70s Hybrid Seperate Master Clean/OD Switching?

[Charlie Wilson]

Hello, well I finally decided to hunker down and study the relay switching in various Dumble circuits and I am still a bit confused by the separate master 70s switching. I was told to study the HRM switching but it looks a little different to me. The HRM (at least a Bluesmaster) has the clean master grounded to the buss bar where the Hybrid does not. Could someone please explain to me how the switching works in the Hybrid?
CW

[erwin_ve]

Charlie: the clean master is grounded at the nc contact on the relay on the 70-ies (2ng gen) hybrid.

[Charlie Wilson]

Thanks Erwin. So in clean mode, the com-OD entrance and clean master 1 are grounded. On the other side of the relay, the com-PI entrance and clean master wiper are connected. In OD mode, the com-OD entrance and clean master 1 are connected to .01 coupler and clean master 3 which shorts out the clean master control and sends the signal from .01 coupler to OD entrance at the same time. On the other side of the relay the OD master wiper goes to PI entrance. Did I get this right? If so, it is different than a Bluesmaster switching and also it is correct on J.Borders 70s Hybrid layout. I thought there was some issues with that.
CW

[erwin_ve]

Thanks Erwin. So in clean mode, the com-OD entrance and clean master 1 are grounded. On the other side of the relay, the com-PI entrance and clean master wiper are connected. In OD mode, the com-OD entrance and clean master 1 are connected to .01 coupler and clean master 3 which shorts out the clean master control and sends the signal from .01 coupler to OD entrance at the same time. On the other side of the relay the OD master wiper goes to PI entrance. Did I get this right? If so, it is different than a Bluesmaster switching and also it is correct on J.Borders 70s Hybrid layout. I thought there was some issues with that.
CW

Yes you got it! To avoid mistakes(brainfarts etc)I wired it like a HRM because I had done that circuit a couple of times. Technically it's the same I think.

[Charlie Wilson]

Thanks again Erwin. I think there is one difference and that is in OD mode, the signal sits on top of your clean master which has a hard wired reference to ground. So its like having a fixed 1 meg to ground resistor at the .01 coupler(in HRM wiring).
CW

[erwin_ve]

Thanks again Erwin. I think there is one difference and that is in OD mode, the signal sits on top of your clean master which has a hard wired reference to ground. So its like having a fixed 1 meg to ground resistor at the .01 coupler(in HRM wiring).
CW

Correct, that would alter the load a little bit compared to the 2nd gen hybrid lay-out.