New Heathkit AS101 owner - First post.

So...at 52-years young, I'm finally getting around to building (starting) my bucket list audio system...albeit on a reasonable budget. I've made some DIY components and have a couple of more in the queue. Included was a nice pair of speakers with full range drivers that I thought sounded pretty great. That is until I visited Kevin (KAB) and heard his 803b horns. To say they were intoxicatingly seductive is a drastic understatement.

This led me to doing some homework on Altecs. All I can say is...I'm all in. But I'm not ready to drop $2K on a pair of multi cell horns and 288Ds, let alone a pair of 515Bs w/cabinets.

So after coming upon an available pair of Heathkit AS101s, and learning a lot about them here and elsewhere, I decided to take the plunge. I got them home yesterday and they seem to be in pretty good shape. The drivers appear mint and the cabinets are OK. The crossovers are a mixed bag. The attenuators seem to be fine. The soldering work is meh. It's the caps that are my concern at the moment. One was replaced and the other are old Chicagos with a +/- 10% tolerance. I wanted to keep the XO stock for the time being so I can hear what they were designed to sound like, then I can customize if necessary.

The schematic calls for an 8uF, 10uf and an 11uf. Thanks to this board I learned I can add capacitance by using caps in parallel so I just bought some Daytons:

4 027-226 Dayton PMPC-4.0 4.0uF 250V Precision Audio Capacitor $3.97 $15.88
4 027-234 Dayton PMPC-5.6 5.6uF 250V Precision Audio Capacitor $4.64 $18.56
2 027-244 Dayton PMPC-10 10uF 250V Precision Audio Capacitor $7.65 $15.30

I figure two 5.6s get me close enough to 11.

So here's a few picks. Other than the XOs, what should I be doing to overhaul these relics? FWIW, they sound great to me, but I don't know how much better they could sound. I know those caps are ancient.

Hello Alan--glad you made it over to our Altec User's Board. Alan had sent me a PM a few days ago at the Lansing Heritage Forum after he read my thread over there about the AS 101's that I used to own (I had threads over there and over here when I owned those speakers). We exchanged a few PM's and I recommended that he visit this forum -- the place to go for all things Altec!

I'm glad you included pics in your thread here Alan, I was wondering if you had the classic "Altec green" drivers or the grey ones that my AS 101's had. I can see yours are green and I'm glad to hear that they're in such nice shape. Besides the new caps, I would definitely clean or replace those 40 year old L Pads. If you decide to clean them, I recommend Deoxit spray. If you want to replace them, Parts express should have something very similar in stock. Cleaning them may be all they need. I liked how my AS 101's sounded with the L Pads "all the way up/full throttle" so I ended up bypassing my L Pads altogether. Between the new caps and bypassing the L Pads, the improvement was impressive. However, cleaning or replacing the L Pads should achieve similar results to bypassing them and by not bypassing them you have more flexibility should you want to adjust them. By the way, I recommend keeping the old caps (and L Pads if you replace them) in a zip lock somewhere. If you ever sell your speakers, there are collectors who really like having the original caps--even if they are leaky and shot!

Here's what my my AS 101's with the grey drivers (8 ohm) looked like:
http://www.hostboard.com/forums/hbmc...2010/12/14.jpg

http://www.hostboard.com/forums/hbmc...2010/12/15.jpg

http://www.hostboard.com/forums/hbmc...2011/09/82.jpg

http://www.hostboard.com/forums/hbmc...2011/09/81.jpg

http://www.hostboard.com/forums/hbmc...2009/02/25.jpg

Another upgrade you might want to try if you want to experiment is to adjust the tuning of the cabinets. AS 101's, like Valencias, were not tuned for really "deep" bass like many later Altecs were (and many other manufacturer's speakers that came along later were--Altec Model 19's, etc.). Those are Altec 416 woofers in your cabs--and they are capable of much deeper bass than you'll get with the stock tuning of those cabs. There are people here who know a lot more about this than I do, but I can tell you that the empirical/scientific method (trial and error method) is a very good way to achieve a "better"/deeper tuning for your cabs. By reducing the port size (blocking off part of the port from the inside of the cab) you can achieve a deeper tuning. You can evaluate your results by listening or by measuring (with a microphone and computer software) combined with listening. For example, you can start by blocking off a small portion of the port by "tacking" a small piece of wood in place to see if you have noticeably improved the bass response, and then blocking off more to see if they sound even better. At a certain point, you'll have blocked off too much of the port and they won't sound right--then you have to go back to a previous tuning/whichever one you liked best and "permanently" block off that portion of the port (use screws to secure the wood you're using to block off part of the port). Properly executed, you can get much deeper bass out of those cabinets than they get with their stock tuning

Personally, I would start with just replacing the caps and cleaning or replacing the L Pads. If you listen to them like that for a while, it will be much easier for you to tell how much of an improvement in bass response has occurred if and when you decide to improve the tuning of the cabs (because by then you'll be very familiar with their bass response with their "factory tuning" using different recordings -- you'll have a good frame of reference).

