Kenwood KA-405 Amplifier Service & MORE than Full Load Test.

Поділитися
Вставка
  • Опубліковано 21 січ 2025

КОМЕНТАРІ • 425

  • @GuyFowler
    @GuyFowler 11 місяців тому +23

    Zen and the art of electronics maintenance

  • @JanWesterink16
    @JanWesterink16 Рік тому +197

    You should rename you channel to the happiest electronics guy. I know absolutely nothing about this stuff but it is just lovely relaxing to see you working on stuff.

    • @mattym8
      @mattym8 Рік тому +19

      So true. This guy is the jolliest electronics tech on UA-cam

    • @gogs1606
      @gogs1606 Рік тому +7

      him and mr carlson the best ones

    • @bobmckenna5511
      @bobmckenna5511 Рік тому +3

      I have worked in the field, and I have to agree with you. He is far too chipper to be an actual electronic technician. Maybe because he’s working for them self :-)

    • @SergZak2023
      @SergZak2023 Рік тому +7

      Mark even laughs when he gets zapped by a residual 320v left in a capacitor!

    • @weyayemanjoe3082
      @weyayemanjoe3082 Рік тому +1

      😂 Nice one 👍

  • @tedmich
    @tedmich Рік тому +79

    I believe VERY few techs will pull all the switches and pots then ultrasonic clean, oven dry, re-lube and reinstall, there's simply too much chance of breaking an old part that could be impossible to replace. I appreciate your confidence and completeness!

    • @pauldavies6037
      @pauldavies6037 Рік тому +6

      I agree it is unnecessary this unit is in very good condition to start with old brital plastic can break so easily

    • @analogaudiorules1724
      @analogaudiorules1724 Рік тому +5

      @@pauldavies6037 if you know what you're doing it is the right thing to do for longevity, with some of those parts, good luck finding exact fitment or old new stock

    • @analogaudiorules1724
      @analogaudiorules1724 Рік тому +11

      @@pauldavies6037 It's the same thing with tech who don't recap vintage amplifiers then cry when one of them shorts out and takes out a transistor, ic or rare transformer you can't find or buy anymore and if you can find an official part is very expensive. An ounce of prevention is worth a pound of cure, this is the difference between a real tech going the extra mile and someone who does the bare minimum.

    • @yanfishtwig2356
      @yanfishtwig2356 Рік тому +15

      Yes but knowing mark he'l just go to the back of his workshop leap on a lathe mold a mold or twizzle a transformer winder and make a new part. Cape or no cape 😁

    • @JonPaul
      @JonPaul Рік тому +3

      He's also washing out all the grease on the controls - I never see him replace that. He does spray a coating in on the contacts but damn, I've made the mistake of washing out that grease and it wrecks the feel of the turn of the "knob" (control)

  • @LukeIshmael
    @LukeIshmael Рік тому +20

    Thank you for providing me with hours worth of entrainment. I’d rather watch your videos than the latest TV series!

  • @lokesh5
    @lokesh5 Рік тому +17

    Mr.Mark is dealing & fixing the problems with a smiling face.. so positive in his profession.

  • @williamhoward7121
    @williamhoward7121 10 днів тому +2

    Has anyone else noticed that Mark has two distinct laughs? One for when something works easily when he thought it was going to be a pain. And one when the repair is a pain, comes out a little different. Basically he's figured out how to substitute a laugh for a cuss word. Brilliant!, You have to watch a lot of his videos to pick up on this, but the old timers to the channel will know what I mean!

  • @NivagSwerdna
    @NivagSwerdna Рік тому +8

    I like the fact you actually test the caps rather than wantonly replacing everything.

    • @ObscuraDeCapra
      @ObscuraDeCapra Місяць тому

      After a certain point it's better to just replace the caps. They WILL fail on a long enough timeline and when something reaches 40+ years... yeah, I don't see why you wouldn't spend the extra $10 just to ensure shit's not going to die six months from now.
      Good way to guarantee future business, I guess.

