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voice of theatr
02-26-2009, 10:13 AM
Hello--I joined this forum a few days ago and I'm already very impressed with the expertise shown here regarding classic "vintage" altecs. I would really appreciate any advice I can get here as it's not easy finding people who know about these older speakers. I have two pair of Altecs that are about 40 years old and I've heard that the caps in the crossovers should always be replaced in speakers that old. My Altec Valencias are from 1969 (for my basement stereo) and I just bought a pair of 1971 Heathkit/Altec AS-101 (same drivers as the Valencias/voice of the theater) from my local craigslist (for my living room stereo). http://i532.photobucket.com/albums/ee329/pullingstringsband/basement1.jpg (left to right Altec Valencia with Altec model 9 on top, heathkit/Altec AS-101) Anyways, the Valencias and AS-101s both have all the original drivers in mint condition and even the original diaphragms. http://i532.photobucket.com/albums/ee329/pullingstringsband/heathkit-1.jpg http://i532.photobucket.com/albums/ee329/pullingstringsband/valencia-inside-cab.jpg I have noticed that the 806A horn in one of the AS-101s is not quite as bright as the other and that motivated me to open the cabinets and look at the caps. There are 3 caps per speaker and a couple of them look like they may have leaked oil at one time--could that be the reason why one of the horns isn't quite as bright as the other?http://i532.photobucket.com/albums/ee329/pullingstringsband/crossover-2.jpg I've been looking to find replacement caps--GPA recommended I use Solen Fast Caps. I went to the Parts Express website and checked the ratings on all their different brands of caps and the closest I've found are Solen Fast Caps. The originals are rated 8 uf 50vdc, 10 uf 50 vdc, and 11 uf 50vdc. All the caps I've seen at parts express are at least 400 vdc but I've heard that the extra vdc just gives you more headroom and won't hurt the sound--what I really need to match up is the uf rating--does anyone know if that's true? The solen has an 8.2 uf cap which I'm assuming is close enought to the original 8, they have a 10 uf cap which matches the original 10, but they don't make an 11 to match the original 11--they have a 12 uf. Is that close enough considering the solens are +/- 5% and the original caps are rated +/- 10%? Also, the "copper" in these crossovers doesn't look so great. http://i532.photobucket.com/albums/ee329/pullingstringsband/crossover-1.jpg Is that anything to worry about or should I replace the caps first and see how they sound before worrying about the "copper".... Lastly, my Valencias have a sealed crossover box which is riveted shut! http://i532.photobucket.com/albums/ee329/pullingstringsband/valencia-crossover.jpg They sound identical to each other but they are from 1969 and I can't help wondering how much better they'd sound with brand new caps. Has anyone out there ever pried open one of these Valencia (type) crossover boxes which are riveted shut? Any advice on how to do this safely? If I ruin my Valencias I'll have to put myself in the doghouse!
P.S. I also have a pair of P.A. Voice of the Theater A7 speakers (in the huge cabinets) that I use for PA for my (rock) band and I'm considering replacing the caps in those crossovers as well--has anyone out there ever opened up the crossover box for an Altec N501-8A crossover before? The speakers/horns sound identical to each other but like my Valencias, I'm wondering how much better they'd sound with new caps......The description of the Solen Fast Caps on the Parts Express website makes them sound like the best thing since sliced bread! "The exceptional Solen line of metallized polypropylene capacitors features a high purity, polypropylene film dielectric. They exhibit outstanding high frequency characteristics, low dielectric absorption factor, high current capacity, and unrivalled handling of fast high current pulses. Designed specifically for use in loudspeaker crossover networks. All values are rated at 400 VDC, except for the 130uF, 160uF, and 200uF values which are rated at 250 VDC. 5% tolerance. "

Thanks for any help on these questions that anyone out there can give me.....
Dave

Zilch
02-26-2009, 02:51 PM
3.3 uF in parallel with 4.7 uF = 8 uF
10 uF in parallel with 1.0 uF = 11 uF

You can break into the stock Altec crossovers, but it's largely pointless to do so. Assuming the Heath driver components are the same as your Valencias, your best option is to build new crossovers for the Altecs.

Actually, your best option is to biamp using a Behringer CX3400 active crossover and push the "CD Horn" button.