Down the road, there are other mods you can try. Zilch (who you noticed chimed in with some advice for me in my LH thread), owned Valencias and had suggested as a possible upgrade for Valencias/AS 101's replacing the stock 806 drivers with 802-8g drivers and replacing the stock crossover with Model 19 crossovers or Z19's (his version of the Model 19 crossover). If you ever decide to try this, Great Plains Audio (former Altec employees using authentic vintage Altec designs and tooling) makes brand new 802-8G drivers and brand new Model 19 crossovers or you could buy vintage Altec 802-8G drivers and Altec Model 19 crossovers on ebay. Selling your 806 drivers would give you a decent chunk of change towards 802-8G drivers. However, if you try this upgrade, I recommend keeping the 806's should you ever want to return the speakers to their "stock" configuration (if you want to sell them some day, etc.) This upgrade extends your h.f. response--you end up with speakers that are very similar to Altec Model 19's (416 woofer with the same h.f. driver and crossover that are in Model 19's). In lieu of that, you could add a tweeter to each AS 101, or you may find that after replacing the caps and cleaning the L Pads that they have plenty of sizzle for you and at that point you may or may not want to experiment with cabinet tuning to improve the bass.....

BTW, many Altec speaker systems with the green drivers are 16 ohm systems. Are your AS 101's an 8 ohm system or 16 ohm? That will affect some of the mods I've suggested..... Again, as I mentioned in a PM to you, congrats on buying a great pair of vintage Altec speakers. Also, welcome to the Altec Users Board!

Thanks for the tip, VOTT. Great to be here!

Mine are 8 Ohms. At least that's what they say on the backs.

I'm planning on swapping out just the caps first and doing a good cleaning on the pots. While I'm waiting for my new caps I might try your suggestion and start playing with the ports. I have a powered 12" sub-woofer with an active XO that I can set to pick up 40-50Hz and down, so getting the 416s down that low is not mission critical. I tend to enjoy the rumble of 25Hz more than the sparkle of 18K. And neither of them are as important as what these 811b horns are doing to vocals and acoustic brass and woodwinds. I'm tickled.

Like I mentioned in my OP, I built a set of speakers utilizing full-range drivers with a bass reflex cab and found not only the port diameter made a big difference, but the length of the port as well. Tough to add more after you've cut it off though! I installed Parts Express L-pads on them to level the highs down about -2-3dB so I'm familiar with them. They look like they'll fit nicely. Did you use the 3/8" long shaft, or the 1". I'm probably OK with the 50W version since I'm only pumping a whopping 3W/ch into them at the moment. It's a glorious triode 3W though!

Here are pics of my first speaker attempt and the L-pads on the inside:

Attachment 1584Attachment 1585

When I get around to really overhauling, they'll make a nice back up set while the Heathkits are in the "shop".

FWIW, the full-range speakers, with a bit of HF attenuation, have an almost dead flat frequency plot from like 80-20K. And they sound pretty nice for what they are, but they do not have nearly the presence of these Heathkits, which I'm willing to bet have a far less sexy response curve. My point is I really don't care much for the numbers; I care about what I hear.

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Originally Posted by alancohen

.......And neither of them are as important as what these 811b horns are doing to vocals and acoustic brass and woodwinds. I'm tickled....... FWIW, the full-range speakers, with a bit of HF attenuation, have an almost dead flat frequency plot from like 80-20K. And they sound pretty nice for what they are, but they do not have nearly the presence of these Heathkits, which I'm willing to bet have a far less sexy response curve. My point is I really don't care much for the numbers; I care about what I hear.

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Well, you hit the nail on the head as far as I'm concerned. Vintage Altecs like your AS 101's are well known and highly acclaimed for their "midrange magic". While they also shine with clean powerful bass and great crystal clear high end as well, there's something indescribably lifelike about the midrange that they produce. I remember when I first bought my Valencias (my first Altecs with horns), I couldn't believe how lifelike brass, strings, vocals, guitars, etc. sounded. Like you could reach out and touch them...... I'm sure there are speakers that have better "numbers" than many of the classic vintage Altecs (as far as measurements), but very few that I've heard can come close to their clean, lifelike, effortless sound. FWIW, I never did the Zilch upgrades (802-8G/Model 19 crossover) to my Valencias or AS 101's--they sounded so great and have such a unique sound that I was leery of defacing a "work of art" and trying to turn them into something else. Since you had asked about what mods can be done to AS 101's, I felt it was important to mention Zilch's mods as a possibile option after you've done the caps, L Pads, and possible cabinet tuning mods....

I started with As101's too, The Altec slide Is a slippery slope, Have a great journey I did. Kicking back and enjoying some great sound now. :)

http://www.hostboard.com/forums/f700...ant-gloat.html

I was wondering if the Zilchlab Econo Wave boards are still available. I came across this video:

Rev Up Your Vintage Speakers, Econowave Style - YouTube

and I happen to have these "made for Ovation" Altec VHF drivers and horns in the mail. It might be fun to play with them.

