After reading quite a few threads in this and other sections of this forum, I get the feeling I may be getting in over my head. You guys and gals speak a language that I just barely understand a little bit of. Most of it is martian. But here goes anyway!
I have a pair of vintage 7 Kappa Infinity speakers. I've had them since new, and have been listening to them almost daily since 1987.
Recently my Emit k tweeters have lost their "presence" in the room. They still kinda sorta function, but not nearly at the level that they used to. Essentially I have lost the highs. I've tried a couple of different amps, preamps and sources with the same results. So I think I have crossover issues on the high side.
With plenty of information out there on what WAS used to build the Infinity crossovers, you'd think that a simple swap of the caps would put you back into the easy chair. Well, not so much, especially armed with very limited knowledge.
The spec. sheet drawing calls for two parts- a 4uf Solen polypropylene cap and a 0.01uf PP Wonder cap. So far I can source neither on my own. Soooo... if they cannot be replaced in kind, I will need/want something fairly close, I think. But knowing very little about sourcing audio parts, I will rely on you professionals to hopefully steer me in the right direction.
Do you know, or have an opinion of where I might find an "equivalent" to the two caps above, or what it might take to get close to those values or characteristics?
Sure do appreciate any information I can get about this dilemma. While it may not be flashy, fancy or expensive, this old stereo and I go way back. I really don't want watch it die yet.
Cheers,
Mark
I have a pair of vintage 7 Kappa Infinity speakers. I've had them since new, and have been listening to them almost daily since 1987.
Recently my Emit k tweeters have lost their "presence" in the room. They still kinda sorta function, but not nearly at the level that they used to. Essentially I have lost the highs. I've tried a couple of different amps, preamps and sources with the same results. So I think I have crossover issues on the high side.
With plenty of information out there on what WAS used to build the Infinity crossovers, you'd think that a simple swap of the caps would put you back into the easy chair. Well, not so much, especially armed with very limited knowledge.
The spec. sheet drawing calls for two parts- a 4uf Solen polypropylene cap and a 0.01uf PP Wonder cap. So far I can source neither on my own. Soooo... if they cannot be replaced in kind, I will need/want something fairly close, I think. But knowing very little about sourcing audio parts, I will rely on you professionals to hopefully steer me in the right direction.
Do you know, or have an opinion of where I might find an "equivalent" to the two caps above, or what it might take to get close to those values or characteristics?
Sure do appreciate any information I can get about this dilemma. While it may not be flashy, fancy or expensive, this old stereo and I go way back. I really don't want watch it die yet.
Cheers,
Mark
Polypropylene capacitors do not 'wear out' so replacing the capacitors won't solve the problem. It is more likely that the tweeters themselves have stopped 'tweeting'. This is a common problem with old tweeters and is caused by ferrofluid inside the tweeters drying out and becoming gummy.
Solen basic caps are crap. 🙂
But if you must .... partsconnexion.com or solen.ca
What you would probably like are some Mundorf Supreme Silver in oil. They are quite sparkling/scintillating caps.
However I do agree, those caps don't go bad.
Best,
E
But if you must .... partsconnexion.com or solen.ca
What you would probably like are some Mundorf Supreme Silver in oil. They are quite sparkling/scintillating caps.
However I do agree, those caps don't go bad.
Best,
E
There are other components in the tweeter section of the crossover which may be suspect. I can see a fuse and two zener diodes in the pdf below.
http://www.infinity-classics.de/technik/manuals/Kappa_7_technical_sheet.pdf
http://www.infinity-classics.de/technik/manuals/Kappa_7_technical_sheet.pdf
I see the Emit k are ribbon tweeters so they do not contain ferrofluid.
Are you sure they are still producing some sound and are not competely silent? Sometimes the output from the midrange speaker fools one into thinking the tweeters are still working.
Are you sure they are still producing some sound and are not competely silent? Sometimes the output from the midrange speaker fools one into thinking the tweeters are still working.
Clean the pots and any unsoldered connections.
Check the resistance of the fuse, it may have had a few close calls.
Even after you clean them, you may not be using the same pot settings as before.
Zeners usually fail open, if they failed closed you would have no signal reaching the tweeter.
Go in and let us know what you find.
Check the resistance of the fuse, it may have had a few close calls.
Even after you clean them, you may not be using the same pot settings as before.
Zeners usually fail open, if they failed closed you would have no signal reaching the tweeter.
Go in and let us know what you find.