  • @codebeat4192
    @codebeat4192 Рік тому +74

    Beautiful amp and repair and service, really love it! Also compliments for the way you filmed the process and progress. It is really a pleasure to watch and your feel for extras/details is exceptional. You are a craftsman that understands added value. I am glad YT recommended your videos. Thank you sharing your work with us, it makes me smile like you always do. 👍

    • @fearandloathing.7823
      @fearandloathing.7823 Рік тому +2

      Beautiful amp and repair and service, really cycling it! Also compliments for the way you filmed the process and progress. It is really a pleasure to watch and your feel for extras/details is exceptional. You are a craftsman that understands added value. I am glad YT recommended your videos. Thank you sharing your work with us, it makes me smile like you always do. 👍

  • @MrAsBBB
    @MrAsBBB 2 дні тому

    I’m 56 and did Electrical and Electronic engineering at college on day release and night college for years as being sponsored by an Oil and Gas company. Mark’s channel brings it all back with fond memories and he is enjoying what he is doing which is a real pleasure to see. Also what he works on is sometimes such a memory jogger which just add to the channels appeal. When I retire which I hope is soon I will start back and get acquainted again with electronics.. Sooo looking forward to it. All the best

  • @geraldcrook9504
    @geraldcrook9504 Місяць тому +6

    Absolutely great to watch a genius at work. As most people watching have said its just cool to see you picking your way through the problems .Keep the videos coming

  • @michaeldibb
    @michaeldibb Рік тому +41

    Always good to see a new Mend it Mark video and nice to see your subscriber numbers are increasing, deservedly .

  • @Willam_J
    @Willam_J Місяць тому +2

    You mentioned that it contained Japanese capacitors. I'm restoring a Roland JX-10 synthesizer, right now. It was made in 1986 and has HUNDREDs of electrolytic capacitors. The ones in the power supply were showing a bit of aging, but likely still had some years left in them. They got replaced, anyway, due to the power supply having transistors and IC's, that are no longer made. No sense in taking chances. Honestly, although I'm changing them all out, I've not found a bad one, yet, and I've replaced over a hundred. Again, I don't want to take any chances, due to the oscillators having specifically matched transistors. If you can even find replacements, you'd have to buy a bunch and match them yourself. It's been a heck of a job, but it's a real pleasure to work on. Really solid craftsmanship. I can't wait to get it finished and play it! Not that I'm trying to make a profit from it, but when replaced, it will be worth about $950. I bought it at, of all places, a hamfest. My wife said "You could go to a hotdog stand and buy a musical instrument." 😆 I think that she's telling me that I have too many, already, but we all know that's impossible! 😂 Love the videos, Mark! To all of you watching this, pay attention to this guy. I'm a retired EE, who got his start as a hobbyist, when I was 9 years old, and STILL work on designing/repairing something, almost every day. This guy is the real deal, and I'm pretty tough to impress. I wouldn't hesitate to let him work on something of mine, and that's high praise. He's also an amazing teacher. Not only does he say what he's about to do, he also explains why, and that's the part that a lot of other channels miss. Sure, they might test a component and show that it's bad, but Mark tells you why he tested that component, or why he was suspicious of it being bad, in the first place. Troubleshooting is a skill, unto itself. No matter if it's an amplifier, a car, or a clock. Once you get some experience, you should already know where you're going to start looking for the trouble, before even taking it apart. If you notice, he always tests everything, before opening it up. Sometimes, finding out what works, is just as valuable as knowing what doesn't work.

  • @andyh5224
    @andyh5224 11 місяців тому +2

    Hi Mark. First one of your videos I’ve watched. You have very impressive skills and great delivery. 👍
    The reason I pressed play was that my Dad, rest his soul, had this same amp as part of a separates system in a wooden stand. I remember being mesmerised as a little boy by the little light that shone up onto the metallic squares on the side of the record turntable as it spun around.😊

  • @admiralhipowa7158
    @admiralhipowa7158 Рік тому +3

    Mark is a master craftsmen, that amp is a beauty.

  • @TheBudgie29
    @TheBudgie29 Рік тому +6

    Another great job Mark, on a wonderful Vintage Amp. Can't wait for the next one to drop.

  • @TheWeepingCorpse
    @TheWeepingCorpse Рік тому +5

    Never stop being you, you are brilliant.