More than you'll ever want to know about Valencias may be found in this thread:

http://www.audioheritage.org/vbulletin/showthread.php?t=14690

N501-8A is here:

http://www.altecpro.com/pdfs/vintage/SpeakerAndMics/crossOverNetworks/N501-8A%20Crossover%20Network%20Schematic.pdf

voice of theatr
02-26-2009, 06:33 PM
Thanks Zilch! I've also considered replacing the 40 year old L-pads on the AS-101s but that gave me a (crazy?) idea. Since I always leave the L-pads "all the way up" on my AS 101s is BYPASSING the L-pads an option rather than replacing it? Would bypassing The L-pads be just like leaving the L-pads "all the way up" and also eliminate any distortion being caused by an old L-pad (or would bypassing the L-pad change the impedence or sound or cause some other undesired effect)? Does anyone out there know if bypassing the L-pad is an option and how difficult would that be to do? I would leave the old L-pad where it is but not have it wired to anything?

Zilch
02-26-2009, 07:45 PM
It just got more complicated.

I checked to see if AS-101 actually used an L-Pad as opposed to a potentiometer. It does, and your Heath system is 8 Ohms; the compression driver would be 806-8A. See the schematic below.

You said 806A, which would be 16 Ohms, implying that your Altec system is 846A, 16 Ohms, instead. Verify via the label on the rear. If so, the crossover is N-800-F, NOT the same as that used in the AS-101, which is the equivalent of Altec N-800-K, what was used in 846B Valencia.

SO, do we know how to make N-800-F? Yes, but we substitute an L-pad for the stock potentiometer attenuation.

Answer to your question can you bypass the L-pads, is, "Yes." I would replace them, however, instead.... :yes:

voice of theatr
02-26-2009, 08:14 PM
You're right--the Heathkit AS 101 has 8 ohms printed on the horn and also has the heathkit part number on it (401-150) so it must be the 806-8a driver--8 ohms. http://i532.photobucket.com/albums/ee329/pullingstringsband/horn-2.jpg My valencias have the 806A (with 16 ohms printed on it) and 416z--is the 416z woofer 16 ohms as well? Does this mean the Valencias are 16 ohm speakers? The spec sheet in the Altec library lists impedence of the Valencias as 8/16... The heathkit woofer has the heathkit part number stamped on it (401-149) which I'm told is the 416Z and it also has 8 ohms printed on it-- is it an 8 ohm version of the 416? The attachment you sent me was a pdf from the original heathkit as 101 manual--is there somewhere I can download the rest of the manual? Is there a manual available for the Valencias? As far as bypassing the L Pad--I'd like to leave these "stock" for now so I'm inclined to just bypass the L Pad for now rather than replace it in case I sell them some year I can just reconnect it. Is there any sonic disadvantage to bypassing it as opposed to replacing it (considering I leave it "all the way up") anyways? Is the wiring complicated to bypass it? Thanks again...

Zilch
02-27-2009, 12:37 AM
You're right-:banghead:


-the Heathkit AS 101 has 8 ohms printed on the horn and also has the heathkit part number on it (401-150) so it must be the 806-8a driver--8 ohms. My valencias have the 806A (with 16 ohms printed on it) and 416z--is the 416z woofer 16 ohms as well?Yes


Does this mean the Valencias are 16 ohm speakers?I guess so.


The spec sheet in the Altec library lists impedence of the Valencias as 8/16... The heathkit woofer has the heathkit part number stamped on it (401-149) which I'm told is the 416Z and it also has 8 ohms printed on it-- is it an 8 ohm version of the 416?416-8Z


The attachment you sent me was a pdf from the original heathkit as 101 manual--is there somewhere I can download the rest of the manual?Not that I know of. You can probably purchase a copy from a purveyor of Heathkit info.


Is there a manual available for the Valencias?I'm it, apparently.


As far as bypassing the L Pad--I'd like to leave these "stock" for now so I'm inclined to just bypass the L Pad for now rather than replace it in case I sell them some year I can just reconnect it. Is there any sonic disadvantage to bypassing it as opposed to replacing it (considering I leave it "all the way up") anyways?None.


Is the wiring complicated to bypass it?Take the lead off the common center terminal and connect it to the other lead on R1.


