Pioneer SX-1980 Full Electronic Restoration at the Bench

[@ElectronicMechanic50]

I've been a electronic tech for 17 years and your bench/workstation is a work of art and makes me envious

[@NovaluxStereophonic]

Oh thank you! I am Very happy with it. I recently posted a video tour of the whole bench on my channel if you are interested.

[@PrimeHiFi]

Ben, fantastic work on this 1980. Your execution and explanation of the power supply rebuild and modifications was amazing. Taking the time to measure the CCS circuit was very interesting and appreciated. I always admire your technical approach to troubleshooting and repair work. It’s something I need to work on myself, and following along with videos like this “looking over your shoulder” is super helpful. Fernando is lucky to have found a tech as dedicated and thorough as you, even if you only work there part time (which is what I think I remember you telling me). Looking forward to the next restoration series!

[@WA2JPU]

Hi Ben. Its clear that you understand the SX 1980 and all of it's issues. I'm impressed. Keep up the good work.

[@adaboy4z]

I was able to watch the restoration video on Yamaha B2 amplifiers from the individual who restored mine, Peter from Audiokarma. He made several changes in the power supply to negate heat and mods to improve life and function. Its is superb!! Great job on the video.

[@sabrowenie]

My coworkers and I picked up some nice gear when stationed overseas. Went broke saving $$ at the clubs and BX. When vintage became popular many of us pulled our gear out of storage. As a former EE, I could read a schematic and actually solder without burning my fingers, so got asked to get their gear running. Not a serial recapper and had access to a DVM and cap tester. Took one look at an SX1980 and similar Marantz receiver. No flippin way was I going to even open one of those beasts.

[@quiksr20]

Testors flat black works perfect on amp heatsinks and seems to match all vintage matte black parts perfect.. I usually get it in a paint pen but its def my goto.. Awesome video!

[@tomarnold6550]

Amazing work! Keep the videos coming.

[@TommyZTrains]

Thank you !, “I’m not touching a thing”, and when I find someone I will allow them to READ what you’ve written in an attempt to see IF they are the “fit” I need. 😅 THANKS !.

[@jubemarsh2202]

Im blown away brother! 🤙 I would love to get one of these! Thank you for sharing 🇺🇸

[@Thechriskraft]

Great work.

[@poormanselectronicsbench2021]

@ 23:20 A fusible resistor there would be a good idea, especially if it protects things if it blows instead of letting a cascade of failures happen. The only downside is, on Digikey's site, the lowest power value fusible is 1W at that resistance. @ 57:00 Can you tell us what RIAA reverse shaping filter you use? I like the possibility of using a square wave as you did for comparision, and that particular filter looks to perform very well.

[@NovaluxStereophonic]

Fusible resistors are generally frowned upon in audio repair as they tend to drift badly when overheated. Its definitely an option but the EW CCS has been documented to be extremely stable. For the inverse RIAA filter I use the board developed by Hagerman Audio Labs. iRIAA2. Works very well and sounds nice too if you want to feed music into a phono stage at the bench.

[@poormanselectronicsbench2021]

@@NovaluxStereophonic Yes, the lowest TC rating on the Digikey selections are +/- 200ppm/C, so, they may introduce some noise, but the benefit of using them to prevent a full scale "Semiconductor Bar-B-Que" might be justified in some designs. And thank you for the Reverse RIAA filter info!

[@jamiewykes8585]

What Onsemi drivers did you go with? I'm currently considering replacement drivers for the left channel of a big Sansui I'm fixing that uses the 2sc2238B/2sa968B. Also, have you ever used modern devices in place of the 2sc2773/2sa1169 power transistors? this Sansui uses 2 of each per channel. Digikey has some Toshiba TTC5200/TTA1943 that look like possible subs. I'll have to drill and tap the heatsink for the different package. thanks

[@NovaluxStereophonic]

MJE15032/33 work well in this application.

[@NovaluxStereophonic]

I am lucky enough to have not needed to replace 80 series transistors yet in my travels. Xraytonyb is in the middle of restoring an SX-1280 and discusses this a bit. It may be worth swinging over to his channel and taking a look at that series.

[@jamiewykes8585]

@@NovaluxStereophonic Thanks, Those are the drivers I was thinking of too.

