MuRF Overview
The Filters:
MuRF stands for Multiple Resonant Filter Array. To check out the Filters, set the MuRF's Pattern rotary switch to "1" and the Bank switch to "A". This Filter Bank is an excellent tool on its own. I have found it very useful in tweaking tones for recording. Switching over to Bank "B" turns on a LFO that modulates the Filters' frequencies by a small amount. There is no front panel control for the speed of this LFO, but there is control input on the back that allows you to do so. As with all moogerfoogers, these Filters are pure Bob Moog-designed analog circuits, which means they produce scrumptious fat sounds.
Animation:
Animation steals the show - it is what makes the MuRF an incredibly versatile effect. The main components are the Pattern selector, the Rate control and the Envelope control. A Pattern is selected with a combination of the bank switch and the Pattern rotary switch. There are 2 x 12 patterns in the MuRF. The Patterns are shown in diagrams in Appendix A of the manual. There are a variety of Patterns, from simple to complex. All have been selected for interesting interaction with a variety of input sources for all Rate and Envelope settings. Each Pattern triggers volume envelopes for the 8 filters in a different way, and in itself each Pattern is a unique effect.
Envelope:
For my money, this is the control that takes the MuRF way over the top. The Envelope control morphs the shape of the volume envelopes sent to the filters. There is a diagram on page 13 of the manual that shows how the envelope shapes change as you advance the envelope control. Completely different effects result for a Pattern at different settings of the Envelope control. At a setting of "2", the MuRF Patterns take on a percussive, percolating feel. At "5" the envelopes are triangle waves - perfect for tremolo-type effects. At long settings, like "6", the transition between steps of the pattern are blurred, creating effects that sound remarkably like a vintage phaser. At "8" the envelopes are reversed, creating an almost "backwards" type of effect. Envelope times are also tied to the Rate control, so they lengthen and shorten somewhat as the Rate is decreased or increased.
Tap Tempo
The MuRF is Moog's first product with tap tempo capability. It's an often-requested feature and is quite beneficial to musicians playing groove or beat-based music. We have implemented it to allow the widest range of accurate tempos by having the time between taps define half the tempo, i.e. when tapping quarter notes, the resulting Rate produced is eighth notes.
Audio Path & Control Inputs
The audio path of the MuRF has two important features: hard bypass and stereo outputs. Hard bypass is a feature often requested by guitar players, who always want their tone unaltered in any way in bypass mode. The MuRF's Audio Input is passed directly to the Left/Mono Output with no tone-altering components in the path, ensuring the bypassed output is absolutely identical to the input signal. When the both outputs are used in a stereo setup, half the MuRF's filters are in one channel, and the other half are in the other channel. This adds an amazing spaciousness to the MuRF's effects that have to be heard. And, As with all moogerfoogers, the MuRF has control inputs for real time control of the Rate, Envelopes, Mix, or LFO/Sweep control with our EP-1 Expression Pedal, or Control Voltages from analog gear, such as other moogerfooger effects. The MuRF plays very nicely with our MF-101 Lowpass Filter, MF-102 Ring Modulator, MF-103 Phaser, and CP-251 Control Processor. If you would like to test these products with the MuRF to check out the "outer limits" of moogerfoogers, please let me know and I'll be happy to send them for your review.