Odds and Ends

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Greetings Synth Seekers! For those of you keeping track, there wasn’t a post last month. The plan right now is for Synth You Asked to occur at the end of each month alongside the other regular Lindby content, but due to some big items we have in the works, we decided it would be best to push it to the beginning of October. And as far as those big items go, keep an eye out both in November and December!

For today’s post, my original intent was to go into the powerful world of Modulation Busses. This is really where some of the most interesting and complex sonic sculpting can occur.

However, upon reviewing the plethora of options that come from this section of the Minimoog Voyager, I realized there were a few quite vital odds and ends that didn’t fit into any of the previous blogs.

So, for the sake of being fully prepared for the wild world of Modulation Busses, I wanted to dedicate today to covering those handful of topics.

Right off the bat, I realized I skimmed over a very unique part of the oscillators. In addition to the main three oscillators, there is a fourth option called Noise. While the other three oscillators use specific combinations of harmonics to produce different waveforms and specific pitches, the Noise oscillator is every harmonic at once. It’s essentially sonic chaos/white noise. It has great use in sound effects such as waves, wind, etc. and is also used to help create percussion sounds.

Noise also plays a significant role as the source for a special circuit called Sample and Hold (which will now be called S&H). S&H is a special source that uses the complete chaos of the Noise oscillator to essentially generate a random pattern. When you hear a synth part in a song where the pitches are jumping all over the place in a seemingly random way, odds are that that synth is using an S&H circuit to make the random nature occur.

Additionally, the rate of change in the S&H circuit is dependent on the rate of the LFO. The S&H “samples” a piece of the Noise oscillator to generate a random pitch and then “holds” said pitch until the LFO has a new oscillation. Both of these factors (the noise being the source and the LFO being the rate of change) can be replaced with new sources, but we’ll cover that a little later. Those Modulation Busses are still calling out, and we need to get to them ASAP!

As we work our way down from the LFO section of the Voyager, we come to two knobs, then two switches, and finally two wheels.

Those two knobs are Fine Tune and Glide Rate. Fine Tune literally tunes the overall pitch of the Moog. It’s also truly the only way to adjust the pitch of Oscillator 1. Given that the Moog is generating voltage via circuit boards to create pitches, the instrument itself is subject to changes in temperature. Basically, the Moog has to warm up, and then you actually have to tune it. It’s the price you pay for analog goodness! Additionally, the guts of the Moog can be subject to ridiculous precise tuning, but instead of going into that here, I recommend checking out this post:

Advanced Moog Tuning Guide

This was shared by someone who talked to an employee at Moog. It’s slightly more in depth, but if you ever own a Voyager, it’s far better to take an hour to do this as opposed to shipping your entire Moog back to the factory to get retuned.

The Glide Rate knob ties into the Glide Switch. These two items work hand in hand to allow a glissando (think when a trombonist slowly slides their slide or when a string player slowly moves up or down a string). The switch turns this feature on and off, and the knob controls how fast or slow the effect is. A stronger setting means a more pronounced glide which means it’ll take longer to slide from one note to another. Given the digital brain of these modern Voyagers means there are more advanced settings, but we’ll save that for when we get to the digital aspects of the instrument. The main focus right now is on the purely analog elements.

The other switch is the Release Switch. Release is the final piece of the roadmap when dealing with envelopes (you can read about envelopes and Release here). Since Release isn’t always desired, this switch gives you the option to immediately turn it on and off without adjusting the Release knobs over in the Envelope section of the Voyager.

The two wheels are the Pitch Wheel and the Mod Wheel (short for Modulation). Many, many keyboards today have both these wheels. The pitch wheel allows you to “bend” the pitch up or down by a certain amount (like how a guitarist bends their strings to raise the pitch). Once again, the digital hybrid nature of the Moog allows this range of bending to range from quite small to quite large, but that will be covered later on.

The Mod Wheel is the primary controller for one half of the Modulation Busses. It can do a whole lot more than that, but we’ll dive deep into the Mod Wheel next time.

The last item to discuss today if the Touch Screen. We won’t go into every possible item it can be used for, but since it can play a vital role in the Modulation Busses, I wanted to make sure I at least went over its four main elements. You can increase or decrease a certain signal three different ways: dragging left and right (the X axis), dragging up and down (the Y axis), or covering more surface area with more of your finger (known as A for area). The fourth parameter is that by touching the touch screen at all, that can trigger a gate to open or close. I feel a bit like a broken record, but many of these abilities tie in to the digital side of things, so once that digital post comes up, we’ll be right back to the touch screen.

At this point, the only items on the front of the Minimoog Voyager that haven’t been discussed (besides the Modulation Busses) are the digital center (and the associated buttons) and four special red switches underneath the Oscillation section. Those four red switches are a post unto themselves, and while they can tie in to the Modulation Busses, knowledge of them isn’t essential the way the other items mentioned above are.

