It seems well made and working fairly well too. I'd use it as a bench amplifier and with a small modification it can be used as a signal tracer. That might be a good project, convert an amplifier into a signal tracer.
The fart machine never gets old. Thanks for showing just how much dust you have to battle with. Yes. The thrill of the chase in a good repair is rather addictive.
My first "challenge" was to get working a Tektronix 7403N modular oscilloscope. Trouble was, I knew nothing very much about electronics at all but I hate to see such beautiful things end up in land-fill so took it as an opportunity to learn. After a great deal of help from an online user group I did manage to get it working and carried out a rudimentary calibration but it was a very steep learning curve!!!🤨
Ithink we all like puzzles to start and the we hit a wall where it's not so enjoyable ,but if we push passed it worth the headaches for the feelings of accomplishment. Best wishes &stay healthy
Very educative to see how you approached this repair. I think I would put it back together, connect some speakers to it and maybe sell it as an retro amp at the same flee market!
You could use the 100V line outs to power a few speakers, up to 5 tapped at 5W. A small bar may benefit such a system! At our works we'd use it for toilet speakers - which with that fart sound would be appropriate! Great clip as always! Thanks!
Loved the video as usual, that wire you got is jumper wire, used for prototyping on a veroboard, that is why you have the different lenghts, saves you some time in cuting and tinning the wires.
I have been binge watching your channel content since discovery around 2 weeks ago. I Repaired the tech of the time, 35+ years ago (VCR's, TV, HiFi) and trended towards IT after. After 25 years in Industry (ROV offshore on Ships as an Electronics Engineer), I have returned to my hometown to provide appliance & electronics repair. I find myself agreeing & disagreeing with familiar diagnostic techniques that I use - in your videos. This refresher is very welcome & has re-awakened the desire to repair every piece of electronics that comes my way logically, very rarely is a diagram available - nice to have, but not the end when you can reverse engineer the device. Thanks.
Looks like a paging system for a small store, waiting room, or hotel lobby. Can have music playing and activate the talk over mic to make announcements.
I would have definitely had surgical gloves on. But that is me! Oh my! You have tremendous patience. 👍. The moment you removed the top, and I saw those output transistors, I was betting they are 2N3055, the workhorse of that period of time. Interesting video. Thanks.
Love your video, it is a class AB amp, single rail, output swings about the half rail value , if bias properly, in these amps a hugh coupling capacitor is required to block the DC , they have poor bass response as at low frequency the capacitors reactance becomes significantly. Great vid
Heya, 1st I would to try to sell it and with the money bay new stuff on the carboat sail. 2st if you can't sell it you still could make it in to a new project and sell that one ..... love to see these repair brings memories up. the only thing I don't like is the smell from old solder desoldering, it gives a "old" daf smell
I would love to see you do some videos actually going round the market and haggling with the sellers. And also seeing whats on offer and what you should buy. It would make a cool live stream too, :)
enjoyable and funny video. I would make a dummy load out-of-it, put a big heatsink and fan inside the case, amp and voltmeter on the front panel and design the electronics. Would make an interesting video series. I think a lot of your viewers would be interested in building a dummy load as they are very expensive to buy.
Yeah I must admit I am very much leaning towards that usage. I think a dual dummy load might be a nice project 😉 I expect you will see it again in that form.
Yes! This is the sort of junk I specifically look for to try and get working, or as you said, I use for parts. Any large resistors, good wire, sockets, knobs, switches, terminal trees, screws, transformers etc etc I cannot think of another reason for it to be used in it's working state....Sorry, can't help there! Cheers, Rick
Wow, how does a guy from Liverpool??? end up in that part of the world, I felt so sure you were somewhere in the old country, never mind though your videos are very interesting, and good to watch ⌚️and after all I'm from Liverpool and I am 3000 miles away in Australia and been here for 53 years and never once went back in all that time, and it doesn't look like I ever will anymore.
