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sx-780

  1. merlynski

    SX-780 Refurb BOM to vet

    I have assembled a BOM for the AF board (GWK-118 only) in the SX-780 for vetting if anyone is willing to look it over. It is not intended to include the STK0050s, the protection relay, front panel controls or the Tuner board parts. I have collected these from multiple posts and old lists on...
  2. Kingbleu

    Pioneer SX-780 need help signal tracing. Powers on no sound. Darlington packs are good.

    I have a Pioneer SX-780 that powers up but produces no sound and no relay click. The STK's (Darlington power packs) are good. I would like some help tracing the signal. I have test equipment that I have picked up over the years. Mostly at garage sales or Craigslist. I have two SX-780's one...
    • Kingbleu
    • Thread
    • no power pioneer sx-780 signal trace stk-0050 sx-780
    • Replies: 78
    • Forum: Pioneer Audio
  3. mykidsbutler

    SX-780 unsteady DC Balance

    Working on a SX-780. Originally had a lot of distortion. Deox’t. Did a recap and replaced some transistors. Everything I have done has improved the distortion to the point were it is barely noticeable. Last thing I did today was to recheck the DC balance. The balance now swings anywhere from 30...
  4. merlynski

    SX-780 project: relay question - resolved

    I am working on an SX-780 that I had happily playing in my motor vehicle (hobby) repair shop for many years. It began having a flaky left channel, then quit completely. I put in an SX-650 I had on hand as it replacement. I am now in the middle of the SX-780 repair. Somebody in the past...
  5. C

    SX-780 Protection Relay Chatters on Startup

    Hello, I have a Pioneer SX-780 that I bought new in 1980 and worked well through the late 90's when it was relegated to a closet. I have since dug it out and I am using it in my office where it works beautifully except for one issue that is more bothersome than anything. On startup the...
    • cgtuttle
    • Thread
    • delay protection circuit protection relay sx-780
    • Replies: 7
    • Forum: Pioneer Audio
  6. T

    Pioneer SX-780 Powers On, No Sound

    Good day Audiokarma, Recently bought an SX-780 for little to nothing knowing it was dead and was wondering if I could get it working, however I don't know where to start. The symptoms I see so far are: - After power on there is no relay click at all from the protection circuit - The lights...
  7. C

    SX-780 - Counterfeit Darlingtons?

    I have a Pioneer SX-780 that was blowing a main fuse (#4 - 4A I believe). I removed the power wires going to the Darlington outputs, replaced the fuse and the unit powered on and lit up AND the speaker relay clicks. Great, right? So, I went to eBay and bought some replacement STK-0050's ($15...
  8. cwh

    Component replacement challange, informed upgrades to an Sx, paging Leestereo

    Currently a parts changing enthusiast who is slowly going down the road to audio electronics proficiency. Or at least "I fix more than I destroy." I just pulled down from the shelf an SX-780 project that's been waiting for a rebuild. Forgot how clean it is, pleasant surprise. Worthy of...
    • cwh
    • Thread
    • pioneer sx-780 upgrade
    • Replies: 63
    • Forum: Pioneer Audio
  9. S

    SX-780 Resistors

    I have a project of restoring my SX-780 in which I am in no hurry to complete, just having fun doing so. I am concentrating on my Tuner assembly board first. I got this receiver from someone in Texas, I took a photo of it, notice how dirty the board is, at first I thought that was dust, but it...
    • SargentRicko
    • Thread
    • pioneer pioneer resistors pioneer sx-780 sx-780 sx-780 resistors
    • Replies: 10
    • Forum: Pioneer Audio
  10. M

    magic fingers

    I have a question about a Pioneer SX-780. I checked one out that a guy was selling on Craigslist for 175 Firm. It appeared to be functioning correctly, but when the tuner was on (FM) and I touched the top or back of the unit, the reception would cut out for a second or two. Actually, I could...
  11. B

    New SX-780! Metallica killed (most) all of it : (

    So, I pick up a Pioneer SX-780 the other day on the side of the road for $10! Score right! Well, I take it home, plugged it up, hook a lamp cord to the antenna connections and by gosh the dang thing worked....well even! So...the radio got old quick, and I had this Gerrard turn table with a...
  12. R

    STK-0050 replacement for SX-780 and others

    Their has been a bit of interest for a replacement of what was the original Sanyo STK-0050 module used in a SX-780 receiver. Many question the integrity of what can be obtained these days as STK-0050 modules. I decided instead of sending these files to individuals or trying to make a buck from...
  13. Bigreddog

    newby here from MS

    Greetings all from the state of Mississippi! I just recently found this forum while researching/shopping for a vintage stereo receiver and turntable. A little history: I purchased my first system at age 13 from Randy Hooper at Hooper Sound in Meridian, MS in 1978. Here is the setup including...
    • Bigreddog
    • Thread
    • hitachi hpm-100 pioneer receiver sx-780 technics vintage
    • Replies: 17
    • Forum: Introductions
  14. T

    Lights up, but no sound from Pioneer SX-780

    when i got home earlier today i went to listen to a record i got in. the receiver was working fine, besides the right speaker was only making a distorted static noise. i then turned the receiver off and checked the wires on both sides. when i turned it back on there was no sound at all. i don't...
  15. Germ_nation

    SX-780 losing left channel

    I acquired this receiver about a month ago and immediately opened it up and did a deoxit cleaning. The past couple days I have started to lose the left channel. At first I thought it was just happening through the phono but now it's starting to happen on the aux also. It sounds like static or a...
    • Germ_nation
    • Thread
    • pioneer sx-780 sx780
    • Replies: 6
    • Forum: DIY
  16. SX-780

    SX-780

    Pioneer SX-780 with new wood Case.
    • strader61
    • Media item
    • pioneer sx-780
    • Comments: 2
    • Media category: Pioneer Gallery
  17. Old school is the best

    Old school is the best

    Pioneer SX-780 found on Ebay for $59.00. Intermittent operation but cosmetically nice. Found a cold solder joint on a voltage regulator. Replaced the component and resoldered. Cleaned, deoxit, tuned DC voltages, set meter's according to manual and Bada Boom!.. MUSIC. Not just music but...
    • rkeller
    • Media item
    • 721 dual pioneer sx-780
    • Comments: 0
    • Media category: Member Galleries
  18. Poor man's pleasure

    Poor man's pleasure

    My computer room listening. Pioneer SX-780 (fixed myself), CS-88A's (Epay special), Sony walkman source.
    • griz780
    • Media item
    • cs88a sx-780
    • Comments: 2
    • Media category: Member's Systems
  19. My Room

    My Room

    1976 Klipsch La Scala speakers Pioneer SX-780 Receiver Pioneer PL50 Shure M44E Pioneer CT-F9191 Cassette Jensen TF-3 speakers Teac A-2070 Reel Teac AN-300 Noise reduction
    • bigolhorns
    • Media item
    • klipsch lascala pioneer sx-780
    • Comments: 0
    • Media category: Member's Systems
  20. My poor lonely SX-780

    My poor lonely SX-780

    • Blue Meanie
    • Media item
    • pioneer sx-780
    • Comments: 0
    • Media category: Member Galleries
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