Crossover Help Needed With ANOTHER Pair of ALTECS

[GM]

Beat me to it.

I've been a big fan of Hakko ever since they came to the USA and it didn't arrive none too soon since Ungar's QA was heading for the toilet while its pricing was skyrocketing. Monthly expenditure on 1000 W elements alone were putting a major crimp in the hobby budget even after we ditched the element destroying wet sponge for 4/0 steel wool pads. Now, after years of heavy use/abuse and many more of casual use, the original tip is finally starting to go bad and I've gone through a surprising few cleaning pads, but the iron is still doing fine AFAIK.

Never owned one of their stations though, being more interested in soldering up slot car chassis or other apps requiring high temp for silver soldering, though with the late, great bang/buck RadioShack 64-2054 soldering iron temp control I can change the tip and dial in whatever temp required to get the job done, even on a PC board/temp sensitive components.

This is the closest holder to what I have, though mine is much more substantial and lower profile. This one would of required me to carry it separately rather than fit in my slot box, so got lucky.

Hakko's insulated storage pouch is a nice accessory to have for folks 'on the go' since you can then handle/store the iron immediately without fear of burning something.

GM

[voice of the theater]

I spent all day Thursday recapping both pair of Model 19's. I also connected the four ground lugs in each of the four speakers by soldering in good quality wire--effectively bypassing the ground lugs. I started about 1 pm, and finished at around midnight. Of course I took some breaks, and some of the time was spent moving speakers around/connecting/disconnecting speakers for A/B comparisons. When I originally auditioned each pair (before I paid for/bought them), I did A/B comparisons and verified that each pair was an identical sounding pair. When I got the second pair home last fall (the pair that was manufactured in 1977), I did A/B comparisons and verified that each of those two speakers not only sounds identical to each other, but also sounds identical to the first pair I bought (the pair that was manufactured in 1978). I felt extremely fortunate at the time that all four speakers had all their original parts in mint condition and all four speakers sounded identical to each other.

Anyways, to determine if this was going to be an upgrade or not, I had decided to continue with my usual A/B comparison process (my amp has speaker A and speaker B switches so it's easy to click back and forth "instantly" between two speakers to listen for differences). So, I put two of the speakers right next to each other, and verified (via A/B comparison) that they still sounded identical to each other (they did). I then recapped/re-grounded one of them, and did an A/B comparison to see if they now sounded different from each other. By the way, I was very careful when recapping this first pair to keep the leads as long as possible on the old caps when I pulled them, so I could put the old caps back in if I didn't like the way the new caps sounded. I have to admit, I was very nervous about doing this upgrade. The model 19's are the best sounding speakers I've ever heard in my life, and I was very nervous about frying something in the crossovers for an upgrade I wasn't even sure they needed. But Altec Best (and later J Henry who also followed Altec Best's recommendation) and others swore by this upgrade and I know Altec Best owns a lot of Altecs and have always felt he knows his stuff. Not to mention, Bill at GPA recommended Solen fast caps when I recapped my AS-101's, and those are the same caps Altec Best recommends.

Well, I did the A/B comparison after recapping/connecting ground lugs for my first Model 19 and low and behold---there was a difference. The two speakers no longer sounded identical. The recapped speaker clearly sounded better than the original. I was surprised by the difference--the sound was clearer, more defined, and appeared to have better high frequency extension and surprisingly also had noticeably "tighter/deeper" bass as well. I have always added about 4 dB of treble at 16 khz for both pair of Model 19's with an equalizer to give them just a little more "air"/"sizzle" in the high end. Well, as soon as I did this A/B comparison and heard the improvement, I set the 16 khz EQ band at flat. The upgraded speaker still had just as much "air"/"sizzle" in the high end that it used to have when I was adding treble at 16khz (prior to the upgrade), but now it didn't need a boost at that frequency and it still had a noticeably clearer, more defined, more balanced sound than it ever had before. It wasn't even close--the recapped/regrounded speaker not only sounded clearer/cleaner/more balanced (with a noticeably more extended h/f response), but I was really surprised that the bass had more "thump" and depth as well. The speakers didn't really sound brighter than before (BTW, they don't need to sound brighter), but the h.f. did seem to roll off at a higher frequency now so there was no more need to boost at 16k. I'm not sure how much of the improvement (or which elements of the improvement) are specifically related to the recapping or the re-grounding, all I know is that the combined effect is incredible.

