RCA equalizer schematic

[dspruill]

Hello everyone,
While perusing the schematics for a RCA tube console for ideas I saw a mention of a equalizer module. It is listed as RCA BE-2A line equalizer. I was intrigued and have been scouring the internet for a schematic to no avail. Anyone have a copy? Or know of a secret place to search?

Thanks,
David

 

[emrr]

It is for equalizing telephone lines to offset capacitive high frequency losses over great distance, and does a narrow peaked high frequency boost via passive resonant LCR.  I seriously doubt one would find it a useful device for general audio.  They seem to sell for a lot at auction simply because no one knows what they are actually buying.  The narrowness of the boost usually looks a stalagmite in the highs, rather than a traditional broader peak or shelving curve.  RCA was not known for producing audio enhancement equalizers.  I can only think of one rarely seen PA line device made up of individual modules, the tilt type EQ included in the MI-12241 preamp, and maybe a few stereo receiver type EQ's on PA gear. 

http://www.groupdiy.com/index.php?topic=16210.0

 

[dspruill]

Thanks Doug!

 

[matriachamplification]

It is for equalizing telephone lines to offset capacitive high frequency losses over great distance, and does a narrow peaked high frequency boost via passive resonant LCR.  I seriously doubt one would find it a useful device for general audio.  They seem to sell for a lot at auction simply because no one knows what they are actually buying.  The narrowness of the boost usually looks a stalagmite in the highs, rather than a traditional broader peak or shelving curve.  RCA was not known for producing audio enhancement equalizers.  I can only think of one rarely seen PA line device made up of individual modules, the tilt type EQ included in the MI-12241 preamp, and maybe a few stereo receiver type EQ's on PA gear. 

http://www.groupdiy.com/index.php?topic=16210.0

I know this is a very old topic but what Doug mentions above is the exact reason we purcahsed one to restore. To document and share some turth about this item.

However my son has a question that is well outside of my know how to answer.

Can we upgrade/mod this unit turning it into a useful item? And if so what would be the process.

 

[emrr]

Hey, a decade later, tastes have changed.  You might like it as is. 

It’s an LC EQ so you can change either but the frequency will also move.  I think those have custom potted caps and inductors so it’d be a total hotrod job to change. 

 

[matriachamplification]

Hey, a decade later, tastes have changed.  You might like it as is. 

It’s an LC EQ so you can change either but the frequency will also move.  I think those have custom potted caps and inductors so it’d be a total hotrod job to change.

Let's hot rod this son of a gun then!  Yes I believe you are correct.

This being my first experience working with Vintage RCA equipment I must reiterate the well known fact regarding the attention to detail in past designs.

Upon opening the unit up seen are the values of each part engraved onto the back faceplate.

The enclosure will need to be refurbished.

I am taking some pics and vid now to share along with notes on the unit to best strategize this project.

More soon...

Wall