hi there this brings back some memories .i used to work on this in the seventies, at the leak wharfedale factory in idle Bradford thi model was a rushed project, at the time leak did not have a reciever amp combo just separates. this was made up of parts from a wharfedale 100.1 amplifier audio stages and leak stereofetic tuner stages due to having excess stock of parts, 1 have two of these in good working order
@@12voltvids hi dave this was a stop gap product and was only produced short term until the new leak 2000 range was produced this model range was well designed, saying that, could not have been worse
Hi Barry, I too was surprised at the weird layout of the 75 unit. Many years ago I fixed a Leak Delta 30 Amp and at the time remember thinking how well laid out it was...! The plugin boards were a great help in fault finding by swapping them over and found a fault on a pre-amp transistor which was not available so replaced with TIP 41C on both boards with crossed legs. Worked great after that. I thought the sound to be good and Leak did have a slightly warmer 'Valve' or as they say 'Tube' over the pond sound. I'm originally from Bradford and remember the factory in the good old days when there were Trolly buses!
First post. I am the client referred to here. Thanks to 12voltvids for accepting the challenge to dig a little deeper into a "piece" of equipment that has questionable value. I love music and the things that produce it. I am new to the game of buying gear that I don't need. What I like doing is finding pieces that may be flying under the radar but are unique and really affordable (read cheap) that can maybe be brought back to life and enjoyed. I have rebuilt a house, furniture, cars, a race car, and a fishing boat. All older and in need of some affection. I find a lot of pride in doing this and also a huge amount of learning. But in electronics I am way out of my pay grade and so it is really fortunate for me to have found someone who will work on and rescue these products. I know I will never learn enough about electronics, there is not enough time left, but as a recent retiree I think I have found a great new hobby. Thanks again for your help and good nature.
Great to see an old classic amp back to operation, even if the construction methods left a lot to be desired. Now if somebody had the matching Leak 'time phase aligned' speakers from the same era, that would be brilliant!.
If you find a worthy xfmr. to use you could change the range in which the sweepers are on the variac so you can get away from the worn out section.... Thanks for another save from the scrap heap! Keep on truckin!
Nice repair, was thinking they had to bodge the resistors to the base of the drive transistors because some units had problems with oscillations in that part of the circuit. A lowish value series resistor in the base is sometimes used to dampen unwanted oscillations.
Mods are quite common on electronics. Usually they are done on the foil side of the board, and then the board is redesigned for future runs.Even field mods by service centers. I can't remember the times I had to cut a trace and add a part and then glue that part down with that yellow contact cement that would oxidise over time, turn crusty brown and become conductive.
Hopefully the auto transformer can be repaired, not a cheap item, and bloody usefull. Perhaps the brush can be shifted to an unused area of the windings to make it smooth again.
That was the last time I was able to get to main electronics to get a transistor. They closed their doors the following week for "inventory" never to re-open.
@@pvb9964 The source is owned by Bell Canada so I think they will be around for awhile as bell sells cell phones cable tv and satellite tv services through those stores. Some of the independent franchise retailers have closed but the corporate stores in the malls are doing ok. I haven't been to one in years mind you but then I don't go into electronics shops much. They may have e some cool gadgets but my old stuff still works and does the job so I have little need for new gadgets.
The thing to note about the Rank era Leak stuff is that it sounds flipping brilliant. Is that not the most important thing in an amplifier or speaker? Can't say I really appreciate the negative tone of these videos. AMps were made for listeners not techs. I get why certain things may annoy techs but this piece of kit has been rocking for over 40 years. How many consumer items made today will last that long?
How had the previous repair person reconfigured both the speaker outputs to run off the one amplifier channel that was working? They must have made some sort of wiring change? And, thanks for being such a good sport about this repair! :-)
That was simple. They just disconnected the left channel wire at the speaker switch on and jumper the right channel over to both sides. I missed that part because my stupid camera was not in record when I thought it was. By the time I realized that it was not running I had already resoldered the correct wire. It was right up in the front where that piece of shielding that I stuck the tape on was. Under that pcbard was were the splice was done.
I used some of that tape to secure a dual cup holder to my Forklift and it is still holding up strong, so I don't think you have anything to worry about with that tape lol
Inquiring minds want to know: How had the previous repair person reconfigured both the speaker outputs to run off the one amplifier channel that was working? Seems like you started to address this in the video, but then didn't? They must have made some sort of wiring change? Maybe on the headphone jack?
DIN levels for inputs were much lower to cut crosstalk so they added the resistors to match what would be coming through from DIN level devices. A pain it as in Europe to mix DIN and line level equipment.
Leak was a fairly expensive and respected make in the 70's as I remember, Ferrari cars are beautiful to look at and drive, but then some are absolute pigs to work on, same difference somewhere there, using something isn't quite the same as having to repair it. Look at the size weight and quality of that transformer!
I'm recently retired and have several variacs (at least three or four more than I need). Maybe we should talk? One is a big VIZ (RCA) 10 amp isolated model with meters and three prong AC jacks, one is a Tenma 5 amp model (two wire), a 10 or 12 amp General Radio model, and a nice Powerstat 5 amp model. Also have a 5 amp isolation transformer. All are really good condition except the GR may be a bit crusty. Maybe yours just needs a new brush?
I am English i agree it is a mess inside, it reminds me of that 70s kit off ebay you looked at. I have a 70s wharfedale cassette top loader deck that's a bit hoeky inside it has a nice low level hum it's proberly a cap on the power side of things.
I just said what it said on the schematic! Actually I said driver board, and then when I was editing I saw "Driver Ass" on the schematic and just had to dub it.
22:51 -I love the song here, the guitar player is a badass. Is there a way to listen to this music online in HQ? Great videos lately 12V, keep up the good work and congrats on 15k subs!
