N201-8A Shopping List

[Edacnz]

Hi all. I am still in disbelief that I have found a pair of Altec 19's locally and now have them sitting in my living room and am falling in love all over again. They are in need of some TCL - I've just ordered recone and diaphragm kits from Bill at GPA.

One of the crossovers is all but dead, so I will recap both of them.

Looking for suggestions for what brand caps to use, and wondering if I should do the inductors too?

Any and all suggestions and advice appreciated. I would prefer to stick with the N201-8A circuit though.

Many thanks.

[gdmoore28]

Hi Ed.

Most folks just use the Dayton Audio poly caps from Parts Express. Last year I ran across a post by a fellow who used the Dayton caps to rebuild his M19 crossovers and posted the process. I can't find that thread right now, but there are numerous M19 crossover threads from stock rebuilds to the Z19 upgrade. Here's where to find the Daytons:

https://www.parts-express.com/cat/crossover-capacitors/292

Most folks use the Dayton NPE (non-polarized electrolytics) with equal capacitance and equal or greater voltage ratings as compared to stock capacitors. If Parts Express does not have the exact capacitors in stock, you can get the correct value by adding two or more capacitors in parallel.

https://www.dummies.com/programming/electronics/components/electronics-components-capacitors-in-parallel-and-series/

Unless they have broken wires or severe corrosion, there is no need to replace the inductors in your crossovers. Keep the stock ones.

Don't neglect to check the function of the L-pads. While listening to the speakers, move the knobs back and forth through their range. There should be no static, distortion, or dropouts. If they have problems, they can usually be cleaned and lubricated inside once the back covers are removed. If they are severely corroded inside, you may need to replace them.

If you already know all of this, please excuse my presumptuousness.

Just out of curiosity, why are you replacing the cones and the diaphragms? Are your drivers damaged?

Would love to see pictures of your Model Nineteens, including inside shots. Pics of your progress through the rebuild would be very helpful to other people who may follow in your footsteps. It never gets tiring seeing these timeless speakers.

GeeDeeEmm

[Edacnz]

Hi Ed.

Most folks just use the Dayton Audio poly caps from Parts Express. Last year I ran across a post by a fellow who used the Dayton caps to rebuild his M19 crossovers and posted the process. I can't find that thread right now, but there are numerous M19 crossover threads from stock rebuilds to the Z19 upgrade. Here's where to find the Daytons:

https://www.parts-express.com/cat/crossover-capacitors/292

Most folks use the Dayton NPE (non-polarized electrolytics) with equal capacitance and equal or greater voltage ratings as compared to stock capacitors. If Parts Express does not have the exact capacitors in stock, you can get the correct value by adding two or more capacitors in parallel.

https://www.dummies.com/programming/electronics/components/electronics-components-capacitors-in-parallel-and-series/

Unless they have broken wires or severe corrosion, there is no need to replace the inductors in your crossovers. Keep the stock ones.

Don't neglect to check the function of the L-pads. While listening to the speakers, move the knobs back and forth through their range. There should be no static, distortion, or dropouts. If they have problems, they can usually be cleaned and lubricated inside once the back covers are removed. If they are severely corroded inside, you may need to replace them.

If you already know all of this, please excuse my presumptuousness.

Just out of curiosity, why are you replacing the cones and the diaphragms? Are your drivers damaged?

Would love to see pictures of your Model Nineteens, including inside shots. Pics of your progress through the rebuild would be very helpful to other people who may follow in your footsteps. It never gets tiring seeing these timeless speakers.

GeeDeeEmm


Hi GeeDeeEmm

Thanks for your response - I appreciate it. I will check out the Daytons. You know, I had a whole heap of posts regarding Altec 19 rebuilds on my old phone, however I lost them all and Google seems to bring up the same things over and over. Hostboard forum has locked me out/is defiunct???

I gave the L-pads a clean up last night which addressed the worst of my concerns with the crossovers. Also managed to do the ground mod on one side before my wife had had enough of me working in the living room. Even before the ground mod, there was still some 'energy imbalance' between the speakers. I will work on the other one tonight and see if I can get them more 'equal' sounding. I will also swap the crossovers between the speakers to help isolate the issue.

Both dust caps have been damaged with splits in them for many years. I rotated both drivers, but one is contacting the inside of the gap, resulting in a slight buzz. the paper there is kicked up and damaged also. I don't think this will be repairable, but it MAY right itself now I have rotated it. The drivers are faded and stained, but functional beyond what I have described.

I will take some pics when possible. For now, the system is sounding OK. My little Musical Fidelity A100x (50wpc solid state) sounds reasonable at low levels, but is oddly not driving these 19's to anywhere near the levels I would have expected at circa 100db efficient. Hmm. Will see what tonight's experiments bring and try and get some photos up :-)

[Edacnz]

Just a quick follow on from the above post.

I decided to put everything back to how it was when I got the Altecs to see if anything I had done was causing the perceived imbalance. I swapped the crossovers over, swapped channels on the amplifier etc. but the imbalance persisted one channel sounding 'down' and a weird phasing effect happening.

