It looks like Sony puts the speakers in series when you select a+b mode. That is a rare but not unheard of approach. It's so satisfying to see something, if unremarkable sounding, working again. This kind of receiver was found in nearly every American household in the 1970s.
when i was in my teen i had an older friend in his 40s and he collected pioneer gear he has a 1980 and a 1250 setup to this day i cannot pass up that vintage pioneer gear . i not have a 1280 a 980 an sg 9500 . i have a few of the prosessors .. i was an electronic nerd as far back as 5 years old i would window shop radio shack so i collect alot of realistic gear as well there is a few vintage recievers i want from them too i have a few eq's so far .. my hoard is just starting
Well, I learned something: clean the controls first! Another tip I learned from one of my instructors was that if you’re getting varying results from similar actions (the sound is there, the sound isn’t there, it’s weak, it’s strong, etc) the cause is likely mechanical; if the error can be reliably repeated, the issue is likely electrical. It doesn’t hold true in every case, but it does serve to guide one’s efforts. Your approach towards ‘going down the rabbit hole’ of determining the cause of the phase shift is spot on, an example of the primary troubleshooting strategy: cut the problem in half wherever possible. Amp or preamp? And you’re halfway home.
Ultrasonic Cleaner on the knobs makes them look new effortlessly. Lysol wipes will add a brilliant shine to them and breaks down residue. Buff with microfibre.
just found this video.....I have the European version of this Receiver "Sony STR 7035L" which has the addition of AM Radio as well as FM and MW. Bought it in around 2003 in mint condition from E.Bay here in the UK.
I love the thing too. It was designed to be a nice receiver for people to listen to the radio. It's like an iPad isn't designed to be a gaming rig! it was for people to use!
This was my first receiver. Bought new when I was 14. I was gonna get a Kenwood but the salesman sold me on this one instead. Sounded much better than the Kenwood. Especially the tuner. 15 watts per channel.
Low powered direct coupled receivers typically put the speakers in series when set to A + B. They do that because the smaller output devices used in them won’t last long at low impedances. If you don’t have a load connected across A then the series circuit is open and you won’t get anything on A + B. I had a small direct coupled Onkyo receiver wired that way, also still have a small dc Yammie and Sansui that’s the same way so it seems to be pretty common with those little guys.
I love these older Sony's, I have a 6060F ill never sell ( one of Sony's best ). I know you have to be real carefull with the glass dial when cleaning, Those letters will wipe right off if your not careful.
I picked up a Sony STR VX3 recently at a thrift store for $5.00 bucks. It was filthy inside, cleaned it up deoxited the crackly controls and it works and sounds great. It is a small thing, rated at 95 watts, I will be using it as my shop radio.
How's the weather in Montana Aidan? Cold I bet and it causes strange wave forms on an oscilloscope😉 You got this one working without spending a dime, nice job. This unit has been well used and abused over the years, hats off to Sony. Almost 50yr old receiver, suspect some components getting tired like caps etc.. Thanks for the video, much appreciated. Stay warm.
You were using the terms Direct Coupled and Capacitor Coupled when referring to the power supply section. Those two terms have nothing to do with the power supply. They are used to describe how the various amplifier stages are Coupled together. That large two-section cap that you looked at is the main filter capacitor(one for each rail) they are used to filter out the 120Hz ripple that exists after rectification. That ripple will be there whether or not it uses a bridge rectifier(four diodes) or full-wave (two diodes). Some power supplies will use caps only while others may use inductors or a combination of each.
I was indeed making incorrect assumptions about the number of diodes on the board and I appreciate the explanation, but I was not using the terms direct coupled and capacitor coupled when referring to the power supply section.