The track is called "Class of 69" and it is a royalty free track from Musicbakery.comI don't know if they will allow previewing in full quality of this track or not. My old company paid thousands to buy a library of music, so I have the rights to use it in my productions.Anyway that is what the title is, and where you can get it.
Thanks Dave....better than I expected outcome. How did you decide which transistor to use...by reference guide or just locating one that had the closest specs as the blown unit ? J K
Hello.. I'm always learning from you . I have a problem with the teac c1. His performance is excellent, but is not recorded and do not wipe the track in advance. Note changed the security key for registration and works guarantor, but not the result, it estimated explain to me where the defect lies. And I should be grateful
OK that is a 3 head deck. If it is not recording, or erasing the previous signal, then you need to look into the record bias oscillator. This generates the AC bias signal that drives the erase head to wipe the track, and provides the bias signal to the record head. No bias signal no erase. No record.
Thanks for the fast reply. Where can I get the AC.? If it were not the cost of shipping high. Posted device for you to note that I am talking to you from Saudi Arabia
Only 1 transistor had failed. Unlike tubes, transistors typically do not have a life expectancy. Vacuum tubes do have a life span, so when you replace a tube it is recommended that you change them in pairs so you don't have strong one and a weak one. This is not the case with transistors. They don't get weak. They keep working until one day they don't. Perhaps a bond wire breaks off the die, or the die breaks down and shorts due to a voltage spike, or a speaker short overload them.In push pull outputs quite often when one fails it will take out the one opposite to, or blow back and take out a driver.In this case the outputs were fine, it was just a case of a driver popping.A disreputable shop that is profit driven will generally feed you a line of bullshit and tell you that they have to replace all the transistors so they can pad the bill. I used to work for such a shop. I was paid commission on the repair, so naturally the higher I could make that bill the better I made out financially. I am NOT in that business anymore. I am not out there to gouge my customers I have retained. I work in a totally different industry, and I am a highly skilled, and well paid union worker. If I was still making a living doing repairs I would not be teaching others how to troubleshoot their own products, or giving other techs, and I know that there are other techs that do make a living doing electronics watching insight on how to troubleshoot.I provide low cost repairs to my clients, and that means only doing what is required to get the unit functional. If a client brought me a device and said, knock yourself out, replace all the capacitors and semis on spec, no expense spared, then I would do that, but the fact is 99.% of people want to get the item repaired for the least amount of money. For the record, I charged the client 70.00 to repair this, and that included parts, and driving into the big city to get the part, I will make money on this repair in the long run from views on youtube, That is where I make my money, not ripping off my customers.
OK, so it has nothing to do with cost or the effort to change the parts. I had wondered if the costumer did not want the expense and that was the reason. Is there things that you recommend that you change just because others parts like it have gone bad? I to that with light bulbs. Have you done a video on how isolation transformers? I could not find it if you did should I look further or do you have something you recommend?
Naturally if I see leaking capacitors I will recommend changing them, or just change them out, but changing out components that haven't actually failed is overkill. Not every capacitor is going to fail. I have an old Panasonic 3/4" VTR that is 40 years old. All original capacitors, and it works perfect, and a 3/4" VTR has literally hundreds of capacitors. All discrete components, and no LSI ICs.Capacitors in power supplies , switching supplies in particular are the ones that fail the fastest just due to the ripple and high frequencies.Small coupling capacitors very seldom fail unless the seal was damaged during installation or a prior service, and the electrolytic dries out. The reason surface mount electrolytic of the late 80's and 90's were so bad was due to a fu** up in manufacturing. The story goes that a disgruntled engineer left one manufacture and went to the competition, and tool the top secret electrolytic formula with him. The company he joined flooded the market with their caps, but the problem was there was a key ingredient missing, and the electrolytic PH wasn't stable, which caused it to corrode the copper wires that connected the capacitor with the outside world. In a few short years the corrosion lead to a leak, and then corrosive liquid got on the board.Older capacitors did not have this problem because they used older formulations of electrolytic. Some old capacitors contain PCBs which is bad, but even worse if they are changed out, and not disposed correctly. So it becomes is the repair affordable, or does it become an uneconomical repair. If it is a rare piece that the client doesn't mind spending a couple hundred dollars recapping the entire board then knock yourself out.Most people, 90% are happy replacing the component that failed and moving forward.Now, on the other hand, if it is a mission critical piece of equipment, such as an audio console on a broadcast operation, or a transmitter, or piece of medical equipment which just can not fail, and it is in operation 24/7 then sure you might want to do a full overhaul and replace all the capacitors, but a piece of stereo equipment is generally not in that category. If 2 or 3 years from now another component fails, deal with it then. I won't even recap all my own gear. I change the part that fails and put in operation until something else breaks.
@@12voltvids YEAH ............HAD A FELLA LIKE THAT KEPT BRINGING IN STUFF TO FIX.....N WHEN I FINNISH THE STUFF HE DIDN T WANT TO PAY THE 30 POUNDS SO HAD TO STORE IT............THE SECOND TIME HE CAME IN.............I SAID 60 POUNDS UPFRONT N I LL TAKE A LOOK AT THE PC LAPTOP............WELL WHEN YOU PAY ME....I LL FIX IT.....HE NEVER CAME AGAIN......HAD TO STORE IT
That would have been a Zenith. Yes that variac is the same one I overhauled and cleaned with DeoXit. It was that video that earned me the 1000 first prize in the contest. Hope to do that again this year if they run it again.
I used to use newer transistors and just swap the leads. They used them on pinball games as display regs. Something about a mje15031 and 15033. Been too long.
That is why I checked the basing before installing it, to be certain that the pin basing was the same. It way. Had it been ECB or BCE I would have had to swap pins. What I was showing it that the collector in most cases it connected to the tab. So once you identify the location of the collector the other 2 are easy to figure out.
