Does anybody make...

That is an odd requirement. Just out of interest… what is the application? You have four different amps and sets of speakers?

My Coincident Statement pre has two independent  transformer based volume, control, only two outs, however.

Yes, adjustable gain would be correct.

I am building some Open Baffle speakers and I want to control each driver separately, I am just looking at options, My SSP-800 is in the shop again, ready to get kicked that into the closest. McIntosh C2700 offers one with 3 channels, which I believe the two outputs are adjustable... My OB are 3 drivers I was thinking 4 would give me some flexibility... I know a DSP would work, just looking at various options since I need a new preamp. 

thx,

Good luck with that one.

I think the Pass Labs XP-32 can do what you want. 
 

In its normal config each channel has two outputs. One has the ability to be adjusted via a smaller gain knob on the front of the chassis. 
 

You can order additional units to stack and control from the one main volume unit. 
 

Would be $$$$$ though.