Attachment 1586

Welcome to AUB, Alan.
You certainly chose an excellent speaker to get started with (as CD says down the slippery slope!)
Recapping those XOs is a no-brainer, you'll hear vast improvement with that. Another thing to check is the diaphragms in your HF comp drivers. Depending on how they've been treated over the many years, they may be in good shape or possibly torn up. Another thing to check is the strength of the magnets on your drivers...the old Alnico drivers can lose quite a bit of their zip again depending on what they've been through.

Thanks, Mike. That brings up an interesting question. I got these speakers from a guy that buys and sells estates. They came from a house that has been closed up for 20+ years. I guess the original owner passed away and his house was closed up until recently when it was sold.

So these speakers haven't had a hard life of use, but sometimes non-use can be worse for some things. There doesn't seem to be any mold or corrosion anywhere. But it would probably be a good idea to remove all the drivers and give them a good look over.

How would I check the magnets? Would they loose their zing more from use, or non-use? Maybe sending them off to Bill for a recharge wouldn't be a bad idea. I know he does that for free with a diaphragm replacement or re-cone, but do you know what he charges a-la-carte? I've read that while GPAs replacement diaphragms are good, they are not exactly the same and might not have that exact "Altec sound". Myth?

I'm in NJ and haven't worked since Sandy paid her visit. As of this morning, my office still had no power. If that's the case tomorrow, I'll pull the drivers and post pics of what I find.

Thank god they survived the storm!!! If they sound good I wouldn't bother messing with them....well of course I'd mess with them but watch that slope. :D
I'll be posting an update on my obsession in a few minutes.

Hi Alan,

Not mentioned yet is the flipping your drivers 180? to help relieve the downward stress of having sat that way for how ever many years.

Also, I noticed you have wired your L-Pad as a series resistor. Doing that will alter what your XO does. You'll want to correct that. Here is how:
https://www.google.ca/search?sourcei...iring+an+L-pad

And yes I know Altec does it that way also. For the life of me I can't ever sort out why. It makes no sense to have an L-Pad and not use it as one.

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Originally Posted by Cal Weldon

Hi Alan,

Not mentioned yet is the flipping your drivers 180? to help relieve the downward stress of having sat that way for how ever many years.

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Excellent suggestion--I've done that with all of my vintage Altecs--glad you thought to mention it!

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Originally Posted by Cal Weldon

Also, I noticed you have wired your L-Pad as a series resistor. Doing that will alter what your XO does. You'll want to correct that. Here is how:
https://www.google.ca/search?sourcei...iring+an+L-pad

And yes I know Altec does it that way also. For the life of me I can't ever sort out why. It makes no sense to have an L-Pad and not use it as one.

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Alan, your crossovers/L Pads are currently wired the way Altec crossovers and the AS 101 crossover are designed to be wired. Keep in mind those crossovers are designed to work with your specific drivers and that re-wiring them as mentioned in the Google search will alter what your crossover was specifically designed to do. In other words, you wouldn't be "correcting" the wiring of your crossover by doing so, you'd instead be "altering" the design of your crossover. I personally wouldn't recommend doing so......

EDIT: In the interest of experimentation, IMHO there is no harm in trying out rewiring the L Pad to see what it sounds like. If you do decide to pursue this avenue, I would recommend rewiring one L-Pad and do an A/B comparison between the two speakers to see if the one with the original wiring scheme sounds/operates "better" or "worse" to your ears than the speaker with the re-wired L-Pad before deciding to re-wire both....

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Originally Posted by alancohen

I was wondering if the Zilchlab Econo Wave boards are still available. I came across this video:

Rev Up Your Vintage Speakers, Econowave Style - YouTube

and I happen to have these "made for Ovation" Altec VHF drivers and horns in the mail. It might be fun to play with them.

Attachment 1586

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I just watched the video and it references an Audio Karma thread. I'm not a member there but some of our Altec Users Board members also belong over there so maybe one of them would know about Zilch's Econowave board. If the guy in the video and/or Audio Karma thread is suggesting that this is a "one size fits all" type crossover to be used with any woofer and cabinet regardless of efficiency, frequency response, etc., then I'm very skeptical of that sort of approach. I have a feeling that Zilch would have known better than that......

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Originally Posted by voice of the theater

Excellent suggestion--I've done that with all of my vintage Altecs--glad you thought to mention it!



Alan, your crossovers/L Pads are currently wired the way Altec crossovers and the AS 101 crossover are designed to be wired. Keep in mind those crossovers are designed to work with your specific drivers and that re-wiring them as mentioned in the Google search will alter what your crossover was specifically designed to do. In other words, you wouldn't be "correcting" the wiring of your crossover by doing so, you'd instead be "altering" the design of your crossover. I personally wouldn't recommend doing so......