Not sure how 'Scousers' end up here but mostly us 'Stokies aka Potters' just escape. Actually that is close to the truth, I voted with my feet after voting against Brexit on paper didn't work out. So when I came here 2016 all I needed to do, was to register as self employed within 3 months (€10) and I was then allowed to find work, then prove income of €6000 per year a little while later (for myself plus the same amount per each dependent person) to get full residence. Now thanks to the fantastic skills of the UK Brexit negotiating team I would need to prove €27,115.20 per year per person even to get the right to live and work in Spain (or retire in Spain for that matter) *before* I could start a business, as initially I can only enter the country on a tourist visa (can't work here) and stay only 90 days out of every 180 days,. Actually I would get an easier path to move here now if I arrived as a refugee on a small boat than come from the UK. How did you end up in Oz? My Uncle and Auntie moved there in the 60s (Brisbane) when Australia were asking for immigrants and went on to a life long career in the police force. Same happened with my best friend at school when I was about 10 yrs old.
Great vid! I think I'd convert it into a guitar amplifier...or use the chassis and transformer to make a new hi fi stereo amp...it could also be made into a valve amplifier maybe using the output transformer....
I realize I am late to your party, but I would keep it as a Bench Amplifier. Maybe re-work the rear panel and install RCA jacks for Input and Output. It was a decent amp. I wouldn't destroy it.
there hook up wires for bread boards for making and testing circuits that you make up before you commit the circuit to actual use hope this as helped love the vids very educational keep up the good work 😀
I think it would be useful as a diagnostic tool (I'd keep it for that). It would enable you to test a wide range of speakers including line speakers which ordinary amplifiers won't drive.
Make a 60Hz sine oscillator and then you can use it as a 115VAC power supply, giving you some power to run US equipment, or make it variable frequency, or selectable frequencies of 50, 60 or 400Hz, so you have an AC power supply to use. Using 2 NPN outputs is because it is quasi complimentary, top has a NPN driver and bottom has a PNP driver, so the bottom is similar in performance to a power PNP device, just needs different biasing.
Actually that is really quite interesting using the output transformer to generate 50Hz/60Hz 110V AC. Especially as it would also provide galvanic isolation from the mains, most switch mode PSU can run 90V-240V so it could make for a rather safer way to work on them as you normally don't have to put much load on the PSU to diagnose faults. Also a variable AC supply could be quite useful, by varying the amplitude of the driving signal. Nice.
I will just use the case for another amplifier( a classic looking style) or a bench top power supply.As for the parts...Very little is worth saving; maybe I would take the ICs, that trim pot and the output transistors...
The fact that it said clearly on the transformer 1A-25W could be some sort of clue yeah? ;) That fart sound would have gone down well in a shopping centre as they turned off for the night lol
Line amps… I keep a few around for hires. Schools, etc., have faulty amps & I install hires as a temporary solution while their amp gets repaired/replaced.
I love a challenge also. I'll pick up stuff from the local recycling center just to see if I can fix or refurbish it. I'm also married, so there's another challenge !! ;-) lol
Well saved ... given how poorly it was looked after and how well you managed to recover it appears to be a robust design (may just need some current limiting on the caps as they charge initially?). Maybe list it for sale and see if you get any interest. Failing that you could make one of those ‘adapt an ATX psu into a bench supply’- type build videos .. they can be popular, but do try not to modify the pc psu itself so a new one could be easily swapped in should a fault arise or more watts needed. Often they spend ages opening and hacking away inside just to save a little space which is generally unnecessary imho. Just an idea. Keep up the great work 😀👍
Enjoyed that. Generally, I would say a power supply would not be worthwhile with a 1 amp current limit but the project to build a power supply may be interesting to a number of your viewers? Maspalomas is our favourite holiday location. Must find out where your shop is and pay you a visit next time wifey and I are over there 😎 We've not been since covid struck; just wondering whether the crumbling shopping centre (Faro 2) is still going.
Yeah Faro Dos is still there and still crumbling. My workshop is fairly near there, definitely within walking distance, but closer to where they have the Wednesday and Saturday market. The amplifier came from there (actually the Sunday car boot / flea market) Drop me an email electronicanaria@outlook.com. Check this video out ruclips.net/video/JU8n_AftyEU/видео.html
MAYBE, convert it into a little guitar practice amplifier?? I'd like learning how to create an effects loop circuit, and adding an instrument jack to an existing radio or amp.