Looking at the .pdf above provided by Galu, I would first take the Zeners out of circuit by clipping one of the component wires of one of the Zeners but leaving the snipped wire rejoinable by resoldering the break. This will isolate the fault if it is indeed the Zener diodes, the tweeters should once again be as they were as in the past. If not, the 'break' can be resoldered. With the rheostat, 'the pot', temporarily short it out with a piece of copper wire bridging across all three terminals so that it is effectively taken out of circuit, this will test that the tweeter is actually working, it could well be the rheostat that is at fault, which is the most likely. The centre wiper may need a clean with CRC or WD-40.
C.M
C.M
Based on what I have seen in the past, I would rethink the entire crossover. Has anyone done a re-design already? Seems like a popular model for it.
Best,
E
Best,
E
I wish people would belt up with their unproven theories about capacitor quality beyond the remark that an 250V MKP (plastic) capacitor is unlikely to wear out. It's irrelevant functionally.
You always need to look at the circuit in these cases to see where time's winged chariot may have deteriorated something. First we look for poor contacts.
Corrosion? Take out the fuse and clean it for fresh metal. The 5R tweeter attenuator may be rusting too. Wipe the contacts by turning it back and forth a few times. There may be crimp connectors to the tweeter that are corroded. Pulling them off and putting them on again gets you fresh metal.
Dry or broken solder joints? Inspect for breaks and reflow with a soldering iron if necessary.
After that, I think we can dismiss problems with the protective Zener diodes. If they break, they should go out of circuit and not affect level. Lastly, it might be good to swap tweeters around and see if the problem follows. Because the last suspect is the ribbon emit tweeter itself. I don't see any difficulty in substituting something else if it is broken.
It is a competent crossover without any obvious problems. The unusual 0.3mH/125uF+5uF trap works at 800Hz and -5dB on the mid's cone edge peak. A nice touch.
Capacitors come in standard values. A 3.9uF MKP standard replacement will sound exactly the same as 4uF if you must. In fact, all the non-polar NPE types would be fairly critical to the sound. NPE do wander with the years, being wet electrolyte devices. Plastic MKP types are very stable. The 0.01uF capacitor is of dubious benefit, only affecting radio frequencies. A competent amp should not care.
You always need to look at the circuit in these cases to see where time's winged chariot may have deteriorated something. First we look for poor contacts.
Corrosion? Take out the fuse and clean it for fresh metal. The 5R tweeter attenuator may be rusting too. Wipe the contacts by turning it back and forth a few times. There may be crimp connectors to the tweeter that are corroded. Pulling them off and putting them on again gets you fresh metal.
Dry or broken solder joints? Inspect for breaks and reflow with a soldering iron if necessary.
After that, I think we can dismiss problems with the protective Zener diodes. If they break, they should go out of circuit and not affect level. Lastly, it might be good to swap tweeters around and see if the problem follows. Because the last suspect is the ribbon emit tweeter itself. I don't see any difficulty in substituting something else if it is broken.
It is a competent crossover without any obvious problems. The unusual 0.3mH/125uF+5uF trap works at 800Hz and -5dB on the mid's cone edge peak. A nice touch.
Capacitors come in standard values. A 3.9uF MKP standard replacement will sound exactly the same as 4uF if you must. In fact, all the non-polar NPE types would be fairly critical to the sound. NPE do wander with the years, being wet electrolyte devices. Plastic MKP types are very stable. The 0.01uF capacitor is of dubious benefit, only affecting radio frequencies. A competent amp should not care.
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It's just routine troubleshooting for us, but it may be daunting for Mark.
Hope we haven't frightened him away!
Hope we haven't frightened him away!
It's just routine troubleshooting for us, but it may be daunting for Mark.
Hope we haven't frightened him away!
Nah, I'm still here... quickly learning, and maybe even understanding a bit better [some of] what makes these speakers work. You guys have given me several avenues to troubleshoot, and as soon as I can get back to the man cave, I'm on it.
I may be a day or two late due to other commitments (yeah, life goes on), but please stand by. I'm anxious to get my groove back on, and you all have given me hope that I will!
I forgot to mention that I bought two more Emits just in case I had/ have smoked the originals (however unlikely to have roasted both). I started a thread on another site to try and discern why the original pair had some sort of goop smeared on them: EMIT K Mystery | Audiokarma Home Audio Stereo Discussion Forums
Don't you just love a good mystery?
Don't you just love a good mystery?
For years I had a set of RS4b with the EMIT. They has thiose dreadful 'polyswitches' on the EMITs - sorta like a self resetting circuit breaker that's never the same once it gets tripped. Great for tweeter survival, but terrible for sound quality.