EDIT: In the interest of experimentation, IMHO there is no harm in trying out rewiring the L Pad to see what it sounds like. If you do decide to pursue this avenue, I would recommend rewiring one L-Pad and do an A/B comparison between the two speakers to see if the one with the original wiring scheme sounds/operates "better" or "worse" to your ears than the speaker with the re-wired L-Pad before deciding to re-wire both....

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I was assuming that Cal was talking about my other speakers when he mentioned the L-Pad wiring, as they are indeed wired as a series resistor quite intentionally. It happens to fit fit that driver and cab configuration.

DIY Speakers

I will certainly flip the drivers. I never thought of that.

As far as rewiring the crossover, I really don't have much inclination at this point to change anything. I'd be willing to bet $1 that the people that set up this system know a little more than me about speaker design. I want to hear then as intended for a while. Only then will I be able to tell if any changes are helping or hurting.

Quote:

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Originally Posted by alancohen

I was assuming that Cal was talking about my other speakers when he mentioned the L-Pad wiring, as they are indeed wired as a series resistor quite intentionally. It happens to fit fit that driver and cab configuration.

DIY Speakers

I will certainly flip the drivers. I never thought of that.

As far as rewiring the crossover, I really don't have much inclination at this point to change anything. I'd be willing to bet $1 that the people that set up this system know a little more than me about speaker design. I want to hear then as intended for a while. Only then will I be able to tell if any changes are helping or hurting.

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It didn't occur to me that Cal was probably talking about your home made speaker system as far as the wiring of the L Pads. I'll bet you're right about that Alan. I agree that the people at Altec (and Heathkit in the case of your crossovers) know a lot more about speaker systems than I do which is why I never re-wired the L Pads on any of my factory Altec crossovers and why I always try to use exact values when replacing caps.

By the way, those are nice looking cabinets that you've built--especially considering they are your first build. The first speaker cabinets that I ever built were in junior high school ("shop" class). They housed 12" full range radio shack speakers and by the standards that I have today they were, in a word, embarrassing (in just about every conceivable way)!

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Originally Posted by voice of the theater

By the way, those are nice looking cabinets that you've built--especially considering they are your first build. The first speaker cabinets that I ever built were in junior high school ("shop" class). They housed 12" full range radio shack speakers and by the standards that I have today they were, in a word, embarrassing (in just about every conceivable way)!

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Yeah, it's been a long time since Jr High shop class for me. But I'm a closet woodworker and keep a few tools and machines around in case I need a new project.

These are still a work in process. The baffles are still just screwed on. I've been playing with the padding type and quantity. Once I'm done, I'll glue the baffle on, fill in the screw holes, sand everything smooth and cover them in a nice paisley fabric :rolleyes:. Or maybe some tie dye.

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Originally Posted by alancohen

and I happen to have these "made for Ovation" Altec VHF drivers and horns in the mail.
Attachment 1586

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University, not real Altecs. Okay at best was my opinion. All the Ovation stuff was University AFAIK.

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Originally Posted by Old Guy

University, not real Altecs. Okay at best was my opinion. All the Ovation stuff was University AFAIK.

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Well that's a bit disappointing. They were billed as "Altec". Oh well, not a big investment.

And it's quite likely I will not need them.

I had noticed while playing an old jazz vinyl this morning that the ride cymbals were shining quite brightly. I'm not sure there is much north of there that I really need to hear anyway.

I might play with them a bit to satisfy my curiosity, but I'm all for keeping things as simple as can be.

Fresh caps should be here in a day or 2. Can't hardly wait.

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Originally Posted by voice of the theater

and that re-wiring them as mentioned in the Google search will alter what your crossover was specifically designed to do.

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Actually it will keep the XO doing what it was does at all L-Pad settings. Having it as a variable resistor will change the XO slope and leave a whole or an overlap at the XO point as you increase or decrease the resistance.

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you'd instead be "altering" the design of your crossover. I personally wouldn't recommend doing so......

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I don't undertand how it can be called a 'design' if it's wired that way.

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Originally Posted by Cal Weldon

I don't undertand how it can be called a 'design' if it's wired that way.

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Did you read this page that I posted earlier?

DIY Speakers

It's wired that way because it achieves the desired result. If you don't agree, you can take it up with Bruce Rozenblit. It's his design. And design is something I'm guessing he knows something about.

Hi Alan,

I'm not doubting that, I am just confused. Why would you not want to keep the impedance constant? Does the shunting cause an excess heat build-up in the L-pad so you're better off changing the impedance the amp sees?

I am curious.

Quote:

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Originally Posted by alancohen

Did you read this page that I posted earlier?

DIY Speakers

It's wired that way because it achieves the desired result. If you don't agree, you can take it up with Bruce Rozenblit. It's his design. And design is something I'm guessing he knows something about.

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I just checked out his website. Bruce is an interesting guy--I like his philosophy/attitude regarding audio. Cool "top ten" list here (of course, we'd all have a different top ten list personalized to our own tastes but his is interesting to say the least): About Us



Some interesting products here: Products

I used to love some of the old Dynaco kits. Obviously, these kits are a whole different breed/niche market, but they bring back memories nonetheless....

