Without any tubes installed, the Voltage is around 385 at the first node and 380 at the second. Shouldn't there be a a larger voltage drop after R29 on the LA2A power supply schematic? I have a 4.7k/2 watt resistor installed as per the schematic.

If there weren't any tubes installed, the voltage on either side of the 4k7 would be substantially the same value, as you discovered.

With the tubes installed, the drop across that resistor can be calculated from ohm's law. Equally, the current that flows in the tubes can be calculated from the drop across the resistor: I = V/R.

I don't remember the exact current of a single channel of UA 610 but it'll be about 12mA so, we'll end up dropping about 50V. The LA-2a all told draws a bit more current so more voltage will be dropped.

So, to drop more voltage for the 610 we'd use a bigger value resistor.

**Or**, a 2nd resistor and cap after the 1st.

What value resistor? Calculate this using Ohm's law 👍

Not sure I understand your question regarding the input stage. Can you post the schematic snippet you're using?