier this powerful with an EF2 seems like a bit of a stretch, and the output stage is a tad underbiased as they usually are... but it is a PA amp after all, they're not expected to be the last word in fidelity, and this one still easily qualifies as hi-fi. If you want a model that's beyond reproach by any standard, the ones to look for would be from their mid-80s lineup, like the P2250. Later ones went back to being a bit more on the rustic side, and by the mid-'90s even the noise level had begun to suffer.
Holly man - you made even the protection cover from output transistor kept outside !!! - unbelievable job !!! - Its a analog monster !! - It last years and years right now !! - Lovelly pro amp !!
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.
I was at a guy's house who'd run a brick and mortar hi-fi exchange for twenty years. Audiophile gear. I checked out his personal system. He had about fifteen amps altogether. Both integrated and pre/power. I was surprised to see one of these in his collection/setup. I asked him about it and he said it's an excellent sounding amp. Pretty high praise coming grom a guy who had his choice of basically anything out there.
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.
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.
@@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.
@@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.
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.
Outstanding work once again Mark, you really are a renaissance Man. It is truly a pleasure to see you refurbish, repair, and fabricate parts where needed. Very impressive work Sir.
Very impressive work you do not everyone can do...fantastic building of the Transistor shields...cool.. nice Equipment you have either...and a great knowledge in Electronics...
Toured in the 80's early 90's with racks of these running massive tour systems and monitors, I cannot remember one failing , rigged through a Trainor tour console, with a complete Shure Microphone's, FX from Peavy, nothing wireless at all, did not exist in my world. Best touring package I had in 25 years on the road. Thanks Yamaha, you made sure a lot of us tour techs looked good to our employers.
I just enjoy these more and more. Been designing electronics professionally and hobby for 40 years, but not really done much faultfinding and seeing your work is inspiring :)
I can't believe I spent nearly an whole hour watching this, but I enjoyed it. Only tiny mention, I tend to preclean all soldier connections and avoid reusing any existing used solder, but not a big issue at all now is it 🤠 "73" from California
I can Mark really doesn't want to see this amp a second time. A thorough cleaning, testing, refreshing caps and heatsink compound and replacing the missing components.
I have to commend Mark again, not just for the diag and repair work, but for the camera work and editing. He doesn't just record one camera angle, but usually gets a close-up of every single step. Like adjusting the pots, he often shows a shot of the pot itself, then a shot of the multimeter. In this video, he showed BOTH pots, the inrush current, a close-up of turning the power switch on and off, plugging in the jacks, adjusting the volume, showing the o'scope, showing the distortion meter, and even making new cover plates for the transistors. I can't imagine how long it takes to make one of these vids. lol Great channel.
Greetings: A fine gem that is. U picked a great unit 4 the presentation. Yamaha, 70s and the problem were great combinations. I miss that era. Things were simple, durable, great quality and function by Ppl and companies that had pride. Now, not the case. All is crap. I serviced that model and many more in the day. Nearly a pleasure 2 service. U did a great job. Thx 4 the share.
yo sueño con tener un taller asi, y por supuesto, tu nivel de conocimiento para hacer tus trabajos... es impresionante, no conozco a nadie en Chile que llegue a ese nivel. Saludos Maestro!
a music venue I used to engineer at in Essex had three of these running FOH, they took a serious amount of punishment as well as cigarette smoke, you sir are a wizard.
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!
During the early 80's i used these amps in my touring PA system, It was a combination of P2200's which had meters on the front, P2201's like this which was the same but with no meters, And also some later P2200 which had 8 output devices per side and could also do a 2 ohm load. All in all i had 48 of these , they are loverly sounding amps.
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.
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.
Mark, you're the best, hands down! I'd love to purchase an older Sansui receiver from you if you ever come across one or have one! I've been looking for YEARS! ANYBODY???
That amp was one of the most transparent of the early amps. Crown was so harsh in the mids but the Yam's were just smooth when the crossed the A-B boundary. Phase linear was also popular and pretty good, and so was McIntosh. The Mc's were a little hyped. Any of these older liner supply amps have a sound quality that makes a lot of modern amps sound like junk even if they have tons more power. Awesome to see your work!
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.
I signed up immediately! I didn't understand a word because I don't speak English but I'm sure it will be great!
? M)) p)ft
I signed up, can't wait. Greetings from Milan, Italy.
