How to repair weak distorted channel Realistic SA 1000 home stereo amplifier D-Lab

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  • เผยแพร่เมื่อ 28 พ.ย. 2024

ความคิดเห็น • 258

  • @grahamhodder6243
    @grahamhodder6243 ปีที่แล้ว +2

    I have a Realistic SA-1000-SA amplifier which is almost identical to this unit (it doesn't have the phono mag/ceramic switch). I also had a low output channel and mega distortion. Also, all the pots on the front panel were noisy and "Clunky". I was lucky that a little bit of good quality contact cleaner and working the pots for about 5 minutes managed to clean up the crud and it now sounds just the way it did when it was new, back in the 70s. Still a great little amp with a somewhat low output (About 20 watts RMS per channel) but in a small room, that's all I need. Thanks for posting this cool video. It brought back lots of memories. Incidentally, I think I paid $99.00 for it at a Radio Shack here in Halifax, Nova Scotia back in the mid 70s.

  • @treadmillrepair754
    @treadmillrepair754 5 ปีที่แล้ว +36

    I been fixing audio equipment for 40 years, fix an amplifier is an art, the new technicians or engineers do not know anything about this.
    Your workbench is very clean, my lab is a war zone.
    Cheers.

    • @markbuxton2368
      @markbuxton2368 5 ปีที่แล้ว +1

      sure is. looking under the preamp board and finding a host of bad small value electrolytics , thats also art :)

    • @manFromPeterborough
      @manFromPeterborough 4 ปีที่แล้ว +3

      @@markbuxton2368 small value electros can be replaced with WIMA film caps, I have upgraded my TC-778 phono stage with 4x 1uF 63v WIMA caps on the in/out coupling links

    • @d3dde76c
      @d3dde76c 4 ปีที่แล้ว +3

      I'm an engineer and I try. Teach them instead of having this attitude.

  • @NebukedNezzer
    @NebukedNezzer 6 ปีที่แล้ว +5

    I was in hong kong 1965 and bought a nice pioneer sa400 amplifier. when I sold stuff at a garage sale I let it go and had sellers remorse ever after. what a stroke of luck to find a pioneer sx-32b receiver in like new condition at a local good will store. 15 bucks. it has exactly the same audio section as the sa400. amazingly some dioxit5 on the switches and controls and it works perfect on its original components. found a SL-D2 turn table free and have it on 10 inch cerwin vega speakers. along with casset tape unit and audio cd player. makes up my main listening system.

  • @acheleg
    @acheleg 5 ปีที่แล้ว +15

    Thank you so much for pointing out the value of discrete- mounted, serviceable analog gear !! I love keeping vintage gear in service and out of the refuse.

  • @goodun6081
    @goodun6081 6 ปีที่แล้ว +13

    The glue used at the factory to hold those capacitors down prior to soldering was probably not the same corrosive stuff that you would see in a Sansui or Yamaha or many other vintage amplifiers. The corrosion inducing glue was generally known as Sony Bond, and it does not soften in alcohol, although you can sometimes hit it with some Freon type component cooler, or one of those "dust-off" type compressed-"air" cans (hint, it's not really air) held upside down as you squeeze the trigger so that the "air " comes out as a liquid, freezing the glue and allowing you to chip it away. Anyday, no day at work seems complete without scraping off some Sony bond that has morphed into something resembling burn sugar, and replacing the adjacent components that it has corroded. PS, we have seen instances where the crimped or riveted-on terminals on those output coupling caps have become intermittent and the measurable distortion goes up and down if you pull on the the leads or flex/rock the capacitor.

  • @jdcdnet
    @jdcdnet 3 ปีที่แล้ว +3

    I am looking at a similar half clipped signal right now from a 1975 Roland JC-120. I suspect the same is going on. Terry, thanks for the video! This amp means the world to the guy who bought it in 1975, so gave me perspective on another couple repair paths and checks before I dive too deep into part level testing. The pots all required complete disassembly and contact cleaning along with reflow. Cheers!