@@AHFixIt Ok, it sure seemed that way. You never spoke about the amplifier stages at all and went right to talking about the power supply filter cap after talking about the coupling. That is the only capacitor you talked about, like that is what made it capacitor coupled. Maybe you should do a video on the differences between direct coupled and capacitor coupled amplifiers. That way your viewers know what it is when you use those terms. This is not the first video you've done where you mention those terms and then go straight to the power supply. Don't get me wrong. I think someone your age even attempting to do these repairs is great. This is a dying art and the next generation needs to learn these skills. Not taking that away from you. Just education. I used to do UA-cam videos, I'm not good at it. You're much better than I am on doing videos. We all have our strengths and weaknesses. Keep up the good work!!!
Maybe unclear about half and full wave rectification. Full wave bridge 4 diodes with no center tap on the secondary or two diodes and a center tap for full wave rectification.
I had a Sansui Au D7 that sat in storage for years. The controls were so dirty on stereo selector switch that I was only getting one channel. After some good cleaning both channels were functioning. I also just got an Ampex tube preamp that has the rotating power switch/knob. It was so dirty it wouldn't even turn. I grabbed some pliers and got it loose and cleaned it up. The unit wasn't powering on so I was worried that the switch was shot which is common for these type of power switches. I cleaned it even more and wallah! Power! It's crazy how much dirty switches and pots can affect a unit.
I thought that receiver's styling looked familiar. My first amplifier was a Sony TA-1130 that I bought in 1975. It's the same vintage as yours. I loved that thing.
In my garage, I now have a Sony STR-V4 that was headed for the trash can. A gent had died, family had called a friend of mine to help clean out the house. My friend knows to grab vintage gear for me and so he intercepted the Sony on the way to the trashcan, along with a turntable. I didn't do much to the Sony, cleaned it up, adjusted per SM and ran it for a couple of months hooked up to EV Sentry 500's in my garage - sounded VERY good and quite loud. I'll sell it as is tho (iowa). EDIT: LOL - This V4 is the same way - apparently the speaker A and B are wired in series. Doh.
For some reason it disappoints me that you don’t give it the same treatment you would have given to a Marantz. I always hope you make the old receivers sound at least as good as new.
I agree. Even lower-end receivers, amps, etc. deserve to be fully restored so that they last another 40-50 years. If not repaired properly when you have it on the bench, the next owner may throw it in the trash when it eventually fails.
Just sliding a legged device can spin off the screwed in leg. I see this regularly on chairs with anti mar leg added on by myself. Receivers in a place can be regularly moved to dust or connect different accessories and one leg may be the one left on the surface causing it to spin.
Plug in headphones or look at your DC offset at posts. Probably should do that anyway first. Then you could scope the output transistors. 10:00 where I am now you'll troubleshoot your way to the trouble. Lower powered amplifiers put A and B speakers in series. More powerful amplifiers put the A and B speaker loads in parallel. You'll see it again my friend. These small entry level basic receivers are generally inexpensive and easy to find. They usually have a warm sound and look nice after a good cleaning. Save them all I say!!!
😊....yea dirt keeps the music clogged up in the signal path. And the smaller wattage simpler units have better isolation because everything isn't sitting on top of each other. = Better Sound Quality
Recap that that board brother. ...she will tighten right up like putting new tires on a car , Including recapping the filter cap as the ripple will be more evident with old capacitor s
Sir; I have an STR-7035 that I bought new in the mid 70s. My recurring issue is the tuner. I have thorouly cleaned the tuner cap wheels just as you did to this unit. It works great for a while, then the reception starts drifting downwards until it quits completely. Do you have any ideas what is happening? And/or would have any interest in working on it. Thanks in advance, Randy
I just recapped and re-diode-ed my new/old Sony 7045. Worked perfectly when I got it (It’s a Sony!) but I did it anyway, only about 28 caps. The 7045 is much beefier than the 7015, and has a 4-gang tuning capacitor covered by a clear plastic dust cover 👍👍. Notice that your receiver, as well as mine, has not one integrated circuit at all?! Great sounding unit, especially when fed with a Dual 1019 and itself feeding newly reformed, recapped Large Advents. Keep it up, Aidan!