It can always be glued back down later. I don't have any contact cement, but it is easy enough to remove and glue down. The guy that owns it can easily do that. It was brought to me to repair the electrical fault, not fix the cabinet.
That case style made me think VMOS FET transistors but now you have said normal transistors so why can a BD131 driver transistor not be mounted somewhere one the case and wired to the holes that the old transistor came out of.
What is wring with the subsiture I used? I match one that had the same gain, same power dissipation but with higher voltage as the original was NLA.Why re-invent the wheel when a different wheel the same size can be used.
You didn't replace the leaking cap shown it the first video? I have hated DIN connectors since they first appeared. You could see the design flaws just by looking at them - puny pins, weak sockets, too many different configurations (some have died off since), and just a pain to get all the different needed types to hook things up. Switchcraft tried to offer better grade stuff but was hampered by the design specs. The speaker connectors are a terrible design and not capable of handling high power. Audiophiles who use those heavy and fancy speaker cables find them a terrible bottleneck. I thought early on that they would be abandoned but the Germans (who introduced the standard - Deutsches Institut für Normung) stuck with them and the rest of Europe went with it. The Japanese even had to adopt them to sell in the European market. Talk about the bad ruining the good...
We have 4 here in the city. Main Electronics home of a million parts. They are 3rd generation. I have been dealing with them for 40 years. Started with the owner Phil, he passed the business on to his son Dan, and now Dan's son Scot has picked up the reins. Phil just passed away this past Oct, and Dan a month later, but the shop is in good hands. That is where I got my ESR meter from, and buy most of my component's there. There is also Lee's Electronics. They are where I got those tube amp kits, and then there is RP Electronics, and Interrior electronics. So yes Vancouver still has parts suppliers.
12voltvids lucky in deed, here in the UK we have none except for a chain store called maplin electronics which is a muppet store with clueless staff never got anything in stock, I have to buy all mine online line now, all our little electronic shops went out of business years ago which is a great shame as they sold eveything.
Well im really supprised you visited this unit again lol, but you have done what the repair company before you could not, or they were too lazy, who knows?. im supprised more hasnt gone wrong with this 1977 unit, the crapacitors are bloody ancient, they would give your e.s.r meter a heart attack lol. Yes the diagrams are crappy, the 47 ohm resistor connected to the base should have been joined with bias resistors if the diagram is to be believed, Errors in diagrams, no supprise :). I would of expected 47k resistors on the tape/line input, but as you said, different standard. 5 Pin din sockets were a bloody nightmare, no one seemed to stick to one standard for levels or pin wiring.
The only reason I abandoned it the first go around is the owner didn't want to repair it initially because he had read many reviews and comments on this unit that called it "Garbage". The fella that owns this unit has brought me plenty of work. The Haffler amps I worked on a few months ago, the Technics tuner with the display problem, Philips CD recorder, and that fancy DVD player a few weeks back. When he was picking up his other stuff I told him that I probably could find a suitable replacement transistor if he had a change of mind and at that point he gave me the green light to proceed, and here is the finished repair. There are not many units that stump me. Not when it comes to vintage audio. I give up relatively quickly on LCD televisions.just because they have so many board problems, especially BGA problems, and there is little if any service data available. Vintage audio though is pretty easy to service unless the parts are obsolete. In many cases such as this one, a replacement can be found. The replacement transistor has higher voltage, and same wattage, but the current is slightly lower, but then again, it is a driver, not an output, and the voltage it is being run at is much lower too, so I don't see that being an issue. At least the power dissipation, and gain were the same as the original.As far as the capacitors go, they actually measured pretty good. ESR wise they are fine. Capacity wise they are all well above the rating, which is very common for the old vintage capacitors.Sure if funds were unlimited, then I could have replaced every capacitor in the unit, but I did measure key caps in the driver stage. Even that one that looked like it was leaking on the first video was actually not. I pulled it, and looked at it. I missed some of the capacitor testing as there was a segment that the camera was in stand by, and I thought it was running, so here I was talking to myself. There was also a long segment (cut out) when I thought the camera was off, and it was actually rolling when I was doing things like hooking up the speaker wires ect. This new camera is great, but the beep that it makes when it is recording, and 2 beeps when stopping is easy to miss when the heater is running. Unlike my other camera there is no red flashing icon on my big screen that I view it on.
Yes he has been a good regular customer, and you have made smashing videos from those repairs :-), and a few pennies from adverts, so its all good :-). I did have another look at the service manual, the editor wants a kick up the jacksie, but he could be dead by now, so ill take my boots off lol. Ive found some horrible mistakes in schematics, capacitors shown reversed, mains transformers shorted out, and all manner of stupid mistakes. Lcd tv's and monitors can be a bloody pain in the backside, if your lucky its a psu fault, if its the main board then you have to decide if its a good enough set to get a repaired board from ebay or whatever. If the lcd is quality then i would keep just the lcd and lift the usefull crapacitors off the pcb, you just have to LOL :-D
One thing i have noticed though, laptop lcd's seem pretty reliable, the lighting how ever may not last. Ccfl tubes last quite well, but led back lighting seems whiter, i use an ancient acer aspire 5315 from 2007 so i only know how well the ccfl's can last. Yes ebay can be hit and miss.
I have a Sharp CCFL LCD that from 2005. I use it as a monitor for security cameras, and it currently has over 40,000 hours on it, and still going strong.Let me know if your LED backlight lasts half as long.
Just watched yo Video take-n a trip into town to a seedy back ally "not the red one but the Blue-un" so yeah just so that yo Barbie kin get Stoned :D ;) Love the 4K BTW..
Have you tested the output voltage on the variac because I have one just like that and when set at 120 on the dial it reads 125 and not 120 so i had to mark on the thing so i know where that 120 is really at.