    • @timwarneka5681
      @timwarneka5681 ปีที่แล้ว +1

      give us an update, please! Did you get the JC-120 back in action?

    • @jdcdnet
      @jdcdnet ปีที่แล้ว

      @@timwarneka5681 Hey, no unfortunately not yet. Mothballed it for now, but hope to get back on it soon.

  • @davidc3572
    @davidc3572 4 ปีที่แล้ว +4

    Great little amp. I bought one of these used back around 1979 while in high school, and used it for 5-6 years through school until I had to go bigger. I miss the clean, warm sound from that Realistic amp. It truly was a little gem.

  • @JeffCounsil-rp4qv
    @JeffCounsil-rp4qv 5 ปีที่แล้ว +1

    Good call on the caps. Sony Bond was used by many brands, not just Sansui to glue the components (for the trip across the pond). Pioneer, Yamaha, Onkyo, Technics, etc. Pretty much anything built in either Japan or Korea. And of course back then they had no idea it becomes corrosive with age, then the corrosion spreads and becomes conductive. Some production workers got carried away with it and blobbed it everywhere! I use toluene to soften the glue because it 1) dries fairly quickly 2) doesn't have water like alcohol has unless you use (expensive) 99% alcohol. 3) it is safe on most plastics (except polystyrene caps but it really doesn't hurt them, just makes them ugly). Though some people don't like the odor, I don't mind it. Look on the labels of solvent-based glues and you'll see toluene is usually the solvent in the glue. Oh, and I love that tune you played!

  • @998cooper
    @998cooper 3 ปีที่แล้ว +3

    Great instructive video. I've just fixed mine which had the same issue. Replaced all caps & is now working fine. Thanks.

  • @djfrank59
    @djfrank59 6 ปีที่แล้ว +4

    Working on vintage solid state can be easy, unless...there are multiple boards mounted on top of other boards. Then it can become an adventure just with disassembly. Once you get into multi-layer boards and SMD's, It can be living hell. I work on a lot of modern pro audio as well as vintage tube gear, and I'll take tube gear any day :) Excellent videos! Keep 'em coming.

  • @videolabguy
    @videolabguy 2 ปีที่แล้ว

    I have to smile. You personify one of my favorite sayings, "Alcohol! Beneficial to both man and machine!" Amen, brother!
    (I use it to clean tape heads and circuit boards!)

  • @philipdecatanzaro1822
    @philipdecatanzaro1822 3 ปีที่แล้ว +1

    Fun stuff. Not many would repair an old Realistic as they weren't regarded as very good back in the day. But Hey - they did the job. I used to work for the Shack back in 1975.

    • @mysteryjesus
      @mysteryjesus ปีที่แล้ว

      That's true. But I remember going to radio shack and hearing some of their stereos and speakers and I remember comparing to my dad's Sony setup and thinking Realistic didn't have the warmth or bass of what we had at home. But then again, it was a small sample of Realistic that I actually heard in the 80s and nothing from the 70s. Generally, Realistic was not highly regarded like other brands. If one was serious about great sound they went elsewhere.

  • @philippvonow1676
    @philippvonow1676 3 ปีที่แล้ว +2

    Yes the knobs and layout style is very similar to my Hitachi SR-903... i have to clean the potis and knobs too once in a while..

  • @kenngray6994
    @kenngray6994 5 ปีที่แล้ว +2

    Just watched your video and measured the collector voltage on my sa1500 and there's a problem. So I will replace all the caps on the main board. Thank you for that very informative video.

  • @maryrafuse2297
    @maryrafuse2297 5 ปีที่แล้ว +2

    These were great value for the money. I still have the SA-1500 from 1976. It sits on top of the Clairtone T 7 that my brother rebuilt for me.

  • @brucejoseph8367
    @brucejoseph8367 5 ปีที่แล้ว +1

    Another great repair. It's a shame that the problem of bad and leaky caps has not yet been solved. More research should be done to overcome this problem. Surely with modern materials this should have been consigned to history by now.