Buy the cheapest caps and parts your looking at capacitor break down on your scope all the parts can be upgraded but your right it is worthless and you have got it working again I call it a win 🏆
Stick on Rubber Feet are cheap even the good ones that once stuck are near impossible to remove, also with regards to the "Faceplate Text" you can rub on decals specific for electronic panels, which you can rub on and cover with a clear coat of acrylic, yeah I know~I know for the mo the Receiver ain't worth mooch, but give the young gal some time and she could bring in enough dosh, to get yo self a really brand new posh Receiver.
Have about 12 integrated amps, 20 FM Tuners and 4 monster receivers. Yamaha, Pioneer, Kenwood, Sansui are my 4 favorites. I do own a SONY integrated amp and matching FM Tuner (3000 series) and Amp has same problem "A" speakers work fine, "B" speakers only get right channel, Time to investigate Volume. Why this company just likes to do things different like being hell bent on flat head screws, that set screw for knob for tuning will be a flat head screw, not Allen. Never seen your signal generator, new addition?
"I thought it was odd that there was a full bridge rectifier... on a capacitor coupled amplifier, you only need two of those diodes." Not true. There are plenty of amplifier designs running on a single supply (which is what you're alluding too with a single filter cap) using a full wave bridge. You don't "have" to have a center-tap/0V ground with a full wave bridge supply. If you were assuming 2 diodes (a full wave rectifier), you DO need a center-tap to give you the negative rail. This, as you discovered is a bipolar power supply with two filter caps in one package.
That solution for the missing leg is going to scratch her desk. Any electronic parts store worth it's salt will have those plastic legs. Are you going to restore the wooden cabinet it's got some real problems.
You should be able to diffetentiate a direct coupled and a cap coupled amp, since you repairing/restoring things. Service manual? You don't take a look into it before you put yout hands into that gear? Not very professional, sorry...
I must say, i would 't call it fixed with muddy sound, no punch and crappy signal treatment. How can a wife appreciate expenses for this hobby, when she doesn't get a chance to get hooked to fantastic sound. It's not the "just" 16 watts. That's not the reason for crappy reproduction and you even see it. Chance missed to shine, i'd say. Yes, it looks crappy, and nobody likes it by the look, it should at least produce a smile every time you hear it. You know, women are practical. If it sounds like a cheap little radio, not long and it will get replaced for a cheap little chinese radio.
As an electronics novice, I find your videos more informative than most repair videos on youtube
By far. 100% agree.
It looks like Sony puts the speakers in series when you select a+b mode. That is a rare but not unheard of approach. It's so satisfying to see something, if unremarkable sounding, working again. This kind of receiver was found in nearly every American household in the 1970s.
As well as many others...no A.....then no B or A/B
often the case with the smaller output receivers.
Every junky low-end receiver in the 80's and 90's did it this way. Sony was just ahead of the game lol.
@@marcvdfv8431my strv 7 Sony does that and it's 150 w per channel
Sanyo did that too on certain models.
when i was in my teen i had an older friend in his 40s and he collected pioneer gear he has a 1980 and a 1250 setup to this day i cannot pass up that vintage pioneer gear . i not have a 1280 a 980 an sg 9500 . i have a few of the prosessors .. i was an electronic nerd as far back as 5 years old i would window shop radio shack so i collect alot of realistic gear as well there is a few vintage recievers i want from them too i have a few eq's so far .. my hoard is just starting
Well, I learned something: clean the controls first! Another tip I learned from one of my instructors was that if you’re getting varying results from similar actions (the sound is there, the sound isn’t there, it’s weak, it’s strong, etc) the cause is likely mechanical; if the error can be reliably repeated, the issue is likely electrical. It doesn’t hold true in every case, but it does serve to guide one’s efforts.
Your approach towards ‘going down the rabbit hole’ of determining the cause of the phase shift is spot on, an example of the primary troubleshooting strategy: cut the problem in half wherever possible. Amp or preamp? And you’re halfway home.
Ultrasonic Cleaner on the knobs makes them look new effortlessly. Lysol wipes will add a brilliant shine to them and breaks down residue. Buff with microfibre.
