Sir.Byrd
Lunatic Member
Matt,
According to this you are getting about 22.8 mA of current, which is very close to spec. To get current from voltage and resistance you simply divide voltage by resistance, so 15.1/.66=22.878
AU-517 recap and clean-up (with nudies!)
- Thread starter pete_mac
- Start date
Matt,
According to this you are getting about 22.8 mA of current, which is very close to spec. To get current from voltage and resistance you simply divide voltage by resistance, so 15.1/.66=22.878
pete_mac
Super Member
Ok... I'm about to finalise this restoration in the coming weeks. Bourns trimpots are going in, and the fuse resistors will be replaced.
I've also got some 15000uf 63v Panasonic THA caps to replace the standard 12000uf caps at some time in future. I won't do this straight away - skippy124 and I are intending to test the amp on a dummy load to see what power it can put out with the old filter caps still in place, and to see how the rail voltage looks and whether there is any sag etc.
When skippy124 and I recapped the driver boards last year, I used Panasonic ECA (AM) 'audio' caps for the 1uf 50v cap on the driver boards, as I could not source FC/FM caps at the time. You can see it in the pic below (the bright electric blue cap on the two parallel boards mounted between the heatsinks):
This looks like a signal path cap to me... I could be wrong though.
The Panasonic ECA are supposedly an 'audio' cap and I have used them in other amps and they seem to sound absolutely fine to my ears. Longievity might not be so great seeing as they are only 85 degree caps, but then again, the standard caps are all 85 degree in most old amps I guess, along with audio caps like the Elna Silmics and Nichicon Muse etc.
The Panasonic ECA caps are rarely mentioned on this forum. Here are some specs:
http://au.element14.com/jsp/level5/m...=en/388706.xml
http://www.farnell.com/datasheets/319799.pdf
My question is... is it work springing for some Silmic II for these 1uf 50v caps? The Elnas are 85 degree like the Panasonic ECA, but I've recently used the Elnas to replace the orange 'low noise' caps throughout this unit.
Or perhaps some small 1uf 50v Panasonic stacked film caps instead?
Or should I just leave it as-is? Am I simply chasing my tail here, and should I just be content that the old 1uf 50v has been replaced with a fresh capacitor of decent quality, and that the amp sounds fine at the moment?
I guess it's just human nature to wonder whether you might be 'missing out' on something...
I've also got some 15000uf 63v Panasonic THA caps to replace the standard 12000uf caps at some time in future. I won't do this straight away - skippy124 and I are intending to test the amp on a dummy load to see what power it can put out with the old filter caps still in place, and to see how the rail voltage looks and whether there is any sag etc.
When skippy124 and I recapped the driver boards last year, I used Panasonic ECA (AM) 'audio' caps for the 1uf 50v cap on the driver boards, as I could not source FC/FM caps at the time. You can see it in the pic below (the bright electric blue cap on the two parallel boards mounted between the heatsinks):
This looks like a signal path cap to me... I could be wrong though.
The Panasonic ECA are supposedly an 'audio' cap and I have used them in other amps and they seem to sound absolutely fine to my ears. Longievity might not be so great seeing as they are only 85 degree caps, but then again, the standard caps are all 85 degree in most old amps I guess, along with audio caps like the Elna Silmics and Nichicon Muse etc.
The Panasonic ECA caps are rarely mentioned on this forum. Here are some specs:
http://au.element14.com/jsp/level5/m...=en/388706.xml
http://www.farnell.com/datasheets/319799.pdf
My question is... is it work springing for some Silmic II for these 1uf 50v caps? The Elnas are 85 degree like the Panasonic ECA, but I've recently used the Elnas to replace the orange 'low noise' caps throughout this unit.
Or perhaps some small 1uf 50v Panasonic stacked film caps instead?
Or should I just leave it as-is? Am I simply chasing my tail here, and should I just be content that the old 1uf 50v has been replaced with a fresh capacitor of decent quality, and that the amp sounds fine at the moment?
I guess it's just human nature to wonder whether you might be 'missing out' on something...
Pepa
Well-Known Member
Question about posting pics
sansui au 517 part 1
sansui au 517 part 2
Why did you replace the original transformers ??
pete_mac
Super Member
Another piece in the puzzle... some Panasonic THA 15000uf 63v caps. These are a slight upgrade in capacitance over the standard items (15000uf vs 12000uf). Same capacitance as the AU-717.
These can be had very cheaply from Apex Jr ($2.99ea) and based upon the evidence presented to me, they are legit.
The only downside is their size - they are 40mm diameter as per the standard caps, but only 50mm tall. This is a cosmetic issue only. The standard caps are 100mm tall from memory.
The 15000uf 80v Panasonic caps that Echowars used in his recently restored AU-517 are taller (80mm) and look nicer, but I just couldn't pass up the pricing on these caps from Apex Jr.
I don't think that I will fit them straight away. Hopefully skippy124 and I will do some testing after the remainder of the restoration is complete, to see how the amp performs with the old filter caps still in place. We'll then fit these at some time in future (or immediately if any issues are revealed with the standard caps) and undertake the same testing to see the difference (if any).
