Conion C100 resto
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Those are 3-way speakers? I would try to find a real tweeter with a 6 OHM impedance & cross it over high with a 2.2uF cap, polyester film are really good for audio. Electrolytics are harsh, brassy....caution said:
IT will be a bit of 'hit & miss' experimentation with caps to get the right blend between mid & high drivers but the bass & treble will help smooth out the response....
Cpl
Thanks bklyn!
Turns out I wasn't wiring the LEDs optimally, but found a great page for figuring out the best way to connect a single LED or multiple LEDs. Just enter the supply voltage and LED current/voltage ratings and boom, it tells you if putting them in series with one load or in parallel with individual loads is best, AND which resistor values/wattages are necessary.
CPL I will try that, thanks. A lot of really high quality 6 ohm tweeters to choose from. Will be interesting to see how it sounds with new highs. The mids use 47uF electrolytics for a crossover.
Turns out I wasn't wiring the LEDs optimally, but found a great page for figuring out the best way to connect a single LED or multiple LEDs. Just enter the supply voltage and LED current/voltage ratings and boom, it tells you if putting them in series with one load or in parallel with individual loads is best, AND which resistor values/wattages are necessary.
CPL I will try that, thanks. A lot of really high quality 6 ohm tweeters to choose from. Will be interesting to see how it sounds with new highs. The mids use 47uF electrolytics for a crossover.
Right, so if the mids are 4 OHMS then the crossover point is around 8500Hz. So, @ 8500 hz & down the crossover attenuates the mid by 6db for every octave lower in frequency. 4250Hz @ -6db, 2125Hz @ -12db etc. So ,in theory, you would need a high, high crossover point so that the tweeter is there to only re-create the top octave, 10-20Khz so a crossover using a 2.2uF cap on a 6 OHM tweeter would net a roll-off point of 12000Hz, -6db @ 6000Hz, -12db @ 3000Hz, etc...caution said:
The reason you want to go high on the roll-off point is so you can allow the treble to pass through while attenuating the mid/high-mid ranges for a 3 way speaker. The M90 is a legendary 2-way blaster & the tweeters are still crossed at 8KHz even though the tweeters are rated to operate with a 2KHz roll-off point.
If you go with a 4 ohm tweeter, you would have to go with a 3.3 uF cap for the same 12K roll-off point...
Don't forget, a Polyester Metal Film cap is best for subtle treble, especially for a tweeter in a 3-way system. You can order a billion of them from china for pennies...just takes 5 weeks to get here. The M90 uses poly-film caps & that is the reason it probably has the clearest mid/treble of all of the 80's grails, not to mention their KILLER 6 OHM tweeters that kicked butt like MAD!!
Cheers,
Cpl
Nope the mids in this thing are 8 ohms. They work fine. I need the replacement tweeters to be loud enough, is 6 ohms too much for a 3-way setup? Is that how I balance its loudness or do I even bother? Starting to get analysis paralysis on this one. Look at these chinsy things that were in there!
I think I will remove the chrome dust caps and apply them to whatever I put in next, if they don't have one already.
I soaked the woofer grilles in apple cider vinegar then scrubbed them down with CLR, they are pretty close but still need a good pre-paint sanding.
I picked up some Duplicolor enamel gloss black tonight with some 600 grit sandpaper as advised. The original coat had a nice rounded smooth look, so it may take a couple coats to get that. I think. Do I even bother with primer??
I had my first foray into plastic surgery tonight, and I'm thoroughly impressed. I wasn't even sure I got enough in there, but it's only been three hours and it feels tough as nails. Will do the other two tomorrow.
I finally sorted out the dial light circuit, I actually calculated the correct resistor value/wattage, I just needed to reconnect them to be in parallel. What a huge difference that made. It was doing something screwy to the whole system in that when I turned it off, it would fade out in two stages, like it was bleeding out the caps or something. Now it turns off instantly Even with a 12-watt load I made of the same resistance, it was still getting too hot. All because the LEDS were in parallel and not in series. Ganging the voltage drops enabled the resistor to operate at a lower voltage I think, and made all the difference. It's now brighter than it was before, and only gets slightly warm with a 1-watt load, although it could be half that and still be fine. Here are a couple before and after the correction.
On top of that, I applied some aluminum tape to the opposite end to get it to fill in with light better. Really makes a difference.
https://www.youtube.com/watch?v=VVRCrh_-6vw
I think I will remove the chrome dust caps and apply them to whatever I put in next, if they don't have one already.
I soaked the woofer grilles in apple cider vinegar then scrubbed them down with CLR, they are pretty close but still need a good pre-paint sanding.