  • @samuelcajeles85
    @samuelcajeles85 5 ปีที่แล้ว +1

    Eminently good repair. Aside from your knowledge in electronic circuits you have the test equipments like the scope which is a must in repairing electronic equipment. However, when the transistor output is shorted, the safe way is to measure first the forward bias if it's within limit. If not, then start checking surrounding components.

  • @ChippyOZ
    @ChippyOZ 6 ปีที่แล้ว +2

    Thank-you for starting to give attention to silver faced amplifiers! Looking forward to more of these for learning and repairs as tube amps are a bit out my reach.

  • @pietroplastina2786
    @pietroplastina2786 5 ปีที่แล้ว +1

    It's less expensive time wise to replace all the caps. Time is what you don't have. But I would of found out which cap.was bad for the next time. However if the all go anyway which I doubt that's fine. Good job. The final result is there . You fixed it. Good luck for next time.

    • @thomaskendall452
      @thomaskendall452 ปีที่แล้ว

      You have to figure that if one cap has died, the rest probably have one foot in the grave as well.

  • @ashokjadhav9904
    @ashokjadhav9904 5 ปีที่แล้ว

    Hi
    That's one cool job.
    BTW
    I had an old service book.
    That showed a way to find a leaky electrolytic capacitor as follows.
    Cut open or desolder , one of the two leads from the pcb.
    Then use an analog multimeter to check the charge and discharge of an electrolytic capacitor.
    Put analog multimeter in ohm range and connect the two leads. Positive terminal goes to the red wire and negative terminal to black wire.
    Healthy capacitor should show very little resistance initially and gradually show higher resistance as it gets charged till it shows a full resistance.
    If the capacitor is leaky it'll show a very little resistance, almost short circuit.
    On the other hand, it'll show high resistance if it's open .
    That way, you have found the culprit.
    Bad capacitor will not show charging. ( No gradual increase in resistance as it is charged).
    Thanks

  • @welyas4064
    @welyas4064 5 หลายเดือนก่อน

    Doh! Have a old Sansui 4000 I'm about to pull apart with this exact issue! Hope it's not due to this terrible corrosive glue you mentioned. Thanks for taking the time to post! Always informative, top tier content on these topics.

  • @TheRadioShop
    @TheRadioShop 6 ปีที่แล้ว +3

    Great outcome of shooting from the hip Terry. That is where experience comes from. As we know those caps go bad after time. Enjoyed the video.

  • @williamfriggle
    @williamfriggle 5 ปีที่แล้ว +3

    So cool to see that amp. I have the same amp. When I was 7 I remember going with my dad to Radio Shack for him to purchase ut. We used it for many years. I tried it and the only thing that I think is wrong is the volume control is noisy. I just ordered on Amazon control cleaner. I'm hoping that will get this awesome amp working again. If anything is wrong with it like yoyrs, I'm screwed. As I don't have your knowledge to do what you did. I'll be keeping my fingers crossed. Thanks for the cool video.

  • @gordonwelcher9598
    @gordonwelcher9598 9 หลายเดือนก่อน

    I had one of these. One of the small TO-92 stretch transistors became intermittant and caused 30 volts dc to be sent to one of my Dynaco A35 speakers, eventually melting the voice coil of the woofer. I was in the other room and didn't notice until it was too late. Just bending the leads would make it fail. It met it's fate with a 10 pound Wildlarizer. The amplifier sounded ok, not as good as a Yamaha or Harmon Kardon. Nice basic appearance and not too big. Very good for the price, $99 CAN on sale.

  • @michaelbird27
    @michaelbird27 5 ปีที่แล้ว +1

    Aloha from Hawaii D-Lab! Long time viewer first time commenter. I recently purchased a Vintage Harmon-Kardon 630 twin powered receiver at a consignment shop for $40. It powers on but does not produce noise in speakers. I searched for repair shops on Oahu but, as you can imagine, they are few and far between. I don't really trust them to give me. A fair deal. I'd love to see about mailing it to you to fix for a video. I'd love to learn about my machine. I really want it to come back to life. If you are interested in making a video of this I'd be happy to pay for shipping and repair.

