Thanks so much cpcatI’m no expert - but I’d say when you get the new preamp, start with the vc in the GG2 bypassed (0db) and go from there - if you get any distortion then simply back the vc on the GG2 down until the distortion goes away.
when shopping for a pre- go for at least 40k input impedance single ended if possible (20k minimum) and one with high output capability so you are less likely to run into overload issues with the 242.
Your advises definitely help me to narrow down the options already, i will target for those with relatively high input and low output impedance preamp first, and also try to use the bypassed to test.
Btw, i tried a quite decent passive preamp but it doesn't fit in my chain, I think i will focus to shop around those active preamp