Altec 32343 Network Divider

[Corona Blue]

Hi Earl K-

Thanks for the link and for looking around for the schematic. I looked before I posted. I must commend you guys for having such a nice library of documents!! Very handy!

The resistors I saw all looked like 10w ceramics... going from memory here... 2 x 5ohm in series and an 8ohm. I will verify how they are wired.

I'm just wondering if it might be worth changing out the ceramic resistors for non-inductive 25w (finned aluminum) resistors that I can bolt to the box for extra cooling. These would have the additional benefit of being much smaller than the huge ceramics.

The 18uf cap that exploded was installed right up against one of those ceramic resistors. I can't imagine the heat would have done it any good. I have no idea how long it was like that. I have not used these speakers much since I have had them.

I was hoping to have a look at a schematic of the network to verify if it has been altered. Just wanted to know. If I get a free hour, I will attempt to derive it for the group.

Best,

Allen

[voice of the theater]

Allen--I saw your photos regarding this thread over at L.H. and am posting the link here since you mentioned you'd be posting the photos here eventually. This may help you to get some more info from our members.
http://www.audioheritage.org/vbullet...What-are-these Your H.F. drivers look very similar to Altec 802-8G drivers and the cabinets look to be home-made, but there are most likely other members here who can be more specific/add to these observations.

By the way, I have used the Solen caps (that you mentioned) in my Model 19's and Model 14's and have found them to have excellent sonic characteristics. However, everyone has their own preferences in caps and I have seen threads regarding capacitor preferences generate almost as "spirited" of a debate as threads regarding wire/cables. Best of luck with your project....

[Corona Blue]

Hi V.O.T.-

Thanks for the cross-link over to L.H., and for the info on the Solens. I went ahead and purchased a set for both networks and I'm sure they will be more than adequate. They would have to be better than the old dried up caps that were in there!!

I tend to prefer paper in oil caps or good quality foil in oil, but with the space limitations on this network box, and the cost of oil caps... HA! The caps would be worth more than the rest of the components combined!

With regard to the HF drivers, I too thought they looked a lot like something that might have come in an old Altec. They actually sound very good whatever they are. Great dispersion pattern and wide "sweet spot." The 123A-1's seem to lack punch. I have no experience with them beyond this project, so I don't know their innate character. Do people ever modify these? Or is that considered sacrosanct amongst the vintage JBL fans? Just curious. I'll re-evaluate them after the XO networks are finished.

Well I hope to have some time to draw up the 32343 schematic. When I do I will post at both forums.

Thanks again for the assistance,

Allen

[voice of the theater]

I'm glad I could help.

The 123A-1's seem to lack punch. I have no experience with them beyond this project, so I don't know their innate character. Do people ever modify these? Or is that considered sacrosanct amongst the vintage JBL fans?

If they were my speakers I'd replace those 123A-1's with a pair of 414's. As you probably know, Altec doesn't manufacture the 414's any more (or any of their high quality speakers) as a result of being bought out by Sparkomatic (to make a long story short). However, Great Plains Audio does manufacture brand new 414's. If you've never heard of GPA, they are owned and operated by former Altec employees who bought the designs, schematics, tooling etc. to make authentic Altec Lansing replacement parts. Here's a link to some brand new 414's http://cgi.ebay.com/Altec-Lansing-GP...item35ad4c1876

This link is for Great Plains Audio's website for more info about the company http://www.greatplainsaudio.com/ If you call them, you can bypass Ebay. Of course you could look for a used pair of 414's, but I'd go for the brand new ones--you will be amazed by their sound and you don't have to worry about buying used (and potentially expensive) speakers that may need re-cones, etc.

I clicked on the links that Earl K was kind enough to provide for you http://altecpro.com/pdfs/vintage/Spe...r%20System.pdf I can see that your crossover was designed to work well with the 414 woofers and Altec 902 h.f. driver which means AFAIK it should also work well with your h.f. driver (other members please chime in to confirm this). Altec used the 802-8G (which is what your drivers look like to me?) in Model 19's for example, and then later switched to the 902 h.f. driver but kept the same crossover--in other words they were used more or less interchangeably by Altec in some applications AFAIK (the 902's replaced the 802-8G's). So, you'd basically have speaker very similar to an Altec 9849-8B studio monitor which was an excellent speaker! You would of course, have to adjust the tuning of your cabinets to optimize them for use with the 414 woofers--there are people here in addition to myself who can coach you on that (a few in particular who are very knowledgeable in cabinet tuning). It's not as hard as you might think.

Keep in mind, you can sell the JBL woofers (ebay, audiogon, craigslist, etc.) to recoup a good portion of the cost of new woofers--so for not much money--you could have some amazing speakers--very similar to Altec 9849-8b studio monitors in home made cabs. Hopefully others here (there are some amazing experts here) will chime in to either support or modify my recommendation......

[bowtie427ss]

I'll pull out an unmolested 32343 this evening and try to get some comprehensive pics that a wiring diagram can be drawn from.