  • @anthony2010707
    @anthony2010707 4 ปีที่แล้ว

    I just discovered your channel and I must admit it is really fun to watch, thanks to your technical know how and expertise.

  • @mysteryjesus
    @mysteryjesus ปีที่แล้ว

    Great video, very informative and makes repairing these easier to understand compared to the majority of videos I've watched the last few years. Thank you!

  • @gatekeeper65
    @gatekeeper65 5 ปีที่แล้ว

    Good day Terry. The adhesive that you referred to in the video wasn't produced by Sansui, nor used only by them. It was used by almost all manufacturers out of Japan and some other countries as well. It was used in audio equipment, TVs, VCRs, radios, and lots of other products. I'll give you a hint as to who produced it,... it's called "Sony Bond". It becomes brittle and conductive after being exposed to constant heat over time, and then becomes corrosive to component leads and jumper wires. I've even seen circuit failures because of diodes that were buried under the stuff, becoming very leaky or even shorting. The companies that I saw being the most affected by its use were Mitsubishi, and Luxman.
    The really stupid thing about this stuff, is that it even after all the lessons learned the hard way about it years ago, it's starting to turn up again in lots of electronics coming out of China. Go figure.

  • @michaelaaronorton4001
    @michaelaaronorton4001 6 ปีที่แล้ว +2

    For years I passed up alot of great solid state gear because all I wanted to buy was tube amps that was a stupid mistake on my part I have a Fisher tx 100 all germanium transistor Avery Fisher's first transistor line of amps built in Germany and I really enjoy the sound of this amplifier as much as the tube HiFi stuff i have even more than the marantz stuff

    • @d-labelectronics
      @d-labelectronics  6 ปีที่แล้ว

      I agree man. The SA-1000 is in my main shop driving a set of Bose 301's. Super rich sound. The amp is a keeper!

  • @stephenflowers8516
    @stephenflowers8516 2 ปีที่แล้ว +2

    I bought one of these amplifiers from Radio Shack in the mid 70s. It was ( For the price) a very good amplifier.

    • @johnbeckham1483
      @johnbeckham1483 2 หลายเดือนก่อน

      How many watts per channel RMS is the Realistic SA-1000?

  • @billmckenna7056
    @billmckenna7056 5 ปีที่แล้ว +5

    Thanks Terry, needed that video :) Have a solid state Standel on the bench right now and its showing similar issues. Will proceed to cap job and see if that fixes.. Kind of figured it was that as its a 1964 era early Solid state thing.

    • @dhart501
      @dhart501 5 ปีที่แล้ว

      Bill what did you find on your Standel amp repair?

  • @justfortier
    @justfortier 5 ปีที่แล้ว +2

    Going to try this with my old Denon DRA-25. It's got dropouts, and crackles I think in the preamp section. Thanks for the video!

  • @learnandteach.108
    @learnandteach.108 5 ปีที่แล้ว +6

    Interesting.
    This clip hold me until it finishes,
    Really amazing.
    Thanks dude, keep it up.👍

  • @marsmediapro
    @marsmediapro 3 ปีที่แล้ว

    After watching this, I betya that my SA-1001 needs to be re-capped- dangnabit! Thanks Terry!

  • @smstiao-tecnologia
    @smstiao-tecnologia 6 ปีที่แล้ว +1

    Another equipment properly repaired.
    Congratulations Terry!

  • @greaterbayareahero1401
    @greaterbayareahero1401 3 ปีที่แล้ว +1

    Great information. You taught me how to detect my distortion problem and saved me a ton. Thanks!

  • @PecanPie1102
    @PecanPie1102 6 ปีที่แล้ว +6

    Solid State it’s the Future.Coming to an amp near you.Terry ✌🏽

    • @d-labelectronics
      @d-labelectronics  6 ปีที่แล้ว

      Love it! Can I use that slogan on the next SSS?

