Balanced 24V Aikido question

[khundude]

I have bought a couple of 24V Aikido boards to do a balanced preamp/canamp. I want to know if there is a way to remove the DC coupling caps. I thought that if a +/-12V ps was used there would be no need for coupling caps. If that is the case, could I not wire one board +24 with the L/R+ signals and the other with -24 for the L/R- signals and tied with a resistor for each channel? I could be way off base but I thought this might achieve a balanced circuit without really altering the circuit in any way?

[Francois G]

The schematic for the 24v board is not available on his website so it is diificult to give difinitive answers about the balance version. But I assume you got the construction manual if you bought the boards from John Broskie -- you should follow the construction manual, or contact John if you are not very experienced in tubes.

In general tube circuits always need a capacitor because the output is a positive voltage with respect to ground. I quess that you will need the coupling cap in the balance version for safety reasons, or else the balance output could be many volts above ground. Aditionally it would be difficult to ensure that the both outputs of a balance pair would be at the same potential, i.e. in DC balance.

Use the caps - good caps are fine!

Hope this helped.

[Francois G]

Forgot to mention that additionally the proposed scheme, if I understand correctly, probably can't work because unlike PNP transistors tube can only ,conduct + to -.