1977 Pioneer AV Receiver (SX 550)

Mark services a vintage Pioneer receiver, and gets a bit carried away. Has he gone too far? Absolute geek!

[@revamp777]

This is the best hifi repair restore technician in the world, breathtaking work .

[@electronicengineer]

Hello Mark! Silver plating the power switch contacts, after perfectly recreating dome shaped surfaces on both contacts... I have not seen anyone on KZbin ever go through that much fine, precision work to restore a vintage power switch! You are clearly in a league of your own. Beautiful attention paid to every detail, to the point that you even consider the next repair person, when reattaching component leads speaks volumes to your ethic as well. I love your work. I am so happy that I found your channel. Please keep it up as this is really great stuff! Thank you for showing all of us how it should be done proper! Fred

[@angappan]

Sony dvd

[@kendom33]

Absolutely agree :)

[@Johnathan_Waters]

Oh yes! Agreed for sure! Subscribed!

[@JonnyMac351]

There's a lot of great content being created like this channel i have a few other repair channels i like to watch while i'm waiting for new content to be released. I probably waste to much time watching all these channels lol.

[@madhatter2k]

@@JonnyMac351 What are your other favourite repair channels?

[@camurabeck65]

I am from Brazil, and this is the best hifi repair restore technician in the world !!!!

[@bobmonzo3137]

These are some of the best repair videos on KZbin. The silver plating was above and beyond what anyone would do. Subscribed!

[@DavidFRhodes]

+1. i was disappointed he didn't use gold however ;)

[@K-Effect]

Silver conducts electricity better than gold

[@DavidFRhodes]

@@K-Effect ah, but gold doesn't tarnish

[@K-Effect]

@@DavidFRhodes high purity silver tarnishes at about the same pace as high purity gold

[@thomasmleahy6218]

Very minor quibble, as the contacts will slowly deteriorate over time from the effects of the electricity when contacts mate and break. It's nowhere near a sealed relay. Future repairmen will probably be more curious about the lighting regulator! Jolly good show 👍

[@Mcqlfc]

The joy of finding a Mark video that I forgot to watch. The guy is a genius and therapy!! Thank you Mark!!!!

You are an Artist in electronics, mechanics, physics and chemistry. I am a a very old engineer and professor that armed valvular and transistor equipments in the 50´s to the 80´s. I admire you , and give me Hope in young people like you. Cheers from Patagonia, Argentina.

[@soulrobotics]

eh! un argentino a la curulla! yo armé equipos hibridos valvulas y transistores por los 70's! y todo empezó con la revista Lúpin a los 5 años! jajaj.

@@soulrobotics Excelente!!!!Saludos

[@mohammadmakhlouf4]

You have a very pure soul and I always enjoy watching you Your follower from Palestine ❤

[@davignonmemarc3000]

What a patient and resourceful person !

[@alanrichardson1672]

Hi Mark, what a pleasure it is to watch a real pro working on this high quality old audio equipment. 👍

[@fretlessfender]

Mark, that re silvering of the contacts was a brilliant move! That is what I like about your channel. Inventive! Love it! Keep up the good work and your channel will grow, you are up there with the best!

[@nakfan]

Exactly my thoughts… just subscribed a few days ago…and after 3-4 videos Mend it Mark is at the top of my list… BR, Per (DK)

[@100SteveB]

I love the engineering that went into making these old units. (I say 'old' reluctantly because I remember when these were the latest thing!) Made to last, and made to be repaired - something so sadly lacking in so much of today's tech. Just love the extra mile Mark always goes when restoring or repairing them. One of the very best techs on KZbin for this kind of stuff.

[@adrinathegreat3095]

They cost about a month's wages when they were new, they were very expensive. I'd guess the cost of that service and repair work would far exceed it's actual value. But it's possibly someones pride and joy.

[@EnthusiastPC]

Your knowledge has become a rare thing these days - which I think is worrisome - but a sight to behold. Absolutely brilliant, please keep teaching this knowledge. Absolutely brilliant!

[@rayofcreation3996]

Quite right. Well said.

[@SS-qy9ec]

I could watch you all day, thank you for such great content!

[@Plons0Nard]

The ions in the silversolution can only travel to the target and deposit there, when the cotton swap (in the stainless steel holder) TOUCHES the target. As soon as you take thw swab off, the deposition proces stops. Just fyi I enjoy these repair video's a lot, impressed with your skills. It puts me in a good mood. And mode 😉 Cheers from the Netherlands 👍🇳🇱

[@TexTom1981]

I worked in a dept. store and sold a TON of these receivers...and the bigger siblings as well. They were quite good for the money and super attractive designs.

