Massenburg EQ schematic?

Hi folks:

Anybody know whether any schematics for George Massenburg's parametric EQs are out there? I'm not looking to clone it, but I want to show my students how it works. Thanks!

Peace,
Paul

Paul,

I have a hand drawn schematic for the 8200, will that do?

Drop me an email: Mark (-at-) Sharktankpro.com and I'll forward it to you.

Mark

I also have a version , i'd be curious to trade you mark

the pirate's cove, had it. but that place is gone... where is are  cj anyway?

okgb said:

I also have a version , i'd be curious to trade you mark

Click to expand...

Sure thing, send me your email and I'll forward the copy I have.

Mark

this looks like a good spot to ask...

i know a guy who has a couple of ITI units and one has a bad op amp

any available...?    ok, that was a stupid question.

are there any available suitable replacements?

@Queef Bag
I think a better place to ask your specific question is in your own thread with a title that draws attention to your specific topic. Putting in a different topic will only prevent people from finding it.

Oh yeah...and it's not polite to hijack someone else's thread...

Hi mark , I have to scan my version to send to Paul as well
[ drawn by someone with a program and not showing servo's ]
also using center tapped pot .
[ p.s., your box is full ]

gboboski     shaw.ca

Sounds good.

I'll forward a copy of what I have to you and Paul.

Mark

...and as always, when emailing schematics, remember to "CC" to [email protected] ...

Jakob E.

Thank you to all the folks who've sent info so far. My students will have a ball studying these! Also planning to show them the Dorsey EQ and a parametric from Urei, plus what I can find of Pultecs and a passive shelving EQ from QUAD.

Peace,
Paul

The Massenburg is very, very close to the Sontec EQ. Same topology.
If you compare the two they differ in only a few component values and the fact that Massenburg Labs used their own op-amp along with a DC servo.
I think I'm right in saying that George Massenburg and Burgess McNeil worked together in the 70's and developed the ITI equaliser (which was a forerunner of Sontec). They then went their seperate ways.
All great sounding EQ's: ITI, Sontec, Massenburg.

...

Yep. Using high quality opamps in the sontec and selecting Freq. bands like used in the Massenburg might get you as close as can be to the original.
If you have seen the silkscreening/docs on Igors Sontec version you might get the picture. Also take a look into our gmail account and find information about opamps if you search deep and loud enough.................. :-X

drpat said:

FYI, there's a DC servo on the Sontec also.

Click to expand...

Yep. The circuit is in the groupdiy account. It's worth looking at because the similarity is striking!