Hi All, First post but long time lurker... Does anyone know the internal tube layout for the Sonzera 50W COMBO? I'm considering some pre-amp tube rolling but I'm unsure of what tubes go where inside of the combo body. I've seen in other posts that there was some discussion of what types of tubes should go into the V1, V2, V3 and V4 slots on the 50W HEAD and then where those slots are located when actually looking into the head opened up ---- but haven't seen anything specifically on the COMBO. With the COMBO input jack on the opposite side of the front panel, compared to the head version, could the COMBO slot locations be different than the head version? Also a little puzzled by the fact that there are two JJ ECC83S tubes installed --- my understanding is that the factory install calls for one JJ ECC83S in V1 and three Ruby 12AX7-HG in the remaining pre-amp slots. I bought it new so I'd like to be able to figure this one out. Any help is greatly appreciated. Thanks in advance!