[@peterlarkin762]

Fair play Mark, nice to keep the original switch going. Artisan electro-mechanical repair! I was going to do the same for my Arcam A60 power switch, then luckily found the exact same switch is still manufactured in the Uk, 45 years later!!

[@tompas11A3n52KkX]

Never seen anyone doing all that work to the contacts points, silver plating and all that. Fantastic work! And another good news is you got yourself a new subscriber! Hurray!

[@MadScientistsLair]

This is probably their best analog receiver lineup overall due to appearance, performance, and ease of service. All have discrete outputs save for the oddball SX-650 which uses SanKen SP-40W modules. I just did an extremely comprehensive service and upgrade on an SX-650 including a full recap, new schottky rectifiers, retrofit OPA1611 opamps and discrete output retrofits. For my efforts, the customer gets

[@jimmy_jamesjams_a_lot4171]

THAT’s my old man’s receiver!! I really love that heavy block of a tuner dial on that beast. And I’m happy to see a view from under the hood. Mine never had that color glow to it so yeah that LED mod is different. Oh my!? The days when knobs and dials had strings wrapped around cogs and strung all in and around the inside. Thanks for a very long life expectancy of these old Pioneers and Yamahas, nobody will ever need another newer model!! Those good ‘ol days, when they used those offset encoders and string wound around little pulley wheels, and those stacks of plated tuning capacitors with ceramic insulation. Single Damned tuning cap is the source of half of the cost and half of its weight…

[@WolfmanDude]

Love your spectrum analyser! What an absolute classic instrument, these still cost 2k on Ebay!

[@nakfan]

Oh, what a joy to watch 👍 Learned a lot too… After watching 3-4 videos with Mark, this channel has gone straight to the top of my viewing list… 338k subs would have been more fitting… He might pass the 100k mark sooner than we think though… All the best from Denmark, Per.

[@vicsutton2]

That is dedication for perfection, workmanship par excellence.

[@quantumleap359]

That damaged power switch is the reason years ago I put all my audio gear on a switched AC mains relay. A remote toggle for the 12 volt relay coil serves as a total system on/off switch. Great video Mark, you had me going at the very end when you *appeared* to let the "disco lights* pass! I was thinking "Mark! 10 volt three lead regulator!"

[@lameduck9]

First time I've watched your videos Mark and I've loved it. I'm not technical at all but your style, presentation and know-how is brilliant. Thanks mate, you've got a new sub

[@danhorton6182]

Awesome work mark, going that deep to clean the switches was a great show of dedication. In order to overcome the flickering lights once switching to led I build a small rectifier using 1N4001 diodes, dropping resistor if necessary and filtering capacitor (maybe 470 uF -1000 uF for those three lights). Hasn’t failed me yet. That regulator mod is a brilliant one.

[@hernancoronel]

How cheap of you Mark to just use silver! You should have gold plated them, LOL! 😂

[@enoz.j3506]

Now that was in depth,very few engineers would of gone that far, made for an interesting repair. I thought when you established the led fluctuations were down to the TX not having a stiff voltage,that a regulator would sort that,then you sorted it. Proper repair. Just to ad,engineers time is expensive,thats the reason most say some items are just beyond economic repair (BER), most customers dont want to spend over what the units worth. I like the old school equipment, and repair for the enjoyment factor,i'm retired & lucky to have that option. Thank you for your uploads Mark.

[@zp5908]

Hey Mark you are genius, & I do share those to my brother in India & my friends too though we are not technicians but love the way you always smile & laugh while enjoying your work to the maximum. Cheers !!!

[@eelofgold]

Love your work mate. You’re the guy I’d want working on my gear. Keep ‘em coming!

[@HarriGary1]

Hearing the birds in the background was nice. That seems like such a peaceful workshop, coming from an automotive technician.

[@richardspees841]

Brought back memories. That was my first receiver when I was a teenager. Nice to see one has survived this long. Thanks for the memories.

[@roasthunter]

Some great attention to detail, it's amazing how you make cleaning and repairing a switch interesting, a testament to the quality of your work and your character, your videos are a joy to watch.

[@rayofcreation3996]

Absolutely!

[@felixthecleaner8843]

just found this channel -it's great! I have a Pioneer Receiver from the same era - it's still awesome sounding. love watching you work.

[@triceps1961]

And I always thought I went the extra mile, but silver plating the power switch contacts is almost unbelievable. Wow

[@montygore1200]

I learned over my many years in this business to look how well a tech keeps his iron tips. This tells me you take pride in the quality of your work. I just found your channel last night and have tons of fun watching. I have never plated anything and was amazed how well you made it work. Thanks for the fun.

