Some equalisers must be less noisey than others. I had a TEAC GE20 connected between the pre and main on my 9090 and it certainly added some background hiss and noise, so I connected to the tape loop monitor and it was fine.
I used to run a Pioneer SG-9 GE connected between the pre and main on my Yamaha A1020 and it was perfect.
I got out the GE9 the other day, cleaned it up, de-ox'd and, just to see how it would perform, connected it between the pre and main on the 9090, and it is perfectly quiet and does a great job.
So, is there a difference between GE units, where some are more quiet or better suited to run between the pre and main, as opposed to connecting to the tape loop monitor?