  • @capelhanbury-tenison1288
    @capelhanbury-tenison1288 Рік тому +3

    Hi Mark, a great film and wonderful service. I'm so looking forward to putting it through its paces again soon.

  • @soulsirius
    @soulsirius Рік тому +4

    One of the most amazing teachers you are on UA-cam. Thanks a lot for these wonderful instructive videos

  • @joseportela205
    @joseportela205 Рік тому +2

    Thank you for your great videos. It is a pleasure invest my time on them!

  • @MrHristoB
    @MrHristoB Місяць тому +1

    Just brought a 1991 Technics amp back to life, Mark, your videos are priceless!! Thank you!!!

  • @geekbot5000
    @geekbot5000 Рік тому +1

    Thank God you posted again, I felt lost without you.

  • @snapcracklenpop821
    @snapcracklenpop821 Рік тому +1

    Thanks. I'm learning a lot from watching your videos. You are a great teacher on top of your obvious expertise.

  • @d_j_duane
    @d_j_duane Рік тому +2

    Hello, These days you don't find much technicians that do these types of devices any more (Where I am at least). I would really like to have some like you nearby to fix some of my old HiFi equipment. I just found my old JVC VN-300 1975 (I think)… And theirs no one to fix it... Great job in refurbishing these equipment's as these were made with quality and longevity in mind...

  • @StevieBGoode
    @StevieBGoode Рік тому +7

    I just recently discovered your channel on random a couple months ago. I'm astounded by your knowledge and collection of machinery. I can only imagine how much all that equipment would cost in a lump sum. Keep up the good work!

  • @monz7951
    @monz7951 19 днів тому

    I absolutely love Kenwood's "square" pcb traces. As always majestic job on the service, Mark

  • @ryzentevfik
    @ryzentevfik Рік тому +8

    Man, there is only one smiling person in the world who does this job so well and that is you. Every time you take us to the magical world of the 80s and 90s. Thank you. 👏🏻

  • @ronaldsanchez1341
    @ronaldsanchez1341 3 місяці тому +1

    I would give anything to have 1/3 of the equipment you have and 90% for the knowledge you possess. You have enlightened me!

  • @quantumleap359
    @quantumleap359 Рік тому +5

    Beautiful restoration and final checkout. Your work is superb Mark!

  • @mollyfilms
    @mollyfilms Рік тому

    Really nice to come across someone you respect, is an expert in his field and explains exactly what’s going on. Makes watching this a good feel rather than a lot on YT these days which is total trash.

  • @gunnarliljas8459
    @gunnarliljas8459 Рік тому +7

    Quality stuff. Both what you're doing and the amp.

  • @robertcobb9026
    @robertcobb9026 6 місяців тому +1

    Brilliant chanel.
    A joy to watch please keep making the video's
    Many Thanks Bob from Ashford Kent

  • @johnwalker6752
    @johnwalker6752 Рік тому +4

    Mark is a natural in front of the camera love this channel who ever thought watching electronics being fixed could cheer u up

  • @steveosshenanigans
    @steveosshenanigans Рік тому +2

    I tell you what Mark ……your thorough a lot of people wouldn’t go that far …..anyway hats off to you well done 👍
    New subscriber

  • @Alan8889991
    @Alan8889991 Рік тому +2

    Dr. Mark, great job , as always, gretings from Croatia....

  • @johnmarchington3146
    @johnmarchington3146 10 місяців тому

    Nice one, Mark. Another excellent job over and above what a lot of other servicemen would do, such as measuring the ESR of electrolytics and replacing the ones that measure a little on the high side. Also all the ultrasonic cleaning you do. Top notch.

  • @Turbo-Drew
    @Turbo-Drew Рік тому +2

    Awesome as Always...Really enjoyed this one.thank you

  • @jaydub8085
    @jaydub8085 Рік тому

    Your videos make me so happy! You appear like you're possibly the nicest man I've never met! Keep it up, and thank you UA-cam algrorithm! I'm so happy I found this channel!!!!

  • @jeffberwick
    @jeffberwick 14 днів тому

    I really like the way you use a square wave input to very quickly test the tone controls and loudness. It's such a great trick! I'm definitely using that next time I test a receiver.

  • @mlprd
    @mlprd Рік тому +3

    I used to have this amp, it was incredible.

