Best way to tap power for 9v reverb?

[joecool85]

I'm thinking about adding reverb to my K20-X and rather than build out the circuit as the K30RX (they share the same board), I'm thinking of using a Belton brick.  This would require 9v DC to supply it.  I'm leaning towards simply attaching a basic 7809 regulator to the positive line of the +/-18v PSU output.  I know that technically this would draw a few ma off that end of the PSU potentially making it unbalanced, but I can't image it would be an issue.  So, what do you guys think?

[g1]

Sometimes the + side of split supply is already used more than the (-) side.  Is it possible to use the (-) side instead? 
Might help keep balance, but possibly not significant imbalance anyway.

[joecool85]

I don't believe the + side is getting any more load than the - side.  I know both sides measure identical voltage, so there is no sag on that side anyway.  I've attached the schematic in case this helps.

[g1]

Should be no problem using the + side then.