G-Pultec Modifications?

[swilliman]

Hi all,

Looking to see if anyone here has modified their G-Pultec builds! More specifically, by adding additional filter stages.

My dream build for a few years has been a copy of Joe Meek's early 60's 'Black Box' equaliser, which was made to Meek's specifications by RACAL. I've attached a few pics. The 'Black Box' was essentially a Pultec with a few additions, which were:

Separate frequency controls for Bass Rejection and Boost (should be easy to adapt).

An additional 'Bass Cut' knob (presumably just a hi-pass shelving EQ).

A 'Middle Lift' knob. I've seen the schematics for the MEQ5 midrange EQ, and I think the 'high boost' section from it could be used in this scheme.

My question is: how difficult is it to adapt the G-Pultec filter circuits? 

 

[swilliman]

A quote from Studio Sound 1993 on the Black Box when Vic Keary of Thermionic Culture owned it!

"In those days Racal were a tiny outfit based in a small workshop in Camberley, and Joe approached them to make him some equipment. He basically gave them the design for an Altec compressor, which they copied for him, and also an equaliser which was based around a Pultec but with extra flexibility. Only one of these equalisers was ever made and we have it here -it's and excellent and quite unique piece of gear. It introduces a little bit of phase shift and second harmonic distortion, but this is one of the things that gives it a very characteristic sound which is especially good on vocals. I know that Joe regularly used it to lift vocals rather than turning up the level -he would boost at 3kHz which pushes the voice right up front in the track."

 

[tony hunt]

that is a great post, thanks

 

[john12ax7]

There is an enhanced pultec design floating around which has some extra features.  Something like separate bass boost and cut just requires you to switch the caps independently rather than together.