  • @MrTopsoil911
    @MrTopsoil911 5 ปีที่แล้ว +2

    I have the Realistic sa1500 and I also did a full recap and works better than new!! Pretty powerful with my Minimis 7 bookshelf speakers

    • @nickking1510
      @nickking1510 5 ปีที่แล้ว

      nigel mahabir I have one also try it on some quality 12 or 15 inch 3 way speakers 🔊 I believe it around 100 Watts rms per channel. Recapping mine soon

    • @thomaskendall452
      @thomaskendall452 ปีที่แล้ว

      @@nickking1510 The SA-1000 puts out 20 wpc rms into 8 ohms; the 1000A puts out 25 wpc rms into 8 ohms.

  • @gerryroberts662
    @gerryroberts662 2 ปีที่แล้ว +1

    Cool, we need more tube amp repaire. keep makeing your videos pls..

  • @adrianalexander7516
    @adrianalexander7516 4 ปีที่แล้ว

    Ive got a teac ag-v8500. im glad people still fix things instead of throwing them away

  • @craign8ca
    @craign8ca 6 ปีที่แล้ว +1

    Darn, I wanted to see how you remove the solder from the leads. Back when I did component level troubleshooting, I had a Pace solder sucker. That thing was great and was the best method of removing solder. In my workshop I've been using solder wick, which is just ok and a little more work. Your repair videos are great to watch.

    • @d-labelectronics
      @d-labelectronics  6 ปีที่แล้ว +1

      Hello, sorry I did not show that. I use Chemtronics solder wick to clear the holes. I do have a Hakko solder re-work station, but use that on dual sided boards. More Solid state sinema soon. TD

  • @barrychristiansen4579
    @barrychristiansen4579 5 ปีที่แล้ว +1

    love it Terry. oh yes ,you've done this before. beautifull work! hope the family is great!

  • @HHTTRRNN
    @HHTTRRNN 2 ปีที่แล้ว +2

    Can you explain to me why one of the transistors is only showing half the voltage value of the other transistor?

  • @MrFlembot
    @MrFlembot 3 ปีที่แล้ว +1

    Great presentation! I might try the cap blast on another old Realistic STA-45 receiver I have. I haven't been able to find a schematic, so it won't be easy to figure out.

  • @stevesulak9487
    @stevesulak9487 11 หลายเดือนก่อน

    I like you. I kinda felt like it should be simple if you break it down properly. You confirmed that. And even if it didn't work... It has to be done anyway. Good video.

  • @afzaalkhan.m
    @afzaalkhan.m 4 ปีที่แล้ว +1

    Excellent repair and diagnoses . Nicely explained.

  • @handrias001
    @handrias001 4 ปีที่แล้ว +1

    Thanks! I think I am able to fix my amp now, looks like i have bad cap, sound comes back to bad channel when i kick amp little bit, but not for long. Thanks for great video. Subscribed.

  • @serpentineflame
    @serpentineflame 5 ปีที่แล้ว +1

    Hello captain, I have been chopsticking around in my one yankee dollar juliette 8-track/record player tuner stereo trying to fix a channel glitch. The balancer potentiometer plays both stereo speakers when wiped all the way right, and then diminishes to nearly nothing as it is swept left. It's essentially a volume control. I will try hooking up all four speaker outputs. The pot itself has the correct values. I have checked both opamps but not the two larger capasauruses, haha. Thanks and much love.

    • @larryshaver3568
      @larryshaver3568 4 ปีที่แล้ว

      I''ve got a magnavox astro sonic that does the same thing. Did you find the cause?

  • @arupdutta2202
    @arupdutta2202 4 ปีที่แล้ว

    I have a Harman Kardon HK6100 - pretty old - left channel sounds heavier than the right....thinking about the changing the capacitors first. Thanks a lot, cheers from Kolkata, India.

  • @teresitamontebon5342
    @teresitamontebon5342 3 ปีที่แล้ว +2

    Hi ,I have a maranta sr2000 the tuner have a problem if you put stereo no signal if mono have a signal,what a problem thank you sir.

  • @moodyga40
    @moodyga40 6 ปีที่แล้ว +5

    hair dryer works well to losing up the caps

  • @thethirdman225
    @thethirdman225 2 หลายเดือนก่อน +1

    These were good value back in the day but they weren't exactly the last word in design. Still, they seem to be serviceable.

