Pioneer SX-1280 MONSTER Receiver Repair

This all original Pioneer SX-1280 had been sitting broken for over 10 years before it showed up on the bench in this video. It would not power on, and once it did, there was some static in the controls. I fixed these issues in the video and also set the amplifier bias and DC offset.
Best tools for working on vintage gear: • Must-Have Tools For Wo...
For how to use DeOxit, I recommend the video by xraytonyb: • How to Clean & Resurre... I had created a video on this, but I used D5 on the pots in the video, which is wrong. I should have used F5 on the pots, as Tony explains in his video. D5 is the proper choice for switches, while F5 is proper for potentiometers and sliders.
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[@xray111xxx]

This IS Pioneer. Not the garbage today. I sold a bunch of SX family, and Spec series Pioneer and early Elite. You had special when you had Pioneer.

[@ronniepirtlejr2606]

I used to have one of these about 10 years ago. I had it paired up with some Cerwin Vega re38 series Tower speakers & A 10-band EQ.

[@j.t.cooper2963]

My brother bought a SX-1250 from a pawn shop in 1981 for $400. We rocked the 80's hard with that beast.

[@er1073]

My SX-950 was real wood too. IO loved this receiver I bought while I was stationed on Okinawa in 76-77. Thanks for sharing your video. Ed

[@hippydippy]

I'd take a 1280 over a 1980 any day. The 1980's were prone to have many problems. I can't recall exactly what they were, but it is common knowledge for Pioneer collectors & enthusiasts. Beautiful piece of audio history.

[@foobarmaximus3506]

No, they weren't.

[@savagedick1462]

@@foobarmaximus3506 Yes they were , the 1980 had a power supply board that was mounted facing down on the bottom of the receiver . It would fry from heat rising and being under spec in component voltage . Still , the SX 1980 is the grand daddy of all vintage receivers. The sansui G series are pretty but not built as rugged , the marantz are ruggedly built but less modern than the sx@@80 line and the technics sa 1000, for being the highest rated at 330 wpc looks like a boombox in comparison.

[@WC0125]

@@savagedick1462 You are both right. They were not a problem IF you only played them at candlelight, background volume and had very good ventilation. If you used them to their potential (and certainly in any cabinet setting), the AWR-154 board, mounted under the main power transformer and, yes facing down, would get hot, cook the components and fail. The carnage was slow but always ugly. The design flaw sure it made getting them from early e-waste easy! By the 1990s nobody was fixing them and they were going to trash. I got one for free from an e-waste pile in 2000. Having resurrected a 1280 in the early 90's I thought the 1980 wouldn't be a problem. Upon inspection it was UGLY. I buttoned it back up as is, put it on a shelf and slowly compiled replacement out of production parts (especially the output transistors) for the future surgery. About eight years ago I re-visited the project. As luck would have it I found Semiconductor Support Services' all new production, new design AWR board. It's not cheap and you need to have technician skill to install it but I gave it a whirl. Shazam! the 1980 came back to life. It turned out the outputs were not bad either. I spoke to the engineer who re-designed and fabricated the new AWR board. There are some modern modification to the original circuit design and the heat generating regulators are moved to the large output heat sinks. With the new AWR board setup the 1980 is a safe and solid powerhouse. Ebay has a couple of other options for new boards as well but they seem to be built just as the original. I think the SSS one I used is still the best. It has an improved circuit design and the heat producing regulators are now heavily sinked. I can rock my version of the SX-1980 with multiple sets of speakers for hours without a hitch (or smoke or fire or even much heat). Certainly something to consider.

[@homeydcatlives]

I've tried finding a link to this board. I can't even find the company you mentioned. The only SSS is in the 'Wafer Fab Equipment Solutions' business. Can you help me?@@WC0125

[@paulv22]

Nice video. Thanks for posting it. One thing I've found that works very well for cleaning the grime off of the knobs and faceplate is a paste of baking soda with a bit of water in it. Just rub the paste on the knobs, rinse them and dry them off. It works on the faceplate too and doesn't affect the black lettering, but obviously you need to take the faceplate off. I've done it on my SX1250 with no problems.