I picked up some Duplicolor enamel gloss black tonight with some 600 grit sandpaper as advised. The original coat had a nice rounded smooth look, so it may take a couple coats to get that. I think. Do I even bother with primer??
I had my first foray into plastic surgery tonight, and I'm thoroughly impressed. I wasn't even sure I got enough in there, but it's only been three hours and it feels tough as nails. Will do the other two tomorrow.
I finally sorted out the dial light circuit, I actually calculated the correct resistor value/wattage, I just needed to reconnect them to be in parallel. What a huge difference that made. It was doing something screwy to the whole system in that when I turned it off, it would fade out in two stages, like it was bleeding out the caps or something. Now it turns off instantly Even with a 12-watt load I made of the same resistance, it was still getting too hot. All because the LEDS were in parallel and not in series. Ganging the voltage drops enabled the resistor to operate at a lower voltage I think, and made all the difference. It's now brighter than it was before, and only gets slightly warm with a 1-watt load, although it could be half that and still be fine. Here are a couple before and after the correction.
On top of that, I applied some aluminum tape to the opposite end to get it to fill in with light better. Really makes a difference.
https://www.youtube.com/watch?v=VVRCrh_-6vw
I really dig your in-depth updates and modifications. I am very curious to see if you can get some decent highs out of this beast. My beat up Helix really lacks in the highs, though I haven't yet bothered to recap anything yet. But I kind of suspect that it was lacking in highs the second it left the factory.
Do you think there are gains in the bass department as well? While the box gets loud, at low volume the bass is not as good as I feel it could be. Maybe that's an artifact of the one-piece boombox designs? There are 3-pieces that really sound much better, for example the sharp WF-939's.
Do you think there are gains in the bass department as well? While the box gets loud, at low volume the bass is not as good as I feel it could be. Maybe that's an artifact of the one-piece boombox designs? There are 3-pieces that really sound much better, for example the sharp WF-939's.
Wel
put some good 4 ohm cone tweeters in there instead & the difference will be like the darkest night vs the sunniest day. cross them high @ 12Khz to roll off the mids completely & only pass the high treble frequencies flat.. Some smaller SANYO, PANASONIC or SONY tweeters would work well here from another blaster or you could go new with a recessed wave-guide to boost output by about 3db...
Tympany makes a good tweeter that is cheap & exactly the same as the old VIFA dome tweeters for about 15-20 bucks each plus shipping....
Also, I have a pair of C-100 woofers & they are great but the are NOT bass cannons in any way. They are good at upper mid-bass @ hi volumes but lack a bit of punch in the 50Hz range...
If you have weak caps in the power block or AMP block, that just makes it worse...
Cpl
I'm kind of a speaker guy so I can answer that question. It's mainly the speakers. The tweeters are paper cones pasted to piezo tweeters so that would be less efficient than the piezos by themselves & without the weight & damping factor of the cone...stragulus said:
put some good 4 ohm cone tweeters in there instead & the difference will be like the darkest night vs the sunniest day. cross them high @ 12Khz to roll off the mids completely & only pass the high treble frequencies flat.. Some smaller SANYO, PANASONIC or SONY tweeters would work well here from another blaster or you could go new with a recessed wave-guide to boost output by about 3db...
Tympany makes a good tweeter that is cheap & exactly the same as the old VIFA dome tweeters for about 15-20 bucks each plus shipping....
Also, I have a pair of C-100 woofers & they are great but the are NOT bass cannons in any way. They are good at upper mid-bass @ hi volumes but lack a bit of punch in the 50Hz range...
If you have weak caps in the power block or AMP block, that just makes it worse...
Cpl
Thanks strag, yeah it may take a couple goes at tweeters but I have no doubt it will sound fine when I'm done. As for the woofers, I really doubt there is any more punch from new caps, I would imagine it would help with other issues related to signal degradation. Easy bass improvement is the mp3 player EQ on your smartphone, or in my case I like to use an mp3 cassette with a bass boost.
So after a couple more days of soaking and new fluid, I think half the chrome is gone and I see copper plating over the nickel. The coil was totally eaten away on one of them and had to trim it back a bit, but it still works. I had to remove the heat stakes holding the battery panel on, but I will use some plastic solvent to reattach it. A major source of creaking was this panel sliding against the chassing when it flexed from being carried, so I'll shave that one end down a bit.
I got down'n'dirty and finished all of the plastic damage, it sort of dripped too much on my first post, but after I got a feel for how little you really need, and I mean LITTLE, it is just amazing. You can see from the pics how it gets into the crack , melts each side, and oozed together. seamless! I love it!
