Help! New Member Has ALS Ribbon Problem!

OK, Robert R!
I will test my woofers with the 9V battery...I already printed out your instructions. Should be easy. Thanks for the further explanation of my crossover, also. Based on what you told me, I interpreted I should be OK using the Platinum ALS wiring diagram and parts list "as is" as my replacement capacitors reference, since my crossover is identical, 'cept for some minor nuances as noted.
Yes, you did get confused on the silver cap specs: mine was 150uF and 100VNP (the actual cap says "150MFD 100WV"). You can see it on one of the last 5 pics (#15?). There is more writing on it, but its hard to read, and at this point, i think its moot and we have it figured out anyway.
My new 150uF 100VNP caps will be in this week, so I hope to solder one in soon, see what i got, and go from there. It's only a 150uF 100VNP (would go 150VNP now with the new knowledge), but I got spares (bought 5), and I'm nipping at the bit to get the speaker working again ASAP!

Then I'll communicate with Sonicraft and see what my other cap options are! And the woofer situation will also be on the back of my mind. I mean, these woofers are 15-20 years old now, and although they don't have a butt-load of hours on them (maybe 100-200 because they sat for years and years unused waiting for a bigger space and the right amps to power them), and while the woofers look pretty good, they may in fact be dried out or who knows what. Heck, the guy at Sonicraft told me electrolytic caps dry up and go bad too over many years, so who knows what sonic probems i may have. On the other hand, the speakers sound great: very clear, very smooth...its not fatiguing at all to listen to loudly. But from what I hear people say about ALS's bass, I think my bass is substandard.
But I like a lot of bass, and I've listened to rock music and jet engines all my life, not to mention loud cars, so it may be my hearing that's substandard!

Then we could talk speaker placement. But that's another topic. I already read some stuff in the Forum on it, and no doubt I am keeping my speakers away from side walls, with the ribbons towards the center---but speaker placement from the back wall and toe in dynamics sound arguable; I mean, the ALS owners manual says you can put them close to the back wall and have no loss of sound quality. I mean, this is Bob Carver talking.

I'll get back to you maybe tomorrow on the woofer test...I can't wait now!

Very Respectfully,
Mariodawg

The new caps, or just one of them, should have that ribbon snortin' fire right away; I suspect you'll change out the other channel's as well. But for the long run, you will probably want to get higher voltage rated ones. If you can find 75uf at 150 or better yet 200 volts, two per channel in parallel would do the trick, Or, failing that, use three at 50ufd, still same higher voltage rating, and bundle them all together; and order another three for the other channel. Or you can go with unequal arrays, like a 100 and a 50. Just add them up to reach 150.

I looked back at some of what I wrote, and it seems that I've been calling C2 a 100uf cap right along. I'll take your word for it; no desire to get into those pictures again at this hour.

My two cents on the woofer replacement:

1. "If it ain't broke, don't fix it." (quote from DaveS, and a lot of others)
2. When it is time to replace them (they'll tell you), see about fitting the later type (Platinum) into your openings, and if it's no problem get those. You have the crossover for them; and in fact with those woofers, you'd have Plats, really, not upgrades at all, in every sense of the word outside of serial number and ancestry.

Rob

HOLY SHAZAM, Bat-Robert R!!!

I went out and did the 9V test on the bad speaker. ALL FOUR WOOFERS MOVED FORWARD, NOT BACK! I of course double checked my battery terminal connections, red woofer wire to positive battery terminal and vice versa---all done correctly! If what you told me was correct, then the whole woofer section on that speaker was out of phase! Remember i mentioned a while back that I noted my red crossover wire was connected to the black woofer wire, and that looked funny (but the instructions are long gone). But there is no way to hear the difference until I get the new cap!

Soooo...with my adreneline pumping I took the front and back cover off my left (good) ALS speaker. The first thing I noted was the red crossover wire was connected to the black woofer wire, and vice versa, just like on the bad speaker. So, I unsoldered the woofers from the crossover like on the other side so I could do a 9V battery test first, and then re-hook everything up to see if I could hear a difference with music playing.

