The Studer "90°" Dome Filter Stereo to Mono Quadrature Summer

[mediatechnology]

I've listened to the mono sum quite a bit and like it.

I and Q presented in stereo as L and R has an image that's pulled hard in one direction.

[KMN]

I've had preamps that had both L+R and L-R options. Not really knowing, I always assumed there must be cases where each would shine... otherwise why add the extra circuitry?

If the is true would there also be instances where an I-Q circuit may sound better than an I+Q circuit?

[mediatechnology]

I've never listened to I-Q but I'm receiving another run of boards today and will be building another one.
I'll let you know.

L+R and L-R on a preamp are both useful when a stereo phono pickup is playing lateral and vertical cut recordings.