  • @bhopale1
    @bhopale1 Рік тому +1

    It’s always a treat to watch your videos and I always say craftsmanship at it’s best

  • @iantyler4045
    @iantyler4045 Рік тому +3

    You certainly go the extra mile by putting all the pots and switches in the ultrasonic bath. Very thorough. For bent over pins I use desoldering braid to wick the solder away. Great video.

  • @NickT6630
    @NickT6630 Рік тому +4

    Excellent video!!!
    You can tell they made much better electrolytic capacitors in the old days.

    • @henriktoth56
      @henriktoth56 Рік тому +4

      And most importantly those were not stressed by switching mode power supply, which is a killer of capacitors in its circuit.

    • @ray-charc3131
      @ray-charc3131 Рік тому

      ​@henriktoth56 I lately find that contact plates with batteries easily go oxidation with the growth of brownish or greenish stuff( depending on metal or copper contact plates it used), they happened on small handheld led lamp type torch and rechargeable battery handheld drill. I think the inside buck switching mode circuit causes them. I take out the batteries to completely disconnecting the circuitry after the use, the problem vanished

  • @RSCuber
    @RSCuber Рік тому +6

    This is one of my new favorite channels and I'm glad to see you getting views and subs. Very well deserved. My favorite thing to watch while I'm working on stuff myself!

  • @Throtmanni
    @Throtmanni Рік тому

    It was the cleanest and most professional work I have ever seen. congratulations.

  • @ashleycox432
    @ashleycox432 Рік тому +2

    Top work as always Mark.

  • @DelmaRaySmithJr
    @DelmaRaySmithJr 15 днів тому

    Do what you love and you'll work everyday for the rest of your life. Loving it!

  • @louisc7748
    @louisc7748 2 місяці тому

    It's a pleasure and inspirational watching your work, doing things correctly isn't that difficult with the knowledge you share.

  • @3rdandlong
    @3rdandlong Рік тому +1

    Loved the old Kenwood Amps. Powerful, with excellent audio quality. Think I saw one in a thrift store recently. Guessing someone got rid of it because it won't work. But from my previous experience, I never went wrong with a Kenwood.

  • @DJWarlock-qd4ls
    @DJWarlock-qd4ls 5 місяців тому

    I can even smell the welding...
    Thanks for sharing your detailed work

  • @fluke196c
    @fluke196c Рік тому +3

    Made my day! Sharter video and Mend it Mark!

  • @robwatkins1547
    @robwatkins1547 Рік тому

    Thank you Mark for another brilliant video, your attention to detail is second to none and it's nice to see a thorough job on all the work you do. Please can I add that who ever keeps messaging me every time I comment I will not text to anyone, I am not interested and if anyone else receives a message, just ignore it, it's possibly a scam.

  • @knifeswitch5973
    @knifeswitch5973 Рік тому

    The “look” with the grounding rings, priceless. I know it very very well.

  • @davidrobertson1980
    @davidrobertson1980 Рік тому +2

    Kenwood quality of course, great to see another one of these still in service. I still have my own Japanese *amps* from 1976, only had a couple of issues like accidentally burning out the power supplies in two of them overdriving far too long, guess they weren't really meant for mobile disco use lol

  • @smarthub56
    @smarthub56 7 місяців тому +1

    who has knowledge of every electronic tool infact mark is a knowledgeable mechanic.

  • @ssnoc
    @ssnoc 2 місяці тому

    I find your channel very enjoyable to watch - you are expert in electronics and me being just a hobbyist, every now and then I actually learn something.

  • @bas7es
    @bas7es 27 днів тому

    I'm addicted to watching this! At 25:26, the lower channel shows some overshoot, which may indicate an issue with a compensation capacitor in the feedback loop.

  • @PhonoDirect
    @PhonoDirect Рік тому

    Recently I have restored two identical Kenwood KA-501 from roughly the same period. The same story, no bias trim pots, only pots for the VU meters.

  • @MarkErikEE
    @MarkErikEE Місяць тому

    Your work with the pots and switches is very thorough, but what I really like is your attitude regarding the capacitors - no need to change what is working within specs. Some guys rip out all the electrolytics and later they are dumbfounded why the amp is sounding worse than before.

