I came here as Ive just been gifted one of these.. its been in an attic for yers....turned it on with a series bulb.... well it worked, ish, everything was crackly.. and the radio didnt work....I saw your review and was about to put it in the trash...but then I decided to give it a look over.. soon found out the bc223 on the psu pcb was open.. so I replaced it , and the uo5 with some bc131s from the junk bag, after bending the legs a bit... Et Voila.... working fine... the 9v one was a bit hot, so I affixed a lump of metal on it , and glued it to the pcb just for luck.... A good spray on all the pots and switches with some phillips.. and I connected it to two altec a7s......The fm was amazing.! very sensitive. . I have so much junk around here , but it picked up well on 2m of wire..... The amp is suprisingly good for what it is, so now ill have to find a home for it. As for you having a problem with the u05 going on yor specimen, its not exactly difficult to find a replacement.. oh ... was that bit made in good ol America???? note although that build is hardly a nakamichi, most of those components were british. not chinese. and as said before, it was made by a relitively small firm...which supplied a living to British peoples.. and the electrolytic caps are still holding out.!..whilst it could have been made better, esp the tuning arrangement, im sure there was much worse!
Thanks I enjoy your videos, I also come from the UK and can remember seeing these units advertised when I was in my teens in the early seventies. They were quite modern looking units for there day. Japanese electronics were of course way better made than most other electronics at that time. But clearly the construction of these units was shocking even for the time. I googled the Delta 75 after watching your video, you're not alone, while Leaks early units had a good reputation, that model is known to be poor quality. In 1971 they were £169 approx same price as a Sony STR-6055, I know which one I would go for! As for DIN sockets, they used to frustrate me too, I have an A&R Cambridge A60 which also has DIN sockets and I have a multitude of phono adaptors. An unecessary complication. Thanks again
This unit will be back on the bench now that the owner has decided that he would like to proceed and repair it. So now I am looking for parts to get the left channel back up and running.
Type Designator: MPSU06 Material of Transistor: Si Polarity: NPN Maximum Collector Power Dissipation (Pc): 10 W Maximum Collector-Base Voltage |Vcb|: 80 V Maximum Collector-Emitter Voltage |Vce|: 80 V Maximum Emitter-Base Voltage |Veb|: 4 V Maximum Collector Current |Ic max|: 0.5 A Max. Operating Junction Temperature (Tj): 150 °C Transition Frequency (ft): 50 MHz Collector Capacitance (Cc): 12 pF Forward Current Transfer Ratio (hFE), MIN: 80 Noise Figure, dB: - Package: X17 So pretty much a standard 10W audio driver transistor
You're being a bit tough here! I own a fully restored Leak Point One Stereo 20 valve pre amp and a valve power amp from the 60s and it still runs beautifully after all these years! I think every company on Earth has at one time released a dud! I'm 58 and SCART connectors were a massive joke. I live in Australia by the way and love tube or valve gear of all types. This unit was definitely designed by someone on ACID!
The Stereo 20 was designed and made by Leak but the Delta 75 was neither - they'd sold to Rank by then and their work was outsourced. The Stereo 20 is point to point wired, simple to work on and reliable. The Delta 75 is a bag of shite - kind of an audio British Leyland.
Dave, after watching you struggle with this POS, I looked, to me, as the piece was assembled by a team. One guy put his board in, the next guy put his board in and so on. For final testing, it looks like some addons were installed to get it working. Just like their cars, strange and had to retuned a lot.
This amp can't feed DC to the speakers as it has output series capacitors. The output from the amp sits at half power supply voltage and the voltage swings around that. That way you need only a single rail power supply and no speaker protection circuit. Downside is bass cuts off at a higher frequency than a DC output amp. I also cannot believe you could not find a standard NPN or PNP driver transistor, which says more about your ability than the build quality of what is at the end of the day a 1970s design.
I did find a transistor. Since there was no direct sub available I had to guess what to use. Normally i would have just gone to the parts store and the owner would have known what were good subs but the parts store owner died and his son was in the process of closing the business. He had no clue what would work. In this video the owner had not even decided if he wanted to fix it. After giving the owner s heads up on it it was determined that we would proceed and I ordered a higher spec transistor with equivelant gain and got it running. This is a quasi class b amp. 4 npn. Remember this is a British amp, we don't see many of them here. It is mostly vintage American and Japanese
Apologies from us British with our bodge job 70's manufacturing, the guys working on it wanted to clock off early on a Friday to get down to the pub!, we did make some good stuff but also some bad haha!.
