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

Mark strips down a 1979 vintage Kenwood Amplifier, sent in because of a bad channel. It turns out to need a front panel service - and its as good as new! Tested to full load, and beyond!

Пікірлер: 370

  • @JanWesterink16
    @JanWesterink16 Жыл бұрын

    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

    Жыл бұрын

    So true. This guy is the jolliest electronics tech on KZread

  • @gogs1606

    @gogs1606

    Жыл бұрын

    him and mr carlson the best ones

  • @bobmckenna5511

    @bobmckenna5511

    Жыл бұрын

    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

    Жыл бұрын

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

  • @weyayemanjoe3082

    @weyayemanjoe3082

    Жыл бұрын

    😂 Nice one 👍

  • @lokesh5
    @lokesh5 Жыл бұрын

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

  • @codebeat4192
    @codebeat4192 Жыл бұрын

    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

    Жыл бұрын

    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. 👍

  • @tedmich
    @tedmich Жыл бұрын

    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

    Жыл бұрын

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

  • @analogaudiorules1724

    @analogaudiorules1724

    Жыл бұрын

    @@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

    Жыл бұрын

    @@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

    11 ай бұрын

    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

    5 ай бұрын

    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)

  • @michaeldibb
    @michaeldibb Жыл бұрын

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

  • @smarthub56
    @smarthub5612 күн бұрын

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

  • @user-hi9xg8my4n
    @user-hi9xg8my4n4 ай бұрын

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

  • @geyerking
    @geyerking23 күн бұрын

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

  • @RSCuber
    @RSCuber Жыл бұрын

    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!

  • @NivagSwerdna
    @NivagSwerdna Жыл бұрын

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

  • @soulsirius
    @soulsirius Жыл бұрын

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

  • @StevieBGoode
    @StevieBGoode Жыл бұрын

    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!

  • @fillo1971
    @fillo197112 күн бұрын

    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 👍🏻💪🏻💯

  • @ryzentevfik
    @ryzentevfik Жыл бұрын

    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. 👏🏻

  • @TheWeepingCorpse
    @TheWeepingCorpse Жыл бұрын

    Never stop being you, you are brilliant.

  • @admiralhipowa7158
    @admiralhipowa7158 Жыл бұрын

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

  • @TheBudgie29
    @TheBudgie29 Жыл бұрын

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

  • @joseportela205
    @joseportela205 Жыл бұрын

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

  • @remcovantriest4357
    @remcovantriest4357 Жыл бұрын

    Thanks a lot for explanation on the load resistor contraption appreciated Mark 🙏🙏

  • @johnwalker6752
    @johnwalker6752 Жыл бұрын

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

  • @BokBarber
    @BokBarber Жыл бұрын

    For reference, the KA-405 was on the "budget" end of Kenwood's integrated amps in 1979/80, and it's still an extremely sold piece of kit.

  • @GuyFowler
    @GuyFowler4 ай бұрын

    Zen and the art of electronics maintenance

  • @andyh5224
    @andyh52243 ай бұрын

    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.😊

  • @quantumleap359
    @quantumleap359 Жыл бұрын

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

  • @bhopale1
    @bhopale1 Жыл бұрын

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

  • @Ivorbiggin
    @Ivorbiggin Жыл бұрын

    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

  • @geekbot5000
    @geekbot5000 Жыл бұрын

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

  • @Throtmanni
    @Throtmanni11 ай бұрын

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

  • @iantyler4045
    @iantyler4045 Жыл бұрын

    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.

  • @Alan8889991
    @Alan8889991 Жыл бұрын

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

  • @snapcracklenpop821
    @snapcracklenpop821 Жыл бұрын

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

  • @capelhanbury-tenison1288
    @capelhanbury-tenison1288 Жыл бұрын

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

  • @d_j_duane
    @d_j_duane Жыл бұрын

    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...

  • @gunnarliljas8459
    @gunnarliljas8459 Жыл бұрын

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

  • @robwatkins1547
    @robwatkins1547 Жыл бұрын

    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.

  • @johnmarchington3146
    @johnmarchington31463 ай бұрын

    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.

  • @mollyfilms
    @mollyfilms5 ай бұрын

    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.

  • @butcharmstrong9645
    @butcharmstrong9645 Жыл бұрын

    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!

  • @joefarr3304
    @joefarr3304 Жыл бұрын

    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.

