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Pioneer SX-780

AM/FM Stereo Receiver

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Pioneer SX-780


The SX-780 features a high output, low distortion power amplifier, a high fidelity equaliser amplifier with low noise and high gain, a high stability tuner section, tone controls with tone defeat function, built in protection circuits and independent power meters.


Tuning range: FM, MW

Power output: 45 watts per channel into 8Ω (stereo)

Frequency response: 5Hz to 80kHz

Total harmonic distortion: 0.05%

Damping factor: 30

Input sensitivity: 2.5mV (MM), 150mV (line)

Signal to noise ratio: 76dB (MM), 95dB (line)

Output: 150mV (line)

Speaker load impedance: 4Ω (minimum)

Semiconductors: 5 x FWT, 11 x IC, 26 x transistors, 22 x diodes

Dimensions: 480 x 140 x 320mm

Weight: 11.2kg

Accessories: FM T-type antenna



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Reviewed Oct 28th, 2017 by MicTod

The 780 is an amazing performer in a small package, weighing in at just under 25 lbs. I was very surprised by the output of a receiver rated at only 45 wpc, but this unit really delivers with what I call 'beef', meaning the output to speakers thru 25' of speaker wire show very little loss of output as compared to speakers thru 5'. No way can I begin to use all the volume this unit can push. Very good tuner section too. A great old receiver often over-looked by those seeking only raw power. 9/10.

Reviewed Dec 19th, 2016 by HEassa

The SX-780 is generally a good receiver for general use but I can definitely see signs of major cost reductions as compared to its predecessor the SX-750. The major issue is the size and placement of the heatsink.

Instead of the massive extrusion with lots of fins oriented to promote good air flow such as used in the SX-750, the SX-780 uses a smooth U-shaped bent sheet metal oriented in the wrong direction for good air flow.

The impact of this change can be clearly seen in the power rating of the SX-780. It is rated at 45 Watt per channel RMS at BOTH 8 Ohm AND 4 Ohm speaker loads. This, I believe, is not because the amp can’t provide more power at 4 Ohms but is because the heatsink cannot dissipate the resulting heat from a higher output power.

I confirmed this by driving two sets of 8 Ohm speakers at the full power rating as indicated by the meters. Very quickly, the heatsink reached a temperature too hot to touch. To compound this issue, the SX-780 does not have any type of thermal cutout to shut down the unit when over temp occurs. If this overheating is allowed to continue, it would have destroyed the output modules in short order.

So while the SX-780 has generally good specs, I feel that it should not be used in a way to push the power amp too close to its limits. I also feel that the older SX-750 is a much better receiver that is rated at an honest 50 WPC into 8 Ohms and 60 WPC into 4 Ohms with other specs comparable.

Reviewed Jun 28th, 2016 by tutor turtle

Lots of value for the money here. 95dB signal to noise ratio is a very respectable number. 45 watts is more than enough for most spaces and all but the most inefficient speakers. The only weak spot in the entire package is the output devices. Pioneer employed an encapsulated device for entire output section. Very nice when it works, fairly cheap to replace when it doesn't, but you have to have a good tech on tap.

Reviewed Dec 29th, 2015 by shmince

I've had mine since i bought it new in 78/79 as a teenager.Other than having to get new powerpacks a couple of times ,this champ has never let me down.I've never pushed the volume past 6:00.Never needed to as this beast will blast you clear out of the basement driving vintage Jensens.Now i've passed it on to my 22 year old. Worth every penny...

Reviewed Dec 01st, 2015 by kennethwr62

awesome unit

Reviewed Nov 12th, 2015 by VintageRich

Have had this unit since I bought it new in 1978. It has been to college with me, was in my fraternity room for four years, got dragged down to the basement bar for parties along with my Cerwin Vega speakers. it has been a trooper- never failed. It did burn a fuse once, but I replaced the internal fuse and it has been fine since. I did have to clean all the pots with contact cleaner, but never had to re-cap it. Love it, and would buy another in a heartbeat!

Reviewed Jul 21st, 2015 by rtksjones

I bought one of these babies off ebay knowing it didn't work. After replacing the power transformer, repairing the power supply, re-capping it (an optional thing), and replacing the output darlington packs, I have an amazing sounding stereo. I used to drool over these receivers back when I was at Georgia Tech. I had forgotten about them. I am so glad I rediscovered them. This is the best sounding system I have ever owned. If you can get one of these, you won't be disappointed.

