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To my old ears....ASC's sound 'dirty' in comparison.
Vexungas are available on amazon.
ASC's are still available from RS/allied electronics.
I'm currently a 15/50 uf motor run capacitor in my.."way too simple" 300b amplifier.
FYI....
"Fan" is the smaller value..'herm' is the larger value.
Follow Ups:
have you tried Wima poly caps? 50-400uF?
I've been using their 400uF at 400V and like them.
I also have some Panasonic at 100uF I like.
I like both better than the oilers I threw out. I had GE in 60 through 120uF.
Prefer the Wima.
Sound wise, in power supply meh whatever- but dimensions of the Wima/Panasonic/etc poly caps is much smaller.
I didn't sift through all the Amazon Vexunga results linked below, but the first few pages seemed to either be motor start or start/run types with specific terminals labled.
In years past, posts here cautioned to avoid motor start caps like the plague for continuous high voltage use, as they will self-destruct. I thought I'd post a reminder to anyone new, who might not be aware of that. Search 'motor start' here for more information.
Do you have a link to the specific ones you used?
Hate to bring up an old person but Dr. LoMu was writing about that and was poo pooed. over and over again.
off Amazon is what I used when my AC unit's capacitor went bad a few years ago. I do remember looking at it before installing it in AC unit and thinking if it was good for audio.
For audio, are you talking about coupling duties or power supply duties (probably better here)?
For power supply applications.
Are you just using the larger half or using both halves?
I have not found that with ASC. GE is a fine bet, though I would suggest 440VAC if you can fit 'em. I use MKV 660VAC for coupling caps, and have no issue with their transperancy.
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
'
Edits: 11/06/24
Polypropylene is the way to go. Much lower dielectric absorption than oil caps.
Polypropylene in Oil. I've got a few ASC motor-run caps described in the data sheet as (metalized?) polypropylene in "spearinol" oil. You can feel the oil sloshing about inside the can if you shake it. IIRC, ASC claims the oil provides cooling, environmental ruggedness and electrical durability.
Haven't seen tests for those, but there's no reason to believe the oil would make DA better . I would consider it an unnecessary contaminant for purposes of passing signal in an audio amplifier.
Besides DA issues:
The "oil" may help with piezoelectric effects by displacing any air between plates and adding mass.
We have had problems with Class 2 ceramics at work being piezoelectric enough that you can see the vibration frequency in the RF output to the antenna. The Class 1 ceramics didn't have the problem, but were bigger and more costly.
I've also run into issues with the high CV product Class 2 ceramics where there is both a very strong drop in capacitance with applied voltage and the aging rate (drop in capacitance with time) is higher than the lower CV product Class 2 ceramic capacitors.
Play safe and play longer! Don't be an "OUCH!" casualty.
Unplug it, discharge it and measure it (twice) before you touch it.
. . .Oh!. . .Remember: Modifying things voids their warranty.
Caps are for PS filtering. Depending on one's interpretation of the term "signal path" I would think these caps pass no signal at any time . . . Except maybe the output cap . . .
On a related subject: Capcitor dielectric absorption (da) is frequently cited as a significant source of capacitor "sound" and distortion if excessive. The typical simplified electrical model of da reveals to me how the characteristic could be a real problem in some apps like an analog integrator or sample and hold. But for an AC signal or audio, the means of signal damage isn't obvious. The da models I've seen aren't too complex. So I'm wondering if anyone has ever simulated da effects in spice? Or conducted physical experiments?
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