Well, I continued by recapping/re-grounding the second speaker. When I finished, A/B comparisons revealed that it sounded identical to the first speaker I had just recapped/re-grounded. Equal improvement. I did the second pair, and compared them one by one to the first pair after each upgrade (A/B comparisons--one speaker at a time), and all four speakers sound identical to each other and all sound surprisingly better than before the recap/re-grounding.

Listening to them one speaker at a time is all well and good (during my A/B tests), but on Friday I moved the 1977 pair back into my (in home) recording studio and moved the 1978 pair back into their usual position in my rec. room and spent some time listening to each pair in stereo/two at a time. I listened to some recordings that I consider to be extremely good (and extremely well mastered) that I have heard several times recently/that I am very familiar with how they sounded on my Model 19's prior to the upgrade. Well, listening to the same recordings on the newly upgraded Model 19's (in stereo/two at a time), I was really able to appreciate the magnitude of this upgrade. Not only do I no longer need to add any treble at 16 khz, but I'm also adding less bass E.Q. as well. After adjusting the EQ, I listened to them in stereo and was blown away by the sound quality. The best analogy I can think of is that I feel like my system has been upgraded to high definition. The sound is incredibly detailed -- noticeably more so than ever before -- amazing definition/clarity/and noticeably better overall tonal balance. I'm adding less treble and bass with my EQ than ever before and the speakers have better low and high end frequency extension and tighter/deeper sounding bass than ever. I also noticed that the stereo imaging is enhanced as well. On certain recordings, I can really pinpoint where each instrument/vocal is located (spatially) in the mix--more so than ever before. It's hard to describe but, for example, lead vocals that are in the center of the mix appear to be even more "dead center" now--there is absolutely no audible wandering on high or low notes--everything is more "locked into place" as far as stereo imaging/sound-stage than I've ever heard before. I know I have good acoustics in my two basement listening rooms--and with this upgrade I can really hear it. Having brand new caps that are up to original spec and properly grounded crossovers has also created this unexpected benefit as well. Words can't adequately describe the difference--treble. midrange, bass all sound amazing/crystal clear and all now all sound better than my Model 14's. The best speakers I've ever heard in my life now sound even better...... I plan on doing the Model 14's this weekend--hopefully the upgrade will have a similar effect on them.

Here's one of the re-capped crossovers:


By the way, in this photo, you can see that I've bypassed the treble pot (in all four of my Model 19's) by soldering the two wires together. I did this upgrade in the fall since I always was listening to the 19's with the treble control "all the way up" which is in the optimum range. When I did that upgrade, I noticed the high end was improved slightly at the time. I'm not going to bypass the mid pots, because I turn them down somewhat towards the optimum range -- and I like being able to "play" with them. I'm sure I'll be "playing" with them now that I've done this upgrade to determine where they sound best in the rooms they're located in. I've thought about fixed capacitors but if I ever move them I'll need to play with the mid pots again--so the thorough cleaning I've given all four mid pots will suffice.......

Here's the old caps--I noticed that the caps from the '77 pair were different from the '78 pair but had the same values (and all four crossovers were wired identically).... BTW, as far as my new capacitors, I was able to get Solen 8's, 6's, 16's, but had to combine Solen 9's and 12's to achieve 21's....



I bought a new soldering iron for this upgrade--followed Earl's recommendation and got a Weller 40 watt. I've always been good at making a nice solder connection but having a new soldering iron made it quicker and easier than ever before. I also bought a pair of Kelley Forceps as per Earl's recommendation and the thought occurred to me that the alligator clip that I use with my "third hand" tool inadvertently acts as a second heat sink as well. I noticed that the forceps got warmer than the part of the leads that were past the forceps--but neither ever got hot so I know I succeeded in keeping the new caps pretty cool.....

Thanks to EVERYONE here who assisted me with this upgrade!!!!!! Think I'll make some lunch and then go downstairs and crank up the Altecs!

[westend9]

Well if there was ever an endorsement for recapping crossover networks, I don't remember a better one. Glad it all worked out so well for you.

Yeah GM, the Hakko stations are pretty good, I use a 936 with brass tip cleaner and have totally weaned myself from the wet sponge. I concentrate on board work so the adjustability is not often used, but it sure comes in handy when working with point-to-point stuff. I am eyeing up the Hakko 808 desoldering tool, now. Reports are that it is akin to sliced bread.