Reviewed May 27th, 2015 by Ray S


Reviewed Mar 26th, 2015 by klipschnut

Bought one off of Craig's List as a consolation prize for the SX 1280 I missed; hooked it up to my Klipsch Belles. I just can't believe this is a 45 watt tuner. The sound is very warm and extremely clean. That little tuner drives those great big speakers until its down right uncomfortable, (Could have something to do with the speakers also). A really great buy for $150

Reviewed Mar 14th, 2015 by DjTommyB

I bought a SX-780 new in 1980 and it was fantastic. I don't have mine any more, but I will eventually pick up another one. This receiver is the best value for the money, and it does have a nice warm sound. You'll enjoy this one.

Reviewed Jan 08th, 2015 by PioneerVinyl

This is a great receiver. I purchased mine online after reading several reviews and I am extremely happy with it. I use it all the time with my Pioneer Pl-518 turntable and it sounds wonderful. Nice full, warm, and clear sound. You can't go wrong with this one.

Reviewed Dec 25th, 2014 by timh0722

Yep, this is a great vintage receiver, picked it up at a boy scout garage sale for 40 bucks including speakers and a cabinet. Took it home and it was dead. Pulled off the cover and noticed a series of fuses. Checked and they were all blown which concerned me since it indicated a power surge might have hit it. Replaced them and cleaned it up inside and out. Plugged it in and it lit right up with great sound. I now use it in my man cave and have it hooked to my flatscreen which I found the TV output was a little thin due to the low quality. I resolved that with connecting in an old pc with some DSP software and now its pretty sweet. I am happy since no one likes to use it except me (so its safe from abuse by younger kids...LOL)

Reviewed Jun 19th, 2013 by jarogerson

I have nothing bad to say about this receiver! It is my first dive into the vintage hi-fi world and has been absolutely fantastic. I got this from craigslist off of someone who found it at an estate sale. $60 for the beast and they threw in some run of the mill Sherwood speakers. I got it home and plugged it in...no cleaning or repair, just plug and play! I upgraded to new Sony 4 way towers and the sound is impressive, crisp from a very low volume setting through house rocking volume (which can be accomlished at the 10o'clock setting!). Running my TV/DVD/CDplayer/Sansui turntable through it, with fabulous results. Who needs surround sound when you have Pioneer SX780 Stereo!

Reviewed Mar 13th, 2012 by guest

Pros: Great warm sound, decent power, cool look (UV meters, dude!)

Cons: Power relay tends to go bad, phono stage is a little noisy (but still better than most of the era), pots tend to get scratchy with age

This is a great tuner. It seems to be underrated for the power it puts out (I have no trouble cleanly driving a pair of cerwin vega LS-12's). Sound is decently warm, but can be a bit muddy at times. Overall has a pretty nice sound on a variety of speaker combinations. The preamp stage is better than many other (standard) 70's tuners, but it still has a bit of electrical noise as integrated phono stages tend to have. The tuner portion seems to be a little sensitive, and doesn't really lock in as well as some of the old onkyo's did.



re: SX-780

I still can't get over how great the records sound than cd on this old receiver I have from a swap meet back in 1985

re: SX-780 Speakers

Can anyone recommend some good speakers for this receiver? Both book shelf and full size would be appreciated.

I currently have a pair of Dayton B652's, would those work well?

Recommended Amp Power: 5-40w
Impendance: 8 ohm
Freq Range: 70hz - 20khz


re: SX-780 Speakers

Mine came with Pioneer HPM-40's and they sound wonderful.

re: SX-780 Speakers

Second that. HPM 40 seems like a perfect match for the SX780. Great quality speaker, reasonable price, but harder to find than the more common (but not quite as nice in my opinion) CS series.

re: SX-780 Speakers

I am using NHT 1.3a's ("Now Hear This" - California company) 1991 MSRP $600 (pair). Found on craigslist for $100 with speaker stands. Beautiful sound. Also saw a pair of Klipsch Model: RF-42 II SKU: 1306334301 (149.00 each) - at Best Buy with matching subwoofer.