Its the same. There is a voltage meter on the front of mine that shows be the voltage. I have to turn it up to 125 on the markings to get 120. When it shows 140, the output is really only 130. The meter on the front is accurate on mine, verified with my DMM.
It is called research. I never pay for schematics. If you search long enough you will find something that is either the exact one, or close enough. The alternative is looking up data sheets for key parts, and then doing a little reverse engineering and drawing your own by looking at the PC layout. This is time consuming, and never fun.
Skl Dj elektrotanya.com is a good one to use, I get a lot of mine off there and they are all free they hold most of the top brand manuals especially if your working on something from the 80s and 90s also eBay is a good source for original paper service manuals, paper ones are better as they are easyer to look at schematics.
Yes, the speakers sound like shit, but that amp sounds rather clippy at that volume. Also, it all sounded mono to me, but all I have to listen with is a 1979 white Bakelite mono earpiece. That probably has some effect on my auditory opinions. XD
It is working in stereo. These are cheap shitty outdoor speakers that have been outside all year long for 7 years. I just took them down for testing. They have no bass as you already heard. What do you expect from Radio Shack.
This is 60/40 and it seems to flow pretty good. I used this for my tube amp build, and this brand is much better than the last experience with Chinese solder was. It is rosin core, and gets the job done. Perhaps not quite as good as the old stock Kester I was used to but it gets the job done.
I made a joke about it on the first look at this and pissed off everyone across the pond. They took it personal like an attack on the British, even though I am also from the same rock.
Frankly, the build quality of this (British) made receiver IS CRAP. I would have expected to have seen stuff this bad being made in bloody China at the time, NOT Britain. However, Britain DID produce some good stuff around the 1960s and 1970s. Hacker Transistor Radios, Roberts Transistor Radios and Dynatron music centres are just a few examples. Don't know if they ever sold in North America or the USA, then again, you always reckoned your stuff was better than anyone elses :)
Only in AMERICA, these came out before u were born when u were using valves. If you want an easy fix try made in the USA,. If life was an easy fix i would be living on a boat In FLORIDA by Don Johnson.
These definitely did not come out before I was born. I am early 60's vintage, and tubes were what was in everything. The transistor had barely been invented. I still have the first transistor radio that my grandmother owned and listened to regularly. A Sony Transistor 6. You can have your Florida boat. They get too many hurricanes for me.
jesus christ mate im repairing an infocus lp330 projector built in the usa, its a fucking joke! dont slag off the english this thing is a fucking nightmare to work on, you americans certainly like your silicone sealant haha, im working on its power board they must have used half a tube of silicone on 5 components, this is what caused it to blow up! the power boards components werent getting any air from the fans and it blew 3 transistors a VIPER100A ST Current Mode PWM Controller , and 2 optocouplers, holy shit its took me 2 hours to get all the crap off, your only supposed to use a pea sized amount ffs. they used all this silicone on the transistos and forgot the most important thing, the fucking thermal grease lmao.
Most of the British gear I have seen has been top quality, and actually this one wasn't the worst I have worked on. I was just poking fun at the way it was put together. It is not a representation of the classic Leak units that preceded it. I didn't show it on the video, but one of the boards that is mounted on the bottom has capacitors that are quite tall standing up on it, so what did they do? They drilled holes in the metal chassis and poked the top of the caps through the holes, and stuck red tape on the top of the capacitor so they didn't touch the board above it. I cut that scene from the video because lets just say I made a few comments about the way that they were installed that would have ruffled a few feathers. But to give this unit credit, it is 40+ years old and only popped a small transistor. All the other components, were fine. And no I am not taking shots at the British. I happen to be of British descent, so please don't take it personal. I am going to be tearing down and repairing a Canadian made system soon that is in my collection, and I will be just as critical of it's construction.
hi there this brings back some memories .i used to work on this in the seventies, at the leak wharfedale factory in idle Bradford
thi model was a rushed project, at the time leak did not have a reciever amp combo just separates. this was made up of parts from a wharfedale 100.1 amplifier audio stages and leak stereofetic tuner stages due to having excess stock of parts,
1 have two of these in good working order
That would explain why it looked like it was just thrown together.
@Conor Hanley hi there the delta 70 amplifiers were well made and a genuine leak design
@@12voltvids hi dave this was a stop gap product and was only produced short term until the new leak 2000 range was produced this model range was well designed, saying that, could not have been worse
Hi Barry, I too was surprised at the weird layout of the 75 unit. Many years ago I fixed a Leak Delta 30 Amp and at the time remember thinking how well laid out it was...! The plugin boards were a great help in fault finding by swapping them over and found a fault on a pre-amp transistor which was not available so replaced with TIP 41C on both boards with crossed legs. Worked great after that. I thought the sound to be good and Leak did have a slightly warmer 'Valve' or as they say 'Tube' over the pond sound. I'm originally from Bradford and remember the factory in the good old days when there were Trolly buses!
OH...........BACK IN THE DAY .......WHARFEDALE SPEAKERS WERE THE NO1 SPEAKERS TO BUY
First post. I am the client referred to here. Thanks to 12voltvids for accepting the challenge to dig a little deeper into a "piece" of equipment that has questionable value. I love music and the things that produce it. I am new to the game of buying gear that I don't need. What I like doing is finding pieces that may be flying under the radar but are unique and really affordable (read cheap) that can maybe be brought back to life and enjoyed. I have rebuilt a house, furniture, cars, a race car, and a fishing boat. All older and in need of some affection. I find a lot of pride in doing this and also a huge amount of learning.
But in electronics I am way out of my pay grade and so it is really fortunate for me to have found someone who will work on and rescue these products. I know I will never learn enough about electronics, there is not enough time left, but as a recent retiree I think I have found a great new hobby. Thanks again for your help and good nature.
