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Pioneer SPEC-1 Restoration

xoaphexox

xoaphexox

Supernatural Anesthetist
Continuing the restoration of several Pioneer pieces. Tonight I finished the SPEC-1.

1. Replaced electrolytic capacitors >3.3uF with Elna Silmic II / Nichicon Muse FG/KZ / Panasonic FC depending on where they are used
2. Replaced caps <=3.3uF with WIMA MKP polypropylene caps
3. Replaced stock diodes with Fairchild Stealth super fast soft recovery diodes
4. Replaced every fuse
5. Reflowed every solder joint
6. Stripped and cleaned chassis with ammonia free windex and Mother's chrome polish
7. Replaced MY4 relay and reed relay with new units
8. Deoxited controls
9. Replaced 8v incandescent power lights

It went really smoothly - only the SPEC-4 unit to restore before my entire rack is complete (see thread http://audiokarma.org/forums/showthread.php?t=263724).

I have been at this for two months - I have never heard SPEC gear before - I am excited to see how it compares to a restored Sansui CA/BA-3000 rack and a Kenwood 700M/700C rack!

:music:
 

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Nice job . What are part numbers for the Fairchild diodes and the replacement MY4 relays ? I have replaced all the electrolytic and film caps(to polypro) in my Spec 1 .I was really surprised how good it sounds especially the phono stage.My Spec 4 restore didn't go well.
 
Its your usual omron my4 dc24v relay - this is only used in the mic mixing board. The reed relay is also a 24v model, same one I used in a sansui ca-3000. They don't often go bad but replacing relays is a habit I have. The giant output relays were never used so I left them alone. The diodes are 8a 600v stealths but that's just because its what I had on hand from previous restorations. I plan to listen to this for a bit and I already have the baggie of parts made up to replace all the power supply transistors with low noise replacements and new bourns trimpots. Surprisingly the operating and service manuals don't mention the adjustment procedures but I am getting 48v steady so I left these parts alone for now. I was anxious to get finished with this project so I didn't replace every part at once : )
 
The right side output relay sticks on mine Spec 1.I have to crank it up then it engages . The meters on the Spec 4 keep moving but no output so I figure it might be the output relay. Thanks for the info .
 
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Sure, I was responding from my cellphone hence the rambling.

The diodes were probably these ISL9R860P2-ND (digikey) although this FFP08S60SNTU-ND is faster
The reed relay was this Z649-ND
The mic relay was this Z2634-ND
 
As a side note, I went through the painstaking (and expensive) conversion of every mylar cap to polypropylene in my Sansui CA-3000 and have always wondered if it was 'worth it'.

Did you listen to your SPEC-1 before and after the mylar to poly conversion? If so, could you elaborate on whether you heard any sonic differences? I can never leave well enough alone so one day I will probably inevitably perform this 'upgrade' but I am curious as to whether or not the tighter tolerances are actually noticeable.

Thanks!
 
I thought the Spec 1 before the change was a little on the harsh/bright side .But the unit is 30 years old .So did it sound like that when new ? .I changed all the mylar caps to Panasonic ECWF and Z type. My Spec 1 now has a very detailed sound when I used it with the Spec 4 and a pair of Snell C V speakers. Used the Z (50v)type caps in the tone control .These caps can be used in Dolby circuits are a 1% tolerance .So like you that can't leave well enough alone I put them in. Unfortunately my Spec 4 crapped out after a week so I couldn't do a good break in period. I'm working on the Spec 4 now.
 
calman46 said:
I thought the Spec 1 before the change was a little on the harsh/bright side .But the unit is 30 years old .So did it sound like that when new ? .I changed all the mylar caps to Panasonic ECWF and Z type. My Spec 1 now has a very detailed sound when I used it with the Spec 4 and a pair of Snell C V speakers. Used the Z (50v)type caps in the tone control .These caps can be used in Dolby circuits are a 1% tolerance .So like you that can't leave well enough alone I put them in. Unfortunately my Spec 4 crapped out after a week so I couldn't do a good break in period. I'm working on the Spec 4 now.
Click to expand...

Yes - I love the little ECQ-P(Z) poly caps - I use them in all my restorations :music: They get a little large in higher values though so I use the WIMA MKP box caps - if I have the space, I will use something even larger like solen/dayton/jantzen but I think that's definitely in the area of diminishing returns.

