Stereo Width Control in Summing Mixer

[RSRecords]

Putting together a summing mixer based on sphere eclipse A. I wanted to add a width control ala the Neve 8816 summing unit. No idea how they accomplish it, but I like the feature. Wondering where in the block diagram I should place the width control. I found this schematic (fig. 3) on the ESP site. FIGURE 3

Would it make sense to place this block between the VE summing amps and the make up amps? Should I bring the level back up before the width control? Plan is to use spa-62s (from the awesome Gary Barnett). Attached schematic of what I'm thinking.

 

[richiyobs]

It's a cool feature to implement... I tested that Esp design on drum stem... It works great... Also have compared It with different designs found on old reviews like old Elektor or similar One... You can also add a capatitor to select the corner frequency operating point...

Best

 

[RSRecords]

It's a cool feature to implement... I tested that Esp design on drum stem... It works great... Also have compared It with different designs found on old reviews like old Elektor or similar One... You can also add a capatitor to select the corner frequency operating point...

Best

OH interesting. Where would the cap go to determine the frequency. Would be nice to leave the lowend alone.

Still undecided about the placement in the circuit. I'd like to drive the output transformers with the doa which would put the width control before the make up gain.

 

[Tubetec]

The Neve era Amek Bc3 has a similar width control , it might be worth looking at for inspiration ,

Its really handy to be able to swing a stereo source L-R, R-L or mono centre with just a single control , it allows you find the sweet spot fast without the need to repatch the inputs ,also a useful way to spot check a stereo source for mono compatibillity .

 

[richiyobs]

OH interesting. Where would the cap go to determine the frequency. Would be nice to leave the lowend alone.

Still undecided about the placement in the circuit. I'd like to drive the output transformers with the doa which would put the width control before the make up gain.

https://groupdiy.com/threads/stereo-spreader-anyone-ever-make-one-like-this.37144/post-541250
You can check this link.... I only simulated this simple version/example.... my proto was a bit noisy, maybe cause i used Tl074... So Is Parked into a drawer for the Moment... But i'd like to redraw It implementing this feature...

Best