I'd look for that first.
I'd look for that first.
Why do people always pay inflated prices for half-broken eBay drivers taken from stripped down old speakers? It's a racket. 😕
Read the schematic. No polyswitches:
Read the schematic, the tweeter has a resistor in front so no real (3 ohm) impedance issues. Except at loud setting.
Read the schematic. You can fit almost any replacement tweeter.
Sorry, bit of a rant there. You get in by unscrewing the bass usually. 😱
Read the schematic. No polyswitches:
Read the schematic, the tweeter has a resistor in front so no real (3 ohm) impedance issues. Except at loud setting.
Read the schematic. You can fit almost any replacement tweeter.
Sorry, bit of a rant there. You get in by unscrewing the bass usually. 😱
To aid your understanding and take nothing for granted, I hope that you & the contributors to the thread are cool with me posting this summary of how the tweeter section works.
- The fuse (1A-30) and the back-to-back zener diodes (1N5343B) are there to protect the tweeter from overload.
- The rheostat (R1) is there to adjust the level of the tweeter.
- The 4uf capacitor (C1) and the 0.20mH inductor (L1) form the actual crossover network which channels the high fequencies to the tweeter.
1. Why do people always pay inflated prices for half-broken eBay drivers taken from stripped down old speakers? It's a racket. 😕
Read the schematic. No polyswitches:
2. Read the schematic, the tweeter has a resistor in front so no real (3 ohm) impedance issues. Except at loud setting.
3. Read the schematic. You can fit almost any replacement tweeter.
Sorry, bit of a rant there. You get in by unscrewing the bass usually. 😱
So, being new here and not understanding all the jargon or attitudes, what all are you talking about?
1. I picked up a pair of Infinity Emit tweeters on, yes, of all places, Ebay. They are in perfect condition, and they don't have stucco smeared all over them. The ORIGINAL speakers were built with gooped up speakers.
I am quite happy with my Infinity speakers, as well as the equipment that drive them. I do not wish to experiment with my audio quality as I have (had) the quality of sound I desired. And since none of these parts and pieces are made anymore, and haven't been for thirty odd years, if I wish to keep my system intact, I must source parts from wherever they can be had. Ebay may be a throw of the dice (I've rarely been burned), but that's where the stuff I want/need comes from.
2. I read the schematic. Please help me understand, where is this resistor in the tweeter circuit you speak of? I see a 3 ohm resistor in the midrange section.
3. As explained earlier, if I had wanted to fit a different speaker in the cabinet, I might not have needed any help at all. Heck, I could replace any or all of the three noise makers and made noise. The reason I'm here is to [attempt to] KEEP my unique ribbon tweeters tweeting. They are sick, and I'm the only doctor they have. Unfortunately, this kind of surgery is not my specialty (I am a high voltage electrician), so I am accessing knowledgeable consultation to help make them well again. If you are that knowledgeable consultant, I welcome your input.
If I misunderstood your post, my apologies. If I didn't, my rant off.
Regards,
Mark
Well folks, I may have found a smoking gun. haven't had time to fully experiment with it, but I'm hopeful. I found a 1 ohm resistance across the fuse. Actually it is not a fuse but a self resetting circuit breaker.
I went to the back of the board and soldered on a bypass jumper. I managed to power it up and it APPEARED to be much better sound from what I was hearing. I'm getting what I think is nice crisp highs like I remember. However, I had to quit to go to work. It is now my intention to power this back up and cut the jumper in mid note so I can compare before and after.
So if this turns out to be the issue, how about I install a real fuse holder on the outside of the cabinet and go to 1 amp glass fuses that I can access easily?
I went to the back of the board and soldered on a bypass jumper. I managed to power it up and it APPEARED to be much better sound from what I was hearing. I'm getting what I think is nice crisp highs like I remember. However, I had to quit to go to work. It is now my intention to power this back up and cut the jumper in mid note so I can compare before and after.
So if this turns out to be the issue, how about I install a real fuse holder on the outside of the cabinet and go to 1 amp glass fuses that I can access easily?
The resistor in the tweeter circuit is the rheostat, which is adjustable between zero and 5 ohms. Hence the statement that the total resistance cannot fall below 3 ohm (the resistance of the tweeter) when the rheostat is set to zero (maximum tweeter volume).
Regarding the 'self resetting circuit breaker', I would simply short it out of circuit by soldering a length of wire across it. It is not necessary, unless you are using an underpowered amplifier or operating continuously at high party levels.
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