Your welcome. Always happy to help.
Great to see an old classic amp back to operation, even if the construction methods left a lot to be desired. Now if somebody had the matching Leak 'time phase aligned' speakers from the same era, that would be brilliant!.
If you find a worthy xfmr. to use you could change the range in which the sweepers are on the variac so you can get away from the worn out section....
Thanks for another save from the scrap heap! Keep on truckin!
Great fix, thanks for showing your work...
Nice repair, was thinking they had to bodge the resistors to the base of the drive transistors because some units had problems with oscillations in that part of the circuit. A lowish value series resistor in the base is sometimes used to dampen unwanted oscillations.
Mods are quite common on electronics. Usually they are done on the foil side of the board, and then the board is redesigned for future runs.Even field mods by service centers. I can't remember the times I had to cut a trace and add a part and then glue that part down with that yellow contact cement that would oxidise over time, turn crusty brown and become conductive.
Hopefully the auto transformer can be repaired, not a cheap item, and bloody usefull.
Perhaps the brush can be shifted to an unused area of the windings to make it smooth again.
Should make a good video!
Congratulations, you fixed the British "Leak". Regards
Well done.
Great videos, I just found your channel and subscribed a few days ago and have now watched several with great interest.
I knew you could not resist the challenge
That was the last time I was able to get to main electronics to get a transistor. They closed their doors the following week for "inventory" never to re-open.
@@12voltvids I'm still mourning Radio Shack closing in Canada....now it is mail order only
@@12voltvids Still mourning Radio Shack closing in Canada, it's successor "The Source" is next I'm sure.
@@pvb9964
The source is owned by Bell Canada so I think they will be around for awhile as bell sells cell phones cable tv and satellite tv services through those stores. Some of the independent franchise retailers have closed but the corporate stores in the malls are doing ok. I haven't been to one in years mind you but then I don't go into electronics shops much. They may have e some cool gadgets but my old stuff still works and does the job so I have little need for new gadgets.
The thing to note about the Rank era Leak stuff is that it sounds flipping brilliant. Is that not the most important thing in an amplifier or speaker? Can't say I really appreciate the negative tone of these videos. AMps were made for listeners not techs. I get why certain things may annoy techs but this piece of kit has been rocking for over 40 years. How many consumer items made today will last that long?
Lots will last if not abused.
How had the previous repair person reconfigured both the speaker outputs to run off the one amplifier channel that was working? They must have made some sort of wiring change? And, thanks for being such a good sport about this repair! :-)
That was simple. They just disconnected the left channel wire at the speaker switch on and jumper the right channel over to both sides. I missed that part because my stupid camera was not in record when I thought it was. By the time I realized that it was not running I had already resoldered the correct wire. It was right up in the front where that piece of shielding that I stuck the tape on was. Under that pcbard was were the splice was done.
Thanks for satisfying my curiosity. Good luck on the variac!
I was not aware of this NPN PNP issue in the 70's it's cool to know !
Most outputs were NPN as I mentioned, high power PNP were not very common. But there were plenty of PNP small signal transistors.
I used some of that tape to secure a dual cup holder to my Forklift and it is still holding up strong, so I don't think you have anything to worry about with that tape lol
Inquiring minds want to know: How had the previous repair person reconfigured both the speaker outputs
to run off the one amplifier channel that was working? Seems like you started to address this in the video, but then didn't? They must have made some sort of wiring change? Maybe on the headphone jack?
Leak units might be crap builds but they always manage to sound good.
DIN levels for inputs were much lower to cut crosstalk so they added the resistors to match what would be coming through from DIN level devices. A pain it as in Europe to mix DIN and line level equipment.
Leak was a fairly expensive and respected make in the 70's as I remember, Ferrari cars are beautiful to look at and drive, but then some are absolute pigs to work on, same difference somewhere there, using something isn't quite the same as having to repair it. Look at the size weight and quality of that transformer!
Great to see it working again =D
Love the mix of resister types.
Just reach into the parts bin and pull one out.
Love your repair videos! The layout of that unit is one of the worst I've ever seen. Mmmm the smell of 1970s solder
I am surprised it doesn't have a positive ground, being British. A Lucas amp.
I'm recently retired and have several variacs (at least three or four more than I need). Maybe we should talk? One is a big VIZ (RCA) 10 amp isolated model with meters and three prong AC jacks, one is a Tenma 5 amp model (two wire), a 10 or 12 amp General Radio model, and a nice Powerstat 5 amp model. Also have a 5 amp isolation transformer. All are really good condition except the GR may be a bit crusty. Maybe yours just needs a new brush?
I am English i agree it is a mess inside, it reminds me of that 70s kit off ebay you looked at. I have a 70s wharfedale cassette top loader deck that's a bit hoeky inside it has a nice low level hum it's proberly a cap on the power side of things.
"Driver Ass" i spit out my rice when you said that LOL
I just said what it said on the schematic! Actually I said driver board, and then when I was editing I saw "Driver Ass" on the schematic and just had to dub it.
22:51 -I love the song here, the guitar player is a badass. Is there a way to listen to this music online in HQ? Great videos lately 12V, keep up the good work and congrats on 15k subs!
The track is called "Class of 69" and it is a royalty free track from Musicbakery.comI don't know if they will allow previewing in full quality of this track or not. My old company paid thousands to buy a library of music, so I have the rights to use it in my productions.Anyway that is what the title is, and where you can get it.
Thanks Dave....better than I expected outcome. How did you decide which transistor to use...by reference guide or just locating one that had the closest specs as the blown unit ? J K
Hello.. I'm always learning from you . I have a problem with the teac c1. His performance is excellent, but is not recorded and do not wipe the track in advance. Note changed the security key for registration and works guarantor, but not the result, it estimated explain to me where the defect lies. And I should be grateful
OK that is a 3 head deck. If it is not recording, or erasing the previous signal, then you need to look into the record bias oscillator.