There are some decent British makes - NAD for instance. I have a 7020e receiver still going strong after well over 25 years. Mind you, it was built in Taiwan...
It's a complementary output (all NPN transistors with a capacitor in the output) which gives the amp a different sound. Not quite to glass bottle tubes but a different sound.
British TV's from that era were also pretty rough, still using valves which virtually guaranteed failure every six months. Sony showed how to make them properly and the trinitron sets just went on for ever. Finally UK manufacturers got the message with the Ferguson TX9 in the late 70's which was bang up to date with very lower power consumption.
If you want impossible to work on; try AKAI tape machines from the early 70's. They have hundreds of wires tacked onto the reverse of the boards which means you can't move anything, or remove any components without risking ripping them off.
Yes I have 2 Akai tape recorders. A 1710W and a GX265. You're right they are a night mare to work on. Another really bad one is the Technics RSM275 which is another deck I was critical on, and that one was from Japan. Not service friendly.
If the owner gives it to me, I will try to find a suitable substitute however it is not my unit, and the owner didn't want me to even try to find a replacement. He just wanted to know what was up with it.
That transistor you removed earlier looks like a MOSFET so I thought why not substitute a VN66AF but I have since found a listing for the MPS-U10 for the transistor you removed, we have ditched the old RANK ARENA integrated amp from Denmark in the dump so we don't have it any more so I cannot ship parts sorry, I am sorry for any comments that I made that where misleading.
Your comments were not blocked. I had a spelling error pointed out to me in the super at the 17:37 mark, so I re-uploaded it with the correction and as as result all the comments were wiped.The transistor that has popped is a standard bipolar 80 volt 2amp.The client that owned it didn't want to spend any money on it, or I would be sourcing a substitute. Now, if he decides that he doesn't want the unit, and leaves it with me, then I will certainly try to find a sub transistor, and un-do the mods that they previous guy did to fool the owner into thinking it was fixed. Right now both speaker outputs are being fed from the right channel. I haven't looked into it further to see where it is bridged, likely at the speaker switch, and balance control. To be fair I don't know if this was done by Commercial electronics (sticker on the bottom said serviced by commercial electronics.) or by someone else that worked on it. The guy that brought it to me bought it used, and it wasn't working properly. He took it to a shop, didn't say who, and they said they fixed it, and to never bring it back.I got the second look at it but he wasn't wanting to spend money. It was more of a look at this and see how bad it is. I have several other pieces from the same guy that will be going up later. I serviced his Hafler amps there last year, and as he said, "This isn't a McIntosh or Sansui, so I don't really want to spend anything on it, have a look and let me know what you find"
Re that transistor, I have about ten in my supplies that will do fine. Mouser or RS or Farnell have hundreds.That Leak is though about ten times neater than your desk..😴
We will see how it works after I repair it. Initially the owner didn't want to fix it, but now he has decided that he would like me to find a substitute part and get it running. I don't think the design is all that bad, just the build quality on a few areas, like the AC cap just hanging there, and metal foil shielding not insulated ect. The British had a reputation for building top quality audio gear back in the 60's and 70's, so if you use those units as a reference, then you get where I am coming from with this one. There has been a lot worse designs and build quality out there than this, but those brands you expect it. Leak used to have a really good reputation before the Rank corp took over. Kind of like RCA in the States. They built good stuff before Thompson got their paws on them. There, I have just pissed off the French.
@ 18:36 : it is not true that only the britishes solder resistors directly to the lead of transistors or other components. I had the opportunity to see inside some of the so praised high-end Bob Carver's products , they're messy and full of that hanging resistors soldered directly to the leads of nearby components. This Leak Delta should be awarded with the a prize of the shoddiest building ever.
It is what it is right. Hey at least it still works after all these years. At least I was able to get a substitute transistor that worked in it. It was the last time I had the opportunity to visit Main Electronics before they cloed their doors permanently. I was talking to the son of the owner that had recently passed, and he told me that day he was closing the shop for a month to count all the inventory. I knew that day that the store was closing and would never re-open. Sure enough after a month or so with the web site say they were closed for renovations, the web site changed to they were permanently closed.
