Wrong: "Orange Drop" is more of a branding than anything. They can be polyester (e.g. 225P), polypropylene (716P), or even a mix (PS). Furthermore, the brand has changed hand 3 times: Sprague/Vishay/CDE. Who knows what has changed in the manufacturing process over time.
There's always something to be learned, for those who observe: what strikes me is the fact that all 3 DUT are known to be "good tone caps", and they all have very hard shells, and one of them has the guts glued or fused, so it could not be unrolled. Maybe, just maybe, this has something to do with the tone. I once squeezed a Chinese CBB polyprop cap and couldn't believe the piezo effect, worthy of a ceramic cap! For some reasons, uploading of a video is no longer permitted here, but you can see the spike from the remanence in the screen capture.
There were various types, over decades, called "orange drop", mkt and mkp, they look almost the same, from various producers.
I was referring to the classic product. They were very specific, I know because I used some when they were appropriate. Like all humans, we can be fast and loose with labels. The one shown was a very common type made by several manufacturers, but not like the originals.
All these "tubular" capacitors are wrapped. Every one. So dismantling them showed you a cylindrical wrap. Big shock. The outer covering is tough and difficult to damage. Another real shock since they had to survive industrial environments. So there is nothing in that video a thought experiment wouldn't have revealed, and as I said, destroying a capacitor is easy to do and probably far more informative than watching that video. That's time I'll never get back.
Yes, deforming many capacitors will generate an output voltage. The same occurs with shielded cables, give that a try. The same thing happens when you quickly rotate a plate tuning type capacitor, but to a much smaller degree. This happens in reverse as well (except rotating a tuning cap). Applying a voltage will change the position of the wrap causing mechanical movement. You can hear some capacitors "sing". The effect is more pronounced with higher "K" dielectrics. This is how varactor tuning capacitors work - although they use the characteristics of special diodes to create the capacitor. Now that is pretty cool too, don't you think?
Now that information is far more interesting and informative than showing someone break open and unwrap a capacitor. Thank you for bringing that up, maybe it will form the basis for some to explore further - because that is cool.
All these "tubular" capacitors are wrapped. Every one. So dismantling them showed you a cylindrical wrap. Big shock. The outer covering is tough and difficult to damage. Another real shock since they had to survive industrial environments. So there is nothing in that video a thought experiment wouldn't have revealed, and as I said, destroying a capacitor is easy to do and probably far more informative than watching that video. That's time I'll never get back.
Yes, deforming many capacitors will generate an output voltage. The same occurs with shielded cables, give that a try. The same thing happens when you quickly rotate a plate tuning type capacitor, but to a much smaller degree. This happens in reverse as well (except rotating a tuning cap). Applying a voltage will change the position of the wrap causing mechanical movement. You can hear some capacitors "sing". The effect is more pronounced with higher "K" dielectrics. This is how varactor tuning capacitors work - although they use the characteristics of special diodes to create the capacitor. Now that is pretty cool too, don't you think?
Now that information is far more interesting and informative than showing someone break open and unwrap a capacitor. Thank you for bringing that up, maybe it will form the basis for some to explore further - because that is cool.
I found my original post with the video.
I have a bunch of these Chinese CBB (MKP) caps, ranging from .022uF to 4.7uF and 100V to 2000V, and ONLY the 1uF 400V ones show this effect.
I have a bunch of these Chinese CBB (MKP) caps, ranging from .022uF to 4.7uF and 100V to 2000V, and ONLY the 1uF 400V ones show this effect.
I've been tripped up by this "Orange Drop" thing in the past. The one to have is the 716P polypropylene, but they did apply the trademarked term to a few others. List here- https://www.tti.com/content/ttiinc/...e-drop-polypropylene-film-foil-capacitor.html
And a datasheet for the polyester- https://www.cde.com/resources/catalogs/418p.pdf
Naturally most of mine are polyester. 🙁 But I do have a few of the good ones. 🙂
And a datasheet for the polyester- https://www.cde.com/resources/catalogs/418p.pdf
Naturally most of mine are polyester. 🙁 But I do have a few of the good ones. 🙂
The trade-name started at Sprague around 1960 for a miniature paper+oil/Mylar epoxy-dip capacitor.