[@hardball107]

Good job. I had a Sherwood s9910 with the same problem, thought I hit the jackpot after cleaning since it was the only problem.

[@climbtibet]

Love the channel just bought a fully restored sx1980; glad I did a lot of these old highly skilled guys are disappearing. Got me 4 HPM-100sto compliment and killing the grass and blowing out the neighbors windows every chance I get! 5 kegger at my place this weekend. Gonna need some bionic ear replacement but enjoying the ride!!!

[@davidbailey6350]

I have a SX 737 I bought in the late 1970’s…. Had a tech clean the pots and she sounds great. Love these ole Pioneers. Meat on the bone, so to speak. Nice job you did… thanks.

[@paulv22]

The 737 is a great little receiver.

[@MichaelYates]

What a Receiver, thanks for another informative video upload

[@raybeckles4480]

I had a 1280 and I sold it I can't wait to purchase one again they work well

[@kensheal9319]

I own a SX 780, and I love it

[@reinkansman1081]

Nicely done Aidan, My father the engineer was impressed

[@troybuff8653]

Do you repair stereo's for customers ? I have a Marantz and a Pioneer both not working would love to send to you to repair if possible Thanks Troy

[@countrykid4517]

Found this channel the other day and I'm hooked your content is amazing and I aspire to learn as much as possible from your videos. I happen to have a Pioneer SX 1980 that I rescued from a moving job and it's complete but quite rough maybe we could figure something out to get it on a video? I would absolutely love to get it working again. Hope to hear from you.

[@ammarasyraf6519]

I love pioneer sx1280 sound . This my dream receiver

[@nickfrench7372]

Looks like a new machine to me!

[@cardtrix1970]

I had one of these years ago; It powered my Kraco.Speakers, Craig 8-Track Player & Julliette Reel-To-Reel. I sold it, tho, but still have my Kraco Speakers, & Craig 8-Track & Julliette Tape Machines. A "Soundesign" receiver has replaced the Pioneer.

[@cheng96818]

Hello. Awesome video. @ 4:08 you mentioned about dc offset and one of the amplifier needs to be adjusted because one is staticky. Would this problem also make one channel sound bad? I have a pioneer sx 1980 and the right channel does not sound as good as the left channel. It still sounds good but needs significant improvement. Especially on phonos 1 and 2. Several techs, work on it but can never fix it. They dont seem to hear what i hear…anything i should mention whenever i go back to the tech (again)?

[@kevinnietering787]

Glad you got all the grit and grime off those knobs

[@azardmohammed2954]

I have been following your posts,particularly repairing the pioneer receivers,I have found great interest and ask do you have any receivers in the sx1280 range for sale

[@mrdoctor333]

One question, I want to change a fuse from a pioneer sx550, it is .8 to -125v, but I only find .8 to 250v, is there a problem if I use it?

[@kenkai6133]

Thank you.

[@gussuk11]

Can you please do a video on the use of the Rightmark software?

[@richardadelberg8961]

So you chalked it up to a fuse and speaker bias. What cleaned up the one bad channel. Just switches and pots?

[@jameshopkins7333]

There's one of these up for auction near Harrisburg

[@saigawesnovember]

I’ve got a Pioneer SX780 that quit on me a couple years ago,it’s actually in very good shape.I just have to have it gone through by somebody that knows what they’re doing. Pretty sure it’s just a fuse. But I’d like to have it gone through by a professional.

[@dontcare563]

Used Audio oscillators aren't that expensive. You really should invest in one!

[@c.r.sherman1795]

Sweet!

[@stackoverflow8260]

Did you have to Crank up the volume knob when you connected the phone directly to the main in? Usually main in sensitivity is much higher than aux of out of phone. I am guessing that aux out on phone is line level?

