Mystery Capacitor and the Tangent RS4 Crossover


 I have a pair of Tangent RS4s whose crossovers I am currently in the midst of trying to rebuild (Early 80s British 2 way speaker). I used to power them in the 80s with an Adcom GFA1 amp (200 watts/channel which I understand both Bob Carver and Nelson Pass had a hand in designing back when Adcom was based in New Brunswick, NJ, my old home town). Apparently, either time or I did a fair amount of damage to those caps (probably both) and some are hard to id, particularly one that looks like a piece of pink sugar coated candy with green, white and violet stripes? I'm working on a schematic for this crossover so I can get some expert opinion on the project and maybe id the capacitor value by process of elimination. But I am new to this and am learning as I go. If there is anyone out there interested or who could lend some assistance I would be happy to share/learn.
I set out to simply replace the caps but am beginning to question the design and wonder if it could not be improved upon. For starters it seems to have a lot of caps for a two way crossover (8 in five styles), plus 2 resistors and 3 coils. Modern designs I have looked at typically have two or three caps for 2 two way crossover.The drivers and cabinets are in good shape and I have always liked this speaker which sports a 200mm Audax bextrene cone woofer and a 19mm KEF t27 dome tweeter, housed in a nicely crafted 42.5 liter walnut veneered mdf cabinet, all of which has held up amazingly well over the yearsI'll try to figure out how to post pictures to this site if anyone is kind enough to offer assistence.


Ag insider logo xs@2xbruce19
You will note in the picture is the infamous pink mystery cap that prompted the start of this thread, which has since measured at 2.25mF. I’d be curious if there is anyone out there who can tell me that the color code matches my measurement.
The capacitor value is 2,200,000pF or 2.2µF which is within tolerance of your measured value at 2.25mF.

Because the first and second digit both are red (2), that’s why the color band look thicker than other bands. The third band is green (5) represents the multiplier, the fourth band is white represents 10% of tolerance and the bottom band is red = 250V.
@imhififan That is good news to hear your take on the value. The cap was somewhat damaged as I removed it from the circuit board so I was just a bit concerned about whether it would measure accurately.
@timlub What kind of speakers to you build? Do you do this professionally? I also built my first speakers in the 70's, 6x9" with whizzer cones in a shoebox sized wooden cabinet and lamp cord to be used as external speakers run by my parents protable record player. Can't say I pursued it much further when I got a chance to buy some used AR2's I was a happy camper.
Hi, @bruce19 I started modifying speakers when I was a store manager at CMC Stereo. I visited the audiophile shops in the St. Louis area regularly. We had a retail store called SpeakerCraft that custom built speakers. In 1980, I took a job as General Manager at SpeakerCraft, we had a division called Marcof Electronics, we built Moving Coil head amps, cables, modified cartridges, tables and built several Amps and Preamps..
It was there that I established a fairly in depth knowledge of Speaker Design. I had a good enough foundation that over the years, I was able to expand my knowledge to a complete understanding of speaker design. The owner there had and still has a full knowledge, but when I left, I just hadn’t absorbed it all yet. I have done hundreds of repairs and builds in the past years, even here on Audiogon, I have done several modifications, a couple of repairs and a couple of designs for members. In my Listening room, I currently have an MTM with 6.8 inch woofers and a dome tweeter, I have a 3 way with a paper cone 10 inch woofer an aluminum 5 inch mid and a ribbon tweeter, I have a pair with the top end Heil AMT with a 12 inch woofer and I am currently enjoying a 15 inch woofer and 1 inch dome in a 2 way. These speakers are 86 db 4 ohm, 87 db 8 ohm, 94db 8 ohm and 95 db 5 ohm. So, that’s the best I can answer, what kind of speakers I build... As far as professionally building. My 15 inch 2 way turned out so radically good and most audiophiles would not believe a 15 and dome to be able to sound as it does, that I truly explored going into manufacturing. I bought domains, registered a name, but no shows, my industry contacts are as old or older than I am or worst... Dead. So, recently I bailed on that Idea.
Smart move. Many years ago I was in the same situation only with turntables. Used some connections, pulled some strings, got into CES as a vendor with a (very) early prototype. That one long weekend seeing what the business is like from the inside turned me off so much, and happy for it, saved me what would have been an awful lot of emotional and more than likely financial pain. The idea that if you build a better mouse trap the world will beat a path to your door is so laughably off it could be a feature length Monty Python movie.
@millercarbon
I hear ya, I have been to at least 20 C.E.S as a buyer, not as a vendor. Even on my end, it was easy to see how cutthroat it could be from the vendor side. Years ago, Randy Patton who briefly owned Threshold, Sumo, Meitner, PS Audio and a few others, recommended me to Martin Logan. I had a call from them asking me to come interview in Kansas. I had no interest in moving to Kansas and did not go for an interview, but that started me thinking about doing my own thing. I would still love to produce speakers, but as I eluded to earlier, I’m getting older. I would love to market this 15 inch 2 way.... At this point, not likely.