Pioneer SX-1250 Stereo Receiver Restoration Overview & Demo
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- čas přidán 5. 07. 2024
- 00:00 - Intro
00:56 - General Information & History
02:27 - Front Panel Feature Review & Demonstration
12:12 - Rear Panel Review
16:26 - A Look Inside of The Pioneer SX-1250
22:08 - Restoration Review
32:37 - Cosmetic Considerations
37:04 - Conclusion
Phono input testing music - Courtesy of "Young Elk"
/ youngelkpdx
References:
Orion Audio Bluebook 2001
hifiengine.com
Links:
novaluxstereophonic.com
/ novaluxstereophonic - Hudba
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Amazing detail on this review. I’ve got a 1280 and deciding how thorough I want to go with the rebuild. This convinced me to do a complete rebuild. Excellent video!!!
This video MUST BE the most detail video I have ever seen wonderful thank you for your time and effort to make this video possible doesn't get any better than this
Impressive video and excellent restoration work. I particularly liked the 2.2 uF replacement by WIMA caps. Now that must be an audible change!
Great video and some good tips. Buying one this coming Sunday from the original owner's wife (he passed away some time ago). Looks to be completely original but like you said, those boards are 45 years old now. I plan on a rebuild fairly soon. I completely recapped my Sansui 990 about a year ago and really enjoyed learning it. It sounds wonderful and looks just as good. I think I may get into rebuilding these vintage pieces, but I know I still have a lot to learn.
Thank you for the feedback. I should have a video up soon with some detail on rebuilding the PS and Amplifier section.
What a stunning piece of
stereo equipment.
Excellent video. I have the little brother SX-1050, unrestored, but still looks and sounds good.
Love these kinds of videos.
I have both the 1250 and 1280 including a 1050, 2 x 750's, 780, and a humble 450.
Sx1980 it seems to me the best one..
Very nice review. I have one and I'll never get rid of it. You actually have one more line level input. You can plug a source into the adapter input and use that switch (next to tape 2). The typical use of adapter was for a graphic equalizer, reverb amplifier or maybe a Dolby NR unit.
Great video, love watching quality work. Are the pliers, for actual strains relieve removal.
Beautiful thank you 🙏
Thank you.
Very good review, thanks for sharing this type of information, question: I have a Pionner pax-20G speakers, can I connect them to my SX-1250?
I don’t see why not. They seem to be a high efficiency design though. You may want to engage the -20dB muting control to get a more usable range out of the volume control. Should be fine for the speakers as long as you don’t crank the volume.
If the 1250 had power meters, it would be the holy grail instead of the 1980. Personally, I loved it just as it is. Beautiful example. Thank you for the video.
Yup I think it’s very nice as well. The little nick & marks give it some character.. I have one the same way.
Why I went for the 1080 back in 1988 when I was a Marine in Okinawa, Japan. The power meters did it for me. Can't really go wrong with any of these though.
I have the European twin of the Pioneer SX- 1250 the SX-5590 all black ,.I’d like to make a recommendation for speakers the TeKton Lore with the factory upgrade package is an absolutely fabulous match ..Truly jaw dropping what the SX-1250 mated with this brand of speaker will do especially low octave slam and rumble with gaming and heavy metal rock ect .
I adore the look of the SX-5590. So beautiful !
Thank you for this video. I am a super-fan of the SX-1250! Certainly one of the best receivers (if not THE best) ever made. I was lucky enough to find one for sale a few years ago (before the prices went through the roof) and it's my pride and joy. I'll never part with it. It was really great watching your excellent explanation of all the features of this incredible machine.
I am interested, though, in your comment that the SX-1250 is only compatible with moving magnet cartridges. I have mine connected to a Pioneer PL-530 turntable with a Denon DL-110 (moving coil) cartridge in Phono channel 1, and in Phono channel 2 to a Micro-Seiki model Bl-51 with a Grado Prestige Green (moving magnet) cartridge. I have done A/B comparisons between the two turntables and I honestly can't hear a difference. They both sound terrific.
Anyway, thanks again for posting this video!