Hi Richard, i am new to your channel. Love it.. just for curiosity, why aren’t you checking the capacitor with meter? Or you did checked it outside video? Thanks
@@LearnElectronicsRepair not sure .when I used to service FAL amps that used the same topology if I remember correctly the quiescent current was about 38 ma
This is a quasi-complementary class B amplifier, with just enough quiescent current to reduce crossover distortion. Built for economy rather than high quality sound. I'd keep it as it is and use it for a bench testing amp, as I think it would be a shame to mutilate it. There are plenty of DIN to RCA/phono adaptor leads on Ebay, which would make input connections easier. A real bargain at 10 Euros considering the transformers alone would cost about 50. I'd love to know what 'HM' input is for.
Me too - had to fart twice 🤣 Yeah 25W also ties in with the transformer 48V at 1A. To have the power supply rated at twice the amplifier REMS output is exactly correct
The first thing that made me shudder was the sight of tantalum bead capacitors, as I'm sure you know, THEY ARE THE WORK OF SATAN! 👿 * thunder and lightening sound * ⛈ If I was restoring this, I'd re-cap it even if the electrolytics test ok and replace the Tants with sub miniature electrolytics, PAT test it, refresh the solder joints and sell it. It is quite a nice amp that can still be used as designed, but it also has the added attraction of having a vintage look.
Your videos are always extremely interesting, I do learn a lot, still I don't really know where to start with my 90's NAD 208 THX amp. I have a short video here : ruclips.net/video/cPsQgt8MiZk/видео.html . When the amp is switched on, the speaker gets pushed down and stays there. I replaced most caps (some where out of spec) but it did not help. It is a quite sophisticated amp (for the time) but is quite amazingly sounding. Do you have any idea what to check ? I asked in a few forums with little success. Thanks a lot for helping ! Perhaps a first in remote electronics repair 🙂
The amp tech is too old. Parts - the case would make a nice case for a power supply - linear or switch mode. Would be a good faraday shield for many noise sensitive circuits. PS wrong input impedance for guitar amp. You can engineer a match - but why?
![Twenty One Pilots - “The Line” (from Arcane Season 2) [Official Music Video]](http://i.ytimg.com/vi/E2Rj2gQAyPA/mqdefault.jpg)
It seems well made and working fairly well too. I'd use it as a bench amplifier and with a small modification it can be used as a signal tracer. That might be a good project, convert an amplifier into a signal tracer.
The fart machine never gets old. Thanks for showing just how much dust you have to battle with. Yes. The thrill of the chase in a good repair is rather addictive.
My first "challenge" was to get working a Tektronix 7403N modular oscilloscope. Trouble was, I knew nothing very much about electronics at all but I hate to see such beautiful things end up in land-fill so took it as an opportunity to learn. After a great deal of help from an online user group I did manage to get it working and carried out a rudimentary calibration but it was a very steep learning curve!!!🤨
Ithink we all like puzzles to start and the we hit a wall where it's not so enjoyable ,but if we push passed it worth the headaches for the feelings of accomplishment. Best wishes &stay healthy
Very educative to see how you approached this repair. I think I would put it back together, connect some speakers to it and maybe sell it as an retro amp at the same flee market!
You could use the 100V line outs to power a few speakers, up to 5 tapped at 5W. A small bar may benefit such a system! At our works we'd use it for toilet speakers - which with that fart sound would be appropriate! Great clip as always! Thanks!
Hahahaa 🤣🤣🤣🤣🤣
connect it to an off-the-shelf timer for scheduled, dusk to dawn, or random farts.
Loved the video as usual, that wire you got is jumper wire, used for prototyping on a veroboard, that is why you have the different lenghts, saves you some time in cuting and tinning the wires.
I find it astounding that electronics can still work - even after so many years of neglect. Very cool.
I must admit some surprise at the fact the Electrolytic capacitors are still functioning.
OMG that fart machine at 48:30 made my day, my week and my year! Lovely Richard, thank you for the great video!
I have been binge watching your channel content since discovery around 2 weeks ago. I Repaired the tech of the time, 35+ years ago (VCR's, TV, HiFi) and trended towards IT after. After 25 years in Industry (ROV offshore on Ships as an Electronics Engineer), I have returned to my hometown to provide appliance & electronics repair. I find myself agreeing & disagreeing with familiar diagnostic techniques that I use - in your videos. This refresher is very welcome & has re-awakened the desire to repair every piece of electronics that comes my way logically, very rarely is a diagram available - nice to have, but not the end when you can reverse engineer the device. Thanks.
