AM/FM Stereo Receiver
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
Accessories: FM T-type antenna
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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
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 IOC386
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.