KINKI Headphone Amplifier Repair (Vision THR-1)

Mark takes a look at a rather high end Headphone Amplifier, from Kinki Studio in China. It was made in 2019, but has no output after 5 years. What went wrong?
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[@ralphalder14]

If Kinki Audio ever teamed up with Schiit Audio they’d have a fantastic opportunity for a new brand name !! 😅😅😅

[@FrankWoodPhotography]

😂

[@wollaminfaetter]

😂😂😂😂

[@tjtreinen7381]

🤣🤣🤣🤣🤣🤣🤣🤣🤣

[@rillloudmother]

at least they would sell a lot of bumper stickers in certain parts of the usa...

[@potassiumchloride6968]

inki pinky ponki💀💀

[@bobgrob4]

70K subs and climbing. We need to get Mark up to about 5 Mil

[@AG-cg7lk]

Companies that grind labels off of components or cover them in goop need a slap.

[@T0pBaNaNa]

I literally threw my hands in the air when i got the notification 😂....Haven't even watched it yet 🤗

[@bobgrob4]

I know...Mark is the best. Love these videos.

[@maksqwe1]

Just got out of the shower, got in bed and thought let’s watch a few videos before bed.. and Marks video pops up!!!

[@petercornell2002]

That amp is SERIOUSLY over-engineered. Something like 2 x 15w for headphones? I love it! Good to see you back Mark.

[@borlibaer]

Yes, overengineered at the wrong Place. Massive enclosure, pippi heatsink plate 😂

[@philippwie3539]

I'd say overpowered and underengineered, the thermal solution is a joke for MOSFETs that beefy.

[@mattparker8747]

Yep, it's audiophile quality 🙂 The clue is in the word audiophile. Someone who loves listening to music is a musicophile. Audiophile just means lover of sound - they just listen to their system....

[@csm0881]

​@@borlibaerĺpp

[@peterlarkin762]

The output spec is there to accommodate very power hungry headphones. Some fancy headphones need a LOT (maybe not quite this much). The sad thing is the case itself would have worked as a heatsink far better. The engineer should know better.

[@pabloluchi3595]

Burnt mosfets, overheathed PCB .. and there is no ventilation holes in that chassis.. My guess,, It will happen again soon. Anyways.. Great repair on this, Mark!

[@edmaster3147]

Mark has the spares on the shelf ;)

[@RedShift5]

I think in this case on FET failed and then cooked the others resulting in total failure

[@absurdengineering]

Last thing I’d have ever expected to see that is a headphone amp lol.

[@LeifES]

Came here just to see the electroshock in the intro again. Haha no, great video!

[@DavidFRhodes]

the best part for sure

[@Rob1972Gem]

Without doubt the best electronic fixing channel on KZbin please please longer videos I have learnt so much from watching your videos please keep the vids coming

[@Mihail_K.]

Such a chunky aluminium enclosure and they put the transistors on that little slab, I guess you could say that's a little... kinki, isn't it.

[@radicalaudiodesign]

That heatsink connects to toplid when screwed down so not so little slab anymore.

[@Mihail_K.]

@@radicalaudiodesign I doubt it makes good contact thermally. And the lack of vent holes... Those transistors shouldn't be getting really hot to begin with but still, it just looks dodgy.

[@Tokaisho1]

I'd say there's an air gap@@radicalaudiodesign

[@SusanAmberBruce]

An improvement would be a thicker longer block of aluminium that gets screwed to the lid and with the mosfets wider apart.

[@andrea.dalessandro]

@@radicalaudiodesign kapton tape instead of thermal paste is an indicator of someone who was asleep at school that day when they explained how to make heat sinks.

[@chezsnailez]

By the time you were able to afford this sort of kit your hearing has deteriorated to the point a 1990s Aiwa all-in-one would suffice...

[@ibrahimkocaalioglu]

We missed you. Nice quick fix.

[@exiledscouser919]

Excellent as ever, it’s our pleasure to see you work through the problems and get them fixed. Thank you as always.

[@user-gu5kk7wr5q]

All done as usual with the efficiency, finesse, and as usual the astounding knowledge you bring to this channel.

[@trickyd499]

Best electronics channel, keep it up Mark!

[@andyfish4821]

Wow, tidy bit of kit....Nice to see you back mark 👏

[@fantummenelkinstruments1959]

Happy days when there's a new vid from Mark! Top notch work once again!

[@andrewwturner]

Excellent as always Mark. Please dont keep us waiting as long for the next one! 😊

[@francomarianardini681]

good to see you back, Mark! ciao from Italy!

[@NoobCannon1234]

Another great video. I wish you posted more often but always a treat when you do. Thanks

[@marjon1703]

Yay!... new 'Mend it Mark' Vid... Happy, Happy, Joy, Joy!

[@D.Hozzie]

You’ve been missed Mark. Thanks!

[@rayofcreation3996]

Mark there you go again. Its an absolute joy watching you perform. Thanks and lots of love. 🎉

[@zuvinrat4155]

Youre back , great episode Mark!

[@user-sr1tq5eb8p]

Thanks Mark, I always enjoy your videos

[@blindbob4115]

I love listening to the sound of you working ❤️❤️❤️ great channel

[@alialmahanawi8409]

Excellent job Mark thanks for sharing 🙏

[@jeremywh7]

Great video as always! Regarding those power transistors; Kapton tape has poor thermal conductivity vs thermal pads - perhaps the root failure was from someone trying to use this as a regular speaker amplifier, overheating to short? But as @pantelisEVs noted, using the chassis seems like a much better idea too (with thermal pads 🐱).

[@sw6188]

You're dead right - Kapton tape isn't designed as a thermal conductor. No way would I use it in place of silicone pads or thermal grease. It's the sort of cheap-ass shortcut that I see in china stuff all the time and just another reason I tell people not to buy this stuff.

[@mactheweld]

thats what i thought and possibly wrong impedance speakers . made that mistake myself used my bi amp speakers (paralleled 🙄) on my rotel 931 amp , like a divi and cooked the o/p transistors

[@eddieMurphy11111]

that's is a superb job, nice to watch somebody who knows what they are doing ,thank you for the video

[@cesio25]

Another great video from most positive technician on YT. Pure pleasure to watch your content Mark

[@fichambawelby2632]

Nice to see you again, Mark!

[@vintagehifirestoration6515]

Hi Mark I look with great pleasure at your videos they are very inspirational and I think I will made my own videos in audio repair soon, I learned a lot from you. Thank you!

[@kjbunnyboiler]

Excellent as always👍👍

[@baronofgreymatter14]

Great to see you Electronic Zen Master

[@lumbo101]

Thank you Mark for another highly entertaining video, so well produced. When that resistor measured 3.9 Ohms I thought you were going to find out it was one of those chokes that looks like a resistor! I’ve been in power electronics for 35 years and not seen a resistor fail short either!

[@user-gs3vc3rq5e]

Like always, great work!

[@sjqideez6626]

Wow Mark, awesome stuff. Thank you

[@hw4527]

Thank you for posting 👍👍

[@robinandreasson4911]

Ahh great content, thanks Mark

[@barrybradfordlocksport]

Great, but not enough uploads mark we love your content

[@DarrenMossAU]

Nice repair. I wasn't expecting that amp to be so well made. Really good workmanship on everything, even the case!

[@DougPowhida]

Very entertaining and educational! Thank you.

[@mattsan70]

Capton tape is terrible as transferring heat. No wonder they cooked themselves - Mark get it back and put some mica or silpads in do a proper job

[@twobob]

0.1 to 0.3 W/m•K ish versus 400 ish. Nah... be fine...what's several orders of magnitude between friends...

[@jimbobroon-wj4qx]

Superb !!! As always😁👍

[@Bigbluevwvan]

Another great fix and Kinki look great build quailty :)

[@MonguzTea]

An electronics engineer would laugh his ass off looking at that thing. The case is impressive the rest not so much.

[@AMByram]

On holiday with my wife in Puerto Rico. She's taking a nap and I'm sipping a gin and tonic watching your vids and listening to the waves. Does it get better?

[@ruaraidhmcdonald-walker9524]

Satisfying repair!!

[@tonibarski4283]

Top video this one ,! well done, enjoyable and knowledgable ( as always )

[@zokxzoranovski5255]

As usual, Mark is the best.. :)

[@danielstan4231]

I love your lab environment.

[@colin4850]

Another great video Mark, could the damage have been caused by some piece of external equipment being connected wrongly, I guess we will never know. Looking forward to next video , keep up the good work.

[@VoeViking]

Another great video. Cheers.

[@stephanloper5740]

Great Video and Work

[@Mickey-Knox]

I love these retro Phil Collins videos!

[@mistersunny3636]

🤣

[@kerrygleeson4409]

Another great video Mark always very interesting thanks for sharing 🦘

[@pantelisEVs]

WOW. Thats the definition of an overkill output stage for headphones! Notes: -These power MOSes could be mounted and take advantage of this chunky bottom plane. -Is this high impedance mode protected in case someone plugs low impedance headphones or overcurrent and damage to the output devices Really interesting design anyway!

[@gibbogle]

Using the bottom plane looks like a no-brainer.