Is it going to be on youtube, or is this going to be somewhere else like Twitch or something?
of course, for me in German 'VE99' and 'curious marc' is nr 1, than 'mr carlsons lab'..
Fabricating those transistor covers is just next-level refurb; not only painting, but matching the text. Awesome.
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.
I would have used TO-3 plastic covers!
@@OC35That was my initial thought as well….
Until you realise that the transistors could get quite hot in operation, particularly at high output powers, possibly leading to the plastic covers partially melting..
Also, since the plastic TO-3 covers just clip on, they could easily be removed by a “curious” owner leading potentially to electric shock if touched.
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.
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.
"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
Wow, that's bizarre.
If it’s the same John I knew him too, I was an AV tech at Gear House in Birmigham and he would come in and service the broken equipment. I think his sons name was Ziggy.
@@robnickels7267 It is indeed sir, and I remember you being there also under the supervision of the "Fat Controller". Mr Mandeville.
WOW ! 100 years ago I picked up a P2200 (same amp only with VU meters) in my last year of high school. I lugged that beast and a pair of Klipsch LaScallas around for years. All through college, got married moved into a brand new home they were with me every step of the way. Fantastic amp, never had a single problem. Makes me sad to see the condition of that old girl that you were working on but you brought her back to life good for another 50years. Great job, respect. I'm in Phoenix, Arizona and enjoy your accent and even temper. Thank You for posting.
Do the meters still work? We rebuild these often but the meter drive circuitry is encapsulated in epoxy, and so, no repair there. I'm going to build/design a replacement board next year hopefully
Dare I say that Mark's videos are on the edge of being therapeutic to watch! Thanks so much, Mark!
He is such a positive guy!
Absolutely! I 100% agree!
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.
it's approaching an addiction for me. I love this guy. Every aspect of his uploads are excellent.
Agreed - I'm working my way through all the past episodes.
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!
Absolutely - go straight there when there is a new one!
Totally agree!
I'm so happy when a new video is uploaded!
I agree!
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.
Mark shows us a level of craftsmanship that many ‘repair shops’ don't even know exists.
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.
Totally agree. I’m sure he’s a guy you could have a drink and share a laugh with too.
Yep, I can think of one with double the subs and I don't get it !
Spot on! Let's get him more subscribers
Like watching a whodone it on telly
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 TH-cam videos.
Mark is one of my favorite net personalities. Straightforward with no mucking about. Can't wait to see the new digs.
@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 TH-cam.
Mark exudes confidence and competence. You know he’ll sort this disaster
This is more than just mending. To see someone taking care to recreate missing parts from raw steel is truly a labor of love.
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.
No surface mount items, no chips...ah the joy of components that can be examined, tested and replaced without magnification!
Built when amps were designed to be fixed before tomorrows gig.
@@alfsmith4936 Nooo, these are built to be fixed during the gig ;)
Great job fixing this amp. These old Yamaha's perform extremely well and are of much higher build quality than what you'll find today. I actually have the model P2250, which is very similar to this one. Thanks for saving this one from the junk heap!
We did some blind shoot outs with amps for a JBL 4435 monitor system at a studio I worked at, we ended up with P2200s over some much more esoteric offerings. The bean counters were thrilled too!
I agree, the old stuff had much better quality compoents in it, and you can hear that. Look how chunky the induktor is, how solid the psu is, maybe not 100 percent efficient in power consumption vs heat. I would also love my old Technics Amp back.
You won’t find anyone as professional as Mark he’s the best !
Mark, your attention to detail and general knowledge and professionalism never ceases to amaze. Good luck in your new workplace
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.
Imagine what it does to ya lungs.
@@BTW... and yet some people are now carrying around pocket sized smoke machines to suck on them at any free moment they have
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.
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.
@@BTW... it's also used in inhalers
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 😂
😂😂😂
I'll be sending him my Dumble next week then.. I don't know why it's not working. It's very light too..
LOL!!!!
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!
7 days on a Sunday 💯😂
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.
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.
It's better to watch you working than to watch a Hollywood action movie. Lots of love and regards from Pakistan. Stay blessed.
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 TH-cam channel one of the best around.
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 know exactly what you mean
I'm American and I love your accent. You are my current favorite TH-camr. Awesome job, I was mesmerized.
Can we all admire what appears to be masking tape with “nope!” written on it :D
"Nope!" ... We can't!