[@D.Hozzie]

Just awesome knowledge Mark. Thank you for the opportunity to join you.

[@thomasmleahy6218]

Most impressive operation so far. Can't believe you plunged into murky waters so willingly and surmounted the many surprises in this operation. Great video 👍

[@cjh0751]

Hooked on your channel Mark. They don't make 'em like that anymore. Beautiful green glow on the receiver. As Eevblog would say " a thing of beauty is a joy forever".

[@paddle_shift]

Enjoy seeing your subtle smile and laugh when you work, also heard a slight whistle too. Doesn't take much to make me happy, your work does that to me.

[@graemeguthrie2054]

Fantastic job and a very good video. You are a very skilled electronics engineer.

[@HansDelbruck53]

Technician

[@johnwilliamson6506]

@@HansDelbruck53 You’re kidding right? This man is every bit an electronics engineer and then some. Many elements of what you see might be classed as technicians work, but I can assure you he is way more than that. Analogue, RF, digital and many more design skills are demonstrated in his videos. And I by no means belittle the name of technician here either, as that is a deeply skilled class. But to have the knowledge demonstrated by Mark there are many years of varied design work gone into achieving that.

[@Arsenal18862006]

Half of the time I haven't a clue as to what you are doing or talking about, I still applaud when the toast pops up out of the toaster 😉. Mesmerising stuff and a bloody genius at work.

[@switthoft]

Loved the needle/frequency adjustment detail. Thanks for showing that approach!

[@saskia6750]

LOve your videos Mark,so glad i found your channel,thank you for your informative work and joyful approach to fixing things x

[@jameshobbs1460]

Just found your channel riecently and your work and attitude are fantastic top notch.. not many people have your skill nor dedication.. you should pass this knowledge along to another.. wonderful.. just wonderful..

[@bhopale1]

Love electronics videos but yours are very well explained and don’t feel board at all, and the end is always happy and that’s the beauty of the KZbin. I do have vintage HiFi stuff and everyone of them need some sort of attention and I think you can be the best person. Please continue to upload new videos

[@spottedtauren]

Absolutely amazing amount of work to get that thing working properly. Great video.

[@ChrisHopkinsBass]

My dad had a Pioneer turntable and amplifier when I was very young. Seeing the knobs and typeface on that receiver brought it all back

[@Andrewong77]

i just got to know your channel....first class in everything....what a joy..

[@rayofcreation3996]

Well this is not just troubleshooting but craftsmanship. Awesome!

[@LZDEN]

first class work Mark,and a very interesting video. well done to you.

[@MrCarlsonsLab]

Nice work Mark!

[@MendItMark]

Thanks! Great to see you on here!

[@tomharris1457]

I love the happy way you work. Fun videos.

[@1bigpaddy2012]

Very impressive work. That’s sure is dedication to your work. Big pat on the back for you mark. “We’re not worthy”

[@johndale7760]

Another great vid Mark, I hope radio tech schools are using your YT clips for practical training! Great work with the contact plating - I must admit I'd probably just clean the contacts and re-assemble, customers just won't pay for lengthy repairs. A couple of points for young viewers (a) don't let your soldering iron anywhere near the dial cord - it vapourises it!, and (b) using the 3 terminal reg for the LED supply was a smart move, but ideally wrap the input/outputs with a 10uF tantalum cap to ground, as they tend to oscillate if not damped. Not want you want in a Rx. Thanks again Mark, your videos are totally engaging and educational.

[@leemartin2978]

I don’t understand the first thing about electronics , but I find this fantastic and interesting to watch. It’s brilliant that people still have these skills, and are repairing this quality equipment. I can’t imagine how much all that testing and measuring equipment cost ? I’m looking forward to watching more having discovered the channel

[@rayofcreation3996]

Exactly!😅

[@madtopp]

tony is a very happy camper mark i have had the nobs of a few times when cleaning the pots so they would come of easy funny enough i was just useing the amp before watching this video with a twin pair of memorex 505 speakers i got yesterday and she performed perfectly. i was a bit weird to see the amp disassembled but really interesting on the same note and if it needs any work again it will be coming back to you as you know i have the next item ready and waiting to be dropped of to you . plus it was nice to see a lot of them machines you use to help repair A GREAT VIDEO

[@jimmyers8795]

Hi Mark, love you videos, I just found this one. I used to do industrial Gold plating on PCBs back in the day, I used Potassium Cyanide too. There was one golden rule - never have acids anywhere near Potassium Cyanide solution including distilled water that you've cleaned acidic products in, Hydrogen Cyanide gas is deadly (used in gas chambers), you really can't be too careful with it.