We'll need to solder on some lugs or ring terminals to facilitate their installation, but it shouldn't be too bad. The two support pins will be clipped off to avoid any confusion or fouling on any wiring etc.
These can be had very cheaply from Apex Jr ($2.99ea) and based upon the evidence presented to me, they are legit.
The only downside is their size - they are 40mm diameter as per the standard caps, but only 50mm tall. This is a cosmetic issue only. The standard caps are 100mm tall from memory.
The 15000uf 80v Panasonic caps that Echowars used in his recently restored AU-517 are taller (80mm) and look nicer, but I just couldn't pass up the pricing on these caps from Apex Jr.
I don't think that I will fit them straight away. Hopefully skippy124 and I will do some testing after the remainder of the restoration is complete, to see how the amp performs with the old filter caps still in place. We'll then fit these at some time in future (or immediately if any issues are revealed with the standard caps) and undertake the same testing to see the difference (if any).
We'll need to solder on some lugs or ring terminals to facilitate their installation, but it shouldn't be too bad. The two support pins will be clipped off to avoid any confusion or fouling on any wiring etc.
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scottrt
Well-Known Member
Those particular caps are at least 2 generations obsolete (i.e at least 2 series of these caps have come and gone since.) So they are at least a few years old. Maybe even 10 years old... I don't exactly know...
Either way, I would expect them to perform much better than your dried out originals. Have you ever cut one of these big filter caps apart and looked at the innards? Some of them are pretty dry. Others loose their electrolyte which corrodes the terminals off (due to the upside down mounting) from the inside-out. Either way, I wouldn't reuse the originals unless original cosmetics are more important.
Scott T.
Either way, I would expect them to perform much better than your dried out originals. Have you ever cut one of these big filter caps apart and looked at the innards? Some of them are pretty dry. Others loose their electrolyte which corrodes the terminals off (due to the upside down mounting) from the inside-out. Either way, I wouldn't reuse the originals unless original cosmetics are more important.
Scott T.
pete_mac
Super Member
Thanks Scott.
The original packing box was dated 18 December 2009, so I am assuming it is either the manufacture date by Panasonic, or the packaging date:
I'm surprised that Panasonic has had two new versions of these caps since that time! I guess they move quickly.
As you say, these would be in far better condition than the originals. EchoWars has also told me to ditch the originals if I'm serious about wanting this amp to last for many years to come, and that makes sense to me.
scottrt
Well-Known Member
I need to 'walk back' my prior comments on age. I hadn't run across this cap in the past because nobody seems to stock it. Further researched convinced me i didn't know wtf I was talking about. It's a great cap, and you got a great price on them.
Hey, at least the diameter means you can use the stock clamps without extra fuss. Half the AU-717 that I've crossed paths with this past year have at least one corroded, leaking main cap. I think you are smart to use them, especially if you like to turn it up now and then.
Scott
Hey, at least the diameter means you can use the stock clamps without extra fuss. Half the AU-717 that I've crossed paths with this past year have at least one corroded, leaking main cap. I think you are smart to use them, especially if you like to turn it up now and then.
Scott
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pete_mac
Super Member
Phew... I feel a little bit better now. Heart attack avoided!
I probably should add a huge thanks to EchoWars for his advice in previous PMs.
Glenn suggested that I be EXTREMELY cautious regarding caps bought from sources that don't buy directly from the factory or distributor. As a result, I did a fair bit of research on the caps and interrogated Steve @ Apex Jr for some time regarding the source and history of the caps. Steve had an issue in the past with a batch of fake Hitachi caps, and as a result I think he is quite particular about who he buys surplus stock from. Personally, based upon the evidence presented to me, I am 100% satisfied that they are legit.
One of the caps was actually dented in transit, so Steve replaced it for me. I might cut open the dented cap and have a peek inside and take some cross-sectional photos.
I just HAD to try them at this price. It was worth the risk. Nichicon Gold Tunes, whilst a great cap, would have cost me $130 landed in Australia. Buying these Panasonics from the usual outlets (whether in the USA or Australia) would have been $70 landed in Australia. These cost me $36 landed from Apex Jr along with about 30 other caps (mainly metallised film, poly caps and orange drops for experimenting, crossover and bypass purposes).
I probably should add a huge thanks to EchoWars for his advice in previous PMs.
Glenn suggested that I be EXTREMELY cautious regarding caps bought from sources that don't buy directly from the factory or distributor. As a result, I did a fair bit of research on the caps and interrogated Steve @ Apex Jr for some time regarding the source and history of the caps. Steve had an issue in the past with a batch of fake Hitachi caps, and as a result I think he is quite particular about who he buys surplus stock from. Personally, based upon the evidence presented to me, I am 100% satisfied that they are legit.
One of the caps was actually dented in transit, so Steve replaced it for me. I might cut open the dented cap and have a peek inside and take some cross-sectional photos.
I just HAD to try them at this price. It was worth the risk. Nichicon Gold Tunes, whilst a great cap, would have cost me $130 landed in Australia. Buying these Panasonics from the usual outlets (whether in the USA or Australia) would have been $70 landed in Australia. These cost me $36 landed from Apex Jr along with about 30 other caps (mainly metallised film, poly caps and orange drops for experimenting, crossover and bypass purposes).