If those HF drivers have been paired with the 32343's all along, they're likely a late version of 806 equipped with 23744 diaphragms and in some cases tangerines.

AFIAK, you would only find 902's in very late 9849's that also used ferrite 414-8E's by this time the networks were no longer labeled 32343, they were instead labeled with "9849-XX loudspeaker system", i don't think there are many examples of Altec mixing alnico and ferrite motors in the same systems.

[voice of the theater]

If those HF drivers have been paired with the 32343's all along, they're likely a late version of 806 equipped with 23744 diaphragms and in some cases tangerines.

AFIAK, you would only find 902's in very late 9849's that also used ferrite 414-8E's by this time the networks were no longer labeled 32343, they were instead labeled with "9849-XX loudspeaker system", i don't think there are many examples of Altec mixing alnico and ferrite motors in the same systems.

They look similar to the Altec 802-8G (great h.f. drivers with 23744 diaphragms and tangerine phase plugs)--but Bowtie is more of an authority here. If he says they're likely late versions of Altec 806's with 23744 diaphragm and possibly tangerine phase plugs, those are also amazing h.f. drivers and I'll defer to his expertise there. I'd still recommend going with Great Plains Audio's brand new (alnico) 414's. The 414 woofers were selected by the Altec engineers to work well with your crossover (and with the 806's)--and they are incredible woofers..... You could also, as I mentioned, go with used 414's but if they need work done on them, you won't be saving money going that route. I checked ebay and I don't see any 8 ohm alnico 414's on there currently. I did see some 16 ohm 414's (a resistor can make 16 ohm woofers work with an 8 ohm speaker system)--in the description for one pair the seller states he was going to send them to Great Plains Audio for service--so you've got a seller who seems to know what he's doing--but with his asking price combined with the cost of servicing them I'd go brand new..... With new 414's installed, and possibly a tuning adjustment to the cabs, you won't be complaining about a lack of "punch" any more!

[bowtie427ss]

Oh i'm no expert here VOTT, but i am familiar with the 9849's as i've owned a few. AFAIK, the 9849 is the only speaker that was factory equipped with the 32343 XO, and the 23746 compression driver. Apparently the 23746 was made with both annular metal and radial plastic(tangerine) phase plugs, i think member RonSSS has examples of each. I currently have 9849-8D's with annular metal phased 23746's, those drivers "look" like an 802-8G with the same new style rear cover and rough cast exterior surface except they're the shorter body and smaller magnet of the 806. Here's a pic of one of my drivers from a while back.

[Corona Blue]

Wow! Thanks so much for your kind help guys!! I spent this afternoon deriving the schematic. Have a look and see if it looks right to you.



I haven't had time to put a meter on VR1 to verify its value. I suspect it is around 100k. (04/25 UPDATE: VR1 is 7 ohm/50 or 100 watt component) And I don't know the values of the inductors. If anybody knows this stuff, I can update it. Once we know it's right, feel free to add it to the documents lib.

VOTT- yes, that does indeed look like the same HF driver! Sorry about those blurry snaps... batteries in the cam were dying so auto focus was dodgy... I will attempt to get some clearer shots tomorrow... for now... just put yer glasses on! :-)

Let me know and thanks again.

Allen

:thankU:

[RonSSS]

The caps you have there are original. All altec crossovers from that era used those black caps with red ends. So I don't think anyone had changed values. I'm betting the blowed up one is the shunt cap that goes across the woofer. Which means someone really cranked the volume!

I don't think you would gain anything by replacing the resistors. They certainly shouldn't be getting hot.

Is that JBL woofer some sort of high powered deal? If someone had these up loud enough to pop that cap, I wonder how the hf fram survived?

I have a pair of the 9849's and I hate to adnit that I've never listened to them......

Ron

Hi Earl K-

Thanks for the link and for looking around for the schematic. I looked before I posted. I must commend you guys for having such a nice library of documents!! Very handy!

The resistors I saw all looked like 10w ceramics... going from memory here... 2 x 5ohm in series and an 8ohm. I will verify how they are wired.

I'm just wondering if it might be worth changing out the ceramic resistors for non-inductive 25w (finned aluminum) resistors that I can bolt to the box for extra cooling. These would have the additional benefit of being much smaller than the huge ceramics.

The 18uf cap that exploded was installed right up against one of those ceramic resistors. I can't imagine the heat would have done it any good. I have no idea how long it was like that. I have not used these speakers much since I have had them.

I was hoping to have a look at a schematic of the network to verify if it has been altered. Just wanted to know. If I get a free hour, I will attempt to derive it for the group.

Best,

Allen

[Corona Blue]

I had a minute to revise the schematic of the Divider Network... just some clean up really. I wanted to show the logical correlation between the Zobel filter in the LF and the LR filter in the HF sections. And I added in the extrapolated inductor values as provided by Earl K. If you have additions or corrections, please advise, and I will do so.





I will re-post on Wednesday with some measurements of the horn driver. One question: If I choose to remove the rear cap, do I need to be careful about anything in particular? What to I need to be wary of?

Thanks!

Allen