[@joanfrellburg4901]

I love the rock solid feel of these units from that era. Great video and skill beyond what I was expecting to see, and the plating, and microscope view wowzers.

Good Job has always, I like the old stuff plenty of room inside..

[@Bevoin1970]

I've just found your channel too. Mostly I have no idea what Im looking at or you're talking about, However I love this Channel. You would definitely be my Go-To man if ever I needed any Hi-Fi fixing. You explain and show things very clearly. Fascinating! Keep up the great work. I think you are a dying breed in this modern throw-away world. 5*

[@michaelclutton8446]

Have just found your channel, really enjoying binge watching the videos

[@TheBudliner]

It’s amazing the wealth of knowledge in this young man’s brain

[@kepler_200]

Thanks for your videos and help. To the community of vintage.

[@littlediablo]

Excellent work Mark.

[@donmoore7785]

The power switch contacts looked totally knackered - impressive repair. A regulator on the lights is the perfect solution.

[@kennorton1478]

wow that is a sophisticated way of repairing electronics. wish you are close to here in Australia to send you my devices that need some taking care.

[@Rondo2ooo]

Back when engineering beautiful receivers made sense because there was good music to listen to on the radio.

[@Stuart_Cox1969]

That was brilliant, I'm really enjoying watching you work, thanks.

[@GreyRockOne]

Beautiful work! Very thorough. although it looks like you forgot the support bracket or bridge on the power switch during reassembly, no problem. Thanks Mark!

[@wookychewbacca5184]

Watching your videos brought back memories of a couple of repairs I did (had been putting off) on both my 1980 vintage stereo components. First was the balance pot on my Sansui receiver, I had tried spray electronics cleaner but that didn't work as I could actually feel something inside had worn. I sourced a used pot online and installed it, success. The other was my Technics SL1600MKII turntable, it would power up but nothing else would happen. On disassembly I discovered the remnants of (IIRC) 2 belts that operated the tonearm functions. I sourced new belts in the form of correct sized "O" rings, again success and now my stereo once again rocks as it should. I still have one "lost cause" in the form of a Marantz SD8020 Compudeck, it never worked correctly with Marantz techs claiming they could find no faults with it

[@koraypekericli]

Brilliant! Thanks for brightening my day with your high mood. Koray from Ankara

[@johnh5896]

My word you do love your craft ,fascinating to watch.I had a 450 that switch was arcing bypassed it threw a line switch for on off and sent it to the pawn shop .People are starting to realize how well those 70s were designed are going ga ga for them now 😅I see the prices going up now

[@jimmyvthejedi]

you're a legend Mark .. you should get an olympic gold mate !!

[@SuperHaptics]

Genuinely cheerful 😊 !!! your videos are a joy to watch thanks man

[@thomasmoorhead2326]

I had a receiver that looked just like that. In face, I can't spot any differences, although I don't remember the model nmber. My dad bought it at a garage sale for $5 in about 1983. It had apparently been dropped onto the front. Wasn't too bad, but it slightly bent the tuning knob shaft. I made a couple of repairs inside also, to the switches/pots. I don't recall the exact damage, but it did work pretty well. I took it to university and beyond. I do specifically remember, though, that even the original incandescent bulbs would pulse with the music. You're correct, it wasn't as sharp as those LED bulbs, but it was still there. It was an apparent "design feature." Love the videos!

[@nt004b9392]

And whilst the wife watches her soaps I watch you 😎 Happy Times.

[@MendItMark]

That's also when I edit them!

[@ferraridinoman]

Such a talented likeable guy! 5 *****!

[@olivertwist1975]

Bringing me back in time when I use to fix those units, with the ECG Cross reference Book the bible of Electronics back then. Though i hated re-wrapping those tuner chord going to the dial indicator. Loving the videos though thanks for the trip back in time

[@WouterB76]

You're very skilled Mark, my compliments!

[@ellesmerewildwood4858]

For tarnished contacts, if the item can be removed from the device, I always use either Evaporust or an equivalent product called Metal Rescue. They are designed to remove rust from iron but also work beautifully cleaning up brass and copper and will remove the blue crusties as well. Neither product will harm paint or plastics or any other metal, either is fantastic stuff. As for the burnt contacts, I've been faced with similar situations and have chosen to sacrifice another new switch or relay by taking out the contacts and replacing the burnt contacts since I don't have the facility to re-silver. In any case, sometimes the contacts are so far gone there's no chance of sanding them down and replacing the contact, if it's possible, is the only solution.