Ahh the Delta's.. "so good they not only killed the company, they killed the brand name" .. even the Chinese didn't want it for their plastic junk.. I worked on these things as an apprentice. Don't think they were actually "designed" as such.. just a heap of surplus boards bought from Philips or somebody like that and thrown together in a box.. and that white vertical cap is original.. and yes.. it's mains live !!! There were other horror makers.. Triumph were awful, Vampower never made 2 things the same, and then there was the "automatic telephone co" who made things that looked like a kid had built them from random stuff in the kitchen. I have done a little memory hunting since earlier and those unobtanium transistors aren't that special in this application.. pretty much any complimentary pair driver transistors will do as long as they can stand the main power rail voltage. Funny thing about them is they actually sounded quite good.. There can't be many left now.. thank (insert fictional deity)
Not sure if I commented this when i first watched the video but... is it a Leak or a "Pyle"? lol If those caps are DALY branded they do seem to have held up OK in some of my Rank and BRC equipment. That grommet support thing though is really half-assed & the ferrite bar being too big to fit straight... There were some seriously good drugs circulating in England back then haha!
At least they remembered to twist the AC lighting pairs to keep hum down lol 6:12 ahh I'm recalling now, wasn't this the one where an output was blown so some shop just mono'd it out and sent it down the road? Ugh, maybe it was that way from the factory looking at the rest of the build!
@@12voltvids That is true... Just re-watching the vids because a Delta 70 is coming up in our local auction this Friday... Based on this, I may have to give it a wide berth, unless it goes for £5 then it's worth a punt.
I have question I hope you can help me about my DIY 15 Band Equalizer. Working only 5 minutes and then scratch sounds then turned off. I need to turn on again and very nice sounds. After 5minutes again turn off. Thanks
Very, I never knew that... They seem to go for decent money too, which is interesting considering they came from the same stable as Bush Arena etc. Maybe I should sell my Arena HiFi record player for £150 too lol
Yes it's a shame Harold Leak pioneered audio amplification and marketed the worlds first amplifiers to offer a real HiFi specification of noise and distortion. His 'point one' series lasted a quarter of a century with many great designs, including sandwich speaker drivers and a rather nice turntable too. They were bought up by the Rank Organisation at the end of the 60s and this is the result. Rushed and cheapened product, not much of the real greatness left. It is not though as bad as suggested and can perform fairly well, the tuner is pure Leak and capable of truly excellent results being the Stereofetic. If you look into early Japanese models from late sixties early seventies - They DO NOT look like they did just a very few years later, many are as big a mess as this. The Japanese learnt very, very quickly as we all know..
I own a Leak Stereo 20 tube pre amp and a tube power amp from the 60s. I live in Australia and had mine restored! It sounds better than most solid state amps and was made to last. The power and output transformers weigh a ton and it was built tough! This amplifier here is a joke and I don't believe it's the same company. Opinions!
It was owned not by Harold Leak but Rank by this time (Early 1970s). No it clearly wasn't the same people this would never have got through original LEAK built quality!
yes it does sound like that. It was probably very similar to theme music used by some. The composer wrote many themes for TV and film. There is one show on TV now that uses a track as their theme music that I have in my library. Its all royalty free from musicbakery.
What negative comments?I took out the part where it appears that I broke the power button, which was not the case as it was already broken and glued in place. It just happened to fall off, and was re-glued , and removed a comment that was directed at the previous servicer as I have no proof that the shop I mentioned had worked on it actually did the bodge work of connecting the left and right channels to the right output to fool the owner. He said the last shop that had it did that, but that wasn't necessarily the one named. I think I was still to the point that this was not the best built piece of equipment. Not saying that the British build crap, but this piece was not a good example. And yes I am aware that Leak did have some fine, and very collectable pieces that were excellent engineering examples. This model, however was not one of them.
I was referring to all the negative comments from your British viewers, who were apparently offended, not any comments made by you. My only comment on the original post was about how I would have substituted the transistor just for the challenge of making the amp work again. No offense intended, and I hope none was taken.
Offend me? Hell no. I have a pretty thick skin.Since the unit is not mine, and the owner brought it in for evaluation I did offer to try to find a suitable transistor, but he wasn't interested in spending any money on it. Now, saying that if the unit should happen to become mine, if the owner says dispose of it, then I will certainly look into experimenting to see if I can find a replacement that will work.
Lucas Engineered Audio KABOOM!... Ok, just joking! I have a Cambridge Audio receiver and have borrowed A NAD C370 integrated amp. They have that unmistakable British sound quality. I like the sound. The later British units seem better built, but, they're built in CHINA!
Leak used to produce famous tube HiFi equipment, but never made a proper transition to solid state, and apparently you can understand why: ways components are mounted, and lack of simple quality and security procedures means this is a bad apparatus, plus even the name sounded like a plumber joke. These seems to be made by hobbyists instead of meticulous japanese or US engineers. Anyway, when working, Leaks employed quality components and produced high quality sound equipment. It's something like a low cost and messy Quad!