I do that at the Cooker before the wife begins
I've worked in nightclubs for a couple years (yes, I have hearing damage) and that sticky residue you mention at 8:49 is most likely from the hazers they use, as opposed to dry ice as you say. Depending on how long this particular unit has been in service, it may have seen both oil-cracker and water/glycol haze in its lifetime.
Excellent video. :)
I’ve watched the Yamaha repair again for the third time. So enjoyable to watch. Like rereading a good book and you still pick up new things from Mark!
what you do goes way beyond repair. you're not just a professional, you're an artist. im so glad that I found your channel. bravo
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.
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.
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.
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.
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
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.
Mark, you make these repairs look so easy! The missing parts is simply amateur workmanship and unforgivable.
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.
@@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.
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.
Also possible that the amp was cannibalized for parts (those rare transistors in particular).
Back in the day, If it works for tonight's gig, it works until it needs fixing again.
Cover fabrication at the end was just amazing. Really rooting for this channel to grow big.
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!
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(;
Sell the amp to Tom Evans as a guide "how to build something that lasts"
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!
A sunday with Mark! Splendid
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.
Absolutely amazing repair! You can't admire more that these amps never get old!
Thanks Mark
This is some serious workmanship. Mark you are amazing.
This channel is criminally under appreciated, when you reworked that motor a few videos ago that hooked me in.
Thanks Mark. Real entertainment on a sunny Sunday afternoon in North west Germany
Had a Yamaha C-40/M-40 combination bought in 1984, a beautiful amp combination and well constructed. Sold them when I was in a 1 bedroom unit and there wasn't a lot of space.
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 😄
I mostly have no idea what you are talking about but your style is very engaging so I keep watching
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!
I was really impressed with the steel bending and the printing. You do wonderful work. Thanks for sharing.
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.
i watch his videos only for pleasure..this guy seems very humble and nice...
Hi Mark, I have this exact same amp and have had it from new when I bought it in the 80's. It still works brilliantly, it is built like a battleship! Thank you so much for uploading this video, I have learned so much from it.
I'll miss the old workshop for sure, Mark. Quaint. Calm. Homey.
I aquired a P2201 in 1986. Legendary. Indestructable. Great sound at home in the HiFi and kicked ass in school gymnasiums, weddings and hockey arenas. That and the P2200 are some of Yamaha's best work.
Having worked with that model in the early 1980s, I can't agree with your assessment at all. Yamaha makes some excellent drums, great brass instruments, very good motorcycles, and they make amps. Not great, not good, but adequate. Yamaha's amps have rather a lot of negative feedback which gives them decent harmonic distortion specifications, but they are an unpleasant source of phase distortion.
Cheers,
Alan Tomlinson
@@diegorhoenisch62 _Phase distortion?_ What?
I mean, with the undegenerated BJT input stage it's not going to be a slew rate king, though relatively high gain ought to help with that, pulling off an amplifier this powerful with an EF2 seems like a bit of a stretch, and the output stage is a tad underbiased as they usually are... but it is a PA amp after all, they're not expected to be the last word in fidelity, and this one still easily qualifies as hi-fi.
If you want a model that's beyond reproach by any standard, the ones to look for would be from their mid-80s lineup, like the P2250. Later ones went back to being a bit more on the rustic side, and by the mid-'90s even the noise level had begun to suffer.
Looking forward to seeing the new workshop.👍🇩🇰
Mark - so impressed with your faultless fault-finding. Your metal-working was the icing on the cake! (and label-printing off the scale..!)
He’s Mend it Mark AND Bend it Mark…!!! those covers are awesome! 👏 🔥
Mend it, Bend it and Print it Mark!
I used to have a P2100 - it worked great - was bulletproof and sounded great too. Nice to see one being fixed.
I am a hard man to impress but you impress me very much Mark
I'm sure that Mark is not that wayl inclined
Holly man - you made even the protection cover from output transistor kept outside !!! - unbelievable job !!! - Its a analog monster !! - It last years and years right now !! - Lovelly pro amp !!
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.
Used a P2201 for 8 years for our band's live shows. Over a thousand shows and never a problem. Great amp. But I do remember it being VERY heavy.
He’s so clever. It seems like there is always something new to learn in each video.
I was at a guy's house who'd run a brick and mortar hi-fi exchange for twenty years. Audiophile gear.
I checked out his personal system. He had about fifteen amps altogether. Both integrated and pre/power.
I was surprised to see one of these in his collection/setup.
