This guide provides a step-by-step guide on how to repair an amplifier. It begins by turning down the volume to zero, then turning off the amplifier and allowing it to cool down. Next, turn the amplifier on, using a screwdriver to screw the back panel. Check for loosely connected wire joints and ensure that the inputs are in place and speaker cables are firmly connected. Older amplifiers may have issues with bad capacitors that can be fixed with a bit of effort.
The guide also covers troubleshooting amplifier issues, such as power issues, sound distortions, and more. It covers various home entertainment devices, from surround sound A/V receivers or conventional stereo receivers to power amplifiers, preamplifier, speakers, and iPod/Bluetooth speaker systems.
The guide also discusses the causes behind frequent amplifier issues and provides solutions for power issues, sound distortions, and more. If the problem cannot be resolved through these steps, it is recommended to take the amplifier to a repair shop and seek electrical assistance.
The guide also serves as a basic guide to selecting a vintage receiver and general repairs needed to bring it back on line. The process typically involves checking connections, testing components, and using a multimeter to measure voltage and current. Common tools used for this process include a multimeter to check if there is power going to sections of the circuitry, as many troubles start there.
📹 How to repair a dead Integrated home audio amplifier step by step
Another Realistic SA-1000 amplifier in need of repair. This one came to the shop missing the fuse. Owner stated that the power …
What to do if the amp doesn’t turn on?
In the event that the amplifier’s negative terminals are not functioning, it is recommended to utilize a multimeter or test light in order to ascertain whether the issue persists.
How do I reset an amplifier?
The latest version of the firmware will be utilized, and any modifications will result in the reversion of all settings to their original defaults.
How long should an amp last?
Amplifier tubes have varying lifespans depending on usage, quality, and maintenance. Preamp tubes can last up to 10, 000 hours, power tubes may need replacement after 1, 000 to 2, 000 hours, and rectifier tubes generally last between 5, 000 and 10, 000 hours. The lifespan of amplifier tubes is affected by usage frequency, quality, and maintenance. High-quality tubes usually last longer than cheaper ones, so investing in reputable brands is essential.
Proper care and maintenance, including regular cleaning, proper storage, and optimal operating conditions, can significantly extend the lifespan of amplifier tubes. There are three main types of amplifier tubes: preamp tubes, power tubes, and rectifier tubes, each with a different function and lifespan.
Do amplifiers have fuses?
The fuse in an amplifier is designed to protect the circuit from tube failure and extreme voltage issues. When a fuse blows, it’s not the fuse itself that’s bad; it’s usually a bad power tube or rectifier tube. Tubes wear over time and will inevitably fail, increasing the likelihood of failure. Understanding this concept is crucial when addressing an amp with a blown fuse or an amp that doesn’t power up.
A fuse is a sacrificial overcurrent protection device in electronics and electrical engineering. Its essential component is a metal wire or strip that melts when too much current flows, interrupting the circuit. In tube amplifiers, when a tube shorts or fails, it draws excess current. When the failed tube draws current beyond the fuse’s value, the wire in the fuse melts, cutting off electricity to the amp. The amp is effectively shut off before more damage can occur.
What is the most common cause for amplifier failure?
Common amplifier problems include no sound, distorted sound, low output, hum, buzz, and overheating. These issues can be caused by loose connections, faulty components, or incorrect settings. Identifying the problem is the first step in repairing an amplifier. Troubleshooting involves checking connections, testing components, and using a multimeter to measure voltage and current. Common tools used include a multimeter, soldering iron, and screwdrivers.
Once the problem is identified, the next step is to repair the amplifier by replacing faulty components, repairing connections, or adjusting settings. It’s crucial to work safely with electronics and follow proper procedures.
Why is my amp turning on but no sound?
To troubleshoot an amplifier, check all possible inputs and outputs, especially if the amplifier has two channels. If neither channel produces sound, the problem is likely in the circuit after the two channels merge. If one channel produces sound but not the other, the problem is in the silent channel. If the amplifier has an aux output, test it to see if it produces sound. If it does, the interruption is likely in the circuit following the output.
If the output doesn’t produce sound, it’s likely in the circuit preceding the output circuit. If the signal is different from the aux output than through the main speaker, pay attention to the signal tapping location. If the amplifier has a spare jack but no aux output, wire a quick-and-dirty aux output in the preamp. This test doesn’t require buffering, as the jack tip should be connected to a safe point in the signal path. If the issue is isolated to a specific area of the circuit, consider the components in that area and what might be causing them to malfunction.
Why is my amp turning up but no sound?
Possible causes of an amp making no sound include blown speakers, faulty output transformers, or incorrect wiring of the speaker jack. To isolate the problem, first test if you can hear anything coming from the speakers. If no sound is heard, it could be the speaker itself. If non-audio sound is heard, it is likely a fault in the preamp section of the circuit.
Audio amplifiers, especially tube amplifiers, contain high voltages. Do not attempt to repair an amplifier without following the appropriate safety protocols, including discharging electrolytic capacitors when troubleshooting the circuit within the amp chassis. Electrolytic capacitors can pose a shock hazard even when the amp is turned off and unplugged.
How do I tell if my amp is fried?
A bad car amplifier can cause various issues such as poor sound quality, distortion, buzzing, poor power output, grounding problems, and general wear and tear. It’s crucial to identify these signs and take necessary steps to replace or repair the amplifier. Muritronix offers car audio amplifier repair services to get your unit back up and running quickly. Contact them today to learn more.
Are amps repairable?