[@georgebarnes8163]

I use Milk of Magnesia (the stuff for upset stomachs) works a treat

[@MrIanmmackay]

Fantastic - You usually lose me soon after the introduction, though I did understand the electro-plating bit in this one and I know how to solder... I've watched a fair few of your videos now and every one is riveting and above all a real education!

[@heidi9272744]

I had one of those Bigtrak toys along tine ago as shown in the intro. Reall fond memories ,

[@mrbrooks9969]

What a great way to spend my morning. Thank you.😊

[@googledagain]

This is all a bit of a blast from the past!! (I used to do tellies - well of course you can't really do much with them nowadays). I looked swiftly at an online pdf schematic and notice that it's an AC 8V take-off from the mains tranny that fed the original lamps. I don't know how the LED mods manifest themselves, but taking into account they can only be internally fed with DC, why not just mod it with a little bridge and a reservoir of some sort - it's AF that's affecting it so something in the 10uF to 100uF range perhaps?. That ought to stop it flickering. I bought an SX727 which is languishing in a spare room awaiting some attention and even have an LED kit for it, so I'll be looking to see if I get some of the same symptoms when / if I finally get around to it! Very interesting and slightly addictive channel! Very nice workshop too.

[@ronaldpors9282]

Mark..your the best and a fine pro..love your video,s thank you. greats from Holland.

[@deangale4496]

Glad I found your uTube channel mate

[@mattyde88]

Danke für deine schönen Reparatur Videos! Ich verstehe deine Sprache leider nicht aber ich weis auf was du hinaus willst. Reparaturen mache ich auch aber deine Profi Ausrüstung hab ich leider nicht. Außerdem kann ich nur mit 8 Fingern arbeiten weil meine linke Hand teilweise gelähmt ist. Aber wie gesagt: Wir lassen uns nicht die Wurst vom Brot nehmen! MfG Mattze!

[@jeremiahchamberlin4499]

I’m glad to learn I’m not the only one who uses a crescent wrench 🔧 on those control mounting nuts. Great job on the master mode switch.

[@plunder1956]

I had (and still own) an Analogue display FM tuner made by Trio. With a good FM aerial it produced a beautifully crisp & clear signal on R-3.

[@clarkpink1955]

Great work mark look forward to your vids

[@RobertMattison-pp6uf]

I still use a Pioneer AV Receiver SX 737 still going strong all these years with no trouble.

[@colinedwards1163]

great job i love the level of detail you go to

[@jefffoster3557]

Wow Mark! Love your thoroughness ! Subscribed. I have a few Sansui G9000s that could use this type of attention. I may have to get one of those cleaners you dunked the components into.

[@anthonydenn4345]

Nice recondition. You don't see anyone on youtube go to the trouble of replating contacts. The resistance test when you finished it was interesting. Might of been revealing if you got a before and after test when you polished them. The cyanide bit sounded odd. I think going by the net, it's used to liquefy the silver. You learn something new everyday. Thanks for another great video : )

[@ExtremeBogom]

Another excellent video Mark. You put a lot into these repairs, not to mention all the filming and what not. A big fan of your videos. Keep on mate :) 👍.

[@machse69]

Excellent video very intuitive and a great job to boot thanks for the upload Mark!

[@GeeWillikersMan]

I had one of these or a model dang similar. It was in my room all through my teen years up until the time I got married. Scrapped it maybe 10 years ago for parts.

[@renaldonormani6646]

Phenomenal switch repair! Loving it!

[@wholiddleolme476]

Those switch contacts remind me of the ignition coil points in the distributor of older vehicles, regular filing of those contacts and dwell angle gap to keep the ignition system functioning at peak. Those were the dayz, thankfully now hall-effect sensors did away with that menace, but created a whole new set of issues lol.

[@mostrush4849]

Hey mark you do magnificent repair jobs and we love to watch you with your beautiful smile. So please be careful about poisoning with chemicals they are silent killers always wear a proper mask it does really matter. And about the regulator I strongly recommend stepdown convertor over them , regulators are hot pains they always kill them self specially when input voltage is much higher than output. I know they are noisy and unfriendly with audio and radio circuits but I think they are acceptable for lighting.

[@zaharmedved4804]

Такой отличный канал с таким качественным контентом и так мало подписчиков. Вероятно что он не рекламирует себя и в этом есть причина. Один из немногих профессиональных ремонтников которых можно смотреть с удовольствием. Браво мастер