Thanks again...There's more? ;)

voice of theatr
02-27-2009, 11:32 AM
Thanks again for all the help! OK, I'm going to try to bypass the old L Pads first, listen to see if there's a difference in sound afterwards, then I'm going to order the new caps--replace those and listen again for any improvement--and then I'm done (hopefully!). I'm figuring that doing this kind of stuff one step at a time and then evaluating any difference after each step will be the best way for me to know how much difference (if any) each step makes. Here's my dilemma. There are 4 terminals on these old L Pads. If I'm going to bypass them, I'm going to leave them in place just so I still have all the "original equipment" but I want to disconnect every wire from them to be sure they're no longer affecting the sound (since I leave them turned "all the way up" anyways). I have no clue which wires to connect to which wires to achieve this bypass (and I don't own a defibrillator)... Here is a visual--I need help! (an understatement)....http://i532.photobucket.com/albums/ee329/pullingstringsband/L-Pad.jpg All of the following description applies to the above photo--I added the photos below just to give more of an overview. As you can see in the above photo (hopefully), there are two upper and two lower terminals on this L Pad. I'll refer to the upper terminal that's closest to the camera as upper near, and the further one as upper far etc. (these LPADS look really corroded). OK, to give you a frame of reference, there are three wires soldered to the upper near terminal of the LPAD. The red one goes directly to the positive terminal on the horn, and the black one goes directly to the 8 uf cap and a very short uninsulated third wire connects the upper near terminal to the lower far terminal of the LPAD as you can see in the photo (I think it's called a "jumper'?). By the way, that "jumper" is the only thing soldered to the lower far terminal. The top far terminal has only one black wire soldered to it which connects to a post on the crossover frame (body)--this post sends one wire to the 10 uf cap (which looks like it has had oil leak all over it from inside) and A SEPERATE WIRE from the post to the 11 uf cap and a third separate wire from the post which looks like it connects to one of the two copper colored squares (i think it's called an inductor?!). Lastly, the bottom near terminal of the LPAD has only one wire soldered to it which looks like it's connected to the bottom of one of the two rectangular copper colored "inductors"(?). As I mentioned, I want to disconnect every wire from these old L Pads to be sure they're totally bypassed--what wires do I connect to what wires to achieve this bypass? I would really appreciate help on this matter--I have no clue and I really don't want to fry anything etc..... Here's a few more photos in case any of these help--I moved one of the caps for the photos to give you a better view....http://i532.photobucket.com/albums/ee329/pullingstringsband/crossover3.jpg http://i532.photobucket.com/albums/ee329/pullingstringsband/crossover-4.jpg http://i532.photobucket.com/albums/ee329/pullingstringsband/crossover.jpg http://i532.photobucket.com/albums/ee329/pullingstringsband/AS101Schematic-1a.jpg Thanks again!!!!!!

Zilch
02-27-2009, 01:15 PM
It's wired wrong, and I want you to figure that out and tell me how.

Check to see if the other one is wired the same way, for starters.

Once we fix that, you'll likely be changing your mind about bypassing the L-pad(s).... :yes:

voice of theatr
02-27-2009, 07:05 PM
I opened up the other cabinet again and they are wired differently! This is a heathKIT so I guess I shouldn't be too shocked. Surprisingly enough, the guy I bought these speakers from (two weeks ago) teaches engineering at a local university and he made a point of telling me how his father was the original owner of these speakers back in the 70's and that his father is an engineer as well! Good thing this isn't a heathkit amp or dynaco amp or there'd be smoke coming out of it! Thanks for catching this for me. Here are some photos of this L pad/crossover wiring...http://i532.photobucket.com/albums/ee329/pullingstringsband/other-L-pad2.jpg
http://i532.photobucket.com/albums/ee329/pullingstringsband/other-L-pad-3.jpg
http://i532.photobucket.com/albums/ee329/pullingstringsband/other-crossover.jpg

