How to connect 2 Pioneer SA-8500 II

Discussion in 'Pioneer Audio' started by pioneerhip, Apr 4, 2016.

  1. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    Hey Hey!

    So be gentle. Im a newbie... I recently decided to make the move into some quality equipment. I inherited 1 SA-8500 II and a Pioneer PL-520 turntable. I had it paired with some cheapo JVC tower speakers. I started reading about how great the Polk Monitor speakers were. So I purchased a set of Polk Monitor 10A and some of the Polk Monitor 5A. Hooked them up to the system and basically just melted into my couch in my music room. I was blown away! Here lies the problem. They are 6 ohm speakers, and I'm afraid that having them both connected to the amp may have fried it. Due to its age I am ready to do a complete overhaul on it anyway. I also just purchased a SA-8500 II on that auction site and it should be here thursday. My master plan is to use one amp for each set of speakers. So I need both amps.

    My question is this: (finally right) how do i connect the amps so there is a master volume. I do not want to have to adjust each amplifier. Thanks for all the help!
     

     

    Please register to disable this ad.

  2. markthefixer

    markthefixer On Hiatus, dealing with Dad's estate full time Subscriber

    Messages:
    21,149
    Location:
    Bensenville,Illinois
    The aux, tuner and tape inputs / outputs (tape) have a sensitivity of 150 mV, the preamp out and amplifier in have a sensitivity of 1 volt.
    The power amplifier input impedance is 50k ohms, while the preamplifier output drive capability is 2k ohms.

    All that gobbletygook means is that the preamp output is matched to and can drive two sa-8500ii amplifiers, so remove the shorting bars
    from between the PRE OUT and POWER AMP IN and connect a pair (one for left channel, one for right channel) of "Y" wye adapters to
    the pre out and connect interconnect cables to both power amp in inputs.

    It would be a VERY good idea to refurb the power sections including renewing the thermal transfer grease used on the output transistors.
    They can drive up to 75 watts into a 4 ohm load. But the outputs WILL get HOT, thus the preventative maintenance.
     
    pioneerhip likes this.
  3. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    Oh that makes sense. So do you keep control of all the audio dynamics on the second amplifier, but the volume on amp 1 controls both of them? My concern is that the Amp that is driving the 10A's I would want to be a bit more on the low end and the 5A's would be lean more towards the mid to high end.
     
  4. whoaru99

    whoaru99 Epic Member

    Messages:
    40,917
    Location:
    LoTL
    Nope. When connected pre out to main in, the second unit functions as just a power amplifier, doing only what is commanded by the first unit. Adjustments of bass, treble, volume control, etc., on the second unit have no effect on the sound.
     
    pioneerhip likes this.
  5. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    Awesome thanks for the info. Now if i could hunt down the last 4 pieces i need to do the complete over haul on the first amp....ugh. Trying to locate :

    stv-3h
    ECQ-V1H684JL
    ECQ-V1H224JL2
    ECQ-V1H105JL5

    Am i missing a magical website that carries these without having to buy them from the auction site. Mouser is showing not available...
     
  6. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    just spoke with mouser and here are the replacements for the last 3 parts:

    505-MKS20.68/63/5
    505-MKS20.22/63/5
    505-MKS21.0/63/5

    maybe that will save someone some time doing the ol research. I think i got my original list from a markthefixer post. So thanks for that!
     

     

    Please register to disable this ad.

  7. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
    22,034
    Location:
    Glen Burnie Md.
    DIODE check the stv-3H out of circuit. BE EXTREMELY CAREFUL of leg movement. They are unobtainable unless you scavenge them from another unit. SLOW AND EASY does it best. You should get a reading around .500v in one direction and an open reading the other direction. If you get those results there is NO NEED to replace the stv-3h. If you break a leg on one, SAVE THE PARTS, and PM Mark the Fixer. He has a jig he uses to repair them. DO NOT POWER UP FOR ANY REASON with the stv-3h's disconnected. You will fry the amp's.
     
    pioneerhip likes this.
  8. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    I am about to start the daunting task of recapping etc of the SA-8500 II. I have all parts but noticed in the product list given in another feed it doesn't give this upload_2016-4-7_16-55-57.png

    as a part that need to be replaced. Did i miss it in the parts list, or are these caps usually fine to leave untouched?
     
  9. petehall347

    petehall347 the brandy coffee man Subscriber

    Messages:
    28,253
    Location:
    uk.. the middle bit
    are you sure its 0.500 ? i thought it would be around 3 times 0.600 ?
     
  10. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    Okay so taking the advice of Markthefixer im asking before buying / making a mistake. I need the 2SA798 for the power amps. Looking on the auction site i notice plenty for sale, but they all have different "G" values. The one on the actual board is an "83G" do i need to make sure i purchase an "83G" or does it matter?
     
  11. petehall347

    petehall347 the brandy coffee man Subscriber

    Messages:
    28,253
    Location:
    uk.. the middle bit
    2SA798 is obsolete so you need a modern sub for it . its that or pay dear for a trusted original .
    subs are generally better than originals in most cases .
     

     

    Please register to disable this ad.

  12. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    Im good with either solution. A modern sub would work fine. Has anyone found a modern sub?
     
  13. QSilver

    QSilver Super Member

    Messages:
    1,208
    Usually in these type of amplifiers with those special transistors, you can sub it with two gain matched KSA992's but they'll have to share the E or emiter leg hole. But that needs to be confirmed by the other guys. The good thing about subbing it with those is that you can gain mach them and sometimes improve the balance of the circuit more than a "new" 2SA798 would.
     
  14. petehall347

    petehall347 the brandy coffee man Subscriber

    Messages:
    28,253
    Location:
    uk.. the middle bit
    if the dc offset at the speakers is ok i would leave them in place .
     
  15. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    Wish I had checked before I started disassembling the amp. Is there a way to check after parts are removed from the amp.
     
  16. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    So a quick question on the new sa-8500 ii that came in from the auction site. When playing every now and then the amp makes a pop ( I would describe it as an electric pop) then plays for a bit then pops again, and then the amp shuts off and comes right back on. Other than that it slams like an sa-8500 ii should. Any ideas where to start or what the issue might be?
     

     

    Please register to disable this ad.

  17. petehall347

    petehall347 the brandy coffee man Subscriber

    Messages:
    28,253
    Location:
    uk.. the middle bit
    no .it is a balanced circuit and needs to be operating that way
     
  18. QSilver

    QSilver Super Member

    Messages:
    1,208
    You will have to test the DC offset when you reassemble the amp. It sounds like your "new" one might need some work too. I would say there are some transistors on the power amp board that are failng. I haven't looked at the schematic yet but if I'm right, it would be best not to use it until your replaced them as if they do completely fail, they'll take out a lot more components...
     
  19. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    As soon as the popping happened the amp came out of service. So now I'm sitting on 2 SA-8500 II that need a complete overhaul. I'm glad my first recapping attempt is going to be on easy to work on pieces:no:
     
  20. pioneerhip

    pioneerhip Active Member

    Messages:
    175
    Location:
    Texas
    Im getting closer to completing the recapping etc... Can someone tell me if theses 4 need to be replaced? They are circled in Red. Thanks for the help!
     

    Attached Files:

Share This Page