Looks like my summer 2013 project will be a Quickie 1.1, my second Quickie, in fact (the first, however, exists only as a scarred plate and a bird's nest of wires and parts, thanks to constant experimenting).
Here's a discussion that we might want to pin as a sticky: how changing the plate load on the 3S4 tubes from resistor to choke to CCS may or may not change the effective output impedance of the preamp, and if so, what that may mean in terms of driving longer runs of cable. Additionally, I'm curious as to whether the coupling capacitors would change in tandem.
The stock configuration appears to yield an effective Z-out of 2000 ohms, as a trioded 3S4 is supposed to be around 4k for plate impedance in this configuration, and the stock plate resistor is also around 4k. The stock coupling capacitor value is 2.2uF, if I remember correctly. Here's where I find things to get murky: the PJCCS supposedly doubles the output impedance (to 4k), from discussions on previous threads. Yet, the coupling capacitor presumably stays the same (e.g., 2.2uF). So, we've effectively doubled the output impedance - does this mean that the capacitor value should also double to keep the same corner frequency in the bass region and/or drive the same length of cable without any issues? The 150H Hammond chokes also present a different puzzle - DCR is 3.7k, so pretty close to the stock value. On the surface, I'd assume this means the same output impedance, and thus, no changes to the capacitor value. But, a choke is not just a resistor! Given the large inductance value, would the coupling capacitor need to change value? For example, on the older SEX amp, going to the MQ iron and choke, which have better inductance than the stock Speco and 30H plate choke combo, bumps the output capacitor value from 1uF to 2.
For what it's worth, I'm probably going to end up with the chokes on this Quickie, to purposely "fatten up" the sound. My Heresies sound thin and pathetic on wood floors with the Stereomour....sometimes accuracy is not more musical!