If you compare this to the photos of the other crossover--the top near terminal has a red wire connected to the positive terminal on the horn, and there is a "jumper" wire connecting the top near terminal on the L pad to the bottom far terminal. However, THERE IS NO BLACK WIRE ON THIS TOP NEAR TERMINAL CONNECTING IT TO THE 8 uf CAP (which the other L pad DID have a black wire)--just the red wire and the jumper on this top near terminal. The top far terminal is wired exactly the same on this L pad as on the other one: it just has one black wire that leads to a post connected to the chassis of the crossover. That post is wired identically to the corresponding post on the other crossover--it has one wire from the post to the 11uf cap, a SEPARATE wire from the post to the 10 uf cap, and one more SEPARATE wire connecting the post to one of the (two)Copper colored "inductors"(?). The bottom near terminal is also wired DIFFERENTLY than the bottom near terminal on the other L Pad. This one has a black wire connecting it to one of the two copper colored inductors(?) just like on the other L pad, but unlike the bottom near terminal on the other L pad, this one has a second wire connected to it. This wire connects the bottom near terminal of the L pad to the 8 uf cap!! Believe it or not, there is an even more disturbing difference on the bottom far terminal. Just like on the other L pad's bottom far terminal, this bottom far terminal has just one wire soldered to it--the jumper from the top near terminal. But as you can (hopefully) see in at least the top photo of this reply, the bottom far terminal of this L pad is physically touching a post in the center of the crossover chassis!!! It isn't soldered to the post so i think it is an unintentional connection, but it is touching the post in the center of the chassis because the whole L pad is facing a different direction (about 90 degrees different) than the L pad in the other crossover which puts the lower far terminal touching the center post in the chassis. I suspect at some point someone was adjusting the treble by turning the L pad knob on the back of the speaker and inadvertantly twisted it too hard and rotated the whole L pad 90 degrees! Anyways, this post that it's touching has a black wire connecting the post to the 8 uf cap, and a separate wire connecting the post to one of the copper colored inductors(is that what they're called?). I checked ALL other wiring on the two crossovers and the rest of the wiring is identical and there appear to be no other "accidental" connections caused by components touching each other. The funny thing is that in spite of all this--the two speakers sound virtually identical to each other. I temporarily have them in the basement next to my Valencias and I've been doing A/B comparisons and (with the help of my alesis graphic EQ that I use for my valencias) they sound incredible--virtually identical to the Valencias when EQ'd the same. Incredibly vibrant, powerful, and crystal clear. At first I thought one AS-101 sounded brighter than the other but I moved the right one to the left side of the room and the left one to the right side of the room to see if acoustics were playing much of a role and they now sound virtually identical. I'm still going to replace all 6 caps because at least two of them have leaked oil and I'm sure it will improve the sound and make them sound even more identical to each other but right now obviously my top priority is to get these things wired correctly. Once the wiring problem is figured out I'll probably still want to bypass the L pads if possible. My rationale is that since I leave the L pad "all the way up" like I do on my Valencias, I'm unneccessarily putting the signal through 40 year old L pads which are "all the way up" and if they were in perfect condition would sound the same "all the way up" as bypassed. But since they're 40 years old and corroded I'd just as soon not send the signal through them unless it's going to be a pain figuring out how to remove them from all wiring....
Well, there you have it--multiple differences in the wiring (good catch)--how can I fix this wiring screw up? Thanks again!

Zilch
02-27-2009, 07:23 PM
Yes, you found it, or at least, what I identified in comparison to the schematic. Only the red wire and the jumper should be connected to the top near terminal.

Move that black wire going to the 8 uF from top near to bottom near on the first L-pad, if you agree that is correct according to the schematic, and rotate the second L-pad or whatever is required to mitigate the short, then compare both crossovers to the schematic to make sure there are no other errors.

Do you also run the attenuation controls on your Altec 846A Valencias at minimum attenuation?

voice of theatr
02-28-2009, 10:47 AM
OK, I got out my trusty soldering iron and moved the black wire that connected the top near terminal to the 8 uf cap and it is now connecting the lower near terminal to the 8 uf cap. I also loosened, rotated, and then re-tightened the L-Pad on the 2nd crossover so that none of it's terminals are now touching posts or any parts of the crossover chassis. I can't understand the schematic but I double checked all connections/wiring on both crossovers and after the two aforementioned changes made this morning they are now wired identically. I also took a close look at all solder connections and gently tugged on all wires to make sure all connections are soldered securely and they are. I closed the cabinets back up, and listened to them for a while at various listening levels and even moved them back to where I had them situated initially (back when one horn had sounded slightly brighter than the other) and they now sound more or less identical! Thanks for the help--who would guess that having things wired correctly and not shorting out would make a difference! ;)