I found five tabs inside the chassis when i opened it, so I got all those back on. The nice thing about the posts and tabs is that just about every time the crack interface was irregular enough to hold the piece into place without any assistance, which to me seemed ideal since I was so afraid of having it start moving out of place once the solvent hit. It took a very steady, double-handed-pinstriping technique to get the tiny bead of solvent right where you need it, but not so close you nudge the part. In one case I slightly nudged it after a tiny bit got on there, but two seconds later the interface was just soft enough that I could just push it back for a few moments and let it set enough to stay put. Awesome.
Three cracks on the tray are now all healed, one crack did a 180 as it went, so you had to push up from the other side to expose the other half. I wasn't sure the solvent would reach the entire length if I dabbed it from the far end, so I quickly laid down a bead along the crack, and wiped it up right away, but in that moment, it didn't waste any time getting to work on the surface. Now that they're repaired I'll sand and polish it and try to minimize them. The top side doesn't look any different. I was thinking I might design a custom liner for the tray to hide the cracks and give it a little bit extra style.
I've also been trying to figure out what to do about the chrome on the tweeter grilles since it's not really mirrorlike, as it should be. It never really was since it was just painted on, so all of my ideas for using Alclad or that Kosutte Gin San chrome powder you rub in seemed messy and temporary. So, I measured the strips and they are 90 mils. I went and found some chrome pinstriping that was 3/32" (93 mils) so I am going to try what mmcodomino did and overhaul them manually. I think it done right it could work fine, sort of like the vertical strips on the M90.
I went spring hunting at the gizmo store and ended up finding a drawer full of some that slip right onto the door posts like a glove, so I opened up the ends and will see how they work once I get the whole unit back together. I might try to bridge them with a third piece and some silver solder.
I also found some 1/16" rubber foam with adhesive backing that was large enough to cut out feet for the bottom. One side was okay but the other side was gone. It drops right in perfectly if you cut it out at 1.58" by 0.4". I used some tar remover to get the old gunk out of there, but I forgot what happens if you are applying it to an unpainted surface, it starts to melt the plastic. You can see the original gray color under there, which I will be exposing soon with my retrobrite process. I was going to do it over the weekend but my source of UV light disappeared, but about a week it seems!
So after a couple more days of soaking and new fluid, I think half the chrome is gone and I see copper plating over the nickel. The coil was totally eaten away on one of them and had to trim it back a bit, but it still works. I had to remove the heat stakes holding the battery panel on, but I will use some plastic solvent to reattach it. A major source of creaking was this panel sliding against the chassing when it flexed from being carried, so I'll shave that one end down a bit.
I got down'n'dirty and finished all of the plastic damage, it sort of dripped too much on my first post, but after I got a feel for how little you really need, and I mean LITTLE, it is just amazing. You can see from the pics how it gets into the crack , melts each side, and oozed together. seamless! I love it!
I found five tabs inside the chassis when i opened it, so I got all those back on. The nice thing about the posts and tabs is that just about every time the crack interface was irregular enough to hold the piece into place without any assistance, which to me seemed ideal since I was so afraid of having it start moving out of place once the solvent hit. It took a very steady, double-handed-pinstriping technique to get the tiny bead of solvent right where you need it, but not so close you nudge the part. In one case I slightly nudged it after a tiny bit got on there, but two seconds later the interface was just soft enough that I could just push it back for a few moments and let it set enough to stay put. Awesome.
Three cracks on the tray are now all healed, one crack did a 180 as it went, so you had to push up from the other side to expose the other half. I wasn't sure the solvent would reach the entire length if I dabbed it from the far end, so I quickly laid down a bead along the crack, and wiped it up right away, but in that moment, it didn't waste any time getting to work on the surface. Now that they're repaired I'll sand and polish it and try to minimize them. The top side doesn't look any different. I was thinking I might design a custom liner for the tray to hide the cracks and give it a little bit extra style.
I've also been trying to figure out what to do about the chrome on the tweeter grilles since it's not really mirrorlike, as it should be. It never really was since it was just painted on, so all of my ideas for using Alclad or that Kosutte Gin San chrome powder you rub in seemed messy and temporary. So, I measured the strips and they are 90 mils. I went and found some chrome pinstriping that was 3/32" (93 mils) so I am going to try what mmcodomino did and overhaul them manually. I think it done right it could work fine, sort of like the vertical strips on the M90.