I believe that your Denon cart is a high output MC which may be why it functions well in your setup.
@@NovaluxStereophonic I'm sure you're right. I remember that the "MM vs. MC" question was part of my calculations when I was looking for a new cartridge, and that might explain how I wound up with the Denon. In any case, I have no complaints! Thanks again for posting your video. Really excellent!🙂
Muito som amigo parabéns
Recapped my bad caps/trans and have a few show heat stress but tested fine..And fixed few others. Still blows the 12A fast fuse. Any troubleshooting ideas where to start? Thanks love the vids!
Blowing a 12A fuse indicates a serious issue. I would start be removing both driver cards and seeing if it goes through the initial soft start process and protection relay click. If that test passes and your +/- 65 volt adjustments are good then your issue is likely with the driver cards. With that big of a current draw though you could have shorted or backwards main filter caps or blown outputs. If you get really stuck feel free to reach out. I offer card rebuilds and full restorations on this model.
I just had the opportunity to pick up an SX-1250. I have been looking for a nice vintage amp and I was fortunate enough to find a mint condition SX-1250 for a good price. Sadly it does have a problem that was disclosed at purchase. Having other vintage gear I do know they can be repaired and I did not hesitate with the purchase. I do believe this unit is from the original owner and has never been touched for any repairs, the unit barely has dust in the internal electronics. The problem with this SX-1250 is the left channel, It has a loud static popping sound even when the volume is turned all the way down, sometimes the popping stops for a few seconds and then back on and at times you can hear audio with some static. You can also hear the relay clicking/switching on and off. The right channel seems to be working just fine. I am not sure were to begin and living in Denver there aren't any competent vintage techs out here. Any suggestions are greatly appreciated. Thanks
It sounds like there is a failing component in left channel driver card. Likely a signal transistors based on the description. Some basic steps that you could try: Disconnect the preout - main in jumpers and see if the problem persists. If the issue goes away, your problem is actually in the preamp section and a simple cleaning of the controls may temporarily resolve the issue. If the issue continues when the preout main in jumpers are disconnected, its definitely in the power amplifier stage. Further diagnosis requires some safety knowledge and should be done by an experienced technician. I do not know any shops in the Denver area but perhaps some other users may chime in with some recommendations. I am playing with the idea of offering a card rebuild service in the future but do not have the space yet to take on outside receiver restoration work.
Good evening I really enjoyed your video. I recently found a Pioneer SX838 at a yard sale everything seems to be in working condition but if I want to do a complete restoration how much would that cost ?The next question how much of a downgrade is the 838 in comparison to the 1250 ?
Congrats on the yard sale find! I would not personally offer a full restoration on that specific unit as the restoration labor and parts would quickly exceed the value of the unit. If it is currently working, my recommendation is to enjoy it in original condition or try to locate a tech in your area that is willing to service the unit. As far as comparing to an SX-1250 its Apples to Oranges. Although the SX-838 cannot touch the output power and distortion spec of a 1250, it appears to have a lot of good features and a decent tuner.
What about front glass? Easy to replace and find?
I have one of these, the signal needle never moves and the 30hz button when jiggled causes the left channel to static and go very quiet, have to jiggle it again to get it back to normal.
Those filter buttons do get noisy, a shot order deoxit inside will resolve quickly but a fair amount of disassembly is required to get to that board. The signal needle will only move on FM, if FM works fine in stereo and the needle never moves the meter movement may be stuck or something may be wrong with that part of the tuner circuit.
Wonderful video. I have the SX-1250 - and never plan to part with it. I installed an LED upgrade kit for the panel and indicator lights - and I'm happy with how that turned out. The only issue I'm currently having is with the FM muting circuit - which does not function. Regardless of the muting switch position, I hear all the static between FM stations. I'm told this is likely caused by a failed part (Reed relay, ASR-005) but I do not have enough knowledge to properly diagnose it. Using an ohm meter, I checked the continuity of the muting switch to the FM board - but that is as far as I've taken it. Ideas?