[@rossthompson1635]

Great video, thank you. If you had been forced to repair the tone control with the broken (split) shaft, do you have any techniques or tips to try? I have the same issue much further down the range on an SX-550 function selector.

[@TommyZTrains]

Hi Ben, becoming a big BIG Fan and just LOVED watching this !. I do however tho / have a question: I just bought one of these "1980's", and, the reason I selected this particular one, was because it had been totally overhauled & "updated" (amid EVERYTHING having been "upgraded" / ALL redone) ... (again: THAT is why I bought it). FACT: I'm enjoying PERFECT function and operation with EVERYTHING on the thing, EXCEPT for one item: The TUNER. I cannot get over a 1 / to a 1.5 (on the Signal Strength meter), + it will hardly pick-up any FM Radio broadcasts ... and, connecting the supplied "Ribbon T antenna", improves things ...but only just slightly. So, I contacted the Seller (and he's been absol. GREAT), *but, he to is VERY bewildered (claiming it worked perfect when HE HAD it) ... SO: I am now having a bit of 'pause' in my going-after 'resolve', (in what appears to be a positive setting) "help-wise" ... here's why. 1) FACT: I have no intention "burning" this thing all day listening to Country Music on the Radio / or the like ... but like ANYONE, "I DO want and NEED it to WORK" !. An analogy: Like a rear window deicer in an Arizona climate ... "I fully get I'll NEVER use the Radio". Anyway: what I'm hoping is that YOU might be able to give me some sense of direction, in WHERE I need ta tell someone to "go", and I'm not intrigued by leaving the unit somewhere / with someone I don't know. ALSO: let me add the FACT that I have sitting (on each side), both Pioneer SX-880, and a TX-9500 tuner, and BOTH will slam 4's, (but mostly ALL 5's) with so-much as NOTHING even connected ! (just the built-in round FM "barrel" they all had coming from the Factory) ... "WHY" ? ... Does all of this possibly clue you in on anything ?. Lastly: I found an SX-1280 (again: all "overhauled" and upgraded that another friend of mine has) ... and that Receiver (tuner-wise) garners nearly the almost exact-same issue / the same sanero ! ... very little / very few FM radio function, while (again) both units (that I preface above) BOTH slam full 5's just sitting right beside one another / with AGAIN, "nothing even connected" !. ANY HELP / or as IMPORTANT: "advice" would be appr. !. Thanks.

[@NovaluxStereophonic]

Hi, glad you are enjoying the channel. When it comes to pioneer tuner diagnosis I generally ignore signal strength meter results since most of the large Pioneers have adjustment trimmers specifically for the signal meter level. This is supposed to be set to 4.7 for strong signals during the alignment procedure. If this control is accidentally touched or dirty you could easily show poor signal strength on the meter when actual reception is fine. Since your 1980 is also showing poor reception of stations that is the more concerning thing. FM tuner alignment requires specialized test equipment, and more importantly lots of experience. I would recommend looking for a repair shop in your area that has a technician that is experienced in alignments. Look for a shop that has a Sencore SG80, Sound Technology ST1000A, or dedicated HP RF generator. An issue like this needs to be diagnosed on a well equipped bench. I cannot offer much insight here. The 1980 and 1280 both have tantalum caps in the tuner boards which are prone to failure in the form of High ESR. I have never seen one not fundamentally function due to bad tantalums but it is possible. Whatever you do, do not twiddle any of the adjustments on the tuner board.

[@TommyZTrains]

I failed to mention that the RECEPTION is aligned with the issue (I get very few Stations). Also, the pointer (say if your tuned to 96.1 FM) says 97 on the dial (the needle is off), so if you move the needle (manually) to align with "96.1" that's fine and dandy ... (it moves easily on it's scale / or that string), but then; (on the OTHER one or two other Stations up the Band width (say like 102.5 or something) .... then THEY tend to be off !, (the needle) for what little they do in-fact come in ... (I just thought that merited mentioning). The AM is complete static (nothing comes in). Lastly: I printed-off your reply / and IF I can find someone I shall preface ALL your remarks / that which you site. All this is so odd, as I have a Sony "under the counter" Radio that I can't even move a mere fraction of an inch / it gets so many stations. So again: Thanks so much !. Best :- ) @@NovaluxStereophonic

[@richardadelberg8961]

Watched most of it!! I’ll stick to 1250’s or mac4100!