As I quite messing with the changes to the Woo 3 I notice, as with all of the modifications I do, it is settling in and in this case sounding very open. I have noticed that I need to leave something alone for a while to really gage whether the changes I have made enhanced the sound or degraded it ( after years of modifying and tinkering I am very well aware of break-in and so forth but sometimes I just like to pick up the soldering iron). Now you could say, well how do you know if you know longer have the base line you were working with, as in the original shipped model? I have two other amps that I compare with and in noticing the difference decay, transparency etc, I can gauge the changes and just the overall enjoyment or lack thereof in listening to the unit.
I have done one more change, of course, to the cathode bias resistor, which I went back to as the battery bias is too low and shifts the operating point of the tube down for the plate voltage. I am using a Riken Ohm for the cathode resistor in place of the metal oxide and I have bypassed this resistor with 200uF's ( I normally use about 400 to 500uF’s so I will experiment more here) of nonpolar Black Gate caps. This adds to the bass impact and enhances overall impact. How much you use in the bypass can affect the sound in either a good or negative way. Too much can color the mids, too little the same and can decrease the ability to add to the bass impact. Some designers prefer to use no bypass some use it. I prefer to tastefully add high quality capacitance. In this case it has also added to the fine detail and hall ambiance.
I also replaced the coaxial cable in with my solid, flat high purity silver, which I do not use sheilding on as I find that sheilding, unless really needed, slightly dulls the sound. The original wire is multi stranded and I do not care for multi stranded wire in the musical path, or much of any where. I use flat silver with teflon tubing so I get about 95% air dieletric.
Oh, and try some 5998 tubes (just drop in). These are a little beefer and enhance the sound.
John