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quadraphonic

  1. josephdaniel

    A Practical Application For Discrete Quadraphonic Sound in 2026 with Modern Source Material

    Hello all, I have a Pioneer QX-949 that I spent a good deal of time rebuilding and listening to. Since completing the rebuild I have been listening to original source material recorded in quad. The matrix modes are interesting, but not very good and lack good channel separation. CD-4 albums...
  2. choadrocker

    QX-8000 lamp question

    Hello, I'm replacing the lights in my QX-8000 and the fuse lamps and the small bulbs are easy to get to, but I cannot figure out how to get at the screw in bulbs behind the meters. Does anyone have any tips for how to get at them? Thanks!
  3. J

    Harman Kardon 900+ Repair

    All- I have picked up Harman Kardon 900+ Quadraphonic Receiver. I know, I know. But I was able to negotiate a fair price and I couldn't resist. There are a couple features about it that I really like: Quadraphonic / Stereo switch. In the stereo mode, this bridges the amplifiers and give me...
    • Jaman87
    • Thread
    • 900+ harrman kardon quadraphonic
    • Replies: 10
    • Forum: Solid State
  4. hatchley_j

    Fisher 701 quad receiver and XP-7B speakers find!

    Stopped in at an antique store in southeast Ohio while traveling through this week and found a 701 quad receiver and XP-7B speakers for sale, $95 for the lot, cosmetically near mint condition including the walnut veneer case and all of the documentation included. The sticker said that the...
    • hatchley_j
    • Thread
    • finds fisher 701 quadraphonic
    • Replies: 0
    • Forum: Fisher
  5. D

    Marantz 4270 - Very weak left channel

    Hello! I bought a 4270 about 5 months ago. When I bought it, it has a very weak left channel, basically no sound. You have to turn the volume up all the way to get any sound out. Every other channel works fine. After pulling the pre-main bridges and putting the right preamp into the left main...
  6. C

    New Guy from PDX

    Hello. I noticed a new member in here also from Portland Oregon. Hello I am from Portland Oregon and have my dad‘s old Quadphonic 4-way 10 speaker High-Fi and some other components. None of the electronics have been powered up in the last 21 or more years now although the loudspeakers and...
    • Cattoo
    • Thread
    • audionics audionicsoforegon cc-2 hifi jamacspeakers jamac peerless pz3 quadraphonic
    • Replies: 25
    • Forum: Introductions
  7. josephdaniel

    Crazy High 15v DC Offset!

    Working on completing a Pioneer QX949 rebuild. Everything was going smoothly and working well but on the very last part that I was changing (out of the hundreds) something went wrong. Both power amp boards were rebuilt and working fine and within spec. However, whenever I changed the four...
    • josephdaniel
    • Thread
    • pioneeer quadraphonic qx 949
    • Replies: 30
    • Forum: DIY
  8. James Cox

    Check out what I saved from the trash today!

    So my buddy called me yesterday and said he seen his neighbor throwing out some giant speakers and a "Big silver radio thing" and asked if I might want it. I told him I had enough problems but to go ahead and grab it and I'd come check it out. Worse case scenario I'd have some switches and stuff...
    • James Cox
    • Thread
    • 6300 fisher speakers free stuff marantz marantz 4270 quadraphonic trash score
    • Replies: 37
    • Forum: Marantz Audio
  9. T

    Panasonic "Q'Sonic" SA-870

    Otherwise known as the SA-8700 (front panel). I am off to pick up a 1972 / 1973 Panasonic Receiver. I have found (literally) nothing online about this system except a few brief notes. It does not have a "true" Quadraphonic decoder... It pre-dates that by a year. The Q'Sonic coder is actually...
  10. N

    Left front channel dead on QRX-5500

    As you may have guessed from the subject line, I am the proud owner of a sansui QRX-5500, whose front left channel is dead. I've checked everything, its not the speaker, the wire, balanced knob turned the wrong way, or anything like that. The channel is dead on both speakers A and B, and even...
  11. Dckt19

    ST-5v quadraphonic receiver

    Hello It was suggested I post here regarding this obscure kenwood receiver I have. If anyone has any info I would greatly appreciate it. Tuner works but it needs new globes which look very strange and it is filthy. Turntable is missing and dirt was coming through the hole, looks like years...
  12. M

    Sansui QRX-7500 rebuild notes

    Hi all, I thought I'd post these extended notes for posterity sake and hope they are of use to someone else that is in the process of rebuilding this type of receiver. I didn't take the time to include every hoop and hurdle. I also note that I'm no expert but I am willing to go down just about...
  13. bouldersound