That was a bit harsh. The crap Motorola transistor was available when the set was built. it has lasted all these years. UK stuff all has 12 months warranty not 90 days so no worries with reliability. The last cap with PVC tape was obviously a bad repair as the rest were all clamped down or tie wrapped in place. Most of the wiring was laced up neatly. it sounded great on the channel that worked. So the domestic electronics industry in the UK was doomed. At least we tried. I will let you get back to your better made and much more expensive US or later Chinese junk.
I own a genuine Leak Point One Stereo valve amplifier which has been fully restored! It's over 60 years old and sounds better than most solid state amps. That's NOT a Harold J Leak amp! I've seen everything his company made!
The original LEAK went broke around 1980 and then came back much later just like MG cars. Probably means someone bought the right to use the name and new ones have nothing else in common with the originals. Don't know about Leak, but MG cars are now made in China.
Si1983h You are right and earlier Leak were also very well made. This one wasn't terrible, just not to the standards of earlier leak and other British amps.
No it was actually the owner of it that compared it to a British Car. He bought it and then realized that is was not a real "Leak" that he thought it was. I got it going and he sold it to another sucker. It had already been to another shop multiple times so he knew all about the quality issues with this one long before I could take some jabs at it.
Right. The "real" Leak amps were works of art. I have worked on some vintage units when I was in the business. That's why I was being hard on the design of this one, because it was not the same as the old ones. It is no different than any other company. There are plenty of examples where a company made fantastic stuff, and sold out, and the new people put profits ahead of quality.
It was burned onto the video. On the large green title where I mentioned that the speakers were tied together by the last tech.I had a typo in the word caught. Just a typo it came out as caught, but my wife pointed that out so I just had to fix it.I blame her, she was rushing me to get done as she had other chores waiting for me.
Ah come on, not all our stuff is that bad..... :) I actually had a very similar unit with the matching speakers when I was growing up. It was built a lot better than that one though. Unfortunately it's power transformer shorted and killed it.
Not all of it is bad, Some of it is excellent. Look at the Raspberry Pi. How many gazillion of those have been made at the old Sony plant in Whales.This one though had me shaking my head. How much trouble would it have been to mount the AM bar antenna straight, or put a strap around that capacitor rather than just leave it hanging by its wires.
AHH i see you removed the british junk title. it did seem to bring out the anti british folks in the comments. i did get quite annoyed by it so thanks dude. us limeys like your videos too :-)
This was made in Bradford UK. If you've ever been to Bradford you'd understand why this is so crap. Most in Bradford can't walk and chew at the same time. Ohm's law... what's that???
Historically they have built excellent products, but I knew this was a piece built after the Rank co took over Leek, and I heard that they basically ran the company into the ground so I had no idea what to expect.
"Europeans loved their DIN-plugs" .. lol I'm European and I HATED them! Always getting lose, always broken, and the regular stuff was so cheaply produced that you pulled the plastic off the plug instead of the plug itself. Don't hold back with critique on that idiotic European "standard" :)
@@danmackintosh6325 It was deleted. I made a few references to it being as reliable as British cars and I guess I struck a nerve. The knives came out unjustified. They took it as an insult against the British. Well I am Scottish / Irish, and my wife is of British descent so I wasn't taking a shot at the British people. It was tongue in cheek humor. Yes the British have produced some excellent audio equipment, Linn, Wharfdale, Leak (the real Leak not this model) Raspberry Pi ect. But there was a few that I am sure they would rather forget about and not be reminded of.
Oh my, well there's nothing inherently wrong about that reference. British cars are notoriously unreliable compared to similar priced models from parts of Europe and the US... I thought I detected a hint of Brit in your voice, wasn't sure though... I think there is a fair bit of room to take shots at the British as a people right now though & justifiably, even though you weren't doing. The place has gone to the dogs lately. I think in all honesty the piece in this video is pretty representative of 70's British industry in general, designed by committee & built to a price by people who didn't particularly want to BE building the things for the wage they were being paid.