[@AHFixIt]

Volume was controlled entirely by my phone at that point, yes. The volume knob was bypassed at that point since it's not part of the power amp.

[@MrStarbor]

aMAZING!!!

[@richardadelberg8961]

I had two mint 1280’s. Two shops said they run hot, burn boards, no replacement output transistors . Recommend to sell my time bombs and buy 1250’s. What do u think

[@AHFixIt]

The two shops didn't want to go out of their way to make modern components work. Check audiokarma. People have found ways to get 1280's and 1980's running again. The one I had did not seem to run hot, and I was pushing my maggies pretty hard with it.

[@lucaspatterson]

Hi Aidan, do you know of a good replacement for those 2SD746 and 2SB706 output transistors on these higher end X80's series?

[@AHFixIt]

Not off hand but I'm pretty sure it's been covered on audiokarma.org

[@richrohde883]

Do u work on vintage pioneer FM cassette car stereos? Remember the old super tuners?

[@c.r.sherman1795]

Are the Hitachis of this era any good?

[@zofo500]

Nice video. Are those KLH Model 6's on the bench?

[@AHFixIt]

Close, they're Model 17's!

[@williamsampson4926]

If I recall these would develop a problem that would blow the top off a ton of the driver transistors literally you could shake it (heavy as it was) and shake out all the blown transistor parts and it would not blow any of the safety fuses except the main power one not the best safety circuit design lol

[@petenamlook18]

Don't you need a dummy load when you are setting the VU meters?

[@AHFixIt]

Not on the SX-1280

[@hrbharti4333]

How I will get??

[@richtrebbien]

What a beauty. This video has not worked as good as your other videos but good enough. So do you think these older receivers sound better than lots of the new stuff? Are they worth the effort because they are so much better? I have a do it all AVR, I like it a lot and I play a lot of digital music with a streamer. I wonder if I'm missing something. Thanks for your work, regards

[@AHFixIt]

I do not have very much experience with new gear so I can't answer your question too well. I'll answer it anyways, though. From what I've gathered over the years, vintage gear from the 70s, FOR THE MONEY, at least prior to 2020, sounds better. There is new stuff that will blow the panels off of any vintage piece, but you're paying thousands of dollars for that stuff. In many cases, a lower wattage (cost) vintage marantz or pioneer or sansui coupled with efficient speakers like Klipsch can sound absolutely fantastic. But you're giving up remote control and many other modern conveniences. Audio is extremely subjective and always comes down to the listener's personal preference. You won't know what you're missing, if anything at all, until you try! Check out Andrew Robinson's KZbin videos on his Pioneer SX-450 and SX-780. He has some good commentary on this subject of old vs new.

[@silentkenda3534]

Do you restore these? I have a SX1280, it’s been in storage for years.

[@Zonfeair]

If you do not get it fully restored would you be willing to sell it? and if so what would you want for it?

[@kenmcmaster6938]

do u have a wedsite?

[@melovemusic69]

So you only repair friends and colleagues?

[@MORONGOBOBO]

Great video. Thank you!!!!

[@quinterod1000]

How much to restore my 780

[@berylhemmings7003]

Need dem

[@NathanThePrezPretlow]

GOT TO BE A FUSE Im from 1970s you always check the fuse.

[@bpalpha]

I can’t believe not one of these audio companies have acted on the current retro/nostalgia buzz amongst audiophiles. Pioneer isn’t doing great and creating a boss monster receiver might be enough to get them on their feet again.

[@johnnyhawkins43]

Could be the transformer !

[@hilariolozano4550]

One question where can I buy receivers

[@j.t.cooper2963]

Really?

[@duchuynh2938]

dep qua

[@vsmichael1]

Why half ass something. Do it right. Why would people subscribe to a person that sets power meters with the amp on its side where gravity holds down on the power meters & doesn’t set them correctly?

[@homeydcatlives]

Get a life.