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? You can support MendItMark here: / menditmark
Пікірлер: 442
@ralphalder145 ай бұрын
If Kinki Audio ever teamed up with Schiit Audio they’d have a fantastic opportunity for a new brand name !! 😅😅😅
@FrankWoodPhotography5 ай бұрын
😂
@wollaminfaetter5 ай бұрын
😂😂😂😂
@tjtreinen73815 ай бұрын
🤣🤣🤣🤣🤣🤣🤣🤣🤣
@rillloudmother5 ай бұрын
at least they would sell a lot of bumper stickers in certain parts of the usa...
@potassiumchloride69685 ай бұрын
inki pinky ponki💀💀
@bobgrob45 ай бұрын
70K subs and climbing. We need to get Mark up to about 5 Mil
@Mihail_K.5 ай бұрын
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.
@radicalaudiodesign5 ай бұрын
That heatsink connects to toplid when screwed down so not so little slab anymore.
@Mihail_K.5 ай бұрын
@@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.
@Tokaisho15 ай бұрын
I'd say there's an air gap@@radicalaudiodesign
@SusanAmberBruce5 ай бұрын
An improvement would be a thicker longer block of aluminium that gets screwed to the lid and with the mosfets wider apart.
@andrea.dalessandro5 ай бұрын
@@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.
@petercornell20025 ай бұрын
That amp is SERIOUSLY over-engineered. Something like 2 x 15w for headphones? I love it! Good to see you back Mark.
@borlibaer5 ай бұрын
Yes, overengineered at the wrong Place. Massive enclosure, pippi heatsink plate 😂
@mattparker87475 ай бұрын
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....
@csm08815 ай бұрын
@@borlibaerĺpp
@peterlarkin7625 ай бұрын
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.
@edmaster31475 ай бұрын
@@peterlarkin762 I kida get the idea that they tried to engineer the mosfets as 'tube' devices, hence the high voltages, which are for headphone output uncommon. FET's often sound nice when warm -70 degrees centigrade und up-. A more common solution is just an arrangement of good op-amps for headphone use, which drastically reduces the amount of components and more importantly, coupling over caps and worse, resistors. Yet, I have never designed an headphone amp nor do I like headphones, so I can be very wrong. In general I would stay away from hard to drive headphones, the same for non-efficient loudspeakers, though there are always many reasons to oppose that.
@pabloluchi35955 ай бұрын
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!
@edmaster31475 ай бұрын
Mark has the spares on the shelf ;)
@RedShift55 ай бұрын
I think in this case on FET failed and then cooked the others resulting in total failure
@absurdengineering5 ай бұрын
Last thing I’d have ever expected to see that is a headphone amp lol.
@maksqwe15 ай бұрын
Just got out of the shower, got in bed and thought let’s watch a few videos before bed.. and Marks video pops up!!!
@T0pBaNaNa5 ай бұрын
I literally threw my hands in the air when i got the notification 😂....Haven't even watched it yet 🤗
@bobgrob45 ай бұрын
I know...Mark is the best. Love these videos.
@LeifES5 ай бұрын
Came here just to see the electroshock in the intro again. Haha no, great video!
@DavidFRhodes5 ай бұрын
the best part for sure
@Rob1972Gem5 ай бұрын
Without doubt the best electronic fixing channel on KZfaq please please longer videos I have learnt so much from watching your videos please keep the vids coming
@AG-cg7lk5 ай бұрын
Companies that grind labels off of components or cover them in goop need a slap.
@trickyd4995 ай бұрын
Best electronics channel, keep it up Mark!
@ibrahimkocaalioglu5 ай бұрын
We missed you. Nice quick fix.
@marjon17035 ай бұрын
Yay!... new 'Mend it Mark' Vid... Happy, Happy, Joy, Joy!
@zuvinrat41555 ай бұрын
Youre back , great episode Mark!
@eddieMurphy111115 ай бұрын
that's is a superb job, nice to watch somebody who knows what they are doing ,thank you for the video
@baronofgreymatter145 ай бұрын
Great to see you Electronic Zen Master
@user-gu5kk7wr5q5 ай бұрын
All done as usual with the efficiency, finesse, and as usual the astounding knowledge you bring to this channel.
@exiledscouser9195 ай бұрын
Excellent as ever, it’s our pleasure to see you work through the problems and get them fixed. Thank you as always.
@andyfish48215 ай бұрын
Wow, tidy bit of kit....Nice to see you back mark 👏
@francomarianardini6815 ай бұрын
good to see you back, Mark! ciao from Italy!