I went spring hunting at the gizmo store and ended up finding a drawer full of some that slip right onto the door posts like a glove, so I opened up the ends and will see how they work once I get the whole unit back together. I might try to bridge them with a third piece and some silver solder.
I also found some 1/16" rubber foam with adhesive backing that was large enough to cut out feet for the bottom. One side was okay but the other side was gone. It drops right in perfectly if you cut it out at 1.58" by 0.4". I used some tar remover to get the old gunk out of there, but I forgot what happens if you are applying it to an unpainted surface, it starts to melt the plastic. You can see the original gray color under there, which I will be exposing soon with my retrobrite process. I was going to do it over the weekend but my source of UV light disappeared, but about a week it seems!
Holy Moly!! You are systematically eliminating the issues like an archeologist...
Amazing work!
Cpl
Amazing work!
Cpl
With any luck I'll have it done this summer, closing in on the difficult ones (for me)
Started to polish the VUs and dial. A couple of nicks in the dial will need some 2000 grit (hopefully not more than that. I tested some on the side last night but need to do a little more on similar acrylic to make absolutely sure it will be okay to use. Novus deep scratch isn't getting it out. I may have to leave it, it's very minor.
Also got replacement antennas, they're extremely close, same length collapsed, but the tip is longer so you have to pull it the tiniest amount to clear it. You can see in the pics from the scuffs on the original one I had how close it is to the new tip. All segments are about 8 mils thinner, enough not to have a snug fit at the first anchor and just feels a bit flimsier, but works!
Started to polish the VUs and dial. A couple of nicks in the dial will need some 2000 grit (hopefully not more than that. I tested some on the side last night but need to do a little more on similar acrylic to make absolutely sure it will be okay to use. Novus deep scratch isn't getting it out. I may have to leave it, it's very minor.
Also got replacement antennas, they're extremely close, same length collapsed, but the tip is longer so you have to pull it the tiniest amount to clear it. You can see in the pics from the scuffs on the original one I had how close it is to the new tip. All segments are about 8 mils thinner, enough not to have a snug fit at the first anchor and just feels a bit flimsier, but works!
I swear you mentioned using a 6Ω tweeter with a 2.2μF poly. I got these coming in the mail, they had a decent rating and will fit inside the original tweeter case, so I can use that to mount it. Not sure where I'd get a waveguide but I don't really think I need one.Cpl-Chronic said:
Gave the front and back a bath, polished the LED meter chrome, and tried to run a retr0brite session but the sun went away, so I turned my attention to the tape door. Amazingly the plastic part is in fantastic condition, no scratches, even the sticker is perfect. But the trim, man, it's all dented and scratched and bent up. It looks like someone tried to open the deck door by pulling on it, so the sides are all bent up. It's held on by glue that I believe is the same as that around the dial window, it was originally very tacky but has dried to a crystalline solid. I can't find anything to lift it.
I fashioned a little trough out of foil and set the door in it, pouring 99% IPA in so it just covered the trim 100%. Went to work and came home with most of it evaporated but it had softened the glue just enough that I could feel it start to separate, but still too much force without bending it. So, I decided to try and distribute the force by holding it down with a piece of Gorilla tape and anchoring the whole thing to the edge of the table, then pushing down on the opposite end of the door, that was able to put enough force on it to slowly separate. I still managed to bend it a tiny bit but it's no worse than what's already there. Lots of little taps and should get that thing looking better than it was. Not sure what I can do about the surface, pretty sure the lettering will take a hike if I sand it.
Finally! Sun!
After a couple of hours the sun had moved enough that I had to prop it up on a chair to stay in full exposure, and as you can see, it was basically done.
The next pic shows how there was still some yellowing around the name plate, so I left it another hour or so.
You can see here that I exposed quite a few imperfections in the plastic, but it sort of comes with retrobriting. I'm fine with them over the yellowing!
If you look at the very beginning of the thread, the second pic shows the battery cover on, and you'd think it hadn't been infused with a flame retardant. It either just had less or the previous owner bought a replacement from another unit. Or it's just really dirty, I haven't cleaned it yet
After a couple of hours the sun had moved enough that I had to prop it up on a chair to stay in full exposure, and as you can see, it was basically done.
The next pic shows how there was still some yellowing around the name plate, so I left it another hour or so.
You can see here that I exposed quite a few imperfections in the plastic, but it sort of comes with retrobriting. I'm fine with them over the yellowing!
If you look at the very beginning of the thread, the second pic shows the battery cover on, and you'd think it hadn't been infused with a flame retardant. It either just had less or the previous owner bought a replacement from another unit. Or it's just really dirty, I haven't cleaned it yet