FYI: One bit of info to add, similar looking Sprague 715P polypropylene Orange Drops are spec’ed with steel leads.
Sprague 716P polypropylene Orange Drops comes with all copper leads. for the magnetophobic.
Sprague 716P polypropylene Orange Drops comes with all copper leads. for the magnetophobic.
Arizona makes new tubular ones... MKT can sound good despite its esr increase at higher frequency VS other film caps or best lythic smooth foils.
As usual esr is not saying all for how a cap will add its signature in the circuit.
As for loudspeaker filter,'there are very good mkt and sometimes mixed mkt/mkp as Axial CDE 940C.
As usual esr is not saying all for how a cap will add its signature in the circuit.
As for loudspeaker filter,'there are very good mkt and sometimes mixed mkt/mkp as Axial CDE 940C.
Last edited:
Hey on the topic of measurements AND sound quality for the best electrolytic
I have some old (20 years+) and potentially dried out Cathode bypass capacitors :as they are currently soldered next to a cathode resistor that gets hot. (picture from the underside of the amp)
They are 100V 100 uF used on a 211 valve at 1000V anode and about 60V or so cathode.
The existing caps are Rifa at ESR of 700 mH
I as thinking of trying a Silmic II at about 100 mH
and been tempted by a Jupiter Cosmos at 1600 mH by the description of it sound earlier in the thread.
Would ESR have any implication on sound in a cathode bypass location, is low always better?
Thanks!
I have some old (20 years+) and potentially dried out Cathode bypass capacitors :as they are currently soldered next to a cathode resistor that gets hot. (picture from the underside of the amp)
They are 100V 100 uF used on a 211 valve at 1000V anode and about 60V or so cathode.
The existing caps are Rifa at ESR of 700 mH
I as thinking of trying a Silmic II at about 100 mH
and been tempted by a Jupiter Cosmos at 1600 mH by the description of it sound earlier in the thread.
Would ESR have any implication on sound in a cathode bypass location, is low always better?
Thanks!
A family/fans site. Explains this "tone control" (a cheap way to make a switched cap across the final tube plate) and how it bot-strapped the company.
https://www.spraguelegacy.com/partners
The patent:
https://patentimages.storage.googleapis.com/dd/d7/70/2b4a5b57de5a7b/US1675831.pdf
A man was seen in a restaurant with a capicator...I mean a capacitor he doesn't share his roof with.
Another couple at another table is talking and the wife is saying to her husband: "look at the young capacitor our neighboor is dinning with! If his wife knew..."
Another couple at another table is talking and the wife is saying to her husband: "look at the young capacitor our neighboor is dinning with! If his wife knew..."
Hey PRR, I remember that ad! It ran for years! Thank you for the memory.
Hi tonescout,
ESR is measured in ohms. You gave inductance values. When a capacitor is good, the ESR value is not important. Compare it to the other impedances in the circuit to figure that out. Also, don't mount capacitors next to things that get hot. Friendly advice.
Hi tonescout,
ESR is measured in ohms. You gave inductance values. When a capacitor is good, the ESR value is not important. Compare it to the other impedances in the circuit to figure that out. Also, don't mount capacitors next to things that get hot. Friendly advice.
thanks and noted : I meant to write millli ohms and it was late in the day! I am often stupid, and my knowledge is poor but not THAT poor!
I did not mount the capacitor here, it was built by a friend 20 yrs ago as I ran out of knowledge on a design I had started to build. He runs a high end valve amplifier company, and I did recently mention this to him this location and he said "these are great caps, and the specification for use is up to 125 Deg C so they will be fine there"
Good to know I can just ignore ESR in the cathode bypass location and just replace with any of these electrolytic based on sound preferences.