Quote:

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Originally Posted by alancohen

and I happen to have these "made for Ovation" Altec VHF drivers and horns in the mail. It might be fun to play with them.
Attachment 1586

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Congrats, Welcome, and Ditto OG not altec.
Also looks like Klipsh K-55 from here, search and you will find the atlas driver part #. Can't tell precisely, so go with OG's info until otherwise.

Don't go too crazy on the VHF $ for a 3 way setup.
I suggest starting cheap, I am back to my $10 on sale Beyma CP-09's for now.
If staying 2-way, maybe just skip to Altec/GPA 902's and play with the XO.
If you can find a cheap prebuilt XO with CD compensation, that may be your quickest route to 'I want to emulate that with good components now'. I've been happy continuing to experiment with EV XEQ-808's.

( Of course perhaps you are already well versed in XO's )


* I make it up a little east of phillipsburg - way sometimes. Maybe we've got the beginnings of an Altec pony express!

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Originally Posted by alancohen

Thanks, Mike. That brings up an interesting question. I got these speakers from a guy that buys and sells estates. They came from a house that has been closed up for 20+ years. I guess the original owner passed away and his house was closed up until recently when it was sold.

So these speakers haven't had a hard life of use, but sometimes non-use can be worse for some things. There doesn't seem to be any mold or corrosion anywhere. But it would probably be a good idea to remove all the drivers and give them a good look over.

How would I check the magnets? Would they loose their zing more from use, or non-use? Maybe sending them off to Bill for a recharge wouldn't be a bad idea. I know he does that for free with a diaphragm replacement or re-cone, but do you know what he charges a-la-carte? I've read that while GPAs replacement diaphragms are good, they are not exactly the same and might not have that exact "Altec sound". Myth?

I'm in NJ and haven't worked since Sandy paid her visit. As of this morning, my office still had no power. If that's the case tomorrow, I'll pull the drivers and post pics of what I find.

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Here's my take on your questions, although there are others here who know more about some of this stuff than me. BTW, I'd love to see the pics you mentioned you're taking of your drivers.

I will always use GPA for any repair work of my Altec drivers but there is some really interesting info on Alnico magnets including their magnetic properties/potential loss of charge etc. here:

Vancouver Audio Speaker Clinic - Magnet recharging

Here are a few things that caught my eye right off the bat:
"Disassembly If an Alnico magnet structure is opened, such as to re-centre a shifted pole-piece, repair a broken throat, or remove a bug-screen, the magnetic field collapses instantly. While this type of damage is not common, ill-advised repairs create very unwelcome problems."

"Pulse loss
Most Alnico compression drivers (JBL LE85, LE175, 375, 2410, 2420, 2440, 2441, Altec 288, 290, 802, 804, 806, 808, Emilar EA-175, TAD 2001, 4001, Goto Unit, etc) have tall magnets, short voice coils, and modest power inputs, so do not suffer degaussing. Those compression drivers with low aspect ratio magnets, especially if used <500Hz (Vitavox S2, University ID series, Klipsch K-55-V, Electrovoice 1823M etc) can suffer flux loss, and will benefit from remagnetization. "

Based on this info, I think your 806 drivers are probably fine as far as their magnetic charge--especially if they not only sound great but also sound identical to each other in A/B listening tests.....

"Pulse loss

For example: Low frequency drivers with 4-inch voice coils (JBL D120, D130, D140, LE15, 2205, 2215, 2231, Gauss, or TAD drivers) can lose 2~3dB, becoming 'dull' or 'slow' sounding, unless they have been grossly abused, in which case they more and sound dreadful. Drivers with short Alnico slugs and 3-inch voice coils, (JBL 2213, 123A, etc) are effected more severely, so typically show 3dB sensitivity loss, while small alnico woofers (JBL 116A, 125A, 127A etc) are commonly 4dB down after quite modest use. Conversely, speakers with higher coercivity ( taller Alnico slugs) and short voice coils, such as Tannoy dual concentrics, Altec and EV woofers, rarely suffer unless they have been badly abused."

Of course I'd never take this info as a guarantee that my Altec woofers haven't lost any of their magnetic charge, but it's interesting that many Altec woofers can be less vulnerable to this problem than many other woofers that are listed above.

To specifically answer your question, putting too much power through Alnico woofers (particularly some of the ones listed above) can cause them to lose some of their charge, I've also read somewhere that dropping them can have a similar effect. I don't recommend you drop them on the floor from a height of more than 100 feet (kidding). ;)