  • @NebukedNezzer
    @NebukedNezzer 6 ปีที่แล้ว +3

    like you, I have used the parts cannon a few times.

  • @Supernaut70
    @Supernaut70 ปีที่แล้ว

    I have the same problem with a Rogue rb-120bt 120-watt bass combo amplifier. I thought it was the output transistors. The problem is that those components don't have numbers. I installed another by trying by error and blew up one of the new power transistors. Thanks for the video. I will reinstall the original.

  • @6A8G
    @6A8G 6 ปีที่แล้ว +2

    Fantastic! Is there a schematic for your stereo wattmeter please?

  • @user-kk4pw2lo1t
    @user-kk4pw2lo1t ปีที่แล้ว

    Thanks, You made it look like fun am ready to tackle my Sony str 6065 weak sound output. .

  • @mikestormm
    @mikestormm 6 ปีที่แล้ว +1

    Great job, as usual!!! Looks like the poor brother on my pioneer sa6200

  • @larryshaver3568
    @larryshaver3568 6 ปีที่แล้ว +1

    amazing sound. I have a realistic rhapsodie with a preamp that has a noisy channel but I lost the manual which as a schematic.

  • @r9700dx
    @r9700dx 3 ปีที่แล้ว

    Awesome information! I would like to know where to get caps and resistors to repair a TEAC reel to reel. Thank you.

  • @rimmersbryggeri
    @rimmersbryggeri 2 หลายเดือนก่อน +1

    I had the same fault on an old akai it was a folded over mica insulator on one of the transistors. Had been like that from new probably. Inherited it from old relatives.

  • @andrewprather9572
    @andrewprather9572 2 ปีที่แล้ว +1

    I have a Soundcraftsmen 2000A...I need to do this to my amp bad one of my caps is loose I think, but want to replace all. Wish I could send you mine don't want to get rid of it.

  • @roberthurless4615
    @roberthurless4615 6 ปีที่แล้ว +2

    HI Terry, another good one. I am wondering how do you know what size of capacitor to order for the different ones in the amp. I am talking about the lead spacing. Is it just from experience, or can you tell from the size of the cap? I am really enjoying SSC, please keep 'em coming.

  • @electronicshelpcare
    @electronicshelpcare 5 ปีที่แล้ว +4

    Thanks for the great video.

  • @rogeronslow1498
    @rogeronslow1498 6 ปีที่แล้ว +1

    I like that thin illuminated magnifier of yours. What is the make please.

  • @CodeLeeCarter
    @CodeLeeCarter 6 ปีที่แล้ว +3

    I've been looking for a great vintage amp like this one, looking for one to build with my Media Center main sound amp.

  • @DeadKoby
    @DeadKoby 6 ปีที่แล้ว +2

    I have a 71 Altec that needs the same kind of help. I'll get to it eventually.

  • @victorg9974
    @victorg9974 3 ปีที่แล้ว +1

    Hi, I just discover your channel and I'd like to congratulate you. I'd like to ask you if you came to shoot a video about your D-Lab Amp Tester. I know it was requested here in the comments, but I could not find it browsing thru your channel. Cheers and thank you!

  • @larryshaver3568
    @larryshaver3568 2 หลายเดือนก่อน +1

    NOW i'm convinced that my Astro sonic just needs to be re-capped

  • @mithunhaque
    @mithunhaque 4 ปีที่แล้ว

    You can also carefully put a bit of kerosene with cotton swap and let the old glue wet for a while and try; the glue with the circuit board will also come out easily. I tried in my JVC amp.

    • @thomaskendall452
      @thomaskendall452 ปีที่แล้ว

      Lighter fluid works, too. That's my go-to solvent for that contact-adhesive-type glue.

  • @Melissa0774
    @Melissa0774 ปีที่แล้ว

    Do you have any videos on how to hook up a vintage tube stereo, like a Fisher 800b, to a laptop or a modern day TV? Is it possible to do that? Can you make a video on that, if you haven't already?