  • @UKDrew
    @UKDrew Жыл бұрын

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

  • @fluke196c
    @fluke196c Жыл бұрын

    Made my day! Sharter video and Mend it Mark!

  • @apislapis
    @apislapis Жыл бұрын

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

  • @iracema1
    @iracema1 Жыл бұрын

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

  • @magentaline
    @magentaline10 күн бұрын

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

  • @damianbutterworth2434
    @damianbutterworth2434 Жыл бұрын

    You seem so happy when things are broken lol.

  • @knifeswitch5973
    @knifeswitch5973 Жыл бұрын

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

  • @rodneydelaney9227
    @rodneydelaney9227 Жыл бұрын

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

  • @MattTester
    @MattTester Жыл бұрын

    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.

  • @davesawyer497
    @davesawyer497 Жыл бұрын

    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! :)

  • @jaydub8085
    @jaydub8085 Жыл бұрын

    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 KZread algrorithm! I'm so happy I found this channel!!!!

  • @kevinisaac9139
    @kevinisaac9139 Жыл бұрын

    Brilliant job Mark you are very thorough and really interesting 👍

  • @Jammerk40
    @Jammerk40 Жыл бұрын

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

  • @ashleycox432
    @ashleycox432 Жыл бұрын

    Top work as always Mark.

  • @NickT6630
    @NickT6630 Жыл бұрын

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

  • @henriktoth56

    @henriktoth56

    Жыл бұрын

    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

    11 ай бұрын

    ​@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

  • @artifactingreality
    @artifactingreality Жыл бұрын

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

  • @dagreatstoney.5869
    @dagreatstoney.5869Ай бұрын

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

  • @paulwooller4524
    @paulwooller4524 Жыл бұрын

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

  • @butterfliesandtape
    @butterfliesandtape2 ай бұрын

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

  • @Toytowner

    @Toytowner

    2 ай бұрын

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

  • @marcparsons1726
    @marcparsons1726 Жыл бұрын

    That was a proper education! Beautiful Kenwood Amplifier.

  • @dustonsmoot8103
    @dustonsmoot8103 Жыл бұрын

    Nice work man.

  • @rongeernaert1208
    @rongeernaert12083 ай бұрын

    Nice tech repair of this Kenwood amp !

  • @garysmith1532
    @garysmith1532Ай бұрын

    Really interesting video, can't believe you removed all those controls on a sub £200 amp, as per another comment, really risky, but informative to watch.

  • @wolfmon9
    @wolfmon9 Жыл бұрын

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

  • @user-sr1tq5eb8p
    @user-sr1tq5eb8p Жыл бұрын

    Excellent video as usual. Thanks 👍

  • @andrewstewart8704
    @andrewstewart8704 Жыл бұрын

    Another top notch repair Mark!

  • @roncarter5532
    @roncarter5532 Жыл бұрын

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

  • @bussypaul7326
    @bussypaul7326 Жыл бұрын

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

  • @mlprd
    @mlprd Жыл бұрын

    I used to have this amp, it was incredible.

  • @kerrygleeson4409
    @kerrygleeson4409 Жыл бұрын

    Fantastic work Mark great channel 🦘

  • @schummiehugo
    @schummiehugo Жыл бұрын

    fantastic job happyman !

  • @davidrobertson1980
    @davidrobertson1980 Жыл бұрын

    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

  • @boredwithusernames
    @boredwithusernames Жыл бұрын

    Thoroughly enjoyed this one Mark, keep 'em coming ;) 👍

  • @darrenwendell1723
    @darrenwendell1723 Жыл бұрын

    Great service as always.

  • @hungvanpham146
    @hungvanpham146 Жыл бұрын

    I love your show so professionalism

  • @bouser210
    @bouser210 Жыл бұрын

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

  • @paulmichaelfreedman8334
    @paulmichaelfreedman8334 Жыл бұрын

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

  • @marktubeie07
    @marktubeie07 Жыл бұрын

    Always a pleasure Mark, nice one mate !

  • @enryfrank
    @enryfrank Жыл бұрын

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

  • @russax1373
    @russax1373 Жыл бұрын

    Lovely Amplifier and a great video

  • @Roundymooney
    @Roundymooney Жыл бұрын

    Nice one Mark.