This generates the AC bias signal that drives the erase head to wipe the track, and provides the bias signal to the record head. No bias signal no erase. No record.
Thanks for the fast reply. Where can I get the AC.? If it were not the cost of shipping high. Posted device for you to note that I am talking to you from Saudi Arabia
So why (or how) did you decide to only replace one transistor in stead of all of them? I sure like to watch you do your work & I learn a lot.
Only 1 transistor had failed. Unlike tubes, transistors typically do not have a life expectancy. Vacuum tubes do have a life span, so when you replace a tube it is recommended that you change them in pairs so you don't have strong one and a weak one. This is not the case with transistors. They don't get weak. They keep working until one day they don't. Perhaps a bond wire breaks off the die, or the die breaks down and shorts due to a voltage spike, or a speaker short overload them.In push pull outputs quite often when one fails it will take out the one opposite to, or blow back and take out a driver.In this case the outputs were fine, it was just a case of a driver popping.A disreputable shop that is profit driven will generally feed you a line of bullshit and tell you that they have to replace all the transistors so they can pad the bill. I used to work for such a shop. I was paid commission on the repair, so naturally the higher I could make that bill the better I made out financially. I am NOT in that business anymore. I am not out there to gouge my customers I have retained. I work in a totally different industry, and I am a highly skilled, and well paid union worker. If I was still making a living doing repairs I would not be teaching others how to troubleshoot their own products, or giving other techs, and I know that there are other techs that do make a living doing electronics watching insight on how to troubleshoot.I provide low cost repairs to my clients, and that means only doing what is required to get the unit functional. If a client brought me a device and said, knock yourself out, replace all the capacitors and semis on spec, no expense spared, then I would do that, but the fact is 99.% of people want to get the item repaired for the least amount of money. For the record, I charged the client 70.00 to repair this, and that included parts, and driving into the big city to get the part, I will make money on this repair in the long run from views on youtube, That is where I make my money, not ripping off my customers.
OK, so it has nothing to do with cost or the effort to change the parts. I had wondered if the costumer did not want the expense and that was the reason. Is there things that you recommend that you change just because others parts like it have gone bad? I to that with light bulbs. Have you done a video on how isolation transformers? I could not find it if you did should I look further or do you have something you recommend?
Naturally if I see leaking capacitors I will recommend changing them, or just change them out, but changing out components that haven't actually failed is overkill. Not every capacitor is going to fail. I have an old Panasonic 3/4" VTR that is 40 years old. All original capacitors, and it works perfect, and a 3/4" VTR has literally hundreds of capacitors. All discrete components, and no LSI ICs.Capacitors in power supplies , switching supplies in particular are the ones that fail the fastest just due to the ripple and high frequencies.Small coupling capacitors very seldom fail unless the seal was damaged during installation or a prior service, and the electrolytic dries out. The reason surface mount electrolytic of the late 80's and 90's were so bad was due to a fu** up in manufacturing. The story goes that a disgruntled engineer left one manufacture and went to the competition, and tool the top secret electrolytic formula with him. The company he joined flooded the market with their caps, but the problem was there was a key ingredient missing, and the electrolytic PH wasn't stable, which caused it to corrode the copper wires that connected the capacitor with the outside world. In a few short years the corrosion lead to a leak, and then corrosive liquid got on the board.Older capacitors did not have this problem because they used older formulations of electrolytic. Some old capacitors contain PCBs which is bad, but even worse if they are changed out, and not disposed correctly. So it becomes is the repair affordable, or does it become an uneconomical repair. If it is a rare piece that the client doesn't mind spending a couple hundred dollars recapping the entire board then knock yourself out.Most people, 90% are happy replacing the component that failed and moving forward.Now, on the other hand, if it is a mission critical piece of equipment, such as an audio console on a broadcast operation, or a transmitter, or piece of medical equipment which just can not fail, and it is in operation 24/7 then sure you might want to do a full overhaul and replace all the capacitors, but a piece of stereo equipment is generally not in that category. If 2 or 3 years from now another component fails, deal with it then. I won't even recap all my own gear. I change the part that fails and put in operation until something else breaks.
@@12voltvids YEAH ............HAD A FELLA LIKE THAT KEPT BRINGING IN STUFF TO FIX.....N WHEN I FINNISH THE STUFF HE DIDN T WANT TO PAY THE 30 POUNDS SO HAD TO STORE IT............THE SECOND TIME HE CAME IN.............I SAID 60 POUNDS UPFRONT N I LL TAKE A LOOK AT THE PC LAPTOP............WELL WHEN YOU PAY ME....I LL FIX IT.....HE NEVER CAME AGAIN......HAD TO STORE IT
@@12voltvids ON MY STUDER REVOX REEL TO REEL....A77.....I PUT ALL NEW PARTS CAPS RESISTERS TRANIES .....ON ALL THE SMALL BOARDS ALONG THE BOTTOM....
The quality goes in before the name goes on .
Is that the Variac you repaired later on?
The ocean goes with the music.
That would have been a Zenith.
Yes that variac is the same one I overhauled and cleaned with DeoXit. It was that video that earned me the 1000 first prize in the contest. Hope to do that again this year if they run it again.
I was being sarcastic. Nice unit anyhow. And congrats on the contest!
nice work!This vidio haven't subtitle,it is important for people in most of the world.
I used to use newer transistors and just swap the leads. They used them on pinball games as display regs. Something about a mje15031 and 15033. Been too long.
That is why I checked the basing before installing it, to be certain that the pin basing was the same. It way. Had it been ECB or BCE I would have had to swap pins. What I was showing it that the collector in most cases it connected to the tab. So once you identify the location of the collector the other 2 are easy to figure out.