I asked him about it and he said it's an excellent sounding amp.
Pretty high praise coming grom a guy who had his choice of basically anything out there.
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.
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.
@@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.
@@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.
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.
Outstanding work once again Mark, you really are a renaissance Man. It is truly a pleasure to see you refurbish, repair, and fabricate parts where needed. Very impressive work Sir.
Excited to see the new workshop!🙂
Superb video - it certainly brought back memories of casting envious eyes over Yamaha amps back in the 1970s, which seemed very classy at the time.
I'm kind of sad that you're moving to another shop yours has such honest character
This show is the best, he got every tool needed under the sun.
It feels like Christmas! Mark has turned up!
Very impressive work you do not everyone can do...fantastic building of the Transistor shields...cool..
nice Equipment you have either...and a great knowledge in Electronics...
Toured in the 80's early 90's with racks of these running massive tour systems and monitors, I cannot remember one failing , rigged through a Trainor tour console, with a complete Shure Microphone's, FX from Peavy, nothing wireless at all, did not exist in my world. Best touring package I had in 25 years on the road. Thanks Yamaha, you made sure a lot of us tour techs looked good to our employers.
Mark, you go after these complete basket cases! Once I saw all those transistors missing, I was yelling TRASH IT! You are amazing!
Sunday is complete… cold beer sitting in the garden with Mark… 🎉😂
I just enjoy these more and more. Been designing electronics professionally and hobby for 40 years, but not really done much faultfinding and seeing your work is inspiring :)
New workshop?.......looking forward to it!
I can't believe I spent nearly an whole hour watching this, but I enjoyed it. Only tiny mention, I tend to preclean all soldier connections and avoid reusing any existing used solder, but not a big issue at all now is it 🤠
"73" from California
I can Mark really doesn't want to see this amp a second time. A thorough cleaning, testing, refreshing caps and heatsink compound and replacing the missing components.
This is not a repear it is a complete makeover.
The making of the heat sink rail covers was great alone.
Excellent video and skills in a fun presentation.
Bien, otro maravilloso video 👍
I didn’t have a clue what you were doing from beginning to end. But I still watched in fascination.
MARKKKK!!!! 😊
I have to commend Mark again, not just for the diag and repair work, but for the camera work and editing.
He doesn't just record one camera angle, but usually gets a close-up of every single step.
Like adjusting the pots, he often shows a shot of the pot itself, then a shot of the multimeter.
In this video, he showed BOTH pots, the inrush current, a close-up of turning the power switch on and off, plugging in the jacks, adjusting the volume, showing the o'scope, showing the distortion meter, and even making new cover plates for the transistors.
I can't imagine how long it takes to make one of these vids. lol
Great channel.
indeed. The viewer almost has a better view than the engineer!
Greetings: A fine gem that is. U picked a great unit 4 the presentation. Yamaha, 70s and the problem were great combinations. I miss that era. Things were simple, durable, great quality and function by Ppl and companies that had pride. Now, not the case. All is crap. I serviced that model and many more in the day. Nearly a pleasure 2 service. U did a great job. Thx 4 the share.
yo sueño con tener un taller asi, y por supuesto, tu nivel de conocimiento para hacer tus trabajos... es impresionante, no conozco a nadie en Chile que llegue a ese nivel. Saludos Maestro!
a music venue I used to engineer at in Essex had three of these running FOH, they took a serious amount of punishment as well as cigarette smoke, you sir are a wizard.
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!
I'm an EET student and I share your videos with my fellow students. You are the reason I got into working on legacy equipment!
Thanks!
During the early 80's i used these amps in my touring PA system, It was a combination of P2200's which had meters on the front, P2201's like this which was the same but with no meters, And also some later P2200 which had 8 output devices per side and could also do a 2 ohm load. All in all i had 48 of these , they are loverly sounding amps.
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.
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.
Mark, you're the best, hands down! I'd love to purchase an older Sansui receiver from you if you ever come across one or have one! I've been looking for YEARS! ANYBODY???
I don't know much about electronics, but it's always like a thriller to watch you; your skills are fascinating.
That amp was one of the most transparent of the early amps. Crown was so harsh in the mids but the Yam's were just smooth when the crossed the A-B boundary. Phase linear was also popular and pretty good, and so was McIntosh. The Mc's were a little hyped. Any of these older liner supply amps have a sound quality that makes a lot of modern amps sound like junk even if they have tons more power. Awesome to see your work!