Hi Everyone,
I just acquired an all original vintage Accuphase C-200 preamp. There are a number of film capacitors (1uf or 2.2uf) on the various audio boards, and I was hoping someone could advise on what type of materia these caps would be made from. The brand appears to be "NTK" but I didn't find anything online from that name. I've seen a couple examples of restorations where some of these caps were changed out for modern poly caps, but I thought I should learn more before replacing the originals as I'm sure they were premium parts back in the day.
Thanks in advance
I just acquired an all original vintage Accuphase C-200 preamp. There are a number of film capacitors (1uf or 2.2uf) on the various audio boards, and I was hoping someone could advise on what type of materia these caps would be made from. The brand appears to be "NTK" but I didn't find anything online from that name. I've seen a couple examples of restorations where some of these caps were changed out for modern poly caps, but I thought I should learn more before replacing the originals as I'm sure they were premium parts back in the day.
Thanks in advance
NTK stands for Nitsuko capacitors: https://en.nitsuko-ele.co.jp/product_information/product_list/
P.S. There should be no need to replace what are likely to be metallised polypropylene film capacitors.
P.S. There should be no need to replace what are likely to be metallised polypropylene film capacitors.
Thanks for the reply.
Not long after posting I finally found a thread on another site that discusses these exact capacitors. As I suspected, they are polyester, so not top of the food chain for sonics. I too assumed they would at least be electrically fine (despite being 50 years old), but apparently they are failure prone as well.
Not long after posting I finally found a thread on another site that discusses these exact capacitors. As I suspected, they are polyester, so not top of the food chain for sonics. I too assumed they would at least be electrically fine (despite being 50 years old), but apparently they are failure prone as well.
PETP looks indeed like the most plausible.
Well-made examples can age forever without any problem (think of mustard caps), but others develop problems, with the metallization being eaten out by corrosion. I am not going to name and shame any brand, but prominent examples do exist.
Japanese manufacturers tend to be extremely meticulous and clean, which is essential in this field, but the construction, tape-wrapped and resin end-filled is one of the most vulnerable (boxed types are more durable), which is why it would be a good idea to test one or two of them, to assess their health condition.
Measuring the loss factor is the most reliable method (it should be around 0.4%), but the nominal value can also be used in advanced cases of degradation
Well-made examples can age forever without any problem (think of mustard caps), but others develop problems, with the metallization being eaten out by corrosion. I am not going to name and shame any brand, but prominent examples do exist.
Japanese manufacturers tend to be extremely meticulous and clean, which is essential in this field, but the construction, tape-wrapped and resin end-filled is one of the most vulnerable (boxed types are more durable), which is why it would be a good idea to test one or two of them, to assess their health condition.
Measuring the loss factor is the most reliable method (it should be around 0.4%), but the nominal value can also be used in advanced cases of degradation
Nonsense audiophool babble.
Define "sonics".
Something properly working after 50 years does not exactly sound as "failure prone", does it?
The very thread you refer to (from Audio karma none less, a big red flag by itself) is chock full of nonsense or contradictory "advice".
A few pearls, copypasted literally:
I don't bother checking the capacitors I pull out (which are pulled "on sight")
Even if they are still within spec, they effect the sound, and not in a good way. Just replace them with a polypropylene film cap.
Those flat gray caps are known to be bad caps.
After restoring both with the same components, I did an A/B test between them. The amp with the polyester caps sounded kind of sterile compared to the other. I just replace those flat grays now when I run across them.
been discussed in the Marantz forum before. Fat browns=good,
Flat grays=bad. 😀 some tend to replace the little green "chicklets" also with Wima stack films, etc. But I haven't had one of those test bad yet.
I recapped my b&k amp not long ago and over half of those caps were brown from heat damage yet everyone tested ok. they got replaced anyway.
(apparently some are Brown, no supposed heat damage involved)
I believe one of these flat grays caused some damage in a Luxman tube amp but not sure.
Know it was bad, though. 🙄
<<<<≤≤<
Could go on for hours.
The lack of self awareness must be some kind of record.
Faith trumps visible evidence every inch of the way.
Oh well.
The things you seem to find objectionable were not posted by me or anyone else in this thread. What you seem to be bothered by are some of the comments in a thread on another website, which also happens to include precisely the information I was seeking. If you feel compelled to rant and rave about something someone posted on another site, do so over there so at least the people can consider what you have to say and defend themselves.
Now I think it's time for you to move on and crap one someone else's thread.
Now I think it's time for you to move on and crap one someone else's thread.