Altec 9440A? - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 27th November 2006, 07:52 PM   #1
Tyimo is offline Tyimo  Hungary
diyAudio Member
 
Join Date: Nov 2002
Location: Hungary
Default Altec 9440A?

Hi!

Has somebody any info about the legendary Altec 9440A amp?
Maybe a schematic?????

Greets:

Tyimo
  Reply With Quote
Old 27th November 2006, 10:06 PM   #2
diyAudio Member
 
tomtt's Avatar
 
Join Date: Aug 2002
Location: kansas city mo, and on occasion, around the world ...
Blog Entries: 15
scroll down-about half way...


http://alteclansingunofficial.nlenet...ers/index.html
Attached Images
File Type: jpg altec9449_1.jpg (16.8 KB, 556 views)
  Reply With Quote
Old 28th November 2006, 05:00 AM   #3
Tyimo is offline Tyimo  Hungary
diyAudio Member
 
Join Date: Nov 2002
Location: Hungary
Hi Tomtt!

Thanks for the link!

It is a goldmine!

Greets:

Tyimo
  Reply With Quote
Old 28th November 2006, 10:43 AM   #4
diyAudio Member
 
Join Date: Nov 2002
The 9440 is a great sounding amplifier. I owned about 10 of them over the years and at one point had 5 of them in my theatre rack running mono bridge at 800 watts a channel. The bad thing about them is that parts are getting hard to find. You don't want to try to use any ECG or NTE parts in one or you will let the smoke out. The driver transistors are not going to be found anymore so this will make a problem.
  Reply With Quote
Old 28th November 2006, 11:27 AM   #5
Tyimo is offline Tyimo  Hungary
diyAudio Member
 
Join Date: Nov 2002
Location: Hungary
Hi Burnedfingers!

Quote:
The bad thing about them is that parts are getting hard to find.
Yes. But I am still dreaming to buy or to clone one......

Tyimo
  Reply With Quote
Old 8th April 2009, 08:54 AM   #6
bobd53 is offline bobd53  United States
diyAudio Member
 
bobd53's Avatar
 
Join Date: Apr 2009
Thanks to tomtt for the link. Unfortunately, my 9440A is several years newer than those documents (13th week of 1982) and also has a label saying the following:
Quote:
THIS APPARATUS
HAS BEEN DESIGNATED
FOR MIL SPEC MANUFACTURE
There's an additional relay not in the 1975-1977 documentation as well as a two-pin connector (with a pair of 1/4" male quick connects) located between the input jacks and the output binding posts. The relay and that connector, along with a small terminal board containing a transistor and a couple of resistors, are wired into the circuit with the thermal switch between the E18 terminals on the output boards. At first I couldn't get the output relay to pull in. I had tried leaving the pins of the extra two-pin connector open as well as shorting them together after power was already on. (There was about a quarter of a volt between the pins when open and one pin goes only to one end of a 510-ohm resistor, so I figured it was safe to try shorting them.) I later discovered that leaving the pins shorted when power was applied would allow the output relay to energize. The additional relay seems to form a latch requiring a power removal for reset if the short is removed from the connector.

Does anyone here know anything about those changes? I have no idea if they're custom for MIL SPEC or if they were standard in later production units.
  Reply With Quote
Old 8th April 2009, 10:45 AM   #7
diyAudio Member
 
Join Date: Nov 2002
Can you post a picture? I don't remember an additional relay.
  Reply With Quote
Old 8th April 2009, 10:18 PM   #8
bobd53 is offline bobd53  United States
diyAudio Member
 
bobd53's Avatar
 
Join Date: Apr 2009
Here are pictures of the extra connector, both relays, and the label on the front panel:

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.

If you scroll to the bottom of the picture of the relays, you can see the terminal board with a transistor, two resistors, and a diode.

Six wires (orange, blue, grey, white, red, and green) go back to the heatsink assembly and a seventh (violet) goes from the relay's normally-closed contact to the transistor on the terminal board.
  Reply With Quote
Old 8th April 2009, 11:35 PM   #9
diyAudio Member
 
Join Date: Nov 2002
I looked at one that was built at the very last of the production run and it has no added circuitry or relay. Based on your pictures it looks like something that someone has added. If it were me I would remove the added parts so it reverts back to the circuit as shown on the schematics.
  Reply With Quote
Old 9th April 2009, 04:15 AM   #10
bobd53 is offline bobd53  United States
diyAudio Member
 
bobd53's Avatar
 
Join Date: Apr 2009
Thanks for the replies.

I was going to do that before I figured out that leaving the two pins of the extra connector jumpered together makes everything operate normally. The workmanship of the mods leads me to believe it was done by Altec, perhaps in their prototype lab. It really looks like it was done during manufacture rather than later.

The cooling fans, on the other hand, were definitely added by someone else. I'll be replacing them with a set of Whisper fans before I put this beauty on the market. I'd love to keep it, but I need the money and my Marantz 510M is a better fit for my home system, anyway. I originally acquired the 9440A so I wouldn't need to take the 510M out of my living room every year for a two-day outdoor event where I was providing sound reinforcement with 4 Altec A-7 Voice of the Theater speakers (also for sale now), but I never got around to making it work before I stopped running the event.

On the subject of selling the 9440A, I haven't decided yet between eBay and Audiogon or on how much to ask. Any thoughts?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
ALtec 9440A... suggestions? Stormrider Solid State 21 20th August 2012 06:47 PM
Altec 604 vs. 605 korneluk Multi-Way 4 23rd March 2009 12:50 PM
Altec 408-A Decker Full Range 0 22nd February 2009 09:30 PM
Altec 811B horns and Altec 414z 12" Speakers xecluded Swap Meet 0 21st September 2008 05:21 AM
altec 9440A hiendaudio Solid State 0 18th April 2004 08:13 PM


New To Site? Need Help?

All times are GMT. The time now is 03:00 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2