How to repair weak distorted channel Realistic SA 1000 home stereo amplifier D-Lab
Вставка
- Опубліковано 9 лип 2024
- Purchased the little jewel of an amp on ebay. Seller was honest, stating that it had a bad channel, true. I was impressed of it's great cosmetic condition and thought, what a super UA-cam presentation. So, here it is! After verifying the fault, it reminded me of vintage tube amp repairs, so I decided to change out all of the main amp caps, hopefully remedying the issue without troubleshooting! It worked! I was happy and a bit shocked. Now I see some similarities between early solid state vrs tube circuits. I plan to feature more of these shoot from the hip approaches.
- Навчання та стиль
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.
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.
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.
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.
sure is. looking under the preamp board and finding a host of bad small value electrolytics , thats also art :)
@@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
I'm an engineer and I try. Teach them instead of having this attitude.
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.
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.
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.
I just discovered your channel and I must admit it is really fun to watch, thanks to your technical know how and expertise.
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!
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.
Interesting.
This clip hold me until it finishes,
Really amazing.
Thanks dude, keep it up.👍
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.
Great instructive video. I've just fixed mine which had the same issue. Replaced all caps & is now working fine. Thanks.
Great information. You taught me how to detect my distortion problem and saved me a ton. Thanks!
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.
love it Terry. oh yes ,you've done this before. beautifull work! hope the family is great!
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.
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.
Another equipment properly repaired.
Congratulations Terry!
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!
give us an update, please! Did you get the JC-120 back in action?
@@timwarneka5681 Hey, no unfortunately not yet. Mothballed it for now, but hope to get back on it soon.
Excellent repair and diagnoses . Nicely explained.
Cool man,Im learning tons,thanks,love your channel!
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..
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.
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.
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.
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!
Thanks for the great video.
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!
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.
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.
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.
Bill what did you find on your Standel amp repair?
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!)
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.
fabulous transistor work
Thanks Terry for the lesson.
Great work as usual!!
another excellent vid. keep em coming
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.
Great job, as usual!!! Looks like the poor brother on my pioneer sa6200
Another great video these new caps will out live us
I bought one of these amplifiers from Radio Shack in the mid 70s. It was ( For the price) a very good amplifier.
I really enjoyed this video!
Thanks, You made it look like fun am ready to tackle my Sony str 6065 weak sound output. .
Ive got a teac ag-v8500. im glad people still fix things instead of throwing them away
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.
After watching this, I betya that my SA-1001 needs to be re-capped- dangnabit! Thanks Terry!
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.
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
I have a Realistic SA 2000. I modified it to add (pre out) (main in) connections. Still looks and sounds new.
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
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!
Enjoyed the video. I have a Harmon Kardon 75+ receiver that I’m going to recap soon for similar reasons. :)
amazing sound. I have a realistic rhapsodie with a preamp that has a noisy channel but I lost the manual which as a schematic.
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
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.
You have to figure that if one cap has died, the rest probably have one foot in the grave as well.
like you, I have used the parts cannon a few times.
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.
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.
nice job Terry.
Cool, we need more tube amp repaire. keep makeing your videos pls..
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.
Solid State it’s the Future.Coming to an amp near you.Terry ✌🏽
Love it! Can I use that slogan on the next SSS?
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.
Great episode
Awesome video ! Thanks !
Thank thank thank you 🙏.... problem solved after watching this clip.
I have a 71 Altec that needs the same kind of help. I'll get to it eventually.
You get to it yet?
I've been looking for a great vintage amp like this one, looking for one to build with my Media Center main sound amp.
Very nice video !
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.
I''ve got a magnavox astro sonic that does the same thing. Did you find the cause?
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.
Great video
Thanks Terry.
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
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
@@nickking1510 The SA-1000 puts out 20 wpc rms into 8 ohms; the 1000A puts out 25 wpc rms into 8 ohms.
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.
Great work
Pretty nice! Thanks.
my car amp take out rough sound when playing music... help please
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.
Thanks your great video
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.
Good, helpful video. It would be better for us novices if you stated where all your equipment connections are made.
Ive got a mono amp from the i think 1980s. Its an amplifier that was used on a paging system. Its been plugged in and on continuously since. Even after the phone system was upgraded, this abandon amp still plugged in and on. It sometimes pops internal breaker when first turned on. It plays good but to me sounds a little off. Maybe a little muddy. Supply voltage only drops 2 volts from no audio to full volume.
Is it possible the caps are bad?. It also has some carbon resistors which i know can raise in value, but trying not to unsolder them to check as i have never had any luck checking them in circuit.
Do you sell the "D-Lab Audio Test Set" or perhaps posted schematic/parts list somewhere?
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.
Awesome information! I would like to know where to get caps and resistors to repair a TEAC reel to reel. Thank you.
Thank you, you are great
hair dryer works well to losing up the caps
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!
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?
Can you explain to me why one of the transistors is only showing half the voltage value of the other transistor?
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.
Having worked on audio gear for obviously some time, what would you recommend as a good set of vintage components for an inexpensive retro system?
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.
Twenty years from now? How about 2023's prices? Even rebadged stuff from Radio Shack and JC Penny (MCS) have climbed up there!
I have an sta-77. Fm works, and I get sound in both channels. None of the inputs work. Suggestions?
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
Thanks you .....very good ....
what solvent do you advice in cleaning potentiometers?
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
Well done
How do you like that Agilent scope you show in this video? Do you recommend it for someone getting into vintage audio troubleshooting/repair? (I'm thinking a good used one, not new)
Hi any chance of a bit of help. My dad bought a leak 70 amplifier off the Internet as spairs or repairs. He has plugged it in and there is zero power getting to it. Where should I start to look for the problem.