Anyways, I then gave the L Pads a (primitive) white noise test. I set my f.m. tuner for mono and tuned it to where there is no station nearby so all I was hearing through the speakers was a nice steady f.m. hiss. I turned the preamp balance all the way to the right and turned the L pad knob all the way down on that speaker and then all the way up to see if it cut in and out etc. and it seemed to work pretty smoothly---it gradually reduced treble from the horn and then when I turned it in reverse gradually it gradually increasied it until it was back "all the way up" where I prefer it on the 101's. Then I turned the preamp balance control all the way to the left and repeated the "test" on the left speaker. This L Pad faded the treble gradually like the other one did, but when I went to turn the L Pad back up it cut out for a split second and when I turned it all the way up it didn't immediately turn the treble all the way up--it "waited" a second and then "faded" back up on it's own. I wiggled the pot. a few more times and it seemed more responsive but I really think i need to replace or preferably bypass those L Pads to get optimum perfomance. By the way, when I first brought these speakers home and opened them up I could smell "contact cleaner spray" coming from the crossovers--I'm sure the guy I bought them from cleaned the pots as well as he could (he must have really saturated the pots for them to still stink when I opened them up the next morning). If there's a way to disconnect all wires from the L Pads and then connect the wires to each other (I would guess in at least two clusters--one positive and one negative?) I would really appreciate some guidance. Otherwise, I can buy 2 new L Pads from Parts Express--but that just seems like a waste considering I'll be leaving them "all the way up" and I just feel like because of that I'm running my signal through an unneccessary circuit.... The L Pads at Parts Express have 3 terminals and mine have 4 so even if I replace the pads (which i'd rather not) I'll still appreciate advice on how to take wires off of the existing 4 terminals and connect them to the 3 new terminals.....

As far as replacing the caps goes--here's what I have in mind. I would rather not have any more caps in these crossovers than I need to have--there are slots for three and I'd like to replace them with 3 or 4 new caps rather than 5 or 6 if possible. The solen fast caps at parts express come in an 8.2 which I'm hoping is close enough to the original 8 uf. Please keep in mind the the originals (which say Chicago Condensor Corp) say that they are 8 uf +/- 10% which means they WERE in the range of 7.2 to 8.8 when they were new. The solens are +/- 5% which means their 8.2 is in the range of 7.79 uf to 8.61 uf -- that should be fine--same range, right? I would think a more accurate 8.2 would be a lot better than an 8 that might be 10% off? Solen does make a 10 uf cap so of course that will replace the 10s that are in there. The third cap that's in these crossovers is the 11 uf. There are three ways I could go here. Solen makes a 12 uf +/- 5%. If I go that route I would in the range of 11.4 to 12.6 which is my preferred route (replacing one cap with one cap) but it seems high (?) compared to the original 11 +/- 10% (range of 9.9-12.1). What do you think? As my second choice I'm thinking of following your suggestion on the 11 and replacing it with a Solen 4.7 wired parallel with a 6.2 (=10.9) or a Solen 4.3 wired parallel with a solen 6.8 (=11.1). Which do you think would be preferable---10.9 or 11.1? That would give me a total of 4 caps per speaker to replace the original 3 if I go with two caps to replace each 11, and replace each 10 with a ten and each 8 with an 8.2. Does that sound about right? Any preference on which configuration to use to replace the 11s? Not sure if I asked you this already, but the Solens are rated to withstand 400vdc and the originals are rated at 50 vdc. From what I understand there's no disadvantage going with a higher power rating is there? It just means they can withstand more current, right?