I took the drivers out again and had another look inside the cabinets. Then I noticed something I hadn't seen before. The input wire on one speaker was slightly thicker than on the other. Tucked in under the pink insulation fluff I found a small coil of this wire - much longer than in the other. I stripped a bit of insulation off it - guess what? Copper. All other wires appear to be silver strands. I decided to replace both sets of input wires with some new copper I have laying about to make sure the lengths and properties were the same.

Hooked it back up and Whammo!

Beautiful, clear, powerful, balanced sound. Awesome. This is what I was expecting from the old girls.

I will stop and consider the recap at this point. There is some burbling in the mid-bass, deep bass is good, mids and highs are, well, ALTEC!

Thanks for your help.

[Earl K]

Very Interesting.

Glad things are working out for you!

:)

[gdmoore28]

Good for you, Ed! I don't understand how what you did made the difference, but it did, and that's all that matters. Strange things happen in electronics to me, too, but because I'm an uneducated oaf!

I don't blame you for reconing your woofs. In that shape, I'd do the same thing. Please be sure to post pics of your progress. This stuff never gets old. Yet.

You've gotten Earl on board watching you now, and he's a sharp cookie. You have a great deal of experience at your disposal, so ask anything you need to know.

Watching with anticipation.

GeeDeeEmm

[Edacnz]

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[Edacnz]

Sorry about the wonky pics.

Been listening to the Altecs tonight. I think they are easily the most satisfying speakers I have had anything to do with. The slight ground they give up to my old khorns is offset by everything that they do better.

I have MASSIVE respect for the people who put these beauties into reality. Doubtless there are better systems out there, but these 19s are sublime.

[Earl K]

Thanks GDM for the vote of confidence!

Ed,

If all your woofers need are new dust-caps I would simply buy something like these ( click the ebay link ) for installation by your local reconing shop;

https://i.ebayimg.com/thumbs/images/g/14YAAMXQsmFRbvLg/s-l225.jpg (https://www.ebay.com/itm/Pair-Altec-Speaker-Vented-Dust-Cap-416-515-803/362341399076?epid=1131506690&hash=item545d3afa24%3Ag%3A14YAAMXQsmFRbvLg&_sacat=0&_nkw=Altec+dust+caps&_from=R40&rt=nc&_trksid=m570.l1313)

FYI, GPA's recone kits are now a bit different than your originals ( GPA's are still highly regarded & are purported to sound great ) <but> I would still attempt to keep your Altec woofs working with mostly original parts if at all possible.

Any experienced reconer ought to be able to install the pictured dustcaps .

COIL Rub ?
A top-tier reconer should be able to recenter your woofers ( by reshimming the VC while the spider has been softened up with acetone/MEK to allow a bit of play/movement of the spider to frame glue line ).
- This is a much trickier procedure & would only be needed/considered if there is a slight rubbing of the voice-coil ( but where the coil is still not damaged ) . Failure of this restoration procedure would trigger a full recone.

:)

[gdmoore28]

I wonder why one of your 416s has an aluminum cap? Have you checked the printing on the back of the cones to make sure that they are both original cones? I think the number should be 21184.

I have a couple of 416Cs with really motley dust caps, so I bought a pair of the vented caps that Earl pictured. The ones I bought are exactly like the originals on my 416Zs. If you are able to get the rubbing woofer working correctly again and replace the dust caps, you may be able to delay reconing for a while longer.

Thanks for the pics. Looks like you have a couple of really good examples to work with. That will make the cosmetic restoration so much easier.

Keep up the good work, Ed.

GeeDeeEmm

[Edacnz]

Hi Gee Dee Emm

The cones are original as best I can tell. The dust caps were both paper, however the discoloured one you see in the pic (since removed) was not Altec. I guess someone replaced the original some time in the past.

I am back to having some problems though.

The left speaker (no dustcap) still sounds 'down' in energy. It's hard to describe exactly but the midbass and mids aren't full sounding as the other channel. It lacks 'snap' too.

I have swapped the crossovers over and tried everything I can think of, but the problem persists.

Some possibilities spring to mind:

1) Maybe the channel has suffered some damage from the PA amps the previous owner was using..

2) Magnet needs regaussing.

3) Lack of dustcap somehow affecting the sound.

4) Maybe the gap has been breathing dust because of the split dustcap - clogging things up a bit.

I would be interested to hear people's thoughts.

I managed to eliminate the slight buzz in this channel by slipping a a fine piece of sand paper into the gap and sanding off the kicked up bit of paper from the voice coil that was making contact. This didn't change the sound other than removing the buzz.

Thanks for the help and encouragement.

[Edacnz]

Gathered the plums today to have a looksee in the hf driver of the speaker which was seeming low. You can see what I found:

81750

81751

81752

81753

My best guess is the diaphragm is original and the dent and rip in the foil was caused by whoever installed it. I could be wrong.

Now await some GPA replacement diaphragms, but in the meantime I have epoxied the rip and we will hear what we hear.......!