I'm repurposing a '50s amp chassis from a phono console into a guitar amp (see attached). The tube complement was 6au6a, 12ax7, (2) el84 and ez81. I'm replacing the 6au6a with another 12ax7. The original power transformer is 210-0-210. The circuit (attached) I'm using calls for a 290-0-290 supply. How do I design the power rail to get the most out of the transformer I have? I'm using two 32uf caps and two 22uf caps for filtering. What I can't figure out is the correct resistors for the power section that supply the el84s. I've searched the web for an easy explanation for calculating the dropping resistors, but nothing has made sense in this application--or with my math skills. Even the online calculators have asked for a spec I don't have (or don't understand). Can anyone help? Thanks!
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