The battery test revealed the same result on the good speaker: when the red woofer wire was connected to the positive battery terminal (and black to negative), all four woofers moved forward---NOT back! So I played some music through that speaker, and went back and forth on the wires. I THINK the bass sounds better, and smoother, when I reverse the wires from where they were originally---but I am holding my final opinion until I get an objective ear to listen to the speaker while I swap wires. I am very hopeful, though! (BTW, all the woofers seem to be in good working order and nothing out of the ordinary noted)

Robert R---you may be upgraded from Hero to Super-Hero very soon! Now where are those damned new caps!!! I'll update again soo as soon as I find an objective ear...

Beside Myself,
Mariodawg

Well, whoever did the conversion/upgrade maybe followed the logic of putting red wires to positive, blacks to negative some place where they shouldn't have. In all the ALS models before the (very rare) Mark III series, the woofers are SUPPOSED to be wired out of phase with the ribbons. It all has to do with the crossovers. The earlier types were of a lower "order", that introduces phase shift to the point that you're better off phasing the woofers "backwards". The newer types had I think 4th order crossovers, which make this phase change unnecessary, and, in fact, counterproductive.

It's standard Industry practice, usually followed, to have plus-to-red move the driver forward, so it's the woofers in the earlier Plats and Silvers that are considered backwards, not the ribbons, which should be wired red-to-red all the way. But the manual for the Originals shows the + lead of the ribbons grounded, and the - lead of the woofers to the hot side of the crossover!
So it appears that the Originals drivers are out of phase all right, but I would have said out of Industry standard as well. We need to look at your ribbon wires and be sure that at his point the red crossover is to the red ribbon lead (or + terminal), and the black crossover output, that comes unchanged from the black power amp output, goes to the - ribbon input.

Now, how are your arrays of four woofers wired with respect to each other? We need to check this, too. The Original woofers, yours, are 4 ohm, and the later types are 16 ohm, so our problems continue. In the Platinums, the four 16-ohm woofers are simply wired in parallel, giving a 4 ohm load. All the pluses wired together, with one crossover output lead to that, and all minuses wired together and connected to the other crossover speaker output. If you ever change to the newer type woofers that's how you would wire it. But if your four 4 ohm speakers were wired that way, you'll have a one ohm load, and you don't want that. In series, they would add up to 16 ohms, too large. So, they need to be wired as a series/parallel combination: Two paralleled pairs of woofers, those pairs then wired in series with each other. Properly done, that would give you four ohms for the whole array. That is how yours should be now: we need to check them to be sure.

I'm going to break off here and go search the Forum. Seems I saw a thread on this very topic recently, and someone had sketched in some hookup diagrams. That's good, because I can't draw for doo-doo. I'll find 'em and get back later.

Robert

Here it is:

Shucks, there goes my lunch break.

Thanks Rich!

OK, Mariodawg, Rich saved me a lot of hunting.
I knew those drawings were in there someplace.

Now, we should confirm that your woofers are wired as shown in Rich's post.


We'd better do this in stages.

First step: Look at the connections that go between the two top woofers. They should be connected to each other with two wires: One, Plus to plus, and two, minus to minus.

Second step: The bottom two woofers should be wired to each other in like fashion - plus to plus, minus to minus.

Double check that the other channel is done the same way.

Ignore all the other wires for the moment.

Are they like that?

Rob

-quote; In all the ALS models before the (very rare) Mark III series, the woofers are SUPPOSED to be wired out of phase with the ribbons. It all has to do with the crossovers.




-sometimes the 1st of two plat designs were called mk3's...on acct they were the 3rd revision of ALS's before mk4's were avail...[originals/ origin upgraded/ plat 2 prs binding posts/ plat mk4's]
-the only other times ive seen 'mk3'...once was a large advertisement [showing the 'all new' model, but mk4's were then 'released']...and a magazine 'test' article of a 'pre-production' unit...again mk4's were released FS

-i think mk3 was a Carver prototype that was replaced before any production began

-^^^this^^^, iz all the info i could ever find on them


-another thread hi-jack

I've always suspected that was the case, that the final tweak (a very small one) that converted the III to the IV was done before production began. The III existed long enough to get a review or two, but as you say, these were probably pre-production models. By now, if there were any out there, likely somebody in this forum would have seen them.

Or would anybody know them if they saw one? They had the same 3-pot setup in the back. Anyway, until a confirmed pair shows up, I'm willing to pronounce them extinct before birth.