  • @Quassi30
    @Quassi302 ай бұрын

    I really like watching your videos... you are a precise repairman. I will probably send you (sometimes) to calibrate my 2 turntables (JVC, Denon) or replace the capacitors.. :) they show me the speed of 33.5 and 44.2 both the same :)

  • @2626sylver2626
    @2626sylver2626 Жыл бұрын

    Beautiful job 👏 👌

  • @hazemal-najjar4834
    @hazemal-najjar4834 Жыл бұрын

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

  • @PhonoDirect
    @PhonoDirect Жыл бұрын

    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.

  • @robinsutcliffe-video_art
    @robinsutcliffe-video_artАй бұрын

    Good service again! At 25:21 in case it's not known - to test the EQ needs a Square wave, because EQing has zero effect on a Sine wave.

  • @andymouse

    @andymouse

    3 күн бұрын

    Bass will have an effect on a 100 Hz sine wave of course etc but the square wave is quicker.

  • @robinsutcliffe-video_art

    @robinsutcliffe-video_art

    3 күн бұрын

    @@andymouse true it will affect some frequencies indeed

  • @nicksmith4507
    @nicksmith45072 ай бұрын

    Nice amp, great video as always.

  • @microteche
    @microteche Жыл бұрын

    Old school servicing done right enjoyed the video

  • @leemparry
    @leemparry Жыл бұрын

    Top job, as always! I don't suppose you've got any plans/schematics for that ESR meter? I definitely need one for the shop!

  • @bobert4522

    @bobert4522

    Жыл бұрын

    Search online, I can guarantee it came out of an old electronics mag 👍🏻

  • @fredzwijnenberg5361

    @fredzwijnenberg5361

    Жыл бұрын

    Please share the schematic Mark...i need it to..its works good..😁👍👍

  • @richardhack9830

    @richardhack9830

    Жыл бұрын

    I was nicely surprised to see Mark using his ESR meter - testing electrolytical capacitors in circuit ! A Google search (simple 100kHz ESR meter) quickly took me to good & efficient schematics, using basic TL082s. Thanks again Mark, pls keep up the good work ! - No need to guess what my next "project" will be... 😅

  • @decibel_tastic2869

    @decibel_tastic2869

    Жыл бұрын

    The one I built was by an Italian guy, I used the entirety of a cheap moving coil voltmeter as the display. It's indicative really. Be aware, discharge large caps pre-test, although the design has a couple of diodes reversed across the probes.

  • @richardhack9830

    @richardhack9830

    Жыл бұрын

    @@decibel_tastic2869 Hello, deciBel_tastic. I have a minor question about your ESR meter. There's always a zero adjustment in the schematic diagrams I found. Is it necessary to readjust at zero regularly, or is it a "set-and-forget" adjustment? Mark had build his adjustment with an external knob. My aim is to use a walwart SMPS power supply (+ some extra capacitor to smooth it down). Thanks in advance for sharing your experience... 😃

  • @Timothycan
    @Timothycan Жыл бұрын

    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!

  • @butterfliesandtape
    @butterfliesandtape2 ай бұрын

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

  • @DavidFRhodes
    @DavidFRhodes Жыл бұрын

    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

    Жыл бұрын

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

  • @BoBB2000

    @BoBB2000

    Жыл бұрын

    Plenty of that already on youtube

  • @mkach2521
    @mkach25213 ай бұрын

    You Sir are to fun to watch!! Thanks

  • @standishgeezer
    @standishgeezer Жыл бұрын

    Superb job!

  • @fernandoalbuquerque1128
    @fernandoalbuquerque1128 Жыл бұрын

    Hey Mark i love yours Videos! You is Professional example, i am from Brazil 😊🤝 sorry my wrong Inglish haha

  • @3rdandlong
    @3rdandlong6 ай бұрын

    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.

  • @SergZak2023
    @SergZak2023 Жыл бұрын

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

  • @hernanmartinez1591
    @hernanmartinez1591 Жыл бұрын

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

  • @vintage_audio_INDIA_7777
    @vintage_audio_INDIA_7777 Жыл бұрын

    Appreciate ✌️

  • @dgedi78
    @dgedi78 Жыл бұрын

    Working great! The soy sauce in your ultrasonic cleaner certainly helped 🤭

  • @daveg8htfadlibaudio250
    @daveg8htfadlibaudio250 Жыл бұрын

    Quality video Mark as always, attention to detail spot on. Have you any valve stuff to do in the pipeline as I think you would do it equally fantastic in your informative way, and it would take me back to the 70's in my head when I built quite a few single ended and push pull amps for my disco when I was still at school. Keep up the good work. Regards Dave. 😀