Pioneer SX780, replace both STK-0050

Рет қаралды 3,016

Күн бұрын

This Pioneer receiver is out one channel... this was a fun project, and these pioneers are so easy to work on, I like that the service manuals is at your fingertips....
be extra careful around these power packs (STK'S) when or if your taking measurements...you don't want to short them out as it's hard to come by...
I would like to thank Tim Corner for giving me these power packs, He upgraded with the new modules STK's on his SX-780 and I was able to use them in this receiver and saved it from the trash....
if you enjoy this video, PLS subscribe to my channel for more repair videos ..

Пікірлер: 25

@dieseltinus6680 5 ай бұрын

I really dislike STK powermodules and that is an understatement. Prefer discrete poweramps. Greetings from the Netherlands.

@patduz 4 ай бұрын

Excellent travail. Bravo aussi pour vos explications précises.

@Justplast 5 ай бұрын

Very good job Joe

@mistermac56 5 ай бұрын

Great job as always Joe. Thank goodness there is the discreet STK replacements available, as you said, the original STK's are almost unobtanium and there are plenty of fakes of them available unfortunately. When I worked at a local (long time closed) local Panasonic service center, Technics had a MOSFET integrated amp that used MOSFET power packs that were proprietary to Technics. They generated a lot of heat and the top cover of the amp didn't have sufficient openings and the cooling fan just didn't move enough air to keep the amps cool and the amps and the MOSFET power packs would fail a lot and we would see a lot of those amps in for repair. Technics went through three revs of the MOSFET power packs and they finally upgraded the cooling fans to push more air through the amps. We were instructed if someone brought in an amp with failed MOSFET power packs and had the original cooling fan, we would upgrade the MOSFET power packs to the last rev and upgrade the cooling fan at no charge.

@clifffton 5 ай бұрын

I love changing STK packs back in the day, at least until they became unobtainium. Simple to daig, even easier to replace.

@alexzildjian 5 ай бұрын

Muchas Gracias por tus excelentes Videos 🙏🙏☺️☺️😃

@collinwood60 5 ай бұрын

Joe, I only discovered your channel about 2 or 3 weeks ago. I think i've already watched about 15 of your videos already. I subscribe to many HiFi repair channels on YT, but yours has become an instant favorite. You do a great job of describing what you are doing and the camera angles are superb as you really zoom in so we can see exactly what you are doing. I just set the power meters on my Pioneer SX-780 a few days ago after watching you. On my unit the right was higher than the left and it was driving me crazy! You are such a great resource for newbies like me wanting to learn this stuff and who love vintage audio gear. Look forward to more repairs!!

@VintageAudioFever 5 ай бұрын

your comment made my day...thank you!!!

@Dratchev241 5 ай бұрын

great, now i want a pioneer sx780

@OKuusava 5 ай бұрын

Not sad that instead having Yamaha CR-620, without packs.

@videocast3655 5 ай бұрын

enjoyed this video a lot. I have my own 780 on my bench right now. started with the same issue, but decided to install the discrete component stk's and do a full recap plus some standard transistor change out. Q19,20,25 and 26 and the protect relay, clean and lube all the controls. still doing recaps at the moment. have to take my time or else..lol

@ripjones5294 5 ай бұрын

I am watching this installment, MULTIPLE times, since I ALSO have a Pioneer 780 to ultimately go on MY bench. Thanks for taking the time to create this content. Working on a Yamaha 600 right this minute with basically NO OUTPUT. Signs point towards that stupid Input/Output switch that seems to always corrode/fail.

@larrymcnair6249 5 ай бұрын

Great Job. Could you possible show how the oscope was hooked up?

@timcorner2821 5 ай бұрын

Nice Job as usual....the packs look familiar....lol

@VintageAudioFever 5 ай бұрын

Yes they do....go read my description!!!

@timcorner2821 5 ай бұрын

Glad they were able to be useful, it's always good to save old gear@@VintageAudioFever

@PatEverton-ey9th 3 ай бұрын

Hey Joe I'm really liking what you do. I also have an sx780 that needs some work. I'm in the Chesapeake/Virginia beach area was wondering where you are located? I'm a retired construction guy/veteran wish i could do what you do.

@VintageAudioFever 3 ай бұрын

Hi Pat The 780 is a real easy receiver to work on....what's wrong with it? I'm Moncton 🇨🇦

@PatEverton-ey9th 3 ай бұрын

@@VintageAudioFever Hey Joe. Thanks for responding to my message. A couple of weeks ago I did a little cleaning out of the reciever it had alot of dust in it. I hadn't use it in over 15 years I bought it in 79after I joined the Army. I also did a deposit on the knobs and switches after watching several videos. It worked just fine for 2 days then the right channel went out. I was wanting to have it restored before that happened so that it would last me the rest of my life . I've always loved that reciever and don't want to part with it. Having a hard time finding someone in this area that can do that. I've watched many other video's on doing that but I'm really impressed by the way you do things. Wasn't very impressed with other people's video's. Was also thinking about adding a bluetooth capabilities.

@raygarafano3633 3 ай бұрын

Very good, as I understand it, its the flat part of the wave that can burn out a speaker or is it too much bias or d.c. voltage?

@raycoxjr1 5 ай бұрын

Joe i am currently working on a Fisher RS2010. It has the STK-0080 power packs even though the schematic shows it should have the STK-0105. I thought they were discontinued... where do you get yours from if you don't mind me asking?

@VintageAudioFever 5 ай бұрын

Hi Ray....you can still get them , just when on Amazon and they actually have the STK's your looking for....I would do some research before I order the STK's....audiokarma is a good place to ask around... thanks for watching my video's...

@danhorton6182 5 ай бұрын

You should be glad it has the 0080. Though in the Fisher it’s being run near its limits. There is board used to replace them (0050 and 0080) using all discrete components. It used resistors, caps and for transistors it uses MJE15032G and MJE15033G and then for outputs there are multiple choices. I generally use NJW1302/NJW3281 or NJW0302/NJW0281 depending on the power output of the amp. I’ve replaced at least a couple dozen of these packs. While in the video he had success, I’d bet all I have that the packs he got are counterfeits. It’s well documented that these counterfeit packs are inferior to the originals and fail more often. I only use the discrete boards for anyone looking to replace them.