Metropoulos Forum

Here is the Output trafo from Marshall Master PA 1973 .





Please help to identify the wires.

Experimental setup:



The results - secondary :

Black - Brown 1,5 V

Black - Yellow 0,6 V

Black - Green 1,5 V

Brown - Yellow 2,15 V

Brown - Green 3 V

Yellow - Green 0,85 V

Which wire is for ground and 4 , 8 16 ohms ?

kochev wrote:Here is the Output trafo from Marshall Master PA 1973 .





Please help to identify the wires.

Experimental setup:



The results - secondary :

Black - Brown 1,5 V

Black - Yellow 0,6 V

Black - Green 1,5 V

Brown - Yellow 2,15 V

Brown - Green 3 V

Yellow - Green 0,85 V

Which wire is for ground and 4 , 8 16 ohms ?

The color code on that xformer follows the standard Marshall color code for a 100 Watt Dagnall based on my calculations of your measurements -

Brown = Common (goes to ground)

Black = 4 Ohm

Yellow = 8 Ohm

Green = 16 ohm

White = Primary Center Tap

Red = V4/V5 Plate

Brown = V6/V7 Plate

Primary Zp-p = 1.7K

Тhanks a lot !

kochev wrote:Тhanks a lot !

Also should note that with that particular primary phasing, the grid of V4 and V5 should be fed from the 82K side of the phase inverter while V6 and V7's grid should be fed from the 100K side of the phase inverter.