In all seriousness, I've never had any of my 416 woofers tested for their magnetic charge. I've been fortunate to buy them all from audiophiles who knew enough not to try to put 300 watts through them or to drop them on the floor! I've owned 416z woofers (16 ohm), 416-8A woofers (in my AS 101's), and 416-8B woofers (in my Model 19's), and they've all sounded phenomenal. Also, when I've done A/B comparisons between a pair of 416-8A woofers for example (in their cabinets), they've sounded identical which makes me think there's an increased likelihood they're intact if they both sound not only identical to each other, but both sound incredibly clean and powerful with not only deep bass, but nice midrange as well. I've read that with woofers that are more prone to this type of loss of magnetism (like some of the more vulnerable woofers listed above), when they lose their charge it mainly effects the upper portion of their frequency response i.e. midrange..... So, I've never had a pair measured but of course it wouldn't hurt to have Bill measure them--there are stories here of people who definitely needed their Altec alnico woofers re-magnetized--most likely they were abused (way too much power or dropped) by previous owners...... Of course if you decide to do this, pack them securely because they are much more likely to be dropped by a Fedex employee (and suffer the resulting loss of magnetism) than they were when they were in their cabinets! ;) There are ways of measuring parameters of your woofers (at home, by yourself) that could give you solid clues as to whether or not they've lost some of their "zip". If you've got suspicions about their condition, this would likely be the best way to start your investigation. I've never had to do it, but there are definitely some experts on that type of thing here on our forum.....

Doesn't hurt to check your diaphragms as long as you are proficient at removing them, cleaning the "gap", and re-installing them without damage. It's not that hard to do this safely with smaller format h.f. drivers like your 806's (and my 802's and 902's). Here's some information regarding that procedure : http://www.greatplainsaudio.com/SmDrvrDiaRpl.pdf

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Originally Posted by alancohen

I've read that while GPAs replacement diaphragms are good, they are not exactly the same and might not have that exact "Altec sound". Myth?

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GPA (former Altec employees) uses authentic vintage Altec designs and tooling. While a brand new diaphragm may not sound identical to a 40 year old diaphragm, of course keep in mind that a 40 year old diaphragm also may not sound like it did when it was new. Your 806-8A h.f. driver takes a 34647 diaphragm. A GPA 34647 will IMHO have the "Altec sound" that the original diaphragm had, and depending on the condition of your diaphragms, may be a nice upgrade in sound quality. Certain original vintage Altec diaphragms aren't currently manufactured by GPA. In this case, substituting a different model # diaphragm for the original will likely result in some degree of change in the "Altec sound", but fortunately the proper replacements are available from GPA for your h.f. drivers if you end up needing them......

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Originally Posted by Cal Weldon

Hi Alan,
Why would you not want to keep the impedance constant?

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Oh man, time to eat crow. I was so concentrated on the L-Pad, I didn't notice you were using it for a FR driver. While my thoughts hold true for a tweeter, when you use it on a single driver it all makes sense. Sorry for the confusion.

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Did you read this page that I posted earlier?

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No. (head held in shame)

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Originally Posted by voice of the theater

I just checked out his website. Bruce is an interesting guy--I like his philosophy/attitude regarding audio.

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Me too. I was trying to think about how I came upon him. It wasn't that long ago time-wise. Maybe quite a bit mileage-wise so it seems longer. Then I remembered. Here's my story if you care to read:

I was a poor man's audiophile in my early 20s, but like most of us, had champagne taste and a beer pocket. I had the best equipment I could afford and listened to music all the time. All my friends were musicians and quite a few went on to be very successful professionals. I played a little guitar, but mainly I was the sound guy for all the middle school bands and all through high school. I loved turning the knobs and bringing the gig to life.

I don't know when it happened, but I got lazily seduced by digital over the years. It started with CDs and then MP3 files. It seemed so easy. It happened so slowly that I never noticed that I was listening, I mean really listening, less and less. In hind sight I guess I assumed it was life encroaching and leaving less time for music. What I have come to realize in the past few months is that it wasn't life's fault. It was the faulty, anemic digital signal. It no longer required the best gear because nothing would help those compressed, degenerated MP3 files. So I slowly drifted away.

Before my recent rebirth, my audio system was a pair of tiny Advent bookshelf speakers with a KLH sub, basic Onkyo receiver and an iPod for input. Yes, I had fallen that far. I used it mostly for TV and hardly ever listened to music. Why bother, it sounded like crap.

Then, as fate would have it, I decided to get back into guitar. I tend to be fairly frugal and pride myself on researching and learning everything I can before making a decision. I decided that I needed a tube amplifier and after many internet hours I decided an old Fender Tweed Deluxe was for me. But spending $2000 on a boutique 12W amp was not going to happen. I found there are kits available and my journey started here:

First build - Boothill 5E3 - Need some help - Telecaster Guitar Forum

Was it really only August! Seems like years ago.

During the process of getting my amp built and running with the help of the board someone posted a link to this guy's blog:

http://sharksphotos.yolasite.com

All of a sudden I felt very inadequate. Scroll down that page and you'll see what I mean. I never saw anything like that. The wiring job itself was a work of art to me, let alone the aesthetics of the chassis. Just beautiful. I was like a junky that just didn't know it yet.

I involuntarily followed the rabbit down the rabbit hole and found Bruce's website. Now granted, his personal wiring jobs of his own amps aren't nearly as OCD as Mark's, but it was the sound of his amps and their design philosophy that was the inspiration.