    Resurrected Sony TC-388-4

    I finally got tired of looking at my Sony TC-388-4 sitting unused in the closet. I bought it as semi-working in a second hand store and never got around to making it work. I started to tinker with it one night and before I knew it I had the front panels off and the supply hub out. The problem...
    • bouldersound
    • Thread
    • open reel quadraphonic r2r reel to reel sony
    • Replies: 3
    • Forum: Tape
  14. B

    Sansui QRX-7500A channel problem using CD-4/4-CH direct function

    Hi! I thought I had everything tested out and working correctly on my recently acquired Sansui QRX-7500A, but I noticed a problem with something I inadvertently overlooked. The reason I missed it is because I tested out all the front and rear speakers on both the A and B systems, but not while...
  15. goldswimmerb

    Marantz 4300 No sound Front Left

    Hey guys, so this is the same amplifer but a new issue arose... I got both of the back channels working after giving PE01 a full rebuild, however now my front left preamp channel isn't working (yes I tested crossing wires). I know the amplifer channel is good. My voltages on that channel in...
  16. Briant8

    Sansui QRX-7500 channel weirdness.

    Hi All, A buddy asked me to look at his QRX-7500, and this is the channel weirdness going on. When I try 2-channel stereo (front speakers) the left side is strong but the right channel is out. But when I try the quad settings, the rear right side is good but the left side is out. All 4 power...
  17. C

    4 Channel Rear Amp Options

    Greetings! I'm very interested with providing an add-on to my existing audio setup. I already have exceptional equipment, but in order to provide more quadraphonic options such as additional channel separation, and customization, I'm very interested in rear amp options. A few quick details...
  18. N

    My Audio Journey Across North America

    Hey folks, My name is Kyle and I’ve been a big fan of AK for the last few years, as it’s helped me immensely when researching vintage equipment. I’m originally from Atlantic Canada but currently living and working in the South Bay Area (just north of San Jose). I’ve always had an interest...
    • NewScot11
    • Thread
    • canada marantz + 2220b mission 700 pioneer qx-747a quadraphonic sansui lm-330 south bay vancouver
    • Replies: 15
    • Forum: Introductions
  19. M

    Help choosing the best quadraphonic receiver

    I have been using a Pioneer QX-949 as my main amp for several years. I’ve been happy with it, but I recently acquired a Sansui QRX-7001 and a Kenwood KR-9940. All these receivers are quadraphonic. From what I can tell they all seem to have similar features. My question is, which of these...
  20. static_ohm

    Pioneer QC-800A + QM800A / Quadraphonic Question

    Hello! New to the AK forums though I've been referencing them for some years.. I posted this question in the Pioneer forum as well. Not at all trying to spam the rooms- just thought it would apply in this forum as well and potentially be seen by more folks. Anyway- I'm considering purchasing a...
  21. static_ohm

    QC-800A + QM800A / Quadraphonic Question

    Hello! New to the forum.. Considering purchasing a QC-800A + QM800A combo- comes with 4 CS-99As, a PL-61 Turntable and an Akai 280D-SS (4 channel "surround stereo" reel to reel machine). Being sold by a single owner that bought the whole thing as a set in 1972. Very well cared for and in great...
  22. R

    Sony SQR-4750 Quadraphonic Receivers

    A friend has gifted me with two Sony SQR-4750 Quadraphonic Receivers. I have cleaned and deoxed both, and they appear to both have the front left channel blown (very weak, and distorted in two or 4 channel mode, better when outputs bridged). We are looking for the schematic today. Anyone have...
  23. B

    Need help with Sony SQR-8750, Please

    i picked up a Sony SQR-8750 this past weekend. Found it on craigslist for $100. went to the guy's house to check it out. sounded great and very clean (with the exception of some cigarette smell), a little static when some of the knobs were turned (will pick up Deoxit). i then asked what the...
    • barthie
    • Thread
    • quadraphonic sony sqr-8750
    • Replies: 0
    • Forum: DIY
  24. Mikefc

    best match for AKAI-GX280D-ss

    Just finished the repair and set up of a gorgeous 4-track AKAI R2R. Does anyone have an idea of a great 4 channel amplifier to mate this up with. I have a 4/2 mixer but it would be fun to drive four discrete channels..
    • Mikefc
    • Thread
    • akai four channel quadraphonic reel to reel
    • Replies: 4
    • Forum: Tape
  25. QSilver

    QM-800 Help

    I got this today to add to my quadraphonic collection and to maybe try bi-amping some speakers. Everything looks reasonable inside although someone has sabotaged the front speaker outputs. I powered it up and I've been trying to set the offset and idle current but I'm have problems.... I cant...
    • QSilver
    • Thread
    • idle current offset pioneer power amp qm-800 quadraphonic quadrophonic vintage
    • Replies: 46
    • Forum: Pioneer Audio
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