Welcome to the channel, it's good to see another old school tech returning to their roots 🙂
Nice to see an old school design amplifier again. So it appeared to be a stuck switch. Good one thanks for uploading.
ah you mentioned muzak, very nice. love your channel, learning a ton!
Looks like a paging system for a small store, waiting room, or hotel lobby. Can have music playing and activate the talk over mic to make announcements.
I would have definitely had surgical gloves on. But that is me! Oh my! You have tremendous patience. 👍. The moment you removed the top, and I saw those output transistors, I was betting they are 2N3055, the workhorse of that period of time. Interesting video. Thanks.
Love your video, it is a class AB amp, single rail, output swings about the half rail value , if bias properly, in these amps a hugh coupling capacitor is required to block the DC , they have poor bass response as at low frequency the capacitors reactance becomes significantly. Great vid
Heya, 1st I would to try to sell it and with the money bay new stuff on the carboat sail. 2st if you can't sell it you still could make it in to a new project and sell that one ..... love to see these repair brings memories up. the only thing I don't like is the smell from old solder desoldering, it gives a "old" daf smell
I actually spotted you pressed the wrong switch...😁
The fart must've been the capacitor discharging...I'll get me coat...
I would love to see you do some videos actually going round the market and haggling with the sellers. And also seeing whats on offer and what you should buy. It would make a cool live stream too, :)
Love challenges and geography lessons! Nice video as usual
lol An old fart sound generator , nice repair video !
enjoyable and funny video. I would make a dummy load out-of-it, put a big heatsink and fan inside the case, amp and voltmeter on the front panel and design the electronics.
Would make an interesting video series. I think a lot of your viewers would be interested in building a dummy load as they are very expensive to buy.
Yeah I must admit I am very much leaning towards that usage. I think a dual dummy load might be a nice project 😉 I expect you will see it again in that form.
Do you mean an active load? or What I refer to as a dummy load, is a 50 Ohm transmitter load. Basically a big non inductive 50 Ohm Resistor.
@@KB1UIF Active load
@@LearnElectronicsRepair Yeah, I thought that was what you meant.
Yes! This is the sort of junk I specifically look for to try and get working, or as you said, I use for parts. Any large resistors, good wire, sockets, knobs, switches, terminal trees, screws, transformers etc etc I cannot think of another reason for it to be used in it's working state....Sorry, can't help there! Cheers, Rick
Nice one Richard, good find...going to enjoy this.👍
Wow, how does a guy from Liverpool??? end up in that part of the world, I felt so sure you were somewhere in the old country, never mind though your videos are very interesting, and good to watch ⌚️and after all I'm from Liverpool and I am 3000 miles away in Australia and been here for 53 years and never once went back in all that time, and it doesn't look like I ever will anymore.
Not sure how 'Scousers' end up here but mostly us 'Stokies aka Potters' just escape. Actually that is close to the truth, I voted with my feet after voting against Brexit on paper didn't work out.
So when I came here 2016 all I needed to do, was to register as self employed within 3 months (€10) and I was then allowed to find work, then prove income of €6000 per year a little while later (for myself plus the same amount per each dependent person) to get full residence.
Now thanks to the fantastic skills of the UK Brexit negotiating team I would need to prove €27,115.20 per year per person even to get the right to live and work in Spain (or retire in Spain for that matter) *before* I could start a business, as initially I can only enter the country on a tourist visa (can't work here) and stay only 90 days out of every 180 days,. Actually I would get an easier path to move here now if I arrived as a refugee on a small boat than come from the UK.
How did you end up in Oz? My Uncle and Auntie moved there in the 60s (Brisbane) when Australia were asking for immigrants and went on to a life long career in the police force. Same happened with my best friend at school when I was about 10 yrs old.
Great vid! I think I'd convert it into a guitar amplifier...or use the chassis and transformer to make a new hi fi stereo amp...it could also be made into a valve amplifier maybe using the output transformer....
