Dumble help please

[piperbob]

I am puzzled. I am beginning to wire up my Dumble 124/4 6L6 clone and am working with the rectifier board. I have the same board as the attached photo and had some questions. The upper right corner has the two red AC wires to the diodes and a blue red wire to the bias circuit. Looking at the lower left corner I see three wires. Black is ground but what is the yellow or white wire doing? Looking at some other picture I have seen these two wires go to the bias pot. Is this so? Why are there two 100uf capacitors on the board? I am looking at the attached schematic and am using this as my bible. This schematic only shows one capacitor,. Do I have the wrong schematic or can someone explain why the two capacitors and white-yellow wires are used. Next question fellows.... what is the value and power rating of the four ceramic capacitors? Thanks for the help.

[Homebelly]

Take a look at the layout for #183.
The boards you have in your picture seems to be from that amp.

It looks to me like the yellow and white wires are going to the bias pot.

The value of the caps on the #183 layout are 0.01uF.

Go take a look in the documents forum for the layout.
I see also from your schematic that you are using Nik's layout as a grounding guide. My schem reading skills are for shit so i'm not sure if the schem you have is from niks version of 124, or the one from this forum.

From my observations Nik tends to use a lot of repeated boards across all of his amps and changes components every once in a while. From memory, all of his OTS/ODS amps use basically the same bias and relay boards with some changes here and there. These same relay boards often turn up in his other channel switching amps also. Not really a bad thing or criticism, just a heads up that if your using various document resources you might find your self painted into a corner.
I speak from experience in this regard.

[martin manning]

Are your boards from J. Borders/AGB Amplifiers? If so go to his site agbamplifiers.com and download the documentation for them. The links are under "Application Notes."

[M Fowler]

Here is the layout that goes with your board.

And Bias-rectifier board.

[piperbob]

Thanks for the help guys!