By the way, to answer your question, yes I do leave the treble control on my Valencia Crossovers set at max as well--they sound nice and crisp that way and don't require as much equalization if I set them that way. I also leave the treble control on my PA speakers (A7 Voice of the Theater in the BIG cabinets) turned all the way up for the same reason (see photo)http://i532.photobucket.com/albums/ee329/pullingstringsband/PA-Crossover.jpg

I've decided I'm not going to mess with the crossovers on the Valencias--they sound identical to each other and they are rivited shut in those "aluminum" boxes which I really don't want to BREAK open. You didn't seem too crazy about the idea of breaking them open in a previous post anyways... As far as the N501-8A crossovers, maybe I'll replace the caps this spring but I'm in no hurry. I only use them for rehearsals with my (rock) band and they sound great--we don't use them for gigs or for mixing or anything critical anyways. I wear ear plugs when playing in bands so even though someone reading this who doesn't know me might think I turn the treble crossover control up because musicians are often hard of hearing--my hearing is actually excellent.... Well, once again thanks--it is huge for me to have someone who really knows classic Altec Lansing gear coaching me.

Zilch
02-28-2009, 12:00 PM
Your existing L-pads have three terminals, once you appreciate that it's the jumper that combines the separate resistor elements of the two conventional potentiometers which comprise them into the equivalent of what more modern L-pads accomplish integrally within a single package.

To bypass the L-pads, connect the red wire from top near to those connected to bottom near by simply unsoldering them and using a wire nut. Leave that connected to top far in place, which simply connects to common; without any of the others, the L-pads will be effectively out of the circuit.

With respect to the capacitors, I typically try to match the values specified by the designer as closely as practical. You can have the debate with yourself as to what your own reality might perceive that to mean. I would use Daytons rather than Solens in these, as the Solens can sound harsh to some.

I am pleased to have been able to assist you in this. I suggest you print out a copy of the schematic, put it in a ziplock baggie along with notations as to what you have done to bring them to your final configuration, and put one in each of these AS-101 cabinets for future reference.

Know that to the extent I may be regarded as an Altec authority, that is unwitting in its entirety; I just help out as I can.... :thmbsup:

voice of theatr
03-01-2009, 11:15 AM
Thanks again Zilch! I bypassed the L Pads in both AS 101s and it did seem to "open up" the sound slightly--I think they might even sound a little cleaner not going through those 38 year old corroded L Pads. I printed 2 copies of the schematic, dated them, and noted what I did to bypass the L Pads/how to reconnect them. I'll store them in a zip lock inside each speaker (along with the 3 caps I'm going to remove). I really appreciate your patience dealing with some long posts with multiple questions. I'll try to keep this one as brief as possible. QUESTION#1 I left the "jumper" cable connected--that's fine, right (since everything else except the ground connection has been removed from L Pads)? I'm ready to order the caps for these speakers. I'm going to use the Daytons as you recommended. I went to the Parts Express website and there are more than one type of Dayton Caps that I can order. I read the descriptions and these caught my eye--they list these as a brand new product--QUESTION # 2: Have you tried these yet or should I use the standard Dayton Metallized Polypropylene Capacitors?

"Dayton Precision 1% Metallized Polypropylene Capacitors 250 VDC, high current capacity
Tightest capacitor tolerance available:+/-1%!
Extra-thick tinned copper leads
Specially designed for crossovers
Dayton Loudspeaker is once again leading the charge at bringing high quality, high value products to the speaker building community. Their new line of 1% tolerance capacitors gives you the ability to construct high-precision crossovers, which can eliminate "stereo wandering" and solidify the imaging and soundstage of your speaker systems. Commercial manufacturers know of this problem and buy thousands of capacitors so they can hand-match them for their products-- now you can effectively do the same, because every capacitor is matched!
These capacitors share the same excellent build quality, long-term reliability, and sonic clarity of the standard Dayton Loudspeaker metallized polypropylene capacitors. Well-known in the industry as the brand of choice for use in loudspeaker crossovers, they offer the performance of boutique capacitors at a fraction of the price. Let the excellent reputation of Dayton Loudspeaker and their Precision Capacitors help you build the best speakers that you possibly can." These are the first +/- 1% caps I've seen anywhere and I guess it makes sense that it would help with tighter stereo imaging?