@andrewwturner5 ай бұрын
Excellent as always Mark. Please dont keep us waiting as long for the next one! 😊
@fantummenelkinstruments19595 ай бұрын
Happy days when there's a new vid from Mark! Top notch work once again!
@NoobCannon12345 ай бұрын
Another great video. I wish you posted more often but always a treat when you do. Thanks
@fichambawelby26325 ай бұрын
Nice to see you again, Mark!
@Trucam20205 ай бұрын
Thanks Mark, I always enjoy your videos
@kjbunnyboiler5 ай бұрын
Excellent as always👍👍
@user-gs3vc3rq5e5 ай бұрын
Like always, great work!
@D.Hozzie5 ай бұрын
You’ve been missed Mark. Thanks!
@alialmahanawi84095 ай бұрын
Excellent job Mark thanks for sharing 🙏
@rayofcreation39965 ай бұрын
Mark there you go again. Its an absolute joy watching you perform. Thanks and lots of love. 🎉
@blindbob41155 ай бұрын
I love listening to the sound of you working ❤️❤️❤️ great channel
@colin48505 ай бұрын
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.
@UnCoolDad5 ай бұрын
Where is part 3 of the AIWA?
@artsimannisto56595 ай бұрын
Yes mee soo eagerly waiting,Hungryfor that.But,sadly,Mark hates cassdecks....
@batmandestroys19785 ай бұрын
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!
@lumbo1015 ай бұрын
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!
@cesio255 ай бұрын
Another great video from most positive technician on YT. Pure pleasure to watch your content Mark
@AMByram5 ай бұрын
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?
@jeremywh75 ай бұрын
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 🐱).
@sw61885 ай бұрын
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.
@mactheweld3 ай бұрын
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
@robinandreasson49115 ай бұрын
Ahh great content, thanks Mark
@sjqideez66264 ай бұрын
Wow Mark, awesome stuff. Thank you
@hw45275 ай бұрын
Thank you for posting 👍👍
@vintagehifirestoration65155 ай бұрын
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!
@chezsnailez5 ай бұрын
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...
@barrybradfordlocksport5 ай бұрын
Great, but not enough uploads mark we love your content
@paulb46615 ай бұрын
Hi Mark, these fabulous fets based on Renesas J162/K1058 have unusual pin-out; the beads actually went on the gate and drain.
@jimbobroon-wj4qx5 ай бұрын
Superb !!! As always😁👍
@stephanloper57405 ай бұрын
Great Video and Work
@VoeViking5 ай бұрын
Another great video. Cheers.
@DougPowhida5 ай бұрын
Very entertaining and educational! Thank you.
@ruaraidhmcdonald-walker95245 ай бұрын
Satisfying repair!!
@zokxzoranovski52555 ай бұрын
As usual, Mark is the best.. :)
@kevinmothers9045 ай бұрын
Mend it Mark notification. Ah! the parts have arrived for the AIWA tape deck. Nope, we've gone all KINKI from China.
@danielstan42315 ай бұрын
I love your lab environment.
@danhorton61825 ай бұрын
Interesting you saying the MOSFETs not needing a heatsink considering how hot they’ve clearly gotten. Excellent video.
@edmaster31475 ай бұрын
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.
@danhorton61825 ай бұрын
@@edmaster3147 well then in reality they could have used TO220 devices then, regardless they don’t look like they’re staying too cold.
@paulb46615 ай бұрын
@@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.
@fl31625 ай бұрын
Another great video.
@Mickey-Knox5 ай бұрын
I love these retro Phil Collins videos!
@mistersunny36364 ай бұрын
🤣
@tonibarski42835 ай бұрын
Top video this one ,! well done, enjoyable and knowledgable ( as always )
@kerrygleeson44095 ай бұрын
Another great video Mark always very interesting thanks for sharing 🦘
@AaronBegley5 ай бұрын
Well done!
@richardbrobeck23845 ай бұрын
nice repair !!
@Bigbluevwvan5 ай бұрын
Another great fix and Kinki look great build quailty :)
@MonguzTea5 ай бұрын
An electronics engineer would laugh his ass off looking at that thing. The case is impressive the rest not so much.
@HAL44005 ай бұрын
Thanks Mark! 🤓
@mixolydian20105 ай бұрын
Cheers really enjoyed the video
@Choralone4225 ай бұрын
Time to get KINKI with Mark! Let's do it!
@rhkavli5 ай бұрын
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.
@michaelclutton84465 ай бұрын
Thanks another interesting video
@DarrenMossAU5 ай бұрын
Nice repair. I wasn't expecting that amp to be so well made. Really good workmanship on everything, even the case!
@JPDESS5 ай бұрын
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.
@skypittman93035 ай бұрын
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.
@pantelisEVs5 ай бұрын
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!
@gibbogle5 ай бұрын
Using the bottom plane looks like a no-brainer.
@thesleepstate5 ай бұрын
This unit is £1199 street
@SusanAmberBruce5 ай бұрын
@@thesleepstate Really, I knew it would be expensive, but that's mental!
@darrenmurphy62515 ай бұрын
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
@rugglez5 ай бұрын
Thanks Mark.
@andygardiner65265 ай бұрын
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?" :-)
@darrenmurphy62515 ай бұрын
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)
@sw61885 ай бұрын
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.
@darrenmurphy62515 ай бұрын
Yes iam running genuine hitachi 2sj50, 2sk135 and some of my spares will be fakes 😢
@sw61885 ай бұрын
@@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.
@richy69ify5 ай бұрын
great video
@MrTurboturbine4 ай бұрын
I love the 555 timer in it's heavily guarded isolation 2:54
@davignonmemarc30005 ай бұрын
A quickie but a goodie !
@artsimannisto56595 ай бұрын
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.
@repairstudent87505 ай бұрын
amazing
@mactheweld4 ай бұрын
great vids mark . would be nice to listen to the repaired equipment operating in real world use
@JoopKomkommerShake5 ай бұрын
Nice amplifier and off course nice repair.
@neilosullivan82165 ай бұрын
I'm surprised you didn't run it under load for a while and test it for hot spots with your thermal camera - perhaps if it returns in the future? 😊
@keithneal53695 ай бұрын
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.
@utp2165 ай бұрын
That’s one chunky chassis! I hope it sounds good on the output side!
@anjkovo21385 ай бұрын
FASCINATING👍👍
@schummiehugo5 ай бұрын
thank you happyman ! gr
@hansjanssen33645 ай бұрын
Thanks Mark, great video. More vintage (90's) high-end gear please! (dare i say Mark Levinson?)
@xtristanox5 ай бұрын
Danke!
@mattsan705 ай бұрын
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
@twobob5 ай бұрын
0.1 to 0.3 W/m•K ish versus 400 ish. Nah... be fine...what's several orders of magnitude between friends...
@nickk61095 ай бұрын
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..
@adalbertus7775 ай бұрын
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. ;)
@edmaster31475 ай бұрын
hear hear, Mark does a great job, smart and capable guy
@wirdy15 ай бұрын
Those that know, know how much thought & time this takes.
@bobrose79003 ай бұрын
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!
@v1970lima5 ай бұрын
Good video as allways, but too short for an addicted fan like me!
@jampskan56905 ай бұрын
I understand very little, but holly cow is that beautiful!
@jampskan56905 ай бұрын
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!
@esiakaharding91245 ай бұрын
you are very good
@gordonm28215 ай бұрын
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!
@sw61885 ай бұрын
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!
@giorgostexnikos69765 ай бұрын
excellent
@faps72835 ай бұрын
tuyệt vời,những kinh nghiệm và máy móc sửa chữa kinh điển
@bluesplayer595 ай бұрын
Marvellous 🎉
@Starcraftowns995 ай бұрын
Mark great video as always. I might be a bit sleepy, but I thought the second from left Exicon was loose in the part where you were installing the beads. Maybe it was deliberate to aid alignment of the pins to the board… if not. It needs to be tightened 😅
@sw61885 ай бұрын
I saw that as well. Hopefully he caught it in time.
@arenaengineering80705 ай бұрын
This headphone amplifier have a big aluminium case, but output trasistor mounted on little heatsink. Case can be a good heatsink.
@jamescollins60855 ай бұрын
I would take advantage of that huge bottom plate and mount them onto there.
@arenaengineering80705 ай бұрын
In this amplifier, you can simply place the output transistors on the bottom side of the printed circuit board, bending the leads and fixing them directly to the bottom of the case. The main thing is to use an insulating thermal pad. As is done, for example, in the Burson Soloist HA160 amplifier.
@jamescollins60855 ай бұрын
@@arenaengineering8070 The Kapton tape used here seems like a bad idea, seeing as it's best known for its thermal insulating properties. A thermal pad would definitely be better. What's the reason for the transistors being unable to make direct contact with the chassis?
@arenaengineering80705 ай бұрын
@@jamescollins6085 The case of the used output transistors is not insulated and in direct contact with the aluminum chassis a short circuit will occur between the + and - power supply. Kapton tape is used in this amplifier more as an insulator.
@jamescollins60855 ай бұрын
@@arenaengineering8070 Thank you for the explanation.