07-30-2023, 03:53 PM
Hi Guys
That is not how you connect RBX. How is it you have an ancient version of it?
Assuming the old version: when used as a raw bias supply with BMK, the negative output goes to the bias pot-0 via 10k or so, otherwise the negative sweep is too extended and of no use for typical amps. If the amp uses low-mu triode output tubes,, or is something else with more usual tubes and Vs is c600V, then a direct connection to the bias pot-0 is okay.
RBX positive output ties to ground at the screen filter cap negative.
Bias pot-X ties to ground either individually through 6k8 or collectively through the same or lower value.
With the current RBX PCBs there are onboard positions for both range resistors, selected and supplied by the user. Follow the kit notes.
That is not how you connect RBX. How is it you have an ancient version of it?
Assuming the old version: when used as a raw bias supply with BMK, the negative output goes to the bias pot-0 via 10k or so, otherwise the negative sweep is too extended and of no use for typical amps. If the amp uses low-mu triode output tubes,, or is something else with more usual tubes and Vs is c600V, then a direct connection to the bias pot-0 is okay.
RBX positive output ties to ground at the screen filter cap negative.
Bias pot-X ties to ground either individually through 6k8 or collectively through the same or lower value.
With the current RBX PCBs there are onboard positions for both range resistors, selected and supplied by the user. Follow the kit notes.