It works, it does not deserve to be trashed or dismantled. Maybe it can be modernized with xlr connectors on the input.
Cool I think I could make use of can't think right now but I'm sure I could 🤓
Challenges keep the grey cells fit.
Rust in Peace now amplifier :)
I realize I am late to your party, but I would keep it as a Bench Amplifier. Maybe re-work the rear panel and install RCA jacks for Input and Output. It was a decent amp. I wouldn't destroy it.
there hook up wires for bread boards for making and testing circuits that you make up before you commit the circuit to actual use hope this as helped love the vids very educational keep up the good work 😀
I think it would be useful as a diagnostic tool (I'd keep it for that). It would enable you to test a wide range of speakers including line speakers which ordinary amplifiers won't drive.
Make a 60Hz sine oscillator and then you can use it as a 115VAC power supply, giving you some power to run US equipment, or make it variable frequency, or selectable frequencies of 50, 60 or 400Hz, so you have an AC power supply to use.
Using 2 NPN outputs is because it is quasi complimentary, top has a NPN driver and bottom has a PNP driver, so the bottom is similar in performance to a power PNP device, just needs different biasing.
Actually that is really quite interesting using the output transformer to generate 50Hz/60Hz 110V AC. Especially as it would also provide galvanic isolation from the mains, most switch mode PSU can run 90V-240V so it could make for a rather safer way to work on them as you normally don't have to put much load on the PSU to diagnose faults.
Also a variable AC supply could be quite useful, by varying the amplitude of the driving signal. Nice.
I will just use the case for another amplifier( a classic looking style) or a bench top power supply.As for the parts...Very little is worth saving; maybe I would take the ICs, that trim pot and the output transistors...
The fact that it said clearly on the transformer 1A-25W could be some sort of clue yeah? ;) That fart sound would have gone down well in a shopping centre as they turned off for the night lol
Line amps… I keep a few around for hires. Schools, etc., have faulty amps & I install hires as a temporary solution while their amp gets repaired/replaced.
I’ve got an old Eagle line amp (70s) out of a church that I hope to restore (one day) that has strip cons on the rear.
😂😂 Love learning from you richard, and you have a great sense of humour
I love a challenge also. I'll pick up stuff from the local recycling center just to see if I can fix or refurbish it. I'm also married, so there's another challenge !! ;-) lol
I have a couple of classic amplifiers to repair myself. Indeed what does one do with such things. An excellent question.
Enjoy the process/challenge is the best I can come up with 🙂
Bin it and save the space.
Great! Thanks
Well saved ... given how poorly it was looked after and how well you managed to recover it appears to be a robust design (may just need some current limiting on the caps as they charge initially?). Maybe list it for sale and see if you get any interest. Failing that you could make one of those ‘adapt an ATX psu into a bench supply’- type build videos .. they can be popular, but do try not to modify the pc psu itself so a new one could be easily swapped in should a fault arise or more watts needed. Often they spend ages opening and hacking away inside just to save a little space which is generally unnecessary imho. Just an idea. Keep up the great work 😀👍
Creative video, thanks :)
Enjoyed that. Generally, I would say a power supply would not be worthwhile with a 1 amp current limit but the project to build a power supply may be interesting to a number of your viewers? Maspalomas is our favourite holiday location. Must find out where your shop is and pay you a visit next time wifey and I are over there 😎 We've not been since covid struck; just wondering whether the crumbling shopping centre (Faro 2) is still going.
Yeah Faro Dos is still there and still crumbling. My workshop is fairly near there, definitely within walking distance, but closer to where they have the Wednesday and Saturday market. The amplifier came from there (actually the Sunday car boot / flea market) Drop me an email electronicanaria@outlook.com.
Check this video out ruclips.net/video/JU8n_AftyEU/видео.html
I would use the case to house a small computer.
Those short bits of wire look like breadboard jumpers
MAYBE, convert it into a little guitar practice amplifier?? I'd like learning how to create an effects loop circuit, and adding an instrument jack to an existing radio or amp.
envy you, live in gran canaria, fixing old amplifiers and have carboot sale there too
a sandblaster or something similar might get rid of the rust, not that we need any more sand...
great vid as usual
Nice vid ! big spark probably inrush current as for the fart who knows !...cheers.
