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SPEC 2 Score!

Discussion in 'Pioneer Audio' started by rhodus, Apr 14, 2018.

  1. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    Just got this off the bay minutes ago. It is in protection and has a broken handle. That's all I know right now but as soon as it gets here I will update and add pics. SPEC 2 AK.gif
     

     

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  2. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

    Messages:
    4,924
    Location:
    Las Vegas Nevada
    Tons of Pioneer power. Your going to like it, after you put some magic back in it.
    Matt's restoration thread is about the only info you'll need.
     
    rhodus likes this.
  3. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    Looking at the specs and service manual it appears the power supply of this thing is less robust than an SX1250 yet it is rated at 250w/channel. Is the 1250 really that overbuilt?
     
  4. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

    Messages:
    4,924
    Location:
    Las Vegas Nevada
    I don't see it that way.
    Looking at it in a reliability standpoint using my experience (Which is a handful of Spec 2's and lots of 1250's)
    The probability the Stabilizer goes out on the 1250 is higher than a failure in the Spec power supply but still a rare accourance.
    All the failures in the Spec 2's I've repaired, are related to the driver boards. One Spec 4 had one of the filter caps was darn near short, which is rare.
    Not much of a trend too compare but the PS are pretty well built.
     
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  5. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    Well here it is. I haven't done anything yet except remove the top and bottom covers. The seller was right about the physical condition. In addition to one broken handle there is also damage to the bottom cover and one of the rear bumpers. Nothing that can't be straightened out and there is no internal physical damage that I can see. It looks untouched on the inside. The filter caps have not vented. I purchased 2 handles on the bay, $150, Ouch! This is one massive beast and I can't wait to dive into it. IMG_20180425_160110124_LL.gif IMG_20180425_160110124_LL.gif IMG_20180425_160124292 (1).gif IMG_20180425_160124292 (1).gif
     

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  6. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    Just ordered parts at Mouser using Matt's bom. $235 with tax and shipping. Unit cost with shipping $635 + 2 handles $150. All in $1,020.00 for one bad ass music machine...SWEET!!
     

     

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  7. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    Here is one amp module rebuilt. The original reed relay had an open coil and I was wondering if that might be why the unit was in protection. I haven't removed the other amp board yet. I decided to not replace the sa798s until I finish the other amp board and then check the DC offset, since I have no way of gain matching. Since I plan on keeping this for myself I have some sa798s on the way. 2 from an sx750 amp board and 2 more from Dalbani in Florida. Is it better to stick with sa798s as long as they work or is it better to gain match new transistors? rebuilt spec 2 amp board.gif spec 2 outputs.gif
     
    Last edited: May 20, 2018
  8. slow_jazz

    slow_jazz AK Subscriber Subscriber

    Messages:
    13,859
    Location:
    SE Michigan, Downriver....
    Congrats..

    Best of luck going forward.
     
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  9. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    Thanks! What do you think about leaving the sa798s in as long as they're working?
     
  10. ivandezande

    ivandezande Super Member

    Messages:
    1,793
    Location:
    Twin Cities
    They will go bad/who knows what their performance is now. New silicon, looks like they're replaced by 2 KSA992's. HFE match, glue/heatshrink them together or something and you'll be golden.
     
    rhodus likes this.
  11. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    I've seen a couple of amp board repairs where the bias relay was removed and the contact points on the board simply jumpered. There is an amp board on ebay right now with this repair. Is that a viable option? What is the purpose of that relay?
     

     

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  12. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    I have received some matched pairs from a very generous fellow AKer.
     
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  13. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    After doing some reading about Spec 2 restorations I found a lone, lonely alert by Markthefixer that the pinouts on the replacement ksa733s are EBC, as opposed to the original 733s ECB. I guess because the replacement part number is nearly identical to the original I assumed the pinout would be the same. Very happy that I found Mark's post BEFORE I powered this up. The two things that must be followed are read,read,read everything you can find on AK, and NEVER assume anything. Thanks Mark!
     
  14. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

    Messages:
    4,924
    Location:
    Las Vegas Nevada
  15. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    I don't know. Let me read up on it and I'll get back to you. Thanks for the heads up
     
  16. rcs16

    rcs16 Super Member

    Messages:
    4,087
    Location:
    Baldwin, Ontario, Canada
    KSA733C is the same pin out as 2SA733
     
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  17. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    EBC?
     
  18. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    2SA733.png
     
  19. avionic

    avionic " Black Knights " Subscriber

    Messages:
    44,725
    Location:
    Fort Dodge, Iowa
  20. rhodus

    rhodus Active Member

    Messages:
    237
    Location:
    Denham Springs, Louisiana
    Thanks. That means I have them in right. So what does yta denote?
     

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