What you are seeing is spent capacitors. These amps were punchy with great transients. The sine wave reflects a need for a recap.
just found this video.....I have the European version of this Receiver "Sony STR 7035L" which has the addition of AM Radio as well as FM and MW. Bought it in around 2003 in mint condition from E.Bay here in the UK.
I would be a good learning exercise to get the waveforms looking good.
I love the thing too. It was designed to be a nice receiver for people to listen to the radio. It's like an iPad isn't designed to be a gaming rig! it was for people to use!
The waveform weirdness it's almost *always* bad electrolytic coupling caps. The power supply cap must be replaced too to address phase issues.
Love that little receiver. Recapping the power supply and power amp would probably help the sound quality and bass capability.
This was my first receiver. Bought new when I was 14. I was gonna get a Kenwood but the salesman sold me on this one instead. Sounded much better than the Kenwood. Especially the tuner. 15 watts per channel.
The Two bearings on the tuning condenser should get a drop of light oil, the the rollers for the string.
Low powered direct coupled receivers typically put the speakers in series when set to A + B. They do that because the smaller output devices used in them won’t last long at low impedances. If you don’t have a load connected across A then the series circuit is open and you won’t get anything on A + B. I had a small direct coupled Onkyo receiver wired that way, also still have a small dc Yammie and Sansui that’s the same way so it seems to be pretty common with those little guys.
my best friend had one of these . it has a great sensitive radio in the unit
I know nothing about electronic but am fascinated with your videos.
I love these older Sony's, I have a 6060F ill never sell ( one of Sony's best ). I know you have to be real carefull with the glass dial when cleaning, Those letters will wipe right off if your not careful.
I picked up a Sony STR VX3 recently at a thrift store for $5.00 bucks. It was filthy inside, cleaned it up deoxited the crackly controls and it works and sounds great. It is a small thing, rated at 95 watts, I will be using it as my shop radio.
I really enjoy your channel. Your honesty is appreciated.
How's the weather in Montana Aidan? Cold I bet and it causes strange wave forms on an oscilloscope😉 You got this one working without spending a dime, nice job. This unit has been well used and abused over the years, hats off to Sony. Almost 50yr old receiver, suspect some components getting tired like caps etc.. Thanks for the video, much appreciated. Stay warm.
You were using the terms Direct Coupled and Capacitor Coupled when referring to the power supply section. Those two terms have nothing to do with the power supply. They are used to describe how the various amplifier stages are Coupled together. That large two-section cap that you looked at is the main filter capacitor(one for each rail) they are used to filter out the 120Hz ripple that exists after rectification. That ripple will be there whether or not it uses a bridge rectifier(four diodes) or full-wave (two diodes). Some power supplies will use caps only while others may use inductors or a combination of each.
I was indeed making incorrect assumptions about the number of diodes on the board and I appreciate the explanation, but I was not using the terms direct coupled and capacitor coupled when referring to the power supply section.
@@AHFixIt Ok, it sure seemed that way. You never spoke about the amplifier stages at all and went right to talking about the power supply filter cap after talking about the coupling. That is the only capacitor you talked about, like that is what made it capacitor coupled. Maybe you should do a video on the differences between direct coupled and capacitor coupled amplifiers. That way your viewers know what it is when you use those terms. This is not the first video you've done where you mention those terms and then go straight to the power supply. Don't get me wrong. I think someone your age even attempting to do these repairs is great. This is a dying art and the next generation needs to learn these skills. Not taking that away from you. Just education. I used to do UA-cam videos, I'm not good at it. You're much better than I am on doing videos. We all have our strengths and weaknesses. Keep up the good work!!!
It's all good man I definitely could have been clearer in my dialogue and editing. I'm jealous you got to interview xraytonyb on your channel!
@@AHFixIt and Mark Walker from Blueglow Electronics. They were great.
Maybe unclear about half and full wave rectification. Full wave bridge 4 diodes with no center tap on the secondary or two diodes and a center tap for full wave rectification.