  • @matx6183
    @matx6183 2 ปีที่แล้ว +1

    Hi D-lab. Would this also potentially be a issue on a Onkyo AV power amp? My right channel is hissing, popping, crackling but all other channels are ok.

  • @antigen4
    @antigen4 6 ปีที่แล้ว +2

    i really don't know why people have interest in these old amplifiers but HEY - wow - it's about time we started resuscitating old junk electronics! we should do that with everything - don't throw anything away - if you buy something use it forever

  • @sgtjenko
    @sgtjenko 4 ปีที่แล้ว +3

    I have an early 80's Sugden amp A25.. I'm getting very intermittent distortion on either speaker do you have any idea what could be causing this or what I can do, it's really driving me crazy.

  • @rayvoorhies7180
    @rayvoorhies7180 3 ปีที่แล้ว +4

    I think the old amps with discreet components will become more sought after in another 20 years. The circuit boards in the 70's and 80's are better and more reliable compared to boards used in the 90's.

    • @thomaskendall452
      @thomaskendall452 ปีที่แล้ว

      Twenty years from now? How about 2023's prices? Even rebadged stuff from Radio Shack and JC Penny (MCS) have climbed up there!

  • @esci8978
    @esci8978 2 หลายเดือนก่อน

    Hello.. Really enjoy your videos.. Can you possibly do a video on your D-Lab Audio Test Center…?

  • @garymagliocca2913
    @garymagliocca2913 2 ปีที่แล้ว

    Question..I have a Kenwood KR 6050. Channel A right and left are ok but Channel B left is scratchy and A is fine. My thought is that the left channel A left should also be scratchy but it is ok. I see where some people have cleaned these successfully. Should I try this first?

  • @vuxnguyen
    @vuxnguyen 4 ปีที่แล้ว

    Hi Mr D-lab, i have the pioneer sa 7700, and the balance is not working properly, if i turn it all the way to the right side but both speakers still singing. Thanks for info!

  • @bigwheelsturning
    @bigwheelsturning 4 ปีที่แล้ว

    Have an older Denon that has a weak RH channel. Works fine in the morning, but as it heats up the sound goes away. Will see if I can fix it or toss it.

  • @bertroost1675
    @bertroost1675 17 วันที่ผ่านมา +1

    The left channel just went out last night on my sa-1000. It's about 90% lower in volume than the right channel, so it's not totally out. I really like this amp too. Are your services available?

    • @d-labelectronics
      @d-labelectronics  16 วันที่ผ่านมา

      Yes, contact me thru d-labelectronics.com

  • @dhart501
    @dhart501 5 ปีที่แล้ว +1

    nice job Terry.

  • @jcmcclain57
    @jcmcclain57 6 ปีที่แล้ว +1

    Thanks Terry for the lesson.

  • @matthewbrown5677
    @matthewbrown5677 5 ปีที่แล้ว +1

    Hi, love your style...were can I learn how to restore old amps are there any books out there.

  • @moodyga40
    @moodyga40 6 ปีที่แล้ว +1

    fabulous transistor work

  • @dal160
    @dal160 4 ปีที่แล้ว +1

    Hi, Just purchased a Yamaha xm4220 power amp and red light protection is
    on, channel d clip light is red also - do you know what this could be?
    any help would be appreciated. Thanks

  • @gearheadted9210
    @gearheadted9210 5 ปีที่แล้ว +1

    Cool man,Im learning tons,thanks,love your channel!

  • @tonyrink9999
    @tonyrink9999 4 ปีที่แล้ว

    Good, helpful video. It would be better for us novices if you stated where all your equipment connections are made.

  • @simonspeaker
    @simonspeaker 4 ปีที่แล้ว +2

    Hi Terry, what is the song? seems to be a reprise of "somebody else" by Jeff bridges but what is the artist?

  • @mrmax1467
    @mrmax1467 5 ปีที่แล้ว +2

    Do you sell the "D-Lab Audio Test Set" or perhaps posted schematic/parts list somewhere?