I'm going to take your advice and wire multiple caps in parallel to achieve the exact ratings as the originals. For the 8 uf I'll use a 3.3 parallel wired with a 4.7, for the 10 I'll use a 10, and for the 11 I'll use a 10 parallel wired with a 1uf.... My crossovers have brackets to hold 3 caps (see photo)http://i532.photobucket.com/albums/ee329/pullingstringsband/other-crossover.jpg
There is room "in front" of the two "far" caps to place another cap without touching the post that's "in front" of the closest cap. Can I tape two caps together with electrical tape and, for example, put a 10 in the farthest bracket with a 1 taped to it (sitting "in front" of it) and put a 4.7 in the middle bracket with a 3.3 taped to it (sitting in front of it), and of course just put the single 10 that replaces the original 10 in the closest bracket. Here's a photo (using "cap shaped containers" to represent 2 caps) to illustrate how I'm proposing to use electrical tape to attach two caps together--Question # 3 Will taping two caps together like this cause any undesired heat or interference or other problems? The old caps are practically touching each other now so I'd like to think it's no problem having them close or touching--what do you think?
http://i532.photobucket.com/albums/ee329/pullingstringsband/cap-model-photo-1.jpg
Lastly, I have limited experience wiring/soldering. I can make a good solder connection--I've had practice repairing solder connections on guitar jacks etc. but I just want to make sure I'm 100% clear on how to parallel wire 2 caps (I know enough not to wire them in a series circuit). I drew a diagram this morning to illustrate how I would probably wire 2 caps in parallel(please excuse the (lack of ) penmanship--my handwriting is even worse than usual when I use a sharpie!). The blue wires are the ones that are currently connecting the caps to the crossover. I would cut the (blue) wires near the caps (one cap at a time to avoid confusion), remove the old caps one at a time and take each of the two wires that connected the crossover to the old caps (blue wires in diagram) and solder each "blue" wire to TWO wires from the new caps ending up with two wires from the crossover (blue) connecting to the 4 wires on the new caps (black) as shown in the diagram. Question # 4--Does this diagram look like a good way to parallel wire the new caps?http://i532.photobucket.com/albums/ee329/pullingstringsband/wiringdiagram1a.jpg


Question # 5 There is a wire coming out of each end of each cap (of course). Is one negative and one positive or doesn't it matter? Thanks again for your help--so much for me trying to keep this post short! d'oh!!

Zilch
03-01-2009, 11:32 AM
1) Taping them together is fine.

2) I've never tried the 1% Daytons; your money, your choice.

3) Yes, you've got "parallel" correct. Think wirenuts and cable ties to facilitate the upgrade.

voice of theatr
03-05-2009, 09:55 AM
Just soldered in the Dayton 1% replacement caps into the Heathkit/Altec AS-101 crossovers. Between bypassing the old L Pads and installing these new caps these speakers sound amazing--crystal clear with noticably improved stereo imaging as well!! They are officially my "first string" speakers for my "main" stereo and the Valencias have been demoted to my second stereo... Thanks for all the help on this!!!! I've read that crossover capacitors have a break in period of 10-100 hours before they sound good. These things sounded great from the second I powered them up--is the sound likely to change in the next 10-100 hours? I'll have to do some homework since the Valencias have the same drivers as the AS 101s. I need to figure out what to do as far as their crossover to get them to sound as good as the AS 101s.... Suggestions are very welcome on this!! I've been told that replacing the crossover is a better option than trying to modify the existing crossover or replace the caps because the aluminum box that holds the crossover is full of a black asphalt type material. I've read horror stories online of people opening the aluminum box and accidentally destroying the crossover. Still open to suggestions on the Valencias.... Maybe I should try to repicate the Heathkit AS 101 crossover for the Valencias--I've read that it's a better crossover than the Altec N801 crossover (and the AS-101s I own would tend to verify that since they sound noticably better than the valencias with the same Altec drivers other than the impedence). I'm wondering that since the drivers in the AS101s are 8 ohms and the drivers in the Valencias are 16 ohms--would the AS 101 crossover work in the Valencias or would it have to be modified?

Zilch
03-05-2009, 12:30 PM
Replace R1, R2 with a 16-Ohm L-pad.

[Or not, as you prefer.... :) ]

CONVERGENCE
03-05-2009, 05:55 PM
C1 8.8 MF
L1 4.5 MH
C2 8,8 MF
L2 4.5 MH

16 Ohms Lf Hf XO 800 HZ Second Order Buterworth 12DB

Zilch
03-05-2009, 07:42 PM
We've done this before, Convergence.

N-800-F is not a textbook crossover; it has HF comp built into it.

Here's some of the rest of what's on the schematic I posted @ #16: