Hello folks,

new owner of a caiman, previously owned a modded tc 7510
After a first quick listen session; I noticed an improvement in mid and highs, more refined, but still a little harsh and pronounced sibilance

SO I couldn't resist and tried the passive mod:

I took away opamp PCB, yes, REMOVED
jumper from opamp pcb socket to rca, no need for caps here, my amp has two nice DC blocking input cap inside, 3.3uF audyn film&foil

Never heard something similar, the most refined and detailed sound so far, clean, airy, not fatiguing at all, no trace of harshness or sibilance

but

bass lack of power, I mean, is tight and deep, but with the opamp in place has more energy, more slam, it's not just a matter of lower output level

So I'm wondering if increasing value for input cap would enhance the bass; my pot is 50k, so the corner point is around 1Hz, maybe the lack of bass is just a matter of mere insufficient current drive capability by the WM8716

So I have to restore the opamp, but want to make it smoother

I noticed the output stage board is missing feedback caps; Stan told me he doesn't install them because the sound seem to be better without

If I'm not wrong, in this way the opamp is working just as a line preamp, linear gain, no HF filtering

SO, if want to experiment to drop in some feedback cap to smooth out some harshness, which value range should I consider?

I'm not able to calculate filter curve for a given cap value for that circuit

I already have some nice wima MKP 150p, 220p, 330p

Hope someone here could help me