If I was bill gates I would use V-Cap Teflon for everything! :)
 
calman46 said:
My Spec 4 restore didn't go well.
Click to expand...

Me neither - it's killing me. It's been at a techs for a while and is coming home this week unrepaired. I am anxious to get it working because the rest of the gear just sits there unused without the power amp. :tears:

Is yours working again yet?
 
Yes it is (so far ) I haven't really got a chance to play it for a few hours yet. It sounds very good though. I did the Ecluser Mod for the DC offset. One board takes longer to settle down but they both due and end around 2mV. What was wrong with yours again ?
 

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That is a wonderful looking collection of gear! I'd bet it sounds amazing.

The SPEC-4 is at house awaiting repair. I don't know what is wrong with it. First my tech friend and I thought it was transistors, then relays, then the transformers. The thing just likes to blow fuses.
 
thanks, it as a very detailed sound to it(Snell CV's maybe) .The spec 1 phono's stage sounds great . Yours shouldn't be to hard to fix . What fuses blow ,do they blow right away ? Don't forget to check the AC cord . Have you tried the Dim Bulb Tester ?
 
I got my SPEC-4 back from Echowars and it works like a champ.

I now have the SPEC-1 back on the bench to replace the diodes and I am working on a parts list for the mylar-to-poly tone control swap we discussed.

Unfortunately I only have about half of these values on hand in ECQ-P(Z) and it's a discontinued line - now I don't have a place to source the remaining values.

I have some of the larger ECW-F (250V) caps but they are physically too large to fit between the wafers of the tone control switches.

What is a guy to do?!
 
xoaphexox said:
I got my SPEC-4 back from Echowars and it works like a champ.

I now have the SPEC-1 back on the bench to replace the diodes and I am working on a parts list for the mylar-to-poly tone control swap we discussed.

Unfortunately I only have about half of these values on hand in ECQ-P(Z) and it's a discontinued line - now I don't have a place to source the remaining values.

I have some of the larger ECW-F (250V) caps but they are physically too large to fit between the wafers of the tone control switches.

What is a guy to do?!
Click to expand...

You haven't been perusing Mouser lately???????? They've picked up a lot of film caps. Panasonic, and the established Cornell Dubliers that are in stock.
 
markthefixer said:
You haven't been perusing Mouser lately???????? They've picked up a lot of film caps. Panasonic, and the established Cornell Dubliers that are in stock.
Click to expand...

I have - Digikey and Mouser are the first two places I always check. Perhaps I was searching in the wrong category - I was looking under 'Polypropylene Film' capacitors of the Panasonic varieties (only ECW found). I did find a few values, but a very small fraction of what is needed for the project.

Do you know offhand the model of Cornell Dublier caps you are referring to? When I search on them a very small set of values is returned.

Maybe it's the 'Polypropylene Film' cateogry itself that is preventing me from finding the values I need? I was under the impression this would be the best technology to use - I don't think there would be any benefit to replacing mylar with mylar :scratch2:
 
Well, there is metalized polypropylene, but also metalized polyester.

and Evox Rifa / Kemet at Mouser, for the first spec-1 mylar value I grabbed, 0.0018uf

But with some of these values, you may have set yourself an impossible task:
pF
1100 1000 to 1200
1800
2400 2200 to 2700
2700
3600 3300 to 3900
3900
4700
5100 4700 to 5600
5600
6800
7500 6800 to 7800
8200
uF
0.016 0.015 to 0.018
0.018
0.03 0.027 to 0.033
0.036 0.033 to 0.039
0.047
0.051 0.047 to 56
0.068
0.075 0.068 to 0.082
0.1
0.13 0.12 to 0.15
0.16 0.15 to 0.18
0.22
0.47
 
Ahh that is what I was afraid of. Would there be any sonic benefit to recapping the ones I can find and leaving the rest alone or is that just a pointless exercise?

Luckily I was able to find all the values I needed for the Sansui CA-3000. I really like the way that turned out so I was thinking I would do it to the SPEC-1 but I can live with it the way it is.

Thanks, Mark - always a lifesaver with Pioneer!
 
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