Re: Altec 1285-8B Crossovers
Looks to be a later variation of the 30923 attenuator board. ArtJ hosts that layout;
http://img101.imagevenue.com/img.php...ecn50130923jpg
It's for the HF driver, the basic "flatten the midband to extend the HF" circuit.
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
bfish
Thanks Brad for the info. Much Appreciated ! :2thumbsup:
Re: Altec 1285-8B Crossovers
You're welcome.
Good ol' Zilch has explored and (ab)used the circuit to some degree. ;) Search his posts for 30923.
Re: Altec 1285-8B Crossovers
Would you mind posting the parts values?
Re: Altec 1285-8B Crossovers
All resistors are 10% , there is two 3.9 ohm and one 6.5 ohm and the one cap is a 6 uF
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
bfish
You're welcome.
Good ol' Zilch has explored and (ab)used the circuit to some degree. ;) Search his posts for 30923.
Which forum he seems to be everywhere these days.I seen him on PE Techtalk this morning even. :D
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
Altec Best
All resistors are 10% , there is two 3.9 ohm and one 6.5 ohm and the one cap is a 6 uF
Then it IS a 30923 for all intents and purposes. Same values.
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
Altec Best
Which forum he seems to be everywhere these days.I seen him on PE Techtalk this morning even. :D
I guess that's one of those "if you weren't in the forest you couldn't hear the tree fall" things. :D
Yeah, Z-man's a forum slut, but he does good work. :)
AK and LHF for the 30923.
Re: Altec 1285-8B Crossovers
OK Thanks, the guy I bought them from on eBay parted them out of a pair of Santiago's but they didn't look like they were stock with them as the 1285's were made in Oklahoma.So I'm pretty sure these were probably some kind of upgrade.
I've never used a 30923 so didn't look familiar.
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
bfish
Yeah, Z-man's a forum slut,
:laffingassoff: :lol: :D ;) Will do, I'll do a quick search after I pull myself back up to my seat. :D
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
Altec Best
OK Thanks, the guy I bought them from on eBay parted them out of a pair of Santiago's but they didn't look like they were stock with them as the 1285's were made in Oklahoma.So I'm pretty sure these were probably some kind of upgrade.
I've never used a 30923 so didn't look familiar.
At least some Santiagos came stock with 30923 boards. They were also offered as add-on accessories, and there are more Altec speaker systems that could benefit from them than not. It's built into the M19 network.
Re: Altec 1285-8B Crossovers
[QUOTE=bfish;1841548 It's built into the M19 network.[/QUOTE]
I don't remember seeing a 6.5 ohm resistor in my 19 X-over I think there is two 3.9 's a 2 and a 3 ohm resistors.But then again you know when it comes to Crossovers I need help for sure. I always thought a Butterworth was something I ate for breakfast.:D
Re: Altec 1285-8B Crossovers
You can tweak the values to suit the app., but it's the same bridged T pad. Try it on your 288s.
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
bfish
You can tweak the values to suit the app., but it's the same bridged T pad. Try it on your 288s.
Well at the very least, it looks like a little reading is in order Thanks Again. :)
Re: Altec 1285-8B Crossovers
Hi John, judging from the pictures, they look like new stock. No, mine weren't delivered with the 30923's. Not something that common, in my estimation. Nice of your seller to include them with your package. If you do decide to try them with your 288's, inform me of your findings. I have been pleased with my 1285-8B results with my 288's without 30923's, or variants, but always interested in possible improvements.
Regards,
Dave
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
DSauro
Hi John, judging from the pictures, they look like new stock. No, mine weren't delivered with the 30923's. Not something that common, in my estimation. Nice of your seller to include them with your package. If you do decide to try them with your 288's, inform me of your findings. I have been pleased with my 1285-8B results with my 288's without 30923's, or variants, but always interested in possible improvements.
Regards,
Dave
Will do Dave. And Thanks for your input. :) One thing I really found appealing about the 1285 is that i can change the crossover points with just a switch of a termial connection very useful when working with Horns.And from some of the reviews that i have read a very good sounding crossover to boot.
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
bfish
Hey Brad, wow, it shocked me that my old hand drawn diagram still exists.
I made a somewhat better one for the board later. Lets get rid of the old one :)
Altec3090430923 | Flickr - Photo Sharing!
:)
Re: Altec 1285-8B Crossovers
Hey Art, Thank You for posting that !!:2thumbsup:
Re: Altec 1285-8B Crossovers
I took a look at my old 30923 and it has the number 391427 on it.
It must be a batch number or inventory number. Who knows.
Yours is old like mine because it has the Callins capacitor.
They have been out of business for a long time.
Mine came from an early 70's model of the 9846 shown in the avatar.
:)
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
Art J.
I took a look at my old 30923 and it has the number 391427 on it.
It must be a batch number or inventory number. Who knows.
Yours is old like mine because it has the Callins capacitor.
They have been out of business for a long time.
Mine came from an early 70's model of the 9846 shown in the avatar.
:)
391427 is the Altec date code. All their date codes from that era start with 391. The 4 stands for the last digit of the year of manufacture--in your case since your 9846's are from the 70's it stands for 1974. The 27 indicates a manufacture date of the 27th week of 1974 FWIW,,,,,,,,
Re: Altec 1285-8B Crossovers
Quote:
Originally Posted by
voice of the theater
391427 is the Altec date code. All their date codes from that era start with 391. The 4 stands for the last digit of the year of manufacture--in your case since your 9846's are from the 70's it stands for 1974. The 27 indicates a manufacture date of the 27th week of 1974 FWIW,,,,,,,,
Thanks very much for that info. I must really be losing it. Their have been plenty
of posts in the past about the 391 numbers and I didn't make the connection.
That's why this is a group effort here. Thanks again..........
:)
Re: Altec 1285-8B Crossovers
Hey Brad, I have been reading about those attenuators well at least about the 30904 and there main function is to match medium efficiency LF drivers to high efficiency HF drivers.I'll assume that the 30923 is a similar network attenuator.It says that the 30904 was specifically developed for the 411.I have a pair of those so this may come in handy. But Thank You for peaking my curiosity which made me dig deeper for a use for these.@Dsauro Dave I probably won't be using these anytime soon.But if i do find an improvement WRT the 1285-8B will be sure to pass it a long.
http://www.lansingheritage.org/image...ome/page14.jpg