On a totally off topic note,GM....... I have finally received into inventory, six new sheets of Baltic Birch ply for the stalled "MLTL Large Model 19" we discussed back in forgotten history. I have the original thread bookmarked and will bring it back to life when I have some birch sawdust on the floor. FWIW, I returned the previous Birch ply that I had, there were quality concerns. For new material, I visited my local hardwoods supplier and was able to select my own sheets out of a birch packing crate that had some indeciferable (maybe Latvian?) script on the crate.

[voice of the theater]

I recapped both Model 14's today. As much as I'd like to say it was another huge success, unfortunately I hit a "snag" and I need to ask the experts out there a question. I started out just like I did with the Model 19's. I set the two Model 14's up one right next to the other and did an A/B listening test to verify that they still sound identical just like they did when I bought them. They do still sound identical. I then recapped the crossover in speaker number one. Here's a photo of the successfully recapped crossover.


Everything was going great and then I hit a "snag". As I mentioned earlier in this thread, unlike the Model 19's, the caps in the Model 14 crossovers are soldered directly to the circuit board of the crossover. I'm not comfortable soldering directly to a circuit board, so as I mentioned earlier in this thread my plan was to clip the leads from the old caps while being sure to leave enough of the old leads intact and attached to the board to allow me to just solder the new caps to them (solder the leads of the new caps to the portion of the old leads I leave intact/attached to the board). You may now be able to guess what the snag was. This process went great for every connection in this crossover but one. I got nice, secure connections from the new lead of each new cap to the portion of the old leads that I left intact/attached to the board, EXCEPT FOR ONE! While soldering in the 2 uF cap, one of the old leads got loosened/removed from the board by the heat of the soldering process. I had no choice but to solder this one lead directly to the board. So, I poked the lead from the new 2 uF cap through the same hole where the lead from the old 2 uF cap pokes through from the other side, flipped the board over and soldered the new 2 uF lead securely to the board just like the old 2 uF lead was. It went well, I breathed a sigh of relief and now had all three new capacitors soldered securely into the crossover. I put the crossover back into the cabinet and did another A/B comparison. The recapped Model 14 now sounded noticeably better than the one with original caps--similar improvement to what I described in my post earlier today regarding the improvement I noticed in my Model 19's after recapping them. I immediately noticed clearer, cleaner, more detailed sound and improved high frequency characteristics--the high end now appears to roll of at a higher frequency...... Substantial improvement in the treble and midrange sound--not sure if the bass is improved. I'll listen to them as a pair to be sure of that......

OK, here's the part where I need to ask a question of the experts out there. I then started recapping crossover number two. Every solder connection went smoothly except the same old 2 uF capacitor lead on this crossover got loosened/detached during the soldering process as happened in crossover #1. So, I had to solder this 2 uF lead directly to the board just like I did in crossover #1. While soldering this lead directly to the board, I accidentally fed a little too much solder to the connection and caused a big drop of solder to form on the board. Unfortunately, this "big drop" of solder touches the solder connection directly below it as well. If you look at the two photos below, the first one shows where I soldered the one 2 uF capacitor lead directly to the circuit board. In the top center of the photo, there are 3 solder connections right next to each other, each one right below the next (three in a vertical row). There is no big drop of solder connecting the top two solder connections (the top one is where the 2 uF lead is attached). In the next photo, you can see where I soldered the one 2 uF lead directly to the board and accidentally dripped a "big drop" of solder that connects the top two out of three solder connections (and possibly the third as well although I think that the second and third were already connected by solder on this crossover). Sorry the first photo is a little dark--I didn't realize the flash didn't go off due to my work light being on.




