New Heathkit AS101 owner - First post.

[voice of the theater]

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.

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....

[gearfreak]

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

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!

[voice of the theater]

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.

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

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?

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......

[Cal Weldon]

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

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.

Did you read this page that I posted earlier?

No. (head held in shame)

[alancohen]

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

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.

[alancohen]

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!

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.

[alancohen]

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)

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.

[alancohen]

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.

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.

[voice of the theater]

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.

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.....

[alancohen]

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.....

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.