You are being very unfair attributing this garbage to the normal standard of British Hi Fi equipment. The original Leak products when produced by Harold Leak and his factory were exemplary products on a par with those products from Quad, Radford etc. Unfortunately,like several of these smaller companies,they failed to move with the times and, eventually,either closed for good or had their names bought by other companies. In the case of Leak,production of products carrying that name was by The Rank Organisation who were better known for televisions and radios amongst other exploits and although some of the earlier Leak items like,for example,The Leak 2000 series and Sandwich speakers were well designed and manufactured,layer products like the Delta range were made down to a price with little interest in the build quality of the products which used various poor quality PCB assemblies from different Eastern manufacturers and thrown together in any way they could to make a working product. Fortunately,this era of embarrassing equipment was short lived and todays British Hi Fi industry boasts companies like ATC,Quad,Rega,Roksan,Audiolab, Sugdon,Wharfedale to name but a few and although, regretfully,many of the assemblies occur in different countries,the quality of design and manufacture is appreciated by all who buy and use it. By the way,as a retired Audio Engineer,I really enjoy your RU-vid videos. Thank you.
I wasn't referring to legacy leak products which were very high quality. I was referring to this one made by Rank Corp. Unfortunately the same is true for many domestic companies that used to have good products
@@12voltvids I am sorry. I meant not to be offensive but am ashamed that such a dreadful product should bear such a proud name and be attributed to us. I have experienced the decline of once proud names with products in other lands also. Some while ago, I purchased a preamplifier bearing the name Adcom which I believed to be a reputable name and brand but found it be cheaply made and poor in performance. I really enjoy your videos and the way you present them and for the ability you have to address many faults in such a wide selection and type of equipment. I am poor in health these days but get much pleasure from videos such as yours.
@@12voltvids VERY GOOD REPAIR....ALL YOUR VODS ARE EXTREMELY EDUCATIONAL......EVEN I M LEANING A FEW TIPS.....HA HA...I LIKE THE SIMPLE REPAIRS LIKE THE SAFTY 10 OHM ....EASY TO FIX.....UND THE REGS......7905....OR ....7812...
12voltvids Yes but the British had a plan to build the cameras !! This amp was designed and built in England !! Like I said they build fine things look at the Merlin engine or Rolls but the wiring just is a lot to be asked for !!
Look at all the problem BMW and Audi owners have. Again mostly wiring problems. Audi especially. They use edible insulation on their wires that mice and rats love. A co worker had his new audi go up in flames on his way to work when a wiring harness that a mouse had chewed shorted and caught fire. Total loss, and insurance didn't pay out enough to pay off the bank loan
We had plenty of crap that was worse than that. I just dismantled a Clation console today for a client, and I even declined to bring the chassis home to tear apart. I should contact the client and ask them for the chassis so you can see how bad this thing is, and it was made in Canada in the 60's.Then there wer TVs by companies like Admiral. I am trying to forget those disasters.
And you said what you said. Taking out the 'British' from the title changes nothing. You've lost a lot of good will from folk this side of the pond with your rantings, quite frankly -- especially when you've waxed lyrical about that overpriced tat by Bose in the past.
Just pointing out the cowardice of 12voltvids in deleting his "British garbage" comment. He should have the balls to stand by his comments. As for cars, you're right -- pretty much everything that isn't Japanese is crap reliability-wise (especially the electrics), and that includes the North American cars.
Hey I happen to be of British decent. OK a little bit to the North but from the same rock out there in the Atlantic. So I can poke fun at their design. Same goes for their cars. Lots of electrical problems. My wife is also of British decent. As to Bose, yes they are expensive, and I always avoided them, and then I had a chance to work on one, and once I saw the build quality I can appreciate why they cost what they do. Many times that works against companies. Look at Blackberry for example. They made excellent phones, in Canada. My Priv for example made in Canada. Fantastic phone, but it was expensive, and for that reason Blackberry has exited the manufacturing business, and shifted their phone production to China just like everyone else.I do not expect the new phones to be even close in quality to the units that rolled out of Waterloo, but that is how things are. For what it is, this unit could have been great but the build quality reminds me of what many high school electronics projects ended up looking like.
im not offended that you dont like the stereo, im offended with your view on the British, i wont say anymore on the subject, everyone has seen what kind of person you are, I for one wont be back.
I have nothing against the British as I am of British descent. Both my parents were from the UK and Ireland. I was just making an observation that this piece of equipment was not the best built, but I have see stuff that is just as bad or worse from the USA, and Canada too. Some of the worst crap I can remember working on was old Admiral TVs, and they were American. Every manufacture has produced shit, as well as some very good pieces. And it wouldn't matter where it was made. I wasn't taking shots at it because it was made in England, I was taking shots at it because this piece was poorly made.
I'm half British myself and im sure there is plenty of good British made gear. 12voltvids looked to be pointing it out as it is and nothing more. Simply it's a poorly put together unit.
