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Pioneer SPEC-2 recap and restoration thread!

I have a copy of this original thread and it is missing some of the various members posts (comments ?). Including this post, the count should be up to 29 posts.
 
mattsd said:
I'm assuming you meant the source I'm using for my audio. I use a Raspberry Pi running Moode Audio player with a heavily modded HiFiBerry DAC+ Pro. With properly ripped files from CDs or downloaded high res files, it is the best sounding digital source I've ever heard, and I've heard many well regarded DACs and CD players at Axpona and the CES show in Vegas.

@xXColdShotXx The white covering is a flameproof fabric weave, it covers the resistors to keep them from flaming out if they fail. They used it on the wires and legs as well as a cosmetic touch.
Click to expand...


your work is by far the best I have seen in quite a long time... thank you for re-energizing me.

I have two questions:
1. The "heavily modified HiFiBerry DAC+ Pro" as to what your modifications were and would you stay with the same pcb?
2. Apple itunes and microsoft no longer allow users to rip their music without pain... what application do you use?

Again, really appreciate your openness to share knowledge with us all... thank you. John
 
I have a question on the D2 zener listed, my old SK series book shows a BZ-340 as a 33v zener. The referenced replacement lists a "512-1N5247B" for the BZ-340 on the amp board, but it is a 17v zener, am I reading something incorrectly?
 
Thanks for your quick response, I went ahead and used the 33v ones I ordered.
Also, thanks for all the time you have spent on this post it has saved me a lot of time and research.
I just have one more question I'm all done and It sounds wonderful but my UV meters aren't working, my question is are the WIMA's film caps possibly causing this issue? I've just been listening to it currently I haven't had a chance to get back into that section.
Thinking of putting in some 1uf electrolytic caps in place of. For all I know I mixed up some transistors still need to get back in there and have a look. Any thoughts at this point would be helpful.
Update: Found couple mistakes with the transistors corrected and kept the WIMA's in place.
I have better movement on the watt meters but not what I would expect I don't know this unit was brought to me with the protection light on. Correcting the transistors made it sound even better.
 
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FYI, my Spec 2 from September of 1978 has a 2sc1384 in the Q13 spot on the meter board not a 2SC945.I replaced it with the 2SC2383 . I'm curious about the 1uf WIMA caps also ? I put them . When possible are film caps always the better replace choice? thanks
>>>>> My Spec 2 is the multi voltage model . The relay circuit on the meter board is different also.
 
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Films are best if they can fit in the space provided. Generally, 1uf 50v or 63 volt values will replace the equal electrolytic caps. Once you increase the voltage values on the films, they get big in size.
For the 70's era boards, you replace the 1uf/6.3 - 50 volt electrolytic's and below with film. The 80 era boards will have the room for larger values and in some high-end equipment, are using them anyway.
 
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My multi voltage Spec 2 has a ASR-028 relay not the ASR-015 . Is the LY2-DC48 good for both of them ?
 
calman46 said:
My multi voltage Spec 2 has a ASR-028 relay not the ASR-015 . Is the LY2-DC48 good for both of them ?
Click to expand...

Yes, that relay is fine for both. As far as the caps go, 1uF films are used because it's getting harder and harder to find 1uF electrolytics. The normal electrolytic replacement, the Nichicon KL series, eliminated the 1uF 50v offering they had and now there is just a 1uF 100v, and there is no telling how long before they stop producing that one as well. Another benefit is film caps have very low leakage, which is needed in those positions.
 
The case from the original (ARS-028) won't fit the new replacement LY2-DC48 , the tabs are different . Maybe able to mod case to fit .
 
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Hello @mattsd I am getting ready to start my restoration project on a SPEC2 using your great thread, and noticed a discrepancy in your part list. The list for the meter amp board shows this for Q12, Q14 and Q15:

Q12: 2SC1384: 512-KSC2383YTA
Q14: 2SC1384: 512-KSC2690AYS
Q15: 2SC1384: 512-KSC2690AYS

Is it possible that Q12 should also read 512-KSC2690AYS? Checking the total amount of transistors needed from your BOM list below are the quantities needed for each:

512-KSC2383YTA | 2. These are needed for Q20 on the 2 power amp boards
512-KSC2690AYS | 2. These are needed for Q14 and Q15 on the meter amp board

Is it OK to assume that I need 3 of 512-KSC2690AYS on the meter amp board? Or do I need 3 of 512-KSC2383YTA 2 for the amp board and one for the meter board?

Regards,
Pedro
 
Go with as published - there was a lot of thought put into those choices, after decades of experience..

It devolves to the functions being performed by the individual transistors.
Just because Pioneer came up with a particular transistor for a specific position, time has revealed their engineering's poor choices.
 
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