The label on the cap says 105C.
on top of a hot wire wound resistor has to be the worst place to mount a capactor.
If this is an example of his layout and workmanship i’d certainly wonder about his “ high end amplifiers”.
on top of a hot wire wound resistor has to be the worst place to mount a capactor.
If this is an example of his layout and workmanship i’d certainly wonder about his “ high end amplifiers”.
I will not name and shame, but it's an interesting point as the location was noticed by a member of this forum a while back - and to be honest that's where the notion of requiring a change/refresh came from.
His products are in small volumes, and in some cases ludicrously priced e.g. over £100k for a line-level pre-amp, I had always looked at the aesthetic quality of his internal work and his apparent knowledge and to a layman like me I put him into the expert category, but hey 🙂
Unfortunately I am also blind to the circuit as he will not share this with me, but it's a 6C45 driver valve, and valve rectified PS producing 12W at 1000V anode.
Is it easy to confirm if the 100 uF is actually the right value?
Hi tonescout,
No, allowing capacitors to run at higher temperatures is never "fine", especially if it was easily avoided. Failure rates double every 10°C rise in temperature. What does that tell you?
My long experience has been that folks who will not release service information typically have poor designs and huge egos. The layout of that cap is a perfect example of someone who doesn't understand electronics well enough to design anything.
There aren't too many different ways to configure a circuit. It will be simple, perhaps with a stupid twist. There isn't anything ground breaking in the design. The value isn't that critical. Just look at other similar designs to get a feel for component values. There are times a "high end" designer will use far larger sized capacitors than necessary. It doesn't have to be the same tube, just a similar one. Just look at designs that are similar.
I can't tell you how many non-disclosure agreements I have signed and the actual technical content is really mundane. Many times containing basic design errors. But oh! What an industry secret! Always over priced, and always could be reverse engineered (which I have done many times because information was too secret to release). This all falls under "give me a break!" Technical information allows a good tech to save a customer service costs, and to identify possible problems with designs later on.
No, allowing capacitors to run at higher temperatures is never "fine", especially if it was easily avoided. Failure rates double every 10°C rise in temperature. What does that tell you?
My long experience has been that folks who will not release service information typically have poor designs and huge egos. The layout of that cap is a perfect example of someone who doesn't understand electronics well enough to design anything.
There aren't too many different ways to configure a circuit. It will be simple, perhaps with a stupid twist. There isn't anything ground breaking in the design. The value isn't that critical. Just look at other similar designs to get a feel for component values. There are times a "high end" designer will use far larger sized capacitors than necessary. It doesn't have to be the same tube, just a similar one. Just look at designs that are similar.
I can't tell you how many non-disclosure agreements I have signed and the actual technical content is really mundane. Many times containing basic design errors. But oh! What an industry secret! Always over priced, and always could be reverse engineered (which I have done many times because information was too secret to release). This all falls under "give me a break!" Technical information allows a good tech to save a customer service costs, and to identify possible problems with designs later on.
While we're on the topic of cathode bypass, are there any good sounding axial electrolytics?
I have a Leak ST60 I have to fix up. No rush, it's been on my todo list for 40 years.
I have a Leak ST60 I have to fix up. No rush, it's been on my todo list for 40 years.
Any good quality part will sound fine. The output transformer and front end, plus circuit determine how it sounds more than any other part.
If you use poor quality parts, yes you will hear that because there is something wrong. Of course it goes without saying, if the part doesn't fit - don't use it. The higher voltage ratings do generally have better characteristics to a point. So that might be a clue.
-Chris
If you use poor quality parts, yes you will hear that because there is something wrong. Of course it goes without saying, if the part doesn't fit - don't use it. The higher voltage ratings do generally have better characteristics to a point. So that might be a clue.
-Chris