So my audio system quest began. First I built a pair of his DIY speakers. I figured nothing else mattered until I at least had decent speakers. Then it was time to build a preamp. His Grounded Grid, as I had come to learn, is a fairly well known and widely modified preamp and from what I've gleaned, can't be bested for triple the $499 kit price. It took me 3 hours to build and I had a very acceptable triode-based preamp.

My next project was his long discontinued 3W cathode follower amp Transcendent Sound Cathode Follower Tube Amp. I bought the instruction manual for $15 and started shopping for parts. I hadn't done anything like the before so sourcing everything was a challenge. Here's my thread for that build.

CFA Build... - Transcendent Sound Message Board

Next I started shopping for a turntable. Thankfully, something prevented me over the years from disposing of my vinyl collection. I found a really clean 1st gen Technics SL1200 for $200 and incorporated it into the system. Even before upgrading the tonearm and cartridge it did not take long to reboot my memory banks and remember how great it was spinning vinyl. I A/B'd an LP with the same music from iTunes and the light came on. That's what was missing!! The vinyl sounded real to me. It sounded...musical. The compressed digital source sounded harsh and stagnant.

That brings us to the present with me awaiting my order for a phono preamp and the Son of Beast 15W push-pull OTL. I haven't heard what an OTL sounds like, but it's supposed to be very transparent and open. That sounds like it's right up my alley. The 3W CFA amp I have now pushes these Heathkits to very loud levels and they have added a dimension I had previously not known. I can't imagine what putting 15W into them will do. While waiting for my next components I'm going through all my records and basking in the memories. With these speakers and this system it's like hearing them again for the first time.

So that's my story. I'm no electronics, acoustic or audio expert by any means nor do I pretend to be, nor do I really have time to be. I still have that champagne taste, but maybe now with imported beer pockets. I can't afford $25K in sound equipment, let alone $250K, but I know what I like and what sounds good to me. I also like building things so this DIY audio gig seems to fit me very well.

Most importantly, I'm learning to just sit and listen again...really listen.

Quote:

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Originally Posted by gearfreak

Congrats, Welcome, and Ditto OG not altec.
Also looks like Klipsh K-55 from here, search and you will find the atlas driver part #. Can't tell precisely, so go with OG's info until otherwise.

Don't go too crazy on the VHF $ for a 3 way setup.
I suggest starting cheap, I am back to my $10 on sale Beyma CP-09's for now.
If staying 2-way, maybe just skip to Altec/GPA 902's and play with the XO.
If you can find a cheap prebuilt XO with CD compensation, that may be your quickest route to 'I want to emulate that with good components now'. I've been happy continuing to experiment with EV XEQ-808's.

( Of course perhaps you are already well versed in XO's )


* I make it up a little east of phillipsburg - way sometimes. Maybe we've got the beginnings of an Altec pony express!

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Wow, lot's of action here while I was typing my monologue!

Nope, not well versed in XOs at all. But I'm a fast study.

Like I mentioned before, these are sounding pretty good to me as is. My new caps should be here tomorrow and I'll see what that does. I'm not sure if I should ask what I should be expecting, or see if I can tell without the seed being planted.

My ultimate goal is to try and reproduce live music as real as possible. When sitting and listening to a live jazz quartet, how much 19-20KHz is really going on? At 52 it's unlikely I'll be able to hear it anyway, at least for much longer.

So...I'm "a little east of Phillipsburg". 10 minutes east to be exact, in Clinton. I like the Pony Express plan.

Quote:

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Originally Posted by Cal Weldon

Oh man, time to eat crow. I was so concentrated on the L-Pad, I didn't notice you were using it for a FR driver. While my thoughts hold true for a tweeter, when you use it on a single driver it all makes sense. Sorry for the confusion.

No. (head held in shame)

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No crow, shame or apology required. It seemed you had a little L-pad obsession going on so I though I'd reiterate. Like I said in my monologue, I'm a couple of months removed from technical knowledge ground zero. I took 2 basic circuits classes at 20 in a local community college and that's was it for the next 30 years. I had designs on getting into the electronics field back then, but life took me in another direction. Whatever it was that clicked for me back then has awakened a bit now. But the desire far exceeds the capability.

Quote:

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Originally Posted by voice of the theater

Here's my take on your questions, although there are others here who know more about some of this stuff than me. BTW, I'd love to see the pics you mentioned you're taking of your drivers.

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Big thanks VOTT. Read and digested. I printed the GPA HF driver assembly doc and will read it thoroughly. I'm a little nervous about taking them apart. They really sound amazing and fairly balanced from L to R. One might be a bit louder, but can that be the capacitors? I think I'll replace them first in the next few days, reassess and then contemplate disassembly.

Quote:

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Originally Posted by alancohen

Big thanks VOTT. Read and digested. I printed the GPA HF driver assembly doc and will read it thoroughly. I'm a little nervous about taking them apart. They really sound amazing and fairly balanced from L to R. One might be a bit louder, but can that be the capacitors? I think I'll replace them first in the next few days, reassess and then contemplate disassembly.

