Bradley -
Actually, the Alembic filters (the bass ones anyway) are sort of opposite of the effect that you'd want to recreate the subtle treble loss of passive electronics and a cable.
The traditional passive losses ARE a low-pass filter, but the Alembic Q-filters are a quasi-parametric filter that's set up more like a bandpass filter. The Q-switch or CVQ is making a sharp and huge resonant peak and the filter knob is shifting the center frequency around. In the low-resonant setting (the least bright sounding one), the filter is acting more like a traditional low-pass, but still has pretty marked effect.
I don't really have much experience with the Superfilter, so I can't really comment on it. The tech description on Alembic's site describes the filters as having relatively steep shoulders (12db/oct) which would probably have a hard time emulating a cable. The damping factor control would definitely be in the ball park though. Traditionally, damping factor is the ratio of output impedance to input impedance between power amp and speaker or between amp stages. A long speaker cable can definitely lower damping factor, so I believe that a long instrument cable has a similar effect, although the numbers might not work out to be audibly significant. I'm not sure how a pot can vary DF though (it's normally a factor of the amplification circuit design). Power amps use negative feedback to reduce distortion (some of the output signal is fed back into the input to reduce distortion on steady state signals) - the DF knob may be adjusting the amount of feedback, although I'm not sure whether negative feedback is used in the preamp circuit.
Actually, one circuit that really does sounds sort of like passive loss is the Sweet Switch which was on the original Paul Reed Smith guitars (I think this largely disappeared in the early 90's). The original PRS guitars had a master volume, rotary pickup selector which included a number of unusual pickup coil combinations, and the Sweet Switch. There was no traditional tone control. The effect of the Sweet Switch was very subtle, a little midrange bump and a gentle roll-off of treble and bass. Since these PRS guitars were passive anyway, it often didn't sound like much was happening (and which is probably why it went away). I think this must have been switching some sort of inductor in (that's how you make a passive midrange control). This may actually be a productive (and inexpensive) area of research for 1dallek1 in trying to warm up the Tribute's tone. I've got some very old PRS Signature guitars that have this feature and it's an interesting facet of a very unique instrument.
I also remember seeing fleeting mentions of Alembic mellow filters which were on guitars back in the early days. I don't know what's up with them, but wonder if it was more probing in this same area.
David Fung