  • @magentaline
    @magentaline 7 місяців тому

    Thank you for the great videos! I like the new shop.

  • @apislapis
    @apislapis Рік тому

    What a great looking amp Mr Wood is! Still don't understand all that you do but it's great to watch.

  • @MattTester
    @MattTester Рік тому +4

    It always makes me nervous now when you spray a front panel with cleaner! Great to see quality components lasting, a really nice amp that I quite fancy myself.

  • @norbertsmallegange6331
    @norbertsmallegange6331 Місяць тому

    At first I thought you were A genuine englishman but on your Facebook account I found out, you are from Australia.... Nice Jobs you do.
    Seems you have a great Community on repairing Stuff!

  • @marcparsons1726
    @marcparsons1726 Рік тому

    That was a proper education! Beautiful Kenwood Amplifier.

  • @dagreatstoney.5869
    @dagreatstoney.5869 9 місяців тому

    Fantastic job, you have a gift to make very complicated work, look doable and actually enjoyable 👍

  • @butterfliesandtape
    @butterfliesandtape 9 місяців тому

    the solder vacuum is so relaxing to watch. nice nozzle cleaning. that's a tasty looking amp. love the simple three inputs.

    • @Toytowner
      @Toytowner 9 місяців тому

      I had one. They were mint till the switches went noisy...

  • @bussypaul7326
    @bussypaul7326 Рік тому

    Hi Mark! Good to see you again! Eagerly waiting for the next! Love from India!

  • @geyerking
    @geyerking 8 місяців тому

    Really impressive work, Mark. And really entertaining. Please more of it.

  • @roncarter5532
    @roncarter5532 Рік тому +1

    What a lovely bit of kit. I do like silver hi fi equipment, even better when it has VU meters.

  • @rodneydelaney9227
    @rodneydelaney9227 Рік тому +1

    Great insightful channel, full of knowledge. Love it Mark 👍

  • @wolfmon9
    @wolfmon9 Рік тому

    Great video's Mark love watching your stuff and your from my part of the UK.

  • @enryfrank
    @enryfrank Рік тому

    ...watching you solder the components is very relaxing for me...🥴

  • @fillo1971
    @fillo1971 7 місяців тому

    Mi fanno sorridere certi commenti, fai li fai qui controlla là, ma invece di polemizzare fate un video riparazione anche voi e vediamo che sapete fare e con che competenze.
    Mike te l'ho già scritto per me sei un tecnico veramente professionale, oltre ad avere tanta serenità la trasmetti anche. Grazie Mike 👍🏻💪🏻💯

  • @philipbarrett3151
    @philipbarrett3151 16 днів тому

    We used to do full power burns on pro amps using electric cooker rings which conveniently metered out at around 8 ohms. Since we risked burning them out, we would put them in a bucket of cold water, when the water boiled the amp was considered suitable to return to service!

  • @davesawyer497
    @davesawyer497 Рік тому

    Thanks for another great fix. I've watched a lot of your videos and they are all great. The other day I was working on a job and getting frustrated due to lack of progress, when I thought to myself to be more like Mark. Relax, Chill out, add an "Oh well" in there. It worked! :)

  • @bouser210
    @bouser210 Рік тому

    I got the same amplifier for 5 dollars . A lot of hissing sounds and speaker connections work when they want. Great video.

  • @butcharmstrong9645
    @butcharmstrong9645 Рік тому

    I so enjoy all of your videos. I binged watched all of them in a few weeks so I am glad to see that you're putting some new one up! BTW, hello from America!

  • @iracema1
    @iracema1 Рік тому

    So much fun to watch your videos! I would much rather have vintage than new equipment!

  • @hernanmartinez1591
    @hernanmartinez1591 Рік тому +1

    I would really like a descriptive video of your lab. I fell in love with the HP multimeter! 😊. Greetings!!!

  • @DavidFRhodes
    @DavidFRhodes Рік тому +8

    Enjoy your videos Mark. i think i've seen all but one of them now. You're a really good teacher..have you thought of maybe doing some fundamentals videos? Not formulas, but how to use a scope and whatnot. I was EE in school for a bit, but have a huge gap between theory and troubleshooting and soldering. thanks

    • @j.harbottle8928
      @j.harbottle8928 Рік тому +2

      Yeah, good idea David, Mark's a good teacher ! Love these vids , like the ol Techmoan's !

