Moog MF Tremolo

Moog MF Tremolo

The Moog Tremolo is one of the more complex Tremolos I've dealt with. Don't let the simplistic controls fool you! There are a ton of things going on underneath the hood of this beast.

Moog states the following on their site about the origins of the effect:

"The MF Trem is an analog tremolo pedal based around a balanced modulator and Sub Audio VCO. This unique design creates a wide range of tremolo effects that are based on phase cancellation and addition. Create classic optical and hard tremolo effects that are reactive to harmonic content, or push up the depth control and shift into the beginnings of lush phasing and chorus. The variable Shape control interacts directly with Tone and Mix to craft subtle swells and gallops to rhythmic percussive, and swirling effects. An expression pedal input adds control over tremolo Speed for beautiful, hands-free swells and rotary effects."

I have not found anything resembling a choppy square wave in the pedal despite the claims above. The choppiest that I've gotten is the reverse sawtooth wave form which is more pulse-eee. 

Even though Moog goes over what it does on the below page, it is still quite confusing as all controls interact with each other and behavior changes depending on where you have the knobs set for each control.

https://www.moogmusic.com/products/minifoogers/mf-trem

Ultimately you will probably twiddle knobs till you find something you like, and then you better write it down! But this post could act as a guide to give you a bit more information.

First we will start with the shape control.

Shape in simplest terms possible, this is in general what this control SHOULD do
Left should be slow onset followed by abrupt drop off (Sawtooth wave'ish)
Center should be an equal rise and fall (Sine Wave-ish)
Right should be abrupt start and then smooth drop off (Reverse Sawtooth waveish)

Those are terms I can understand, but the reality is, there is a lot more to it than that!

First let's start with the tone control at noon and see what we get.

 Shape - Center     Tone - Center     Speed - Slow     Different Depth Settings

So immediately we see something interesting here.  This should be the smoothest rise and fall of the wave shape on the pedal. This should be your sine wave. First concentrating on around 60 or 50% or below this is pretty correct. 

We can see by the picture above, it resembles a sine wave at 50% or below on the depth, a bit to the triangle side of things, but pretty smooth, a bit lop sided and this sounds very pleasing to the ear. It is one of the smoothest waves I've heard come out of a Tremolo pedal. It just sounds great!

Things however shift a bit when you crank the depth above the 50 - 60% mark and the signal starts to "gallop"  As we can see above at about 75% it starts doubling the speed, and no longer emphasizes the peaks at the same level in each cycle. One is significantly louder than the other. 

When we reach 100% on the depth, we go back to emphasizing each peak equally, but the 2 shapes in the cycle are not symmetrical to each other. They are like the same shape mirrored backwards against the other. 

Now keep in mind, the ONLY knob we touched here was the Depth knob. Now you have some idea of how interactive these controls are.

Moving on, lets turn the shape knob all the way to the left.

Shape - Left     Tone - Center     Speed - Slow     Various Depth Settings

So we see about the same type of behavior here. We expect to see a sawtooth-ish wave here, and that is what we get from about 50 or 60% and below on the depth setting. At 75% we see the same behavior of splitting the wave form and emphasizing one peak more than the other in the cycle. 

When we hit 100% we also see the same behavior of the mirrored shape, still split.

Now with the shape knob all the way to the right, we get a reverse sawtooth with the same behavior as well.

Shape - Right     Tone - Center     Speed - Slow     Various Depth Settings

Right away you can see, just with the shape and depth knob interactions, we are getting quite the pallet of sounds.

Now the shape knob not only affects the "Shape" of the wave form, but also speed. Shape at the center position is the slowest, but if you move it right or left, the Trem speeds up. So when adjusting the shape, you may need to adjust the speed to compensate.

The Depth control as we see above also has an effect on the speed, because shortly past noon on that control as we see above starts chopping the wave form in half. 

The Tone control is pretty interesting as well. Below noon, it will apply the Tremolo effect in various degrees to just the low frequencies in your signal, with a more non effected amount of high frequencies. Similar functionality can be found on Trem pedals such as the Red Witch Pentavocal or the David Rolo Twin Peaks Tremolo.

The implementation sounds very good on this pedal. They state when the tone control is maxed, the Tremolo effect is much more pronounced and affects all frequencies.

This can be confusing to the ear, because the higher you dial in the tone control, the more pronounced the effect is, which kinda sounds like depth doesn't it?! :)

To my ears adjusting the tone control in conjunction with the shape knob at least gives a perceived effect on the shape. So lets repeat our tests with the following settings.

Tone - 100%     Depth - Noon     Speed - Slow     Various Shape Settings

So despite not stating so, the tone knob also affects the shape similar to what turning the depth knob up did. When turned all the way up, we can see that we again have the galloping feel going on, with one wave peak being emphasized more than the next. This looks to happen from about 3 o'clock and beyond on the tone knob approximately.

Speed range is also affected by which wave shape you are working with. 

Sawtooth (Left)
Slowest: ~1358 ms/cycle
Fastest: ~54 ms/cycle

Sine (Center)
Slowest: ~1787 ms/cycle
Fastest: ~90 ms/cycle

Reverse Sawtooth (Right)
Slowest: ~760 ms/cycle
Fastest: ~52 ms/cycle

The expression pedal implementation is good, it controls the Speed. The slowest heel down speed on the expression pedal is set with the Speed knob.

So for the noise floor, on my Princeton reverb I can turn the volume up to about 4.3 on the amp before I start noticing any audible ticking, or thumping, but if you turn the volume up any louder than that you can definitely hear it. This may be a concern if you are playing live at stage volumes. Depending on the amp you have. This was with no other effects in the chain, just guitar --> pedal --> amp.

So my over all opinion?

If you just dive into this Tremolo with no knowledge of what it's actually doing, then you can have a frustrating time trying to dial in traditional sounds. If you are looking for simple, easy, and predictable, this may not be your pedal.

This Tremolo has a lot of character, and it is easy to see why people love it so much, despite not being super simple. The wave shapes you see above are pretty non typical of what you see in other Tremolos and the fact is, the things just sounds great.

This pedal strikes me as exceptionally smooth sounding, even without a perfect sine wave.

This is a complex machine that gives you back what you put into it, and that can take some work.Those with short attention spans best stear clear. For people that want something fairly unique, that sounds great. This is probably the pedal for you.

Pro's
  - Very smooth sounding
  - Doesn't give you the cookie cutter standard wave shapes you are used to seeing on other Trems
  - Good for those who like to experiment and tweak
  - Expression pedal implementation is good, with the ability to set the slowest speed.
  - Analog Circuit
  - True Bypass
  - Sine, Sawtooth, and Reverse Sawtooth type shapes
  - Ability to create more rythmic galloping sounds with your Trem due to non equal emphasis on peaks in the trem cycle

Con's 
  - Controls are interactive with each other, and those interactions can get complicated
  - The pedal may not be as quiet as you'd like it to be when playing at higher volumes.