The sound of a tube amp can sometimes be lost, and most errors can be fixed. DIY projects on a guitar amplifier can be repaired by a layperson, especially when it comes to replacing defective valves. The best way to do this is to identify the defective tube by performing a visual test. Valves are not always visible from the outside, so it’s essential to test them before replacing them. This will help ensure the amplifier works properly and prevent any issues from recurring. Overall, DIY projects on guitar amplifiers can be a simple and effective way to fix common issues.
How do I know if my stereo amp is blown?
This article provides seven key signs that your amplifier needs repair:
- The amplifier is not turning on; it keeps blowing fuses; excessive overheating is occurring; the sound is humming or buzzing; the bass output is weak; the smell is burning, especially at loud volumes; the amplifier is restarting or cutting out; or the amplifier is not functioning properly.
Amplifiers can be damaged by faulty components or a combination of them. These signs can indicate minor issues or more serious problems. If any of these signs are present, it’s a good sign that your amplifier needs repair. If you notice any of these signs, it’s a good indication that your amplifier needs repair.
How to troubleshoot a stereo amplifier?
An amp can cut out due to various reasons, including blown speakers, RCA signal cables, amp impedance limit, thermal issues, inadequate power supply, improper gain control settings, and protection mode. These issues can be caused by various factors, such as a faulty power supply, improper gain control settings, or a damaged amplifier. To repair a car amplifier, it is essential to check for warning indicator lights, which indicate that the amplifier is in “protection” mode.
If the LED remains illuminated, it indicates that the amplifier is in “protection” mode, which could be due to various factors such as a damaged power supply, improper gain control settings, or a damaged amplifier itself. It is crucial to find a repair shop or a professional to address these issues.
📹 How to repair weak distorted channel Realistic SA 1000 home stereo amplifier D-Lab
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 …
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.
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.
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 articles! Keep ’em coming.
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 articles are great to watch.
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 article. I will reinstall the original.
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 article.
I’m an retired teck i did 20 years of tv and audio repair back then what is your opinion on why the chinese import capacitors replacement are so much smaller at the same value and voltage than the older Japanese capacitors we used to see in these equipments, what technology made them so much smaller do you think they will last 20-30 years like the old ones did ? Do you also have a solution to clean these old oxidized yellowish aluminium front plate without erasing the printing ?
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 website 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 website) but in a small room, that’s all I need. Thanks for posting this cool article. 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.
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 article! 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!
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
Did you have your negative probe grounded to chassis when checking the output transistors? I have an occasional distorted left website (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.
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!
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.
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 article. I’d love to learn about my machine. I really want it to come back to life. If you are interested in making a article of this I’d be happy to pay for shipping and repair.
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.
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
Hi! I have a Realistic STA-46 from 1974. It’s beautiful! But… recently, the mode selector knob is shifty. With my turntable phone input, radio, and both aux I use for 5 CD disk changer and dual cassette player. The volume and clarity goes in and out (especially B speaker). I’ve reset everything. When I touch the the mode knob, and hold it still, the sound is clear and loud….. But as soon as I let go…. It goes in and out. I can still listen, but sometimes get static, or a burst of sound that makes me jump! Do you have any advice? Or a possible article to direct me to? Thanks!!!!o
man-o-man I love youtube….you search for something and you get your answer. I have a Yamaha CLP-250 that is having issues with the amp board…I find that if I touch the top of the 4700UF 25v cap (about 18 mm x 33 mm) that the piano plays at the right volume. I tried re-soldering that one cap and am having spotty results so am buying a new cap to replace it. Is the diameter and height important? Do you have a recommendation for store to buy a bunch of the others? Amazon is going to be expensive….You got me thinking I should replace all of the caps Thank you for this article
Hello captain, I have been chopsticking around in my one yankee dollar juliette 8-track/record player tuner stereo trying to fix a website 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.
Great article thank you, keep up the good work Question: i have an old Tempest Solid State Stereo amp, it powers on and plays for about 5min and then the speakers just switch off and just very softly buzz, i have to put the whole system off and wait like 15min then i switch it on and it plays for 5min again and the same thing happens… Could this be due to a faulty capacitor…??
Hello, I have new amplifier (very cheap madison MAD1305) and it has very distorted mid frequencies, I can hear it in voice or in windows sound when I am manipulating with volume bar. Any tips? I am to lazy to claim it because it’s from e-shop from different state. There are 4 big electrolytic capacitors (50V, 3300 uF) which look very cheap, do you think it’s bad even in new amplifier? I can imagine that capacitors were years somewhere before they inserted them into amplifier. PS: in headphones it sounds good, no distortion
Good day Terry. The adhesive that you referred to in the article 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.
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.
I’ve got an SA-700 amp that sound great but the left website works for about 15 seconds then shuts off for maybe a minute, then starts the process all over again. This happens on speakers A as well as speakers B and I dont have any test equipment nor do I have anything putting off a lot of heat. What would you guess my problem would be?
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
hey pal – i own a model 1 play differently mixer and 1 of my websites the right side is playing at about 1/4 volume, pops in and out to full volume sometimes and when i bring the slider up and down it maxes out the LED lights for a second. Do you have any ideas what could be causing this? and how i could fix it? thanks pal
I have an Optonica SA 5606 that’s acting all kinds of glitchy. The Aux website (de facto CD website) cuts out and buzzes maddeningly. Now the phono is cutting out, sending signals left and right intermittently to my speakers . Anyone with any ideas? I suspect a recap is in order given its age (40 years roughly).
Back in the late 70s and early 80s realistic about the most bottom end amplifier stereo you could buy for poor high school kid who only made his money from cutting grass delivering newspapers and other little odd end jobs. As a teenager we drooled over the magazines for Kenwood and Sherwood and occasionally we got to see a mono block with some exotic name but in reality a Realistic was all we could afford.