Robert R

As to the thread, it's really all about ALS crossovers anyway, and the only difference from the III to the IV was a slight crossover change. So you're right on message.

Hello Again!
I've been busy doing several projects, my apologies.

I missed the last woofer wiring thread, so I'll have to get back to that one.

First off, I had two objective ears sound check (listen to) my good speaker Monday night to determine if my woofers were out of phase. As suspected, they agreed it sounded better with the red crossover wire hooked to my red woofer wire, and black to black. So I soldered them up, and put the speaker back together.

Then, my 100uF 100VNP (bi-polar") caps came in yesterday. I soldered the new cap in place, glued the one resistor set back on top of the coil where it was, and soldered the crossover wires back into the speaker, sticking to the red-to-red, black-to-black phasing.

Result: My speakers sound significantly better, with more bass and I think a more volume overall, and a better overall stereo effect and soundstage. What I couldn't tell was an improvement between the new-cap-speaker and the old-cap-speaker. Because of this, I am leaving my one remaining old silver cap in place for now---as I have bigger fish to fry. But this will be revisited later when I research replacing these caps with higher voltage ones anyway, and I look into those audio-grade caps from Sonicraft.

You asked about my fuse protection: 250V 5 amp fuses. Do you recommend something else?

The rest of my week looks rather busy. It may be several days before I get back to you on the woofer wiring. I will get back, though!

Oh, and did I say "Thanks" for helping me get back on-line---and making my Carver system sound better than ever!!!!?

Happily Jammin' Once Again,
Mariodawg!

Hi Mariodawg,

You needn't apologize for any time lost; it's your deal, not mine. I get the exact same pay here every day, whether I work or not.

I never expected that you would hear the slightest degree of difference between the new and old caps. Your biggest problem at this point is with their reliability, and that can only be solved by finding some caps that are rated for higher voltage. 150 volts minimum, but for real peace of mind, 200 volts. This is not just from me, but from the guy that designed the system.

As to phasing, it may well be that your ribbons are wired with plus to black, as the schematic shows the Originals were. If that is the case, the woofers being black-to-black would be preferable; then both driver array would be out of phase with each other, the desired situation.

As to fuses, the chosen value is a compromise between speaker safety and unnecessary blowouts. Five amps was the value used early on, but lowered to as low as 3.2 later on. Check through the manual's section on factory engineering changes and you find several fuse changes. I'd try some 4 amp slow blow ones first. If they hold under all reasonable conditions, you are safer with them in there. And after a time, you might even try some at 3.5, to see if they hold. One good thing:
When one blows, you won't need a meter to find the problem.

Robert R

Copy all, Robert R!

I see I made a mistake in my last reply---my new caps are 150uF 100VNP, just like the old ones. Just had to clear that up.

I will be looking for 4 amp slow-blow fuses then. I like the idea of added protection. But what about the 250V voltage rating? Does it matter on a fuse?

I B Jammin',
Mariodawg

lAs I said, the cap numbers and voltages are confusing, when they are both about the same. So now we both got it wrong once. Main thing is, it's right in the speaker, at least the microfarads. You still need a higher voltage cap.

For the fuses, 250 volts is fine.

RR

Hey mariodawg,

I take it the speakers are going OK. Two points:

First, as I sort of feared, the woofer holes in your Originals are slightly larger than the later Platinum types require. There was a fill-in bracket obtainable at one point, not sure about now; probably not - it was from the factory. But the original (FL) type woofers are still obtainable for replacements, or something could be fashioned to sub for the brackets (which were two-piece, I think). Don't know if the FL is for FLat, but it works for remembering, regardless.

And second, did you have any luck in your higher voltage NP capacitor quest? I keep hoping you'll find some and save me (and maybe others) the trouble...

RobertR

RatShack are stupid ass sales kids... Mine told me they didn't have the pen too...
Knowing what idiots they are, I went and looked anyway....
Of course they had it...

It wouldn't hurt to go and look yourself.. you may be able to be up and running tonight.
"If you want something done right, do it yourself"

This thread saved me today. Never heard of this pen until now. Had a trace open up this weekend and the Shack had one amazingly.
One point I can add, it is best to apply the liquid with a softer second item. I have little applicators that are topped with paper ends. The pen requires you to press in the plastic point before you squeeze, and I got very nervous doing that on the rebuilt ribbons.