Anyways, here's my question for the experts. After examining the circuit board in both speaker crossovers, I noticed that some of the solder connections that are very close to each other/right next to each other are either on the verge of touching or appear to be actually touching due to the amount of solder used. Other solder connections on the boards are far apart from each other and are not touching or on the verge of touching any other solder connections. For example, on the left side of both photos you can see where two "separate" solder connections (that I haven't touched) that are right next two each other are clearly connected to each other by the amount of solder used. My hypotheses is that the solder connections that are extremely close to each other on the board are actually connected to each other at some point so it's OK if the solder touches or is on the verge of touching these connections together whereas the solder connections that are isolated must remain isolated and must not touch anything else. Is this theory correct and therefore is it OK that the "big drop" of solder is connecting 2 out of the 3 solder connections (or 3 out of the 3)? If not, I'll have to try to "melt off" the big drop of solder and I'd really like to avoid having to do any more soldering directly to this board other than the one connection I've already done. I'm not going to hook this speaker up to my amp for fear of potentially causing damage until I hear from the experts out there that it is OK for the connections that are that close on this board to touch due to the amount of solder used because they are connected anyways. The recapping process went great on both Model 14's and I have nice, secure solder connections for all of the new capacitors -- the only snag is that I need to know is if this "big drop" is a problem. The 2 uF cap is securely soldered in place but I'm not sure if the connection that the "big drop" causes to the next solder connection is a problem. I'm trying to not beat myself up too much considering all four Model 19 recaps and both Model 14 recaps went great/all nice secure solder connections and the only potential snag is this one "big drop". However, it's hard to not beat myself up about this when I'm afraid to hook up my Model 14's to my amp because of this "big drop" of solder....... Thanks in advance to anyone who can shed light on this question---in the meantime my Model 14's are out of commission:doh:

[Earl K]

You need to buy ( & then learn to operate ) a solder sucker ;



- I typically use a solder sucker to clean up a pc boards' ( pads/holes ) before inserting the leads of any new components .


- FWIW, in practise, I use a solder sucker 5 times more often than desoldering braid ( which you should also own ) .


Here's a good ( step by step ) article on desoldering ( found by Googling "solder sucker ) . Click the following logo ;



- BTW, I agree with the authors advice about using only a 25 to 30 watt iron when working on PC boards ( like what is displayed ) .
- Crossover boards are a bit different in that the traces are typically much larger/thicker & more robust .


cheers <> EarlK

ps ; Glad your new caps are working out for you .

[voice of the theater]

Thanks for the info Earl--I'll read the article this afternoon. I still need to know -- can I leave that big drop of solder where it is in the meantime? Is it OK for those two (or 3) connections that are right next to each other to touch? Are connections that are that close to each other on this board/grouped together, connected at some point anyways? I'm guessing that if they weren't connected at some point they wouldn't be grouped together so closely--there are plenty of other connections on the board that have more space between them and those three look purposely "grouped together" (as do the two connections to their left in both photos that are grouped together and are also touching due to the amount of solder used when the boards were originally assembled). My Model 14's are out of commission until I get an answer to this question as I'm afraid to hook up my amp to that speaker until I hear that it's safe to do so with that big drop of solder connecting two (or three) of the solder connections......

[aditya]

...........I still need to know -- can I leave that big drop of solder where it is in the meantime? ..............

...............My Model 14's are out of commission until I get an answer to this question as I'm afraid to hook up my amp to that speaker until I hear that it's safe to do so with that big drop of solder connecting two (or three) of the solder connections......

Hi VOTT,

I just saw your post.........and compared both the pictures posted by you.
As the pictures were a bit dark, I also processed them so that no wrong conclusions are there.

Yes you can leave the soldering as it is.
It is one and the same (common) joint electrically for all the individual 3 of them.

Generally speaking, close-knit joints like these mostly belong to a common point, but this may not be always true. But in this case it is a common joint and you can happily power up & commission your Model 14's......enjoy

Aditya

[voice of the theater]

Aditya--thank you so much for your answer to my question--you just made my day! I was ecstatic that the recap for all four Model 19 crossovers went so well--all solder connections nice and neat and secure and a substantial improvement in the sound of all four Model 19's. Likewise, every solder connection in the Model 14 crossovers were nice, neat, and secure except the one connection in question where a drop of solder dripped--it was a secure connection but that connection was not neat. I had a feeling that those three connections shared a common joint and that it was actually not a problem but as I mentioned I didn't want to power up that particular Model 14 until I got a definite answer. The first recapped Model 14 sounded so great that I can't wait to now power up the second one and hopefully verify that it has also received a substantial upgrade in sound quality. I'll do some listening today and tomorrow and hopefully post some good news soon! Thanks again to everyone here for all the help on upgrading the 19's and 14's crossovers.....

[Altec Best]

Hey VOT, It's really nice to see you making so much progress !! Keep up the great work ! :2thumbsup:

[voice of the theater]

Hey VOT, It's really nice to see you making so much progress !! Keep up the great work ! :2thumbsup:

One of the best recommendations I ever got on this forum was when you recommended I upgrade to Solen Fast Caps and solder in wire to connect the four ground lugs in my Model 19's. Now my only regret is that I didn't do it sooner! I'm amazed at the improvement in sound quality--thanks again!!