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Yes, one H.F. driver sounding slightly louder than the other could be bad capacitors and could even be dirty or worn out L-Pads. I think you've got a good plan--after cleaning the L Pads and replacing the caps, see if the H.F. drivers sound "identical" then. BTW, acoustics can also be a surprisingly important factor. If after cleaning the L Pads and recapping the crossovers one still sounds slightly louder than the other, try putting the right speaker where the left one is now and vice versa and see what that does.....

Quote:

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Originally Posted by voice of the theater

Yes, one H.F. driver sounding slightly louder than the other could be bad capacitors and could even be dirty or worn out L-Pads. I think you've got a good plan--after cleaning the L Pads and replacing the caps, see if the H.F. drivers sound "identical" then. BTW, acoustics can also be a surprisingly important factor. If after cleaning the L Pads and recapping the crossovers one still sounds slightly louder than the other, try putting the right speaker where the left one is now and vice versa and see what that does.....

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Interesting that you mention that. I did exactly that when I noticed the right speaker was a tad louder. I switched them and now they sound perfectly balanced. FWIW, they are 10' apart, 10' from my head and I sit smack in the middle.

I'll let you know what happens when I replace the caps.

Quote:

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Originally Posted by alancohen

I figure two 5.6s get me close enough to 11.

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Hi Alan, Solen makes an 11 uF capacitor if you want to keep the correct tolerances.

BTW ~ Welcome to the Altec Board !

https://www.solen.ca/pub/index.php?c...2&s2=3&s3=&s4=

https://www.solen.ca/pub/index.php?c...u2=3&s1=2&s2=3

Thanks AB...and thanks again. Good to be here.

Man, I searched all over for an 11uf cap. Oh well. The Daytons are probably in my mailbox already. I guess I'll go ahead and use them. From what I can discern that would probably lower the XO point a bit? which is OK by me.

OK.. Sorry I'm late to your thread but was without Internet,power,etc... for most of last week.

Quote:

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Originally Posted by Altec Best

OK.. Sorry I'm late to your thread but was without Internet,power,etc... for most of last week.

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I'm in Hunterdon county, but my house is on a main trunk line so we only lost power for 4 days. I have friends and fellow employees that are still out. Sucks. How are we supposed to listen to our Altecs for Pete's sake.

Quote:

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Originally Posted by alancohen

Sucks. How are we supposed to listen to our Altecs for Pete's sake.

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Yes it does. Exactly I had no tunes for a week :frown2:

Quote:

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Originally Posted by Altec Best

Yes it does. Exactly I had no tunes for a week :frown2:

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I would go crazy not being able to hear my speakers for that long. That month it took them to go to GPA and back I almost lost my mind...well what mind that I have left....which wasn't much. :D

Quote:

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Originally Posted by alancohen

That brings us to the present with me awaiting my order for a phono preamp and the Son of Beast 15W push-pull OTL. I haven't heard what an OTL sounds like, but it's supposed to be very transparent and open. That sounds like it's right up my alley.

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Looking forward to knowing what you think of the OTL amps, though the 15W version would be more than too much for me. I was looking at the ~1.5W and ~4W single-ended models.

* Noting that the Trancendent design/s (?) spec low output impedance.

Anyone else playing with OTL's, SE/OTL's ?

Quote:

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Originally Posted by gearfreak

Looking forward to knowing what you think of the OTL amps, though the 15W version would be more than too much for me. I was looking at the ~1.5W and ~4W single-ended models.

* Noting that the Trancendent design/s (?) spec low output impedance.

Anyone else playing with OTL's, SE/OTL's ?

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Me too! I'm a little concerned. In Bruce's words "The result is an unbelievable clarity and realism that no other configuration can achieve. The music leaps out of the loudspeaker and floats in the room eliminating any “box” like sound. It is silky smooth yet possesses uncanny detail and three dimensional imaging. It has to be heard to be understood. Words alone cannot reveal the OTL tube amp experience."

So far my new Heathkits have done that already. I'm a little scared to think what both combined might image like.

15W is probably overkill for me too. The 3W transformer-coupled cathode follower I'm using is more than enough, but the room they will eventually end up in is 25' x 40' and I might need the extra headroom. Besides, the 15W is actually more affordale due to the most recent redesign change that eliminates the separate high voltage and bias transformers. It actually runs cooler too.

You might want to look into his 300B, 1W monoblocks. Rumour has they are the shizzle.

BTW, my new caps arrived. Yippee!

Quote:

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Originally Posted by alancohen

.....BTW, my new caps arrived. Yippee!

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Every vintage Altec I've ever recapped sounded noticeably better after a re-cap and thorough cleaning of the crossover pots/L Pads with deoxit (to varying degrees--some sounded surprisingly better, some had more of a subtle improvement but definitely still noticeable). Drum roll, please!

Gearfreak: Or, you can buy these!!

W Classic Western Electric Altec 300B Single Ended Stereo Tubes Power Amplifiers | eBay