ALS Platinum Mark IV Crossover Problem

Carver Speaker Discussions and Questions
User avatar
Robert R
TFM-75
Posts: 882
Joined: Tue Aug 05, 2008 2:05 pm

Re: ALS Platinum Mark IV Crossover Problem

Post by Robert R » Sat Aug 22, 2015 6:19 pm

sea,

Damn - I fall asleep and when I wake up you've got it going. I had the next note, about what to do about the break, all written. But now you don't get that. If it's working, no reason to argue how.

Anyway, one of the two ways I had in mind is essentially what you did - get some foil in there. If it stays and doesn't stray off to the side and short the whole business, you have some ribbon-afterlife to look forward to, though ultimately a rebuild is indicated. Since you can't get one right now anyway, what you've done is about the best that can be done.
The other method I was going to describe involves "circuit writer", and you might want to get some of that on hand just in case this goes bad or another such problem develops. It's a sort of conducting glue - silver-laced silicone.

By now you must be experiencing the wonderment that we all feel when we see how all that power gets into those ribbons - you wonder how the hell it ever works at all. But it does, of course. And how else would you do it? You can't solder to that Al trace, and any more aggressive hardware-based mechanical connection would fail due to the constant vibration. Bob's a sharp guy, and if there were a better way he'd have used it.

When rebuilding these, one trick is to take a knife and chamfer the edge of the board just a bit so it doesn't present such a sharp corner to the Kapton. I invented that trick for myself, but later found out that the pros already use it, and that Bob recommends it, as well. That and several other tricks make the rebuilt ribbons theoretically better than new.


If it makes you or anybody feel any better, you might well have had this same failure sometime soon with a lot smaller amp, and maybe will yet again. Old ribbons tend to do this - it seems to be part of their 'life-cycle'. This final event usually takes place when running loud, though not necessarily in clipping. The thing lets go with a distinct "snap", followed by eerie silence. You would have seen a small arc there, if you'd had your eye on the spot. Think of it like the heart attack that would have happened pretty soon, even if the guy hadn't shoveled that snow. Maybe this all makes you feel worse, not better. But that's the reality.


Hope your crossover suffered no lasting trauma. I should have caught this sooner, but you happened to catch me in mid-migration, and James has been utterly immersed in his projects, of course. It really annoys him that he needs sleep.

Happy listening!

RR
"You know what folks? I'm happy."

User avatar
sea
TFM-25
Posts: 386
Joined: Thu Apr 17, 2014 1:47 pm
Location: NC Piedmont

Re: ALS Platinum Mark IV Crossover Problem

Post by sea » Sat Aug 22, 2015 6:23 pm

Robert R wrote:sea,

Damn - I fall asleep and when I wake up you've got it going. I had the next note, about what to do about the break, all written. But now you don't get that. If it's working, no reason to argue how.

Anyway, one of the two ways I had in mind is essentially what you did - get some foil in there. If it stays and doesn't stray off to the side and short the whole business, you have some ribbon-afterlife to look forward to, though ultimately a rebuild is indicated. Since you can't get one right now anyway, what you've done is about the best that can be done.
The other method I was going to describe involves "circuit writer", and you might want to get some of that on hand just in case this goes bad or another such problem develops. It's a sort of conducting glue - silver-laced silicone.

By now you must be experiencing the wonderment that we all feel when we see how all that power gets into those ribbons - you wonder how the hell it ever works at all. But it does, of course. And how else would you do it? You can't solder to that Al trace, and any more aggressive hardware-based mechanical connection would fail due to the constant vibration. Bob's a sharp guy, and if there were a better way he'd have used it.

When rebuilding these, one trick is to take a knife and chamfer the edge of the board just a bit so it doesn't present such a sharp corner to the Kapton. I invented that trick for myself, but later found out that the pros already use it, and that Bob recommends it, as well. That and several other tricks make the rebuilt ribbons theoretically better than new.


If it makes you or anybody feel any better, you might well have had this same failure sometime soon with a lot smaller amp, and maybe will yet again. Old ribbons tend to do this - it seems to be part of their 'life-cycle'. This final event usually takes place when running loud, though not necessarily in clipping. The thing lets go with a distinct "snap", followed by eerie silence. You would have seen a small arc there, if you'd had your eye on the spot. Think of it like the heart attack that would have happened pretty soon, even if the guy hadn't shoveled that snow. Maybe this all makes you feel worse, not better. But that's the reality.


Hope your crossover suffered no lasting trauma. I should have caught this sooner, but you happened to catch me in mid-migration, and James has been utterly immersed in his projects, of course. It really annoys him that he needs sleep.

Happy listening!

RR
Thank you for all your help. I did learn a lot about the ribbons and that is always exciting. See you in a couple of weeks.

User avatar
Robert R
TFM-75
Posts: 882
Joined: Tue Aug 05, 2008 2:05 pm

Re: ALS Platinum Mark IV Crossover Problem

Post by Robert R » Sat Aug 22, 2015 7:41 pm

At the Fest, besides messing with the speaker kits, we will super-glue James to a very large tree, and play the entire score of "Naughty Marietta" endlessly into his ears (through some of Watershed's Bose speakers), while we tickle him mercilessly with random bits of scrap aluminum, until he breaks down and finds some new ribbon material...
"You know what folks? I'm happy."

User avatar
sea
TFM-25
Posts: 386
Joined: Thu Apr 17, 2014 1:47 pm
Location: NC Piedmont

Re: ALS Platinum Mark IV Crossover Problem

Post by sea » Sat Aug 22, 2015 8:20 pm

Robert R wrote:At the Fest, besides messing with the speaker kits, we will super-glue James to a very large tree, and play the entire score of "Naughty Marietta" endlessly into his ears (through some of Watershed's Bose speakers), while we tickle him mercilessly with random bits of scrap aluminum, until he breaks down and finds some new ribbon material...
Sounds like a plan........

User avatar
BarryG
Newbie
Posts: 48
Joined: Thu Jul 24, 2014 4:00 am

Re: ALS Platinum Mark IV Crossover Problem

Post by BarryG » Sun Aug 23, 2015 9:13 am

Glad you located the problem! Looking forward to meeting you!

BarryG
Carver C-11 (BillD modified by Dennis Miller),Carver TX-11b, Carver SD/A-390t, Carver C-9, Carver M-1.0t MKII Opt. 2, Carver M-500t MKII (RichP’s final MKII before retirement), Carver TFM-45, Carver m-4.0t (Kevin is repairing it), Cambridge Audio DAC, Tube Buffer (MusicFidelity Clone), Sony Blu-Ray Player, Technics SL-7 turntable with Technics 310MC moving coil cartridge, DBX 3bx-ds, Polk SDA1B’s (upgraded and modded by me), Carver ALS (Original upgraded), Sunfire Subwoofer TES-EQ10, Interconnects by Doug, Speaker Wires by Doug, Salamander Archetype Equipment rack X2.

Post Reply

Return to “Carver Speakers”