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Scored SX-1080 today!!!

gyusher said:
These guys are getting harder and harder to find in decent condition. A couple years ago you could find mint 850/950/980/1050/1080s for less than 100.00 on eBay. . . Not so today otherwise I would still be buying and selling these old girls.

Take care of these guys they are about gone never to return. . . :cry:
Click to expand...

So I guess I should be considered REALLY lucky that I got my one-owner SX-1050 with manual and schematic for the grand cost of....$0.00?

There's a long story behind that personal gain. But it was well worth it.

Still, congrats on the SX-1080. Looks sweet! And all the information on both the 1080 and 1050 in here is quite interesting.

-Evan
 
One piece of advice - keep it cool! The 80s series had problems with their power supplies, about 95% due to heat. Unlike the big Marantz 2500 & 2600 that uses fan cooling Pioneer just uses those massive heat sinks. Buy (4) hockey pucks and set it on it. That will put it up far enough to get some air underneath and then make sure to keep the top clear of any obstructions to let it breathe. Incidentally, congrats on the find. :thmbsp:
 
Sweet Crooner!!!

That is one sweet SX 1080. Great price too! A keeper!!! Let use know how she sounds and the speakers you are using :thmbsp:

Eric
 
Thanks guys, I'll keep an eye on the heat dissipation. So far it's the regulator board that runs quite hot. The actual power transistor heatsinks run very cool. Of course, I am not cranking her up :D

I plan to recap the voltage regulator board tonight, some of the caps do look quite bad, and probably ready to go.

The speakers I am using are 1987 vintage B&W DM110i's. Excellent two way units that sound very extended and detailed on top. Decent bottom end for a 10 inch woofer.

Regards,
crooner
 
Those regulators...

in the pic are pretty typical of those old units. Many of them ran hot and the boards clearly couldn't handle the heat long-term. One thing I've done is to add more heat sinking onto the existing piece of aluminium - the more metal you can expose to air the better with them. Also, I'd suggest tightening that mounting screw on the TO-220 cases to make sure you're getting the best heat transfer properties. You'd do that if you fit a bit more heatsinking material anyway.

I remember when those boxes used to show up at the back door of the shop - we were totally unprepared to move those huge things around the shop floor back in the day.

Cheers,

David
 
Yes, excellent idea!
I have some extra heatsinks from discarded PCBs. I am going to experiment a bit...

Regards,
crooner
 
Update SX-1080 voltage regulator board

Hi guys,

Finally finished the board. Not all capacitors were replaced, 4 original ones in good condition still remain. A couple of charred resistors were also replaced. Unit should be more reliable.

I tried to add extra heatsinking to the TO220 transistors but I found that the soldering traces on the board are quite weak from heat and this would stress them further. The original heatsinks should be sufficient, hopefully :D

I recommend this job to any potential SX-1080 owners out there. And thanks again to Gonzothegreat, the mighty Echowars, and to all who have responded to this thread.

Regards,
crooner
 
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My 1080 (found at a garage sale for 5 dollars including 4 speakers) runs hot on the reg board so I set a small quiet muffin fan on top to help suck some of the heat out , seems to work OK that way .
 
I was testing her after the upgrades and well... got carried away with the power levels, and tried to match the meters to 120 watts per channel. I blew the 2A fuse on one of my B&Ws. This receiver is one mean beast!

The local rock station was playing some Pink Floyd :D
With compressed FM broadcasts there is very little peak material being reproduced, and it's quite easy to crank it up, methinks.

Well, at least the fuse served its purpose :D

I got some spare fuses from RadioShack and resumed listening, this time at more "sane" levels :)

The receiver sounds very good indeed, specially with quality FM broadcasts like those originating from our local college jazz station at 88.3 MHz. Announcers sound very natural without heavy chestiness. Jazz piano, bass and drums sound convincing. Good cymbals.

At low levels, the bass is there but never overpowering. This is with the fixed loudness compensation and tone controls defeated. Overall, a well balanced unit.
 
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Adding Heat sinks and such...

Me thinks the good people with Pioneer had there stuff together.