This receiver sounds great at low volume with any decent pair of wide range speakers. Best wishes for you and yours.

re: SX-780

I have pulled my ol Pioneer sx-780 out of storage and want to set it up. The original speakers are gone but I came across some circa 1967 Pioneer CS-51 bookshelf speakers. The labels on the back say 20 watts and 16ohm.
Anyone familiar with these and would they work with the SX-780? My original speakers were matched to the rcvr/amp
specs but not sure about these. Any help would be appreciated

Re: Pioneer SX-780 Stereo Receiver

Hello All:

My name is Charles, and even though, I do have a more up-to-date "Separates Based" System, I've been toying with the idea of putting together a Vintage Audio System as well. And I am fascinated with trying to put one together as well. I loved these components when they were popular during my youth.

The Pioneer SX-780 was one always one of my favorite models when I was growing up, as it has struck the "Sweet" spot in Pioneer's heralded SX-80 Series back in the late 70's.

I am thinking about either seeking out THIS particular model, or a "LIKE" model Harman/Kardon Twin, Marantz or Sansui model (similar in price and power).

I have never purchased anything vintage before. So then, I have a couple of questions which I want to ask so that I want to be aware and know what I am up against.

And those questions are:

(01). Where do I find these Receivers/Components so that I don't get taken to the cleaners or anything?? Like for instance, what would be the going price for a Pioneer SX-780 Stereo Receiver in Mint Condition vs. one which is NOT in Mint Condition, and if I have to get one which does need some work done to it, what do I need to check for, and if something does come up, do I need to locate a Technician in my area which specializes in restoring older components?? And if so, what would I pay for a restoration (ball park)??

(02). I have checked e-Bay, and does any of you know that they are overpriced or not?? I found a couple of ones on e-Bay which are priced between $300.00 and up to $450.00. That's not too much, is it??

I recall these being only $400.00 when they were brand new back in 1978-79. A "fully" restored one is about that much now on e-Bay.

ANY advice or insight would be appreciated.

Thank You SO Much In Advance.


re: Re: Pioneer SX-780 Stereo Receiver

These were something under $300, new. $125-$150 unrestored, yard sale would be half that. Fully Restored $300 - $400 means all new Nichcon capacitors, NOS Sanyo Darlington pair outputs devices, all switches, relays and pots noise-free. Cabinet and front panel scratch-free. There was a rare option for real walnut cabinet, most came in simulated wood vinyl wrap. How much extra that's worth it to you? Having The Original box (matching serial numbers on box) adds value. That might be where the $450 price tag came from. Condition is everything in this market.

re: Re: Pioneer SX-780 Stereo Receiver

I am using NHT 1.3a's ("Now Hear This" - California company) 1991 MSRP $600 (pair). Found on craigslist for $100 with speaker stands. Beautiful sound. Also saw a pair of Klipsch Model: RF-42 II SKU: 1306334301 (149.00 each) bookshelf style- at Best Buy with matching subwoofer.

This receiver sounds great at low volume with any decent pair of wide range speakers. Best wishes for you and yours.

Honestly, if you use the same "known brand" (ie: timber matched) speakers (ie: same brand) on Channel A & B, this receiver will sound great. Don't pay attention to the snobs - this is a great receiver. I have the 780 on NHT as mentioned and the sx-650 on Realistic Ones'1 and I prefer the "newer vintage" speakers to the older "vintage seakers" by far - this receiver deserves 1990s forward speakers because the receivers did not improve so much but speakers did! Don't be afraid to use more modern combinations!

snhalder's picture

re: SX-780

I love this retro receiver. A gift from my brothers (who thought the old guy would appreciate a receiver that was popular in his youth... ) ;-)
Just replaced the Onkyo TX-8511 in my office with this and really like the sound! Maybe it is just a better match for my ancient Speakerlab S3 speakers, but it is warm and sounds better for all types of music at all volume levels. Though the power output rating is technically lower, it seems to have much more top end - really stunning.

dmeth's picture

Pulled from a shelf in the garage....

So my parents have had one of these receivers in their garage since i was born, along with a pair of bose 301 series III speakers. The receiver was just sitting uncovered in the garage for years. Both the receiver and speakers were exposed to hot (>90) and cold (<32) temperatures, as well as various dusts and aerosols. the first test after hooking everything up yielded impressive results, with next to zero perceptible noise or distortion across frequency and volume ranges. The receiver also powers my sony MDR-V6 headphones very nicely (first time using these headphones with something other than my laptop or a portable device). Overall I am very impressed with this receiver. I was wondering if there is any sort of maintenance i should do considering the conditions in which the unit was stored in for 10+ years without use.

re: Pulled from a shelf in the garage....