Hi Richard, i am new to your channel. Love it.. just for curiosity, why aren’t you checking the capacitor with meter? Or you did checked it outside video? Thanks
I think I would build a class A 6v6 tube guitar amplifier out of the case.
I do not like to work on things that are easy. The more challenging the better.
What you have there is a quasi complementary push pull amplifier.High power PNP trasistors were hard to come across..
@rob titheridge Is that why it draws such a low quiescent current?
@@LearnElectronicsRepair not sure .when I used to service FAL amps that used the same topology if I remember correctly the quiescent current was about 38 ma
@@robtitheridge9708 Yeah it's 40mA. I was expecting a class A to be much higher so your suggested topology make sense to me.
You see 2n3055 darlington a lot in linear power supplies. Ameritron for one
This is a quasi-complementary class B amplifier, with just enough quiescent current to reduce crossover distortion. Built for economy rather than high quality sound.
I'd keep it as it is and use it for a bench testing amp, as I think it would be a shame to mutilate it. There are plenty of DIN to RCA/phono adaptor leads on Ebay, which would make input connections easier.
A real bargain at 10 Euros considering the transformers alone would cost about 50.
I'd love to know what 'HM' input is for.
Ahh apparently that is from the Spanish, it means something like 'Piped Music'.
The mains transformer is clearly marked 1a25w 1 amp 25 watts....
❤
Well, if nothing else, it's a nice little fart box! ;)
I would buy it. restore it and put it on a shelf.
Hi im fighting with a vintage radio receiver . Do you know where to buy high voltage condensers etc? Regards
i think the wire you were given is KYNAR WIRE.
Ahh so it is for breadboarding?
@@LearnElectronicsRepair it can be but mostly used for modding games consoles and I phone repair
@@robtitheridge9708 which makes sense as it came from a phone repair shop 🙂 Seems like it was a nice freebie anyway
yep will be single core kynar, i ordered some by accident, its low amperage but still quite useful
Maybe some place needs a background music/paging amp.
@49:25 On that back plate I C ... A 25 W
Is that not 25W
P.S.
I love the fart sound
Me too - had to fart twice 🤣 Yeah 25W also ties in with the transformer 48V at 1A. To have the power supply rated at twice the amplifier REMS output is exactly correct
Could be useful for driving avionics equipment
And small ones look on in sympathy :-)
Don’t line amps work in bridge?
Ahhh, pretty rooosty, yaah?
Looks like Something from WW2...lol
maybe a small guitar amp for someone
I think I would complete the restoration and list it on eBay. Get your money back.
The first thing that made me shudder was the sight of tantalum bead capacitors, as I'm sure you know, THEY ARE THE WORK OF SATAN! 👿 * thunder and lightening sound * ⛈
If I was restoring this, I'd re-cap it even if the electrolytics test ok and replace the Tants with sub miniature electrolytics, PAT test it, refresh the solder joints and sell it. It is quite a nice amp that can still be used as designed, but it also has the added attraction of having a vintage look.
Your videos are always extremely interesting, I do learn a lot, still I don't really know where to start with my 90's NAD 208 THX amp. I have a short video here : ruclips.net/video/cPsQgt8MiZk/видео.html . When the amp is switched on, the speaker gets pushed down and stays there. I replaced most caps (some where out of spec) but it did not help. It is a quite sophisticated amp (for the time) but is quite amazingly sounding. Do you have any idea what to check ? I asked in a few forums with little success. Thanks a lot for helping ! Perhaps a first in remote electronics repair 🙂
micrófono e hilo musical . Microphone and piped music. H.M. must (EDIT: MIGHT) be "piped music."
it says HILO on the front. Which means "Piped" piped music {noun} ; hilo musical {m} [Spa.] ; música ambiental {f} (en un supermercado, una fábrica)
Gracias Chicos
I love amp farts. Lol ... Not really though.
The amp tech is too old. Parts - the case would make a nice case for a power supply - linear or switch mode. Would be a good faraday shield for many noise sensitive circuits.
PS wrong input impedance for guitar amp. You can engineer a match - but why?
LOL 💨
3:04 xDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD
Is this video a joke?