I could not find that transistor. Old parts are hard to find. Ever tried the MJE 15029 and MJE15031? They work quite well if you cross the legs
We do what we can to find suitable replacements.Some times we get lucky and other times not.I got lucky this time.
Gee, it seems like Leak and Lucas have a lot of common; British electronics and British electrics.
the double sided tape looks conspicuous now and is going to get mucky later !
It can always be glued back down later. I don't have any contact cement, but it is easy enough to remove and glue down. The guy that owns it can easily do that. It was brought to me to repair the electrical fault, not fix the cabinet.
That case style made me think VMOS FET transistors but now you have said normal transistors so why can a BD131 driver transistor not be mounted somewhere one the case and wired to the holes that the old transistor came out of.
What is wring with the subsiture I used? I match one that had the same gain, same power dissipation but with higher voltage as the original was NLA.Why re-invent the wheel when a different wheel the same size can be used.
My fisher stereo also has a real wood top.
You didn't replace the leaking cap shown it the first video?
I have hated DIN connectors since they first appeared. You could see the design flaws just by looking at them - puny pins, weak sockets, too many different configurations (some have died off since), and just a pain to get all the different needed types to hook things up. Switchcraft tried to offer better grade stuff but was hampered by the design specs. The speaker connectors are a terrible design and not capable of handling high power. Audiophiles who use those heavy and fancy speaker cables find them a terrible bottleneck. I thought early on that they would be abandoned but the Germans (who introduced the standard - Deutsches Institut für Normung) stuck with them and the rest of Europe went with it. The Japanese even had to adopt them to sell in the European market.
Talk about the bad ruining the good...
YEAH..........RIGHT ON..........BUT STILL USE MINE...THOUGH MIND YOU
You have electronics stores in Canada still?! You have my envy. ;-)
Thx for very helpful videos.
We have 4 here in the city. Main Electronics home of a million parts. They are 3rd generation. I have been dealing with them for 40 years. Started with the owner Phil, he passed the business on to his son Dan, and now Dan's son Scot has picked up the reins. Phil just passed away this past Oct, and Dan a month later, but the shop is in good hands. That is where I got my ESR meter from, and buy most of my component's there. There is also Lee's Electronics. They are where I got those tube amp kits, and then there is RP Electronics, and Interrior electronics. So yes Vancouver still has parts suppliers.
12voltvids lucky in deed, here in the UK we have none except for a chain store called maplin electronics which is a muppet store with clueless staff never got anything in stock, I have to buy all mine online line now, all our little electronic shops went out of business years ago which is a great shame as they sold eveything.
@@jessie4pink615 I GOT A BAN YEARS AGO FROM 1 OF THEIR SHOPS ....IN LONDON.....
Cool
Well im really supprised you visited this unit again lol, but you have done what the repair company before you could not, or they were too lazy, who knows?.
im supprised more hasnt gone wrong with this 1977 unit, the crapacitors are bloody ancient, they would give your e.s.r meter a heart attack lol.
Yes the diagrams are crappy, the 47 ohm resistor connected to the base should have been joined with bias resistors if the diagram is to be believed, Errors in diagrams, no supprise :).
I would of expected 47k resistors on the tape/line input, but as you said, different standard.
5 Pin din sockets were a bloody nightmare, no one seemed to stick to one standard for levels or pin wiring.
The only reason I abandoned it the first go around is the owner didn't want to repair it initially because he had read many reviews and comments on this unit that called it "Garbage". The fella that owns this unit has brought me plenty of work. The Haffler amps I worked on a few months ago, the Technics tuner with the display problem, Philips CD recorder, and that fancy DVD player a few weeks back. When he was picking up his other stuff I told him that I probably could find a suitable replacement transistor if he had a change of mind and at that point he gave me the green light to proceed, and here is the finished repair. There are not many units that stump me. Not when it comes to vintage audio. I give up relatively quickly on LCD televisions.just because they have so many board problems, especially BGA problems, and there is little if any service data available. Vintage audio though is pretty easy to service unless the parts are obsolete. In many cases such as this one, a replacement can be found. The replacement transistor has higher voltage, and same wattage, but the current is slightly lower, but then again, it is a driver, not an output, and the voltage it is being run at is much lower too, so I don't see that being an issue. At least the power dissipation, and gain were the same as the original.As far as the capacitors go, they actually measured pretty good. ESR wise they are fine. Capacity wise they are all well above the rating, which is very common for the old vintage capacitors.Sure if funds were unlimited, then I could have replaced every capacitor in the unit, but I did measure key caps in the driver stage. Even that one that looked like it was leaking on the first video was actually not. I pulled it, and looked at it. I missed some of the capacitor testing as there was a segment that the camera was in stand by, and I thought it was running, so here I was talking to myself. There was also a long segment (cut out) when I thought the camera was off, and it was actually rolling when I was doing things like hooking up the speaker wires ect. This new camera is great, but the beep that it makes when it is recording, and 2 beeps when stopping is easy to miss when the heater is running. Unlike my other camera there is no red flashing icon on my big screen that I view it on.
Yes he has been a good regular customer, and you have made smashing videos from those repairs :-), and a few pennies from adverts, so its all good :-).
I did have another look at the service manual, the editor wants a kick up the jacksie, but he could be dead by now, so ill take my boots off lol.
Ive found some horrible mistakes in schematics, capacitors shown reversed, mains transformers shorted out, and all manner of stupid mistakes.
Lcd tv's and monitors can be a bloody pain in the backside, if your lucky its a psu fault, if its the main board then you have to decide if its a good enough set to get a repaired board from ebay or whatever.
If the lcd is quality then i would keep just the lcd and lift the usefull crapacitors off the pcb, you just have to LOL :-D
LED monitors are the worst. Its a crap shoot most times. Change the entire board,and hope the one you get off ebay is good.