One of my SX1250s ( I've got two of em') ran hot to the touch on the port side for whatever reason for over 25 years (since the first day I brought it home) and one day just started to shut off. After a trip to the local repair station, the thing has run cool. Seems a transistor on the bias control was not up to speed. The board was broken down and the faulty part replaced. No more heat problems. Mr. EchoWars 'opening salvo' concerning having Bias set correctly is ... on target.
I've also been concerned about power caps, if the bias will adjust within limits, you are good to go, they may leak, they may puff up like they are ill but (and this is from several sources) very very rarely go bad. If they do, visit with mpercy@pacbell.net. Nichicon 22,000ut x 80V ... 63mmx100mm $31.00 x 4 (for a SX1250) will take care of the problem. I spent over a week
dealing with THIS non problem (more grey hair was all I got).
My tech has 33 years in the same location and 40 in the repair business and has yet to replace the first one. My CAPS look like they are fried but the unit is dead quit and since it has been repaired (once in 28 years), runs cool to the touch even when at high altitude on cruise. My neighbors love me ... but you know this already.

Have a Good German Beer & Enjoy
pc
 
Yes, certainly. These units were throughly engineered. Pioneer knew their stuff.

The electrolytics are long lived. Rarely I have found bad ones in the power amp, preamp and tuner sections. The power supply circuit does run quite warm on these units, and hence the "preventive maintenance" performed in this area.

It should be noted that I detect no audible differences with the new upgraded parts, meaning that the old "tired" looking components were still performing fine. A testament to the quality of the parts used.

The receivers of the mid to late 70s are something special, never to be repeated again. I guess Pioneer and other notable Japanese manufacturers wanted to tell the world, and specially the US consumer, that receivers could be made equaling or even surpassing separate components.

I myself used to be prejudiced against receivers, partly because of the endless commentary from the (now dreaded) glossy mags. But somehow I always had fond memories from the good ol' days. The build quality of old Pioneer stuff has always impressed me. Can't beat the gorgeous metalwork and quality feel these units have.

Now that I have better speakers and source material I know what these units are capable of, sonic-wise. My SX-1080 sounds as good as one could wish for. No audible distortion that I can discern. Great with all kinds of music. Not at all harsh, fatiguing or all those other adjectives the reviewers in the 80s and 90s had for Japanese electronics. Mid-fi definitely NOT!

I have been giving the SX-1080 a real workout today. Everything from the gorgeous vocals of Jennifer Warnes singing Lenny Cohen's songs to the traditional reggae sounds of Jamaica, courtesy of Bob Marley and the Wailers. In all instances, the Pioneer delivers :thmbsp:
 
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24/7

In the late 70s I bought a new SX-1250 and about 6 months later I bought a new SX-1050, the 80s were out and I got them both new at a considerable discount (almost 1/2 price)I kept them both untill about 1992, never a hiccup and the 1050 was a daily driver used all day every day. I never put one in a cabinet or did I put anything on top, however I do put a CD player on top now.

I also owned several seperate systems over those years and any serious listening was done with the seperates. Marantz early then Adcom, Sony ES, Acurus, Anthem and Rotel all came afterwards.

I always thought of the receivers as receivers and I never felt they sounded as good as any of the seperates that I owned. I used them for everyday listening and the seperates for special occasions.

I will say that both those Pioneer receivers did fine with any speaker I put on them including Definitive Technology's BP-20 when it first hit the market before the upgrade that raised the impedance from a little over 2 ohms to over 4 IIRC. I had several good seperate amps that did not like those BP-20s period, they would shut down so out of desperation I tried them on both the 1250 and the 1050 with very good results. Never a hiccup, I dont remember them getting more than warm even.

That one incident made me a believer in Pioneer receivers from that period.
 
The power amplifier sections of the 1050 and 1250 are high-current power amps in every objective sense, having beefy TO-3 devices, ample heatsinking, and most importantly a power supply that can deliver the goods. They weren't marketed as high-current amps as such, but all that marketing buzzword means is an amplifier that can deliver the current that a low-impedance load will attempt to draw from it. Some modern amps sold as "high-current" really aren't in the same league...I hate it when marketing mooks attempt to co-opt Ohm's Law... :rant:

I'd be willing to bet that a 1050 or 1250, after suitable recapping and EchoWars-style upgrading, would hang with any SS separates at the same power level. You might get a little more resolution out of the separates, but I bet it wouldn't be a lot and if you blindfolded everyone all bets would be off. :D

I prefer the flexibility of my Luxman separates in the main rig, but anywhere else in the house receivers rule the roost...handy to have the pre, power, and tuna in one box.

TP
 
The 1080 uses a different encapsulated output transistor. I would assume the 1280 and 1980 use these as well. So far, mine runs very cool with the heatsinks barely warm to the touch.

Sonically, I find the 1080 every bit as good as the SX-850 perhaps even more detailed, with better portrayal of strings and the human voice. The extra power reserves do make a difference in the overall sound.

For what it's worth, I've never encountered a Pioneer receiver with blown outputs. The protection system does work on these designs. Just imagine replacing those carefully matched output devices!
 
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