Don't have an address for them really. Have some russian ones I got from e-bay. And there we have the big drawback of paper in oils. If you get NOS there is apparently a big difference in quality...not all paper in oils are created equal. (same for polyprop but I would guess less variation)
Giovanni's suggestion is a good one. Unfortunately most are indeed 1uF -2uF.
tubemaster said:
Try eBay. I got some very nice caps of 40uF, 55uf and 100uF for a very good price. Be sure to just search 'All Categories' as listers put them all over the place.
One important thing to note- get motor run caps and not motor start caps. Motor runs are designed for continuous duty. Also, motor caps will be rated for AC voltage. I've been told you can double that for DC use but I use the AC * 1.4 rule.
I am using salvaged Microwave oven caps in my Parafeed amp. I am using them for power supply filtering. They are rated at about 1500V and look very robust. If you use a CCS source in your design, it is surprising how little capacitance you can get away with in your power supply. The CCS, if good, will supply clean DC at a constant current, so all that heavy duty filtering you usually need for SE designs becomes largely redundant. I do however use two large filtering chokes.
Shoog
Shoog
Excellent question.
My answer is : I don't know.
But like you said reliability is good.
And there is anecdotal evidence that the oil "dampens" leading to good sonic qualities. Why else would a lot of "boutique" caps use oil? Maybe someone in the know can shed some light on this.
The paper in oil thing ...once again...just speculating here..is a tone thing...paper also has better di-electric qualities compared to teflon. But this can only be said of paper with a certain type of "dryness" I suppose.
Last but not least..if using older caps with oil in putting them in your amp will save them from being dumped in some landfill where they will pollute groundwater with heavy metals.
This is the closest thing I have seen to quantitative proof that paper in oil is a good thing:
http://members.aol.com/sbench102/caps.html
I really like polypropylene in oil caps becuase they are inexpensive, easy to get as motor run caps, and relatively easy to work with.
Here is an amp that uses a bunch of inexpensive 10uF poly-in-oil caps:
http://boozhoundlabs.com/monkey/
I also like these for speaker crossovers. You can sometimes get good deals on low voltage (200V or so) Russian surplus PIO caps on eBay.
To me the sound of oil caps in general is clearer, more relaxed, and perhaps tonally a bit darker. Of course meaningfully describing sound is a hard thing to do, so ymmv.
High voltage, low value oil caps like those mentioned in microwave ovens would make great coupling caps, and really great parallel feed caps.
jsn
http://members.aol.com/sbench102/caps.html
I really like polypropylene in oil caps becuase they are inexpensive, easy to get as motor run caps, and relatively easy to work with.
Here is an amp that uses a bunch of inexpensive 10uF poly-in-oil caps:
http://boozhoundlabs.com/monkey/
I also like these for speaker crossovers. You can sometimes get good deals on low voltage (200V or so) Russian surplus PIO caps on eBay.
To me the sound of oil caps in general is clearer, more relaxed, and perhaps tonally a bit darker. Of course meaningfully describing sound is a hard thing to do, so ymmv.
High voltage, low value oil caps like those mentioned in microwave ovens would make great coupling caps, and really great parallel feed caps.
jsn
Hey Bas,
I'm good, thanks. Haven't been able to spend much time on tube stuff lately, but thought I would stop in and see what was going on.
My cats finally clawed up my straight-8 speakers, so I might be building something to replace them. That will be fun.
I'm not sure I have said it directly, but thanks for the Zine. It looks great and the content is first rate. Looking forward to the Xmas edition!
Here is the link for those of you who haven't seen it:
http://basaudio.net/diymag.htm
jsn
I'm good, thanks. Haven't been able to spend much time on tube stuff lately, but thought I would stop in and see what was going on.
My cats finally clawed up my straight-8 speakers, so I might be building something to replace them. That will be fun.
I'm not sure I have said it directly, but thanks for the Zine. It looks great and the content is first rate. Looking forward to the Xmas edition!
Here is the link for those of you who haven't seen it:
http://basaudio.net/diymag.htm
jsn
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.