I had a Sansui Au D7 that sat in storage for years. The controls were so dirty on stereo selector switch that I was only getting one channel. After some good cleaning both channels were functioning.
I also just got an Ampex tube preamp that has the rotating power switch/knob. It was so dirty it wouldn't even turn. I grabbed some pliers and got it loose and cleaned it up. The unit wasn't powering on so I was worried that the switch was shot which is common for these type of power switches. I cleaned it even more and wallah! Power! It's crazy how much dirty switches and pots can affect a unit.
You had the loudness button depressed throughout your scope testing which may have affected the waveform.
Yup, that is a mistake I consistently make!
Flat flat flat!
Aidan, you are a braver man than I Gunga Din! I appreciate your patience and perseverance. I would have chucked it at 9 minutes.
I thought that receiver's styling looked familiar. My first amplifier was a Sony TA-1130 that I bought in 1975. It's the same vintage as yours. I loved that thing.
Those are quite desirable now, hopefully you’ve still got it
@@christopher3963 I sold it to my brother. D'oh!
Thanks
Thank you!
I’ve had one of that model that was completely silent. Turned out the speaker output contacts on the back just needed a bit of deoxit!
I love it - "The sound is completely unremarkable"! I figure the oddness in the sinewave is coz a capacitor or two is out of spec...
In my garage, I now have a Sony STR-V4 that was headed for the trash can. A gent had died, family had called a friend of mine to help clean out the house. My friend knows to grab vintage gear for me and so he intercepted the Sony on the way to the trashcan, along with a turntable. I didn't do much to the Sony, cleaned it up, adjusted per SM and ran it for a couple of months hooked up to EV Sentry 500's in my garage - sounded VERY good and quite loud. I'll sell it as is tho (iowa).
EDIT: LOL - This V4 is the same way - apparently the speaker A and B are wired in series. Doh.
That pointy sine wave indicates time to recap it. Just the ones in both A and B rails.
For some reason it disappoints me that you don’t give it the same treatment you would have given to a Marantz. I always hope you make the old receivers sound at least as good as new.
I agree. Even lower-end receivers, amps, etc. deserve to be fully restored so that they last another 40-50 years. If not repaired properly when you have it on the bench, the next owner may throw it in the trash when it eventually fails.
Nice job 😎👍👍
Who ever knew the tuner glass thing would fall out raise your hand, lol 🖐
Just sliding a legged device can spin off the screwed in leg. I see this regularly on chairs with anti mar leg added on by myself. Receivers in a place can be regularly moved to dust or connect different accessories and one leg may be the one left on the surface causing it to spin.
Plug in headphones or look at your DC offset at posts. Probably should do that anyway first. Then you could scope the output transistors.
10:00 where I am now you'll troubleshoot your way to the trouble.
Lower powered amplifiers put A and B speakers in series. More powerful amplifiers put the A and B speaker loads in parallel. You'll see it again my friend.
These small entry level basic receivers are generally inexpensive and easy to find. They usually have a warm sound and look nice after a good cleaning. Save them all I say!!!
😊....yea dirt keeps the music clogged up in the signal path. And the smaller wattage simpler units have better isolation because everything isn't sitting on top of each other. = Better Sound Quality
that waveform looks like the claw my cat lost the other day
16:50 .... A+B puts the speakers in series.
Thanks!
Thank you!
Thank you! It's therapeutic in a sense watching you troubleshoot and then succeed! 😁@@AHFixIt
The phase difference at 39:45 is a dirty loudness push switch. You'd really see it on a square wave.
Recap that that board brother. ...she will tighten right up like putting new tires on a car , Including recapping the filter cap as the ripple will be more evident with old capacitor s
@AH-Fix-it How did you know to use Deoxit F5 instead of the D-5. Is there a way to tell what pots are in in what devices?
Did you put in the correct speaker fuses?
