Cinema Engineering 7080-B EQ wiring diagram and schematic needed

[Winston]

Hi Guys,

Would anyone have any wiring diagrams and / or schematics for this beast?  What is 7080-B:

Cinema Engineering 7080-B is a six-band tube equalizer, transformer I/O uses AT-13B, AT-20, AT-118 Transformers.  These are open frame modules used in vintage UA consoles.  Just got one of these and would like to fire it up.

Excerpt from the "Operator Adjustable Equalizers: An Overview" -  http://www.rane.com/note122.html

"Art Davis's company, Cinema Engineering, developed the first recognizable graphic equalizer [4]. Known as the type 7080 Graphic Equalizer, it featured 6 bands with boost/cut range of 8 dB, adjustable in 1 dB steps. (After Art Davis moved to Altec, he designed a 7 band successor to the 7080 known as the Model 9062A. A hugely successful graphic equalizer selling into the '70s.) Being an active design, the 7080 allowed signal boosting without loss -- a nice feature. (With passive units, boosting of signals requires an initial broad band signal loss and then reducing the loss on a band-by-band basis. For example, flat might represent 16 dB loss while a 6 dB boost represented only 10 dB loss. It was all a matter of reference point.)

Another innovative feature of the 7080 was the first use of staggered mixing amps to aid in smooth combining of the equalized audio signal. Cinema Engineering designed 3 mixing amplifiers for 6 bands. Using this approach, no amplifier mixed adjacent bands. The center frequencies were 80 Hz, 200 Hz, 500 Hz, 1.25 kHz (labeled 1.3 kHz), 3.2 kHz (labeled 3 kHz), and 8 kHz. The amplifiers mixed 80 Hz + 1250 Hz, 200 Hz + 3200 Hz, and 500 Hz + 8 kHz respectively. Using separate amplifiers to mix signals spaced 4 octaves apart, resulted in seamless recombination at the output. (Later Art Davis would use a similar technique in the design of the first Altec-Lansing active graphic equalizers.)"

Thanks for your help.

Winston

 

[Aardman]

Hey!  I don't have any info but do have 4 of the amps and 2 sets of the inductors sitting right here.  I have no supply for them and no docs but was interested in hearing them too.
Anyone?

 

[emrr]

I think there's something about it in one of the Audio Cyclopedia's.  Not sure how detailed. 

 

[Aardman]

I think there's something about it in one of the Audio Cyclopedia's.  Not sure how detailed. 

Thank you.  I'll have to see if I can find or borrow a copy.
The amps I have are complete and in fairly good shape but the eq stuff for them is missing everything other than the tray of inductors 
Still, there's hope!

 

[Winston]

Bump.  Anyone?

Winston

Hi Guys,

Would anyone have any wiring diagrams and / or schematics for this beast?  What is 7080-B:

Cinema Engineering 7080-B is a six-band tube equalizer, transformer I/O uses AT-13B, AT-20, AT-118 Transformers.  These are open frame modules used in vintage UA consoles.  Just got one of these and would like to fire it up.

Excerpt from the "Operator Adjustable Equalizers: An Overview" -  http://www.rane.com/note122.html

"Art Davis's company, Cinema Engineering, developed the first recognizable graphic equalizer [4]. Known as the type 7080 Graphic Equalizer, it featured 6 bands with boost/cut range of 8 dB, adjustable in 1 dB steps. (After Art Davis moved to Altec, he designed a 7 band successor to the 7080 known as the Model 9062A. A hugely successful graphic equalizer selling into the '70s.) Being an active design, the 7080 allowed signal boosting without loss -- a nice feature. (With passive units, boosting of signals requires an initial broad band signal loss and then reducing the loss on a band-by-band basis. For example, flat might represent 16 dB loss while a 6 dB boost represented only 10 dB loss. It was all a matter of reference point.)

Another innovative feature of the 7080 was the first use of staggered mixing amps to aid in smooth combining of the equalized audio signal. Cinema Engineering designed 3 mixing amplifiers for 6 bands. Using this approach, no amplifier mixed adjacent bands. The center frequencies were 80 Hz, 200 Hz, 500 Hz, 1.25 kHz (labeled 1.3 kHz), 3.2 kHz (labeled 3 kHz), and 8 kHz. The amplifiers mixed 80 Hz + 1250 Hz, 200 Hz + 3200 Hz, and 500 Hz + 8 kHz respectively. Using separate amplifiers to mix signals spaced 4 octaves apart, resulted in seamless recombination at the output. (Later Art Davis would use a similar technique in the design of the first Altec-Lansing active graphic equalizers.)"

Thanks for your help.

Winston