If you check the schematic you should be able to trace which pins of the reed relay are used to activate the relay coil. You could measure the voltage there and see if it is indeed changing state when you are locked and between stations. If that is working an relay is not activating you could try to solder a jumper between the contacts to simulate it closing and see if muting works. That would isolate the relay as the issue. Good luck!
@@NovaluxStereophonic Many thanks! Next time I open the unit, I will take another look at that part.
I have the 5590 version, running 4 HPM 100s excellent amp, very powerful!
Can you tell us how much of a sound difference between an un-restored and restored 1250? Thanks
So far I have not come across one of these that was fundamentally working on arrival. If I ever end up with a decently working one in original condition and a restored unit at the same time I will try to do an A/B and share some impressions. My gut says that a fully restored and aligned unit would have better FM stereo performance and be more reliable in general.
I'm restoring a sx 1250 and just finished a sx1280. Can you post the transistor part numbers you used on the stabilizer boards. The 1250 is so much easier to work on! Great Video
A good sub list is readily available on multiple posts on audio karma. MJE15032/33 is what I tend to use for the larger ones.
Is the fm signal about 10 times louder that the aux signal on yours? Also I would like to have you restore mine at some point.
No, the balance between tuner and line level is pretty good on these pieces. If you are using a phone on aux for example those can be a bit quiet. If you try plugging a CD player into Aux you may notice improved level balance.
You can PM me on my Facebook business page regarding restoration.
@@NovaluxStereophonic Very cool. Thank you. Do you restore these?
@@2comicsonabench Yes I do. It’s not cheap but it’s a great investment if your piece is in good cosmetic condition.
how much would a full restoration like this cost? amazing video
Please contact me through my business page on facebook and we can discuss details. Rates can fluctuate depending on parts availability and the condition of the unit.
I recently purchased my great uncle's house and he had this SX-1250 and a RT-707 tape deck in his garage, just sitting after he passed and the house went to my aunt. She moved everything to the garage and rented out the house. The great thing is, it's an insulated garage and they are in the same condition that this one is in. At this point, I'd say the capacitors need a replacement and it may need a calibration but the odds I found about $4 grand sitting in my garage is pretty crazy. I thought about restoring it and selling it but I also have always had an interest in HAM/short wave radio and before I bought the house I even started lightly dabbling in HAM operator's license with a Baofeng UV-5R and online knowledge.
I'm more of a computer/retro video game console repair guy. I can solder and know how to test with a multimeter, etc and reflow cold joints, the works. I'm just curious if it's worth restoring and THEN selling or just selling as-is. I'd say some purists may want it to be all-original, and I can almost guarantee it still is. I haven't opened it yet, but my great uncle was a radio operator and a radio technician so he may have done some repairs on it over the years. He loved to sit and talk on his radio in his free time, though. He even wired speakers into the living room ceiling so he could be hailed while he was relaxing on the couch. 😂
This house is honestly a really cool HAM operator time capsule. Our water heater/utility closet actually has an old desk he installed with tons of old frequencies for local operator friends he had.
Definitely worth restoring but it is not a job for a beginner. I have a video posted outlining the rebuild of the power supply and amp sections. It’s pretty intimidating for a first piece to work on. If it looks to be outside of your skill set it may be worth selling as is.
I am guessing the adaptor was mainly used to put an equalizer in the chain.
Ditto for the RG-1
Clearly you know a lot more about these than I do, but I think you are wrong about the multipath function. To my recollection, the multipath circuit function is to correct the situation where the signal from a single station is arriving by more than one path. FM signals bounce off of structures and it is possible that one path is significantly longer than another. In that case, they will arrive at slightly different times, one appearing as a ghost to the other. I don’t know how the circuit works, but it somehow filters the ghosts out.
I have an immaculate SX-1250 that I bought new. It worked fine last time I used it but it has not been powered on for at least six years. I’m considering taking it to a local audio shop to have it gone over and restored as necessary. I’m NOT going to power it on until I have that done.
You are absolutely correct regarding multi path.
Color me dumb, but I've not heard of a 'stabilizer' board. What does it do? Also, missed a solder connection at 32:26. lol. I know you caught it, just teasing.