Sir; I have an STR-7035 that I bought new in the mid 70s. My recurring issue is the tuner. I have thorouly cleaned the tuner cap wheels just as you did to this unit. It works great for a while, then the reception starts drifting downwards until it quits completely. Do you have any ideas what is happening? And/or would have any interest in working on it. Thanks in advance, Randy
I just recapped and re-diode-ed my new/old Sony 7045. Worked perfectly when I got it (It’s a Sony!) but I did it anyway, only about 28 caps. The 7045 is much beefier than the 7015, and has a 4-gang tuning capacitor covered by a clear plastic dust cover 👍👍. Notice that your receiver, as well as mine, has not one integrated circuit at all?! Great sounding unit, especially when fed with a Dual 1019 and itself feeding newly reformed, recapped Large Advents. Keep it up, Aidan!
*refoamed I assume
@@johnnytacokleinschmidt515 O yes. Darn auto correct
Buy the cheapest caps and parts your looking at capacitor break down on your scope all the parts can be upgraded but your right it is worthless and you have got it working again I call it a win 🏆
Much respect to you. How did you learn how to do this?
Nice work... way to polish that turd! LOL. It's probably fine for what it is.
but did you calibrate your oscilloscope before you probed the unit?
Very interesting to watch so thank you from me
While you were staring at the two bulbs for the faceplate while you were in there why didn't you change them?
They work
You're about as sharp as the edge of town. Lol
Stick on Rubber Feet are cheap even the good ones that once stuck are near impossible to remove,
also with regards to the "Faceplate Text" you can rub on decals specific for electronic panels, which
you can rub on and cover with a clear coat of acrylic, yeah I know~I know for the mo the Receiver
ain't worth mooch, but give the young gal some time and she could bring in enough dosh, to get yo
self a really brand new posh Receiver.
Have about 12 integrated amps, 20 FM Tuners and 4 monster receivers. Yamaha, Pioneer, Kenwood, Sansui are my 4 favorites. I do own a SONY integrated amp and matching FM Tuner (3000 series) and Amp has same problem "A" speakers work fine, "B" speakers only get right channel, Time to investigate Volume. Why this company just likes to do things different like being hell bent on flat head screws, that set screw for knob for tuning will be a flat head screw, not Allen. Never seen your signal generator, new addition?
Definately needs a recap across the board to fix the phasing and distortion. Your ears didn't lie, the scope proved it indeed sounds like doodoo :).
"I thought it was odd that there was a full bridge rectifier... on a capacitor coupled amplifier, you only need two of those diodes." Not true. There are plenty of amplifier designs running on a single supply (which is what you're alluding too with a single filter cap) using a full wave bridge. You don't "have" to have a center-tap/0V ground with a full wave bridge supply. If you were assuming 2 diodes (a full wave rectifier), you DO need a center-tap to give you the negative rail. This, as you discovered is a bipolar power supply with two filter caps in one package.
I have two feet/legs for that unit. They came out of another vintage Sony unit.
That's because its a Sony, no baloney! 😁
I see a lots of pots to replace >:)
an underwhelming vintage sony. i had no idea such a thing existed :(
That solution for the missing leg is going to scratch her desk. Any electronic parts store worth it's salt will have those plastic legs. Are you going to restore the wooden cabinet it's got some real problems.
regrets are to be expected Corky.
You should be able to diffetentiate a direct coupled and a cap coupled amp, since you repairing/restoring things. Service manual? You don't take a look into it before you put yout hands into that gear? Not very professional, sorry...
T00ner
It's a foot, not a "leg"! Cheers!
can't win 'em all lol
I must say, i would 't call it fixed with muddy sound, no punch and crappy signal treatment. How can a wife appreciate expenses for this hobby, when she doesn't get a chance to get hooked to fantastic sound. It's not the "just" 16 watts. That's not the reason for crappy reproduction and you even see it. Chance missed to shine, i'd say. Yes, it looks crappy, and nobody likes it by the look, it should at least produce a smile every time you hear it.
You know, women are practical. If it sounds like a cheap little radio, not long and it will get replaced for a cheap little chinese radio.
say it aint so