    • @BoBB2000
      @BoBB2000 Рік тому

      Plenty of that already on youtube

  • @kevinisaac9139
    @kevinisaac9139 Рік тому

    Brilliant job Mark you are very thorough and really interesting 👍

  • @bobmckenna5511
    @bobmckenna5511 Рік тому +1

    I didn’t catch that comment about the Japanese screwdriver. I looked closely at the second time when you were taking the chassis apart, it looked like a Phillips. I’d be grateful to learn what the difference might have been.

  • @artifactingreality
    @artifactingreality Рік тому +1

    I just found your channel. I like your style. I have subscribed

  • @Timothycan
    @Timothycan Рік тому +5

    Great job, very thorough. Only thing: I've had two amps faulty, one Denon and one Kenwood (a later one) that had intermittent faults, that of one channel occasionally failing. Turned out to be dirty contacts on the speaker protection relays. I note you didn't clean or replace the relay - those faults can be (as mine were) very intermittent, only showing up occasionally. I don't know how common that fault is, only that I've seen it twice now!

  • @Jammerk40
    @Jammerk40 Рік тому

    Very nice work! Ready to play for another 20 to 30 yrs

  • @kerrygleeson4409
    @kerrygleeson4409 Рік тому +1

    Fantastic work Mark great channel 🦘

  • @paulmichaelfreedman8334
    @paulmichaelfreedman8334 Рік тому +7

    I use Kontakt K60 for pots and switches. Always a great result and also very good lubricant.

  • @rods6405
    @rods6405 Рік тому

    25:43 the channel on the lower trace has HF boost all the time! You can see the over shoot on the leading edge! Great work great video!
    just watched another video or yours its actually that channel of the oscilloscope!

  • @schummiehugo
    @schummiehugo Рік тому +1

    fantastic job happyman !

  • @userbosco
    @userbosco 14 днів тому

    Hearing the hum of your equipment in the background would put me to sleep in 5 minutes 😂🥱

  • @Trucam2020
    @Trucam2020 Рік тому +1

    Excellent video as usual. Thanks 👍

  • @paulwooller4524
    @paulwooller4524 Рік тому

    Love watching your videos - makes repairing some sad objects fun👍🏻👍🏻🤗🤗

  • @dustonsmoot8103
    @dustonsmoot8103 Рік тому +2

    Nice work man.

  • @brianhoskins1979
    @brianhoskins1979 Рік тому +1

    You can't beat that old HP rack mount test gear. Really nice they are. I've always wanted an 8903 Audio Analyser but not managed to get there so far and, to be fair, I wouldn't use one enough to justify it.

  • @maryrafuse3851
    @maryrafuse3851 Рік тому +1

    Mark you would love my Sony amps. The Sony TA-2650 and my TA-F3A. They are works of very durable art built in an era of quality construction, and they sound magnificent. When made in Japan was the last word in quality.

  • @butterfliesandtape
    @butterfliesandtape 9 місяців тому

    interesting to see what bass and treble do in that waveform you showed us on the monitor, loudness too! very interesting!! lovely amp!

  • @andrewstewart8704
    @andrewstewart8704 Рік тому

    Another top notch repair Mark!

  • @joefarr3304
    @joefarr3304 Рік тому

    I look forward to your videos and really enjoy them. I'm not an audio electronics guy and pick up so many little hits and tips - throwing a square wave into an amplifier to help test the tone controls for example. Thanks for making these.

  • @SergZak2023
    @SergZak2023 Рік тому

    Mark's paper towels can double as blue notebook paper...or vise versa. Good job on the service, Mark!

  • @hazemal-najjar4834
    @hazemal-najjar4834 Рік тому

    really i feel happy when i am watching your videos its really great and your knowlage 100% great keep going BOSS

  • @telegraphhill803
    @telegraphhill803 Рік тому

    I also tried ultrasonic cleaning in the past but now to mechanical cleaning of contacts with fibre brush and contact grease at the end. Needs more time but I give an guarantee of 3 years for my work.