[@thesleepstate]

This unit is £1199 street

[@SusanAmberBruce]

@@thesleepstate Really, I knew it would be expensive, but that's mental!

[@PrimeHiFi]

All the thermal mass of the over-built chassis and they choose to mount TO-3P lateral mosfets which are no doubt biased into class A to a tiny piece of metal as a heatsink! You can tell they’ve been getting excessively hot by the board discoloration. Even the cases of the MOSFETs have discolored. And scraped part numbers on the components! This amp is over-engineered except for where it counts. Good for the warranty period and then will give you a bunch of trouble afterward. The company scraping part numbers and not providing even a simplified schematic screams stay away… Great work on the repair, Mark 👍🏼

[@nevillegoddard4966]

@@PrimeHiFi ...And yet I wonder if the manufacturer even has a repairs department if miracle Mike wasn't there to mend it? I'll bet not! I just HATE it when manufacturers scrape off part numbers!😠😡🤬🤬! It seems almost CRIMINAL!

[@AaronBegley]

Well done!

[@richardbrobeck2384]

nice repair !!

[@danhorton6182]

Interesting you saying the MOSFETs not needing a heatsink considering how hot they’ve clearly gotten. Excellent video.

[@edmaster3147]

4 mosfets for a device with has an output of just a few watts, the FETS should stay extremely cold, yet they decided to large packets, I'd suppose at least.

[@danhorton6182]

@@edmaster3147 well then in reality they could have used TO220 devices then, regardless they don’t look like they’re staying too cold.

[@paulb4661]

@@edmaster3147 These lateral FETs have their Rds on the high side and benefit from sensible thermal arrangement, especially that they should ideally be run with high DC bias.

[@fl3162]

Another great video.

[@skypittman9303]

Call me an oddball but I think all videos of the unscrewing fast forwards would make a good ASMR compilation. Another great video Mark, it made my day after work to relax and watch. Cheers future watchers and enjoy.

[@JPDESS]

Hi, some micas and thermal paste should work better to dissipate the heat than capton tape on those mosfet, it is not suppose to break.

[@mixolydian2010]

Cheers really enjoyed the video

[@michaelclutton8446]

Thanks another interesting video

[@HAL4400]

Thanks Mark! 🤓

[@paulb4661]

Hi Mark, these fabulous fets based on Renesas J162/K1058 have unusual pin-out; the beads actually went on the gate and drain.

[@Choralone422]

Time to get KINKI with Mark! Let's do it!

[@rhkavli]

As usual, the Chinese doesn't know how to spell. But I was surprised by the build quality and the component selection. At least the ones that survived the anonymisation process.

[@UnCoolDad]

Where is part 3 of the AIWA?

[@artsimannisto5659]

Yes mee soo eagerly waiting,Hungryfor that.But,sadly,Mark hates cassdecks....

[@batmandestroys1978]

Good point! Mark needs a rest on that one, but will suddenly strike back with it repaired in another video! I cannot wait for that one!

[@kevinmothers904]

Mend it Mark notification. Ah! the parts have arrived for the AIWA tape deck. Nope, we've gone all KINKI from China.

[@rugglez]

Thanks Mark.

[@JoopKomkommerShake]

Nice amplifier and off course nice repair.

[@enoz.j3506]

People are saying why have a large piece of thick aluminium as a case, and not fit the power transistors to it, well i will explain, the transistors collector is live,+- 80volts ,and your relying on a piece of very thin kapton tape,just think of the shock risks,if the tape broke down,swarf etc,the case would be sitting at 80 od volts (enough to give a shock) ,its that simple,it wouldnt meet the safety specs,even though its made in China.

[@nevillegoddard4966]

@@enoz.j3506 We just used the regular mica washers & silicon grease under our power transistors that have 1200V on them with no problems! The pcb should NEVER get so hot that it discolours like this one did. It will eventually become conductive. The uniform discolouration under all the mosfets means they've ALL been overheating. $1000 for a piece of 💩 that just looks good, feels heavy, but WILL fail! Kinky CRAP!

[@enoz.j3506]

@@nevillegoddard4966Yes ,as a qualified electronics engineer,for 40+ years,mica washers and silicon grease was & still is, widly used,mica withstands 1000 deg c,Kapton 260 degs c,big difference,got to look at worse case cenarios,to blue the legs on those fets,i dont know ,as you say the fact that the pcb is burnt means,bad designe & will conduct eventually. I dont know why they didnt use insulated fets,then bolting to chassis would be the way to go.Its made in China,nuff said.Make it look good and it will sell.

[@richy69ify]

great video

[@mactheweld]

great vids mark . would be nice to listen to the repaired equipment operating in real world use

[@davignonmemarc3000]

A quickie but a goodie !