One thing i have noticed though, laptop lcd's seem pretty reliable, the lighting how ever may not last.
Ccfl tubes last quite well, but led back lighting seems whiter, i use an ancient acer aspire 5315 from 2007 so i only know how well the ccfl's can last.
Yes ebay can be hit and miss.
I have a Sharp CCFL LCD that from 2005. I use it as a monitor for security cameras, and it currently has over 40,000 hours on it, and still going strong.Let me know if your LED backlight lasts half as long.
Just watched yo Video take-n a trip into town to a seedy back ally "not the red one but the Blue-un" so yeah just so that yo Barbie kin get Stoned :D ;) Love the 4K BTW..
Have you tested the output voltage on the variac because I have one just like that and when set at 120 on the dial it reads 125 and not 120 so i had to mark on the thing so i know where that 120 is really at.
Its the same. There is a voltage meter on the front of mine that shows be the voltage. I have to turn it up to 125 on the markings to get 120. When it shows 140, the output is really only 130. The meter on the front is accurate on mine, verified with my DMM.
From where I can get the magnifying gear that you are wearing
I got it at Lee's electronics.
Good old English amp
sir I m open smps but which components is bad so plz help me...
How do you get the schematics all the time? I believe they are not free..
It is called research. I never pay for schematics. If you search long enough you will find something that is either the exact one, or close enough. The alternative is looking up data sheets for key parts, and then doing a little reverse engineering and drawing your own by looking at the PC layout. This is time consuming, and never fun.
Skl Dj elektrotanya.com is a good one to use, I get a lot of mine off there and they are all free they hold most of the top brand manuals especially if your working on something from the 80s and 90s also eBay is a good source for original paper service manuals, paper ones are better as they are easyer to look at schematics.
@@jessie4pink615 www.hifiengine.com/manual_library/philips/cdr600.shtml
HERE IS THE FREE ONLINE SERVICE MANUALS UND OPERATING MANUALS YOU CAN GET FREE THAT I USE........SKI DJ
www.hifiengine.com/manual_library/philips/cdr600.shtml
Yes, the speakers sound like shit, but that amp sounds rather clippy at that volume. Also, it all sounded mono to me, but all I have to listen with is a 1979 white Bakelite mono earpiece. That probably has some effect on my auditory opinions. XD
It is working in stereo. These are cheap shitty outdoor speakers that have been outside all year long for 7 years. I just took them down for testing. They have no bass as you already heard. What do you expect from Radio Shack.
I was just making a funny. Discerning stereo from mono on UA-cam can be tough. I don't really use a mono earpiece.
i see ya got new solder. is it good enough?
This is 60/40 and it seems to flow pretty good. I used this for my tube amp build, and this brand is much better than the last experience with Chinese solder was. It is rosin core, and gets the job done. Perhaps not quite as good as the old stock Kester I was used to but it gets the job done.
Looks like a rats nest. What a mess. I agree with the LSD comment.
I made a joke about it on the first look at this and pissed off everyone across the pond. They took it personal like an attack on the British, even though I am also from the same rock.
Is it possible to repair that variac?
It has been repaired.
Done years ago.
6:33 PNP NPN "oh" PNP NPN "oh" "dada-da-dadadada-dada, dada-dada-da da I am the music man" Sorry I'll get me coat
A little bit more info on the Leak Delta 75: elektrotanya.com/?q=showresult&what=leak%20delta%2075&kategoria=&kat2=all
Iwas also
☺
Frankly, the build quality of this (British) made receiver IS CRAP. I would have expected to have seen stuff this bad being made in bloody China at the time, NOT Britain. However, Britain DID produce some good stuff around the 1960s and 1970s. Hacker Transistor Radios, Roberts Transistor Radios and Dynatron music centres are just a few examples. Don't know if they ever sold in North America or the USA, then again, you always reckoned your stuff was better than anyone elses :)
jour good men i look video,s
Only in AMERICA, these came out before u were born when u were using valves. If you want an easy fix try made in the USA,. If life was an easy fix i would be living on a boat In FLORIDA by Don Johnson.
These definitely did not come out before I was born. I am early 60's vintage, and tubes were what was in everything. The transistor had barely been invented. I still have the first transistor radio that my grandmother owned and listened to regularly. A Sony Transistor 6.
You can have your Florida boat. They get too many hurricanes for me.
jesus christ mate im repairing an infocus lp330 projector built in the usa, its a fucking joke! dont slag off the english this thing is a fucking nightmare to work on, you americans certainly like your silicone sealant haha, im working on its power board they must have used half a tube of silicone on 5 components, this is what caused it to blow up! the power boards components werent getting any air from the fans and it blew 3 transistors a VIPER100A ST Current Mode PWM Controller , and 2 optocouplers, holy shit its took me 2 hours to get all the crap off, your only supposed to use a pea sized amount ffs. they used all this silicone on the transistos and forgot the most important thing, the fucking thermal grease lmao.
Most of the British gear I have seen has been top quality, and actually this one wasn't the worst I have worked on. I was just poking fun at the way it was put together. It is not a representation of the classic Leak units that preceded it.
I didn't show it on the video, but one of the boards that is mounted on the bottom has capacitors that are quite tall standing up on it, so what did they do? They drilled holes in the metal chassis and poked the top of the caps through the holes, and stuck red tape on the top of the capacitor so they didn't touch the board above it. I cut that scene from the video because lets just say I made a few comments about the way that they were installed that would have ruffled a few feathers. But to give this unit credit, it is 40+ years old and only popped a small transistor. All the other components, were fine.
And no I am not taking shots at the British. I happen to be of British descent, so please don't take it personal. I am going to be tearing down and repairing a Canadian made system soon that is in my collection, and I will be just as critical of it's construction.