  • @richardbrobeck2384
    @richardbrobeck2384 5 ปีที่แล้ว +1

    Another great video these new caps will out live us

  • @taineasy
    @taineasy 4 ปีที่แล้ว

    Did you have your negative probe grounded to chassis when checking the output transistors? I have an occasional distorted left channel (sizzle type sound) but only with some cd's. I really notice it in vocals and piano passages. The amp has been completely rebuild and sounds fine with cassette, radio and lp's. I'm thinking the CD player has the issue but want to be sure.

  • @dennisperusse3837
    @dennisperusse3837 6 ปีที่แล้ว +1

    Enjoyed the video. I have a Harmon Kardon 75+ receiver that I’m going to recap soon for similar reasons. :)

  • @hectorvaldez239
    @hectorvaldez239 3 ปีที่แล้ว +1

    I have an sta-77. Fm works, and I get sound in both channels. None of the inputs work. Suggestions?

  • @russellhltn1396
    @russellhltn1396 6 ปีที่แล้ว +1

    I'd still want to run a test on the caps removed just to see what it was and how bad it got. I'm guessing one of them got leaky and affected the bias. Usually,. they go high ESR and you lose signal.

    • @MarkTillotson
      @MarkTillotson 6 ปีที่แล้ว

      Since the amp was still working (when not saturating negative), the feedback loop must have been closed and working, the output bias can then only affect the heat dissipation and amount of x-over distortion. So I'd suspect the input stage was being pulled out of balance by a leaky caps. On a single rail amp such imbalance won't fry the speaker and could have been gradually getting worse over time.
      Its just possible to make out on the schematic that the input stage is single-ended with a cap in the
      bias for the input transistor base - so yes, it is the bias that's out, but not the common sort of bias
      you think of with an amp... The input stage bias network is high impedance so it wouldn't take much leakage to start pulling it away from nominal.

  • @1834RestorationHouse
    @1834RestorationHouse ปีที่แล้ว

    I bought one of these brand new back in 1978. It desperately needs to be recapped whenever I get a break from fixing everyone else's amps.

  • @reyneldofonseca9782
    @reyneldofonseca9782 ปีที่แล้ว

    Soy de cuba y tengo un realistic y no encuentro el problema distorsiona y no da el voltaje medio tendrá el esquema y me lo facilita gracias

  • @robertking1032
    @robertking1032 3 ปีที่แล้ว

    I have similar problem on right channel, left channel sound proper but right its very weak, sometime distorted. If I turn up 2 or 3 times the volume of the channel go back working again! Another symtoms of bad caps and filters?

  • @sunnyray7819
    @sunnyray7819 5 ปีที่แล้ว +2

    Im trying to learn this stuff... Got a Marantz 2226B, Sansui G3000 and others.................. I did a video on my channel called Junk or Treasure a couple days ago showing some of my stereo components....

  • @michaelaaronorton4001
    @michaelaaronorton4001 6 ปีที่แล้ว +2

    That's actually a decent sounding stereo amplifier for what it is

    • @d-labelectronics
      @d-labelectronics  6 ปีที่แล้ว

      At first, I thought it was cheaply built, but the sound is Monsterous!

    • @MarkTillotson
      @MarkTillotson 6 ปีที่แล้ว

      It looks well laid-out and fairly easy to work on too. And the pots were all good (or did you secretly de-oxit them?). Probably low mileage, one careful owner.

  • @unusualpond
    @unusualpond 2 ปีที่แล้ว

    Well done. How long did you spend and what would it cost to have such a job done professionally? Thank you

  • @paulozabalotnicu1897
    @paulozabalotnicu1897 5 ปีที่แล้ว +3

    hi,i like to ask you one question :i have one amplifier Kenwood KA701with rustling noise problem....i give for two shop to repair...no one find the problem...only left side with this problem,do you have any idea where is the problem?the noise is exactly like radio station can't catch the signal..thank you

    • @JeffCounsil-rp4qv
      @JeffCounsil-rp4qv 5 ปีที่แล้ว +1

      Sounds like a transistor has become leaky (noisy) somewhere. Usually manifests inself as a "crackly" or "staticky" sound.