[@repairstudent8750]

amazing

[@jampskan5690]

I understand very little, but holly cow is that beautiful!

[@jampskan5690]

The Engineers that designed the thing clearly didn't want the likes of my novice hands to go gleam inside it's internals, what with all of those different sized screws and what not!

[@nickk6109]

love the metal back to the mosfet, with a metal screw into a combined metal heatsink.. (I have a set of these same fets). I'd probably want insulating inserts or plastic screws..

[@darrenmurphy6251]

i love mosfets in audio output they often blow up a little more gracefully than bipolar fire mongers and the usual 100r gate resistors protect the driver stages (usually)

[@sw6188]

The trouble with MOSFETs in audio output stages is that 30 years after the unit was made and you need to change out some transistors, they are obsolete and impossible to obtain. A good example are the 2SK1058 and 2SJ162 pairs. Used in many amps, they are now obsolete. BJT transistors are much easier to find - I have large stocks of genuine ones, many more than the MOSFET stocks that I have.

[@darrenmurphy6251]

Yes iam running genuine hitachi 2sj50, 2sk135 and some of my spares will be fakes 😢

[@sw6188]

@@darrenmurphy6251 The Hitachi 2SJ and 2SK series MOSFETs are pretty much bulletproof. I had an amp come in for service that the owner replaced the fuses with nails and drove the thing to max - yet the MOSFETs didn't die. In fact, in the past 40 years I have only replace ONE of these Hitachi devices. They just don't fail. I have good stocks of them.

[@MrTurboturbine]

I love the 555 timer in it's heavily guarded isolation 2:54

[@keithneal5369]

Talk about overkill. Just shows what extremes some people will go to just to listen through headphones. God knows why you need so much power. As always your video's are educational and entertaining.

[@darrenmurphy6251]

wonder if someone ran high impedance mode into low impedance headphones = loads of heat then eventually mosfet failure i dont think that was a heatsink but just a way of thermally ballancing the high and low side mosfet pairs , like those little alluminium twin to92 clamps for input differencial pairs we used to see in the 90,s i didnt see any switching relay to select a lower rail voltage by selecting a lower voltage secondary winding just a protect relay for high and low impedance modes

[@anjkovo2138]

FASCINATING👍👍

[@faps7283]

tuyệt vời,những kinh nghiệm và máy móc sửa chữa kinh điển

[@schummiehugo]

thank you happyman ! gr

[@artsimannisto5659]

well,aiwa is ,i think, way pain ina ass. HOPE THAT we see that soon enough,thumbs up. Thanks,Mark,top guy in repair business.

[@adalbertus777]

Good to see you're back Mark! You've set the bar very, very high when it comes to electronic repair videos. Different camera angles, zoom-ins, lightening, post-production and so on. I wonder how much time did you spend making this, relatively short one. ;)

[@edmaster3147]

hear hear, Mark does a great job, smart and capable guy

[@wirdy1]

Those that know, know how much thought & time this takes.

[@andygardiner6526]

I really appreciate the quality of that unit but, at some point during manufacture, the question must have been "Are we designing this box to survive re-entry from orbit?" :-)

[@v1970lima]

Good video as allways, but too short for an addicted fan like me!

[@utp216]

That’s one chunky chassis! I hope it sounds good on the output side!

[@hansjanssen3364]

Thanks Mark, great video. More vintage (90's) high-end gear please! (dare i say Mark Levinson?)

[@esiakaharding9124]

you are very good

[@gordonm2821]

You would think if they were throwing that amount of money at it you would have transformers feeding the XLR outs. Also I think it’s a bit overkill sanding off the component text. I think if someone was looking to copy the idea they would not copy this design!

[@sw6188]

A good balanced output stage can be done cheaply and well with op-amps but yes, for the money this thing costs I would expect to see transformers in it!

[@juancarlossanchez118]

Los vídeos de electrónica más extraordinarios 👏🏼👏🏼👏🏼👏🏼👍🏼

[@giorgostexnikos6976]

excellent

[@bobrose7900]

Quality balanced connectors possibly the reason they are used but it does seem strange. Nice unit, made in China! It would have been nice to have done a performance test, i.e. frequency sweep at various gains and THD to see if it was worth the money... Great video at usual, thoroughly enjoy them but this was a bit short!

[@xtristanox]

Danke!

[@bluesplayer59]

Marvellous 🎉

[@tschobban]

sorry ;) .. i dont speak englisch very well, becaus i find the wörter nit so schnell. =( ... i like your videos. very nice, high quality of knowledge, funny, perfect =) greetings from aschaffenburg, bavaria