carlsbro cs40-60 mk1 output tx issue

[blindboybenton]

Hi

This is my first post on here. please be nice to me

Im new to valve guitar amp repair., but not new to electronics. Have decided that i would like to learn. I am aware of the high voltages I do have some test equipment inc a scope and a sig gen
I have been given a old british carlsbro cs40-60 mk1 with valve rectifier to learn on. The amp had been gutted to be rewired and never done
Ive started to rebuild and i have come to a stop point. Unable to find a schematic online. not for this model with the valve rectifier
The output tx primary has 2 x red wires soldered together ( ct ??)
and 2 white wires and 1 brown and 1 blue
Multi meter on the reds
white wire = 20ohm
white wire = 47ohm
Blue wire = 41ohm
Brown = 18ohm
If i disconnect the reds and measure interdependently one red is connected to the 2 whites and the other red is connected to brown and blue
with the same resistance than above. All the wires look like they have been soldered on to something. This amp was working before my friend gutted it
The secondary has 3 wires Ground/4ohm/8ohm

All the schematics i look at have 3 wires for the primary?? Right

can anyone help

[vetter]

It seems your amp has an ultra linear OTX , I guess th white 47ohm and blue 41 ohm are the plate leads while those at around 20 ohms are the wires supposed to be connected to the 1k screen resistor. I'm re-drawing a schematic for this amp. Are you sure the OTX is 8ohm and 4 ohm ? If yes it gave me an information I was looking for a long time ago. On mine only the higher Z out was connected but an extra tap was unused so after measurement I guess it was half impedance the one already connected. Just to help dating my amp is Serial number 360, is yours after that? I heard abbout the number 367 owned by an australian fellow. Good luck with this amp it's a wonderful guitar and bass amp, be careful and don't burn it.