The most important thing right away is to blow out all of the dust using compressed air or dust off. I've actually had receivers not working at all because all of the dust causing minor shorting between the components. The unit will also run cooler with the dust removed.

If you know how to solder, it's also not a bad idea to check all of the solder joints for cracking using a magnifying glass. If any is noted, it can be reflow end by applying a small amount of solder paste and reheating. If you decide to resolver the joint make sure you use a solder with lead like 60/40 to match the original solder, and always clean your work using either circuit card cord cleaner or denatured alcohol and a stiff brush.

re: Pulled from a shelf in the garage....

I completely agree on one hand, but on another (as a "way back machine" PC Tech) think that some of that dust is "Magic Dust" and should be left alone... My local shop costs $50 bucks for an accessment = well worth it if you decide to care because they are truly knowledged... just my two cents... this receiver is worth repair...

Pioneer SX 780 question...

I recently purchased a Pioneer SX 780. It had bad sound when tuned to FM stations and barely had any sound when using the record player with it. I replaced the darlington power packs and the FM stations come in with GREAT sound now, but I have no sound from any other imputs. When I switch it to FM, after a few seconds you hear a click and the sound comes on. Switch it to anything else, nothing. Switch it back to FM, and again, after a few seconds, you hear a click and music. Does anyone have any suggestions as to what can be the problem?


Yes I work on them and most of the time, they need cleaning of the selector swhich really good and then it lock in..

Jim Salamoni

re: SX-780 - protection circuit?

Hi. I saw this note regarding a pioneer sx-780. Mine has worked great the last 2 years but now doesn't send power to the speakers. Can you help describe how to troubleshoot? I used to turn on the unit and in 3 seconds or so the protection circuit would turn on and music would play. Now I turn it on and no 2nd sound. I suspect this switch is bad or dirty. I am not an electrician but figure I should be able to figure it out with a little help. Thanks in advance if you have any ideas/diagrams/descriptions.

Bellingham, WA

re: SX-780 - protection circuit?

The output devices are the weak point in this design. Sanyo STK-0050, Have a trusted technician replace both.

Delay in power on and Random Click Off

@hdstonemeister The receiver does have this delay. If you look at the service manual provided on this site, it notes that there is a delay due to the mute switch. I can attest that my receiver has the same behavior with any of the inputs. You turn it on, no matter the position and you get the delay.

I now have an issue where it clicks off, whenever the hell it wants to, in all input positions, and comes back on whenever the hell it wants to.

I feel like the board gets overheated or is overly susceptible to humidity, as it often seems to happen when the humidity has kicked up. Unfortunately I can't help you with your overarching problem, but I hope this helps you in some way. I'm asking my Dad, an 40 yr+ Electrician and Electronics geek to weigh in on mine, so I'll let you know if he has any ideas for yours.

Are your other inputs on when you click the dial over? I've found generally have to be on for you to hear it click onto the selected position. There is always a few second delay.

re: Delay in power on and Random Click Off

The delay is working on mine,only I found 4 fuses inside....It blows one of 4 under the hood..and it is the forth that blows,even after i replace it all the time....will it be worth getting fixed ? or move on to another ......reciever and bury this proud reciever? but i love this one....?

re: Delay in power on and Random Click Off

You have a shorted transistor. Let me see if I understand this, the fuse does not blow until after the delay comes on? or does it blow before then? If this first is true, then you have a shorted output transistor. Either way, it will be inexpensive to repair. It would worth the repair.


Yes, I know there is a "delay", but this takes several minutes sometimes, not the few seconds that the manual states. I found out that the problem may be corrorided contacts within the switches. What I have done is ordered parts to do a complete recap and when I take it apart for that, I will clean the switches completely. Thanks for the help.




I just acquired this from my brother who got it at a flea market. I have not even powered it up but he said it seems to work. WIth the manuals , i will have no trouble checking it fully out.



The manuals you have archived are a fantastic asset to the community. Thank you.

Thank you!

Thanks to the poster. After some 35 years my SX780 quit working, and I hope to get it sorted ASAP with the manuals I just downloaded.

sx 780

looking for the schematics on sx 780

pioneer sx 780

anyone have a sx 780 schematic diagram??



Pioneer SX-880

I'm looking for Pioneer SX-880 and can't find. This is the most similar. Thanks for yours web, allways will be useful.

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