I have my first TUBA board stuffed and ready to setup/test. Hoping for some thoughts on 3 questions.
Question 1: is the target 2V across the 1084 reg a "hard" target, or can it be reduced to any value between 2V and the max 1.5V dropout voltage spec'ed in the datasheet?
I ask b/c I'd really like to test the TUBA with my upcoming Big MoFo build - which will require 24V @ 2.5A per channel. Reducing the voltage dropped across the reg to 1.7V would reduce the heat that needs to be dissipated by 0,75W.
Question 2: can the TUBA otherwise handle 5A output, 2.5A per channel? I followed Mark's advice and had the boards made with 2 oz copper - so I'm hoping the traces can handle the current and won't overheat the board. The choke is rated for 5.2A - so 5A is pushing things, and I believe inductance varies inversely with current - so maybe I'd be compromising the hash filter.
Question 3: Assuming I make no construction mistakes, is there any obstacle to adding a second identical hash filter, so that each channel has its own and can be powered by its own separate SMPS? I figure I could add a second identical hash filter, cut the trace between C2 and C3 and connect the second hash filter by exposing the trace near TP1. I'd lose TP1 as a test point for the other channel, but there's room to connect a grabber probe to the output leg of the original choke.
many thanks in advance, Derek