Pioneer refers the regulated power supply board as the “stabilizer,” it provides regulated +/- 65V along with other misc. regulated voltages for various circuits.
That’s a keen eye on the solder joint. That picture was taken before that board was removed from the chassis. I think I had tried to replace a couple of components while it was hanging in the chassis and quickly realized that it was much easier to undo the connections and pull the board. I just chose that still image as it clearly showed the black and blue lamp wires under the board.
@@NovaluxStereophonic Ah, I see. Suprised I've not heard that term before. But then at my age, I'm forgetting a lot fast. lol. (Except I still have a keen eye for techy stuff.) I appreciate the quality and depth of your videos. Thanks, Ben.
What is the price range for a complete rebuild on one of these?
This depends on the electronic and cosmetic condition of the unit and the going rate for bench labor in your specific area. If you are local to NYC and are interested in a full restoration you can reach me on my Facebook business page to discuss.
I guess the stereo light only works in FM? Thats weird though as I thought mine was malfunctioning.
On some receivers the stereo light indicates stereo or mono operation for all sources. On the 1250 it is just an indicator that the FM tuner is receiving a stereo multiplex signal.
Pioneer stereo receiver,
from the seventies correct?
Roughly 1978
I just bought one but will not power on what could be problem ?
It could be anything really but chances are if you are getting no lights, no relay click, no movement of the tuning meters, one or more of the fuses has likely blown. If this is the case, replacing the fuse has little chance of fixing the issue. If you do not have experience working on audio electronics I would encourage you to take it to a qualified professional for diagnosis.
@@NovaluxStereophonic thinking about buying this 1050 also. Do you think the filter caps are bad? It looks to be leaking or may just be dust but I also see some rust on the back screws.
You seem very knowledgeable so I thought I’d ask you.
www.ebay.com/itm/154476543272?hash=item23f784fd28:g:FgkAAOSwBxJgtD~3
@@coreysykes6222 Sorry, I am cutting it a bit close. From the bottom they look fine. The top you may just be seeing the shrinkage of the outer wraps exposing the glue that holds the plastic cap in place. Hard to tell without actually disconnecting from the circuit and measuring on a quality capacitor analyzer.
@@NovaluxStereophonic thanks for all the info you helped me with appreciate it
I can't get 0 volts on one of the amp boards. It moves up and down erratically to 1 volt
That amp card likely needs service. Could be an issue with the differential input pair or other out of spec components.
@@NovaluxStereophonic I do have a filter cap that looks like it leaked out goo some time ago from the middle .
Hey where are you located?
NYC
I was told that the heat sinks are not aluminium, but pot metal. I always thought they were aluminium.
Glad I could help…
is 1500$ to much for one? and would be getting a 1050 for 700$ be better?
Price depends greatly on cosmetic condition and if it has been restored or serviced. The pieces higher up the line tend to fetch higher prices in the long run, however the 1050 is still a great piece. I would look out for one that is in good cosmetic and electrical condition that you like the sound of. If it’s simply an investment piece go for the 1250, 1280, 1980, etc.
@@NovaluxStereophonic I think i will be buying a 1250. I think they will only go up[ in value so might as well get one now before they are to expensive
@@NovaluxStereophonic What would cause this problem "It will play for about 10 to 15 minutes and then the right channel will quietly stop working, But if you then power off and let sit for awhile the right channel will work again"
@@chrissieser5659 Hard to say for sure without looking at it but that symptom sounds like either dirty controls that need to be cleaned or intermittent protection relay contact. If turning the volume up a bit causes the dead channel to kick right back it it’s probably the relay. Best to track down a good local tech and have the unit serviced.
@@NovaluxStereophonic Thank you
Pioneer should come out with a sx 2050 350 watts per Channel and kick audiophiles in the ass
I can get 100mv though.
Ben, where are you base? Are youin Australia ?
NYC USA
What about front glass? Easy to replace and find?
No easy to find an original but there is no lettering on the glass so a replacement can be made if you have a local shop that cuts glass.