Equipment:
Behringer UCA202 USB audio interface
Alto S-8 mixer
Audacity (free DAW software)

Sound was taken from AUX1 send of mixer - so it was not going through any EQ or something else yet, just preamplified

Recordings:
True Native Konami SCC :)
FPGA SCC from GR8NET (external 3.5 mm output)
FPGA SCC from Carnivore 2 (external 3.5 mm output)
FPGA SCC from MFRSCC+SD cartridge

UPDATE:
FPGA PSG from MFRSCC512+SD - firmware updated to latest by M.Pazos, also: soldered external output and cut off pin 49, Philips audio fix removed
FPGA PSG from Carnivore 2 - updated to latest new firmware, also: two capacitors removed
To get SCC sound only (no PSG) - patched version of vgmplay for MSX was used (with disabled PSG)