Like always, I will leave you with a video demonstrating each of these items.

Now that these odds and ends are crossed off, we’ll take the plunge into the Modulation Busses next time!

The Lovely LFO

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Greetings once again feller synthesis seekers! As the Summer of Synths comes to an end and as we look ahead to the Fall of Filters (which really isn’t the case since I already did a post on filters, but one must embrace the power of alliteration), we’ll wrap up August with a short post on LFO’s.

The big reason for the brief post is threefold: first, my wife and I were totally absorbed by the Rio Olympics; second, preparing for the school year (new schedule for my piano students, getting my entire year set up with the bands/orchestras/choirs I accompany, etc.); lastly (and most important to you, the reader), Lindby has a lot of new content on the horizon.

In fact, to accommodate this new content, Master Claset’s Theory Corner and Synth You Asked will now be posting once a month rather than every other week. If you want to be totally up to date on all these new Lindby endeavors, make sure to subscribe to our monthly mailing list by going to our homepage and scrolling down to the bottom! With that said, let’s return to LFO’s.

LFO stands for Low Frequency Oscillator. It functions just like the oscillators we discussed in the second ever Synth You Asked post. (I’d definitely recommend checking it out before reading the rest of this post!) The main difference is that the LFO is very slow and thus at a very low frequency. In fact, they’re so slow and low that we can’t even hear them!

Because of this, the LFO isn’t used for the sake of generating pitches. It’s used as a means of modifying and modulating aspects of the sound: pitch, waveform, filter settings, etc. This is accomplished via two main waveforms: a triangle wave and a square wave. The triangle makes the changes nice and smooth while the square wave is direct and instantaneous.

For the LFO section of the Minimoog Voyager, there are only two parameters to consider: LFO Rate and LFO Sync.

LFO Rate refers to how fast or slow the oscillations occur. It ranges from 0.2 Hz (one oscillation every five seconds) up to 50 Hz (50 oscillations every second). Since the human hearing range does go down to 20 Hz, we could technically hear the very high end of an LFO, but it’s hardly practical given what the main oscillators can do.

The LFO Sync provides four (technically five) methods to start/restart the oscillation process. They are as follows:

Off/Sync: The LFO runs independently unless something is plugged into the LFO Sync jack on the back of the Minimoog Voyager (this will be covered at later time).

MIDI: The LFO can be controlled via MIDI signals (once again, this will be a topic to discuss later with MIDI in general).

KB (Keyboard): The LFO resets whenever a new note is played on the keyboard. This can be useful when you want a new pitch to correspond to what the LFO is doing.

ENV. GATE: This will allow the LFO to be reset via an external gate plugged into the Envelope Gate Source jack (like Sync, this will be covered when we discuss physical inputs/outputs).

Lastly, the LFO plays an integral role in the S&H circuit (Sample & Hold), but I’d like to save that for the next post where we discuss Modulation Busses and the wealth of options entailed there.

As always, here’s a video that properly demonstrates everything discussed above.

We’re closing in on having covered all the basics. Next time, we’ll harness all of these ideas and put them to work!

Enjoying Envelopes

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We find ourselves once again sauntering through the summer of synths. Last time, we went over the tone sculpting power of filters and how we can use them to let through and/or block low sounds, high sounds, or both.

In addition to filters, we’ve figure out how make pitches using oscillators and how to adjust the primary sonic nature of said oscillators by using different waveforms.

Now we need to harness the actual execution of our pitches. At the moment (presuming we’re using a keyboard to make notes occur), when we strike a key, the note instantaneously starts, remains the same while we hold it, and then immediately stops when we let go. A nice start, but we can go so much further with the power of envelopes!

Before we get into what envelopes are in the synthesis world, I want to say you have to dig pretty deep in the dictionary to find an appropriate definition of the word.

We’re certainly not dealing with items made to contain letters, but we’re also not dealing with many of the other definitions. In fact, I had to go down to the sixth definition to find something even close to what we’ll be discussing today.

Just so we have it, said definition was: “Electronics: a curve joining the successive peaks of a modulated wave.” Not the most enlightening definition in the world, so we’ll focus on four easy letters instead:

A. D. S. R.

These four letters stand for Attack, Decay, Sustain, and Release, and they are the building blocks of any synthesizer envelope. To get a better idea of what each of these words mean, let’s put them into a visual format:

ADSR

Each line goes along with one of the letters. The first rising line is Attack, the next falling line is Decay, the flat line is Sustain, and the final falling line is Release. Moving left to right on this picture represents moving forward in time, while moving up and down represents how “strong” the envelope is (this “strength” can represent volume, brightness of tone, etc.).

The Minimoog Voyager has two envelopes: the volume envelope and the filter envelope. We’ll discuss volume first as I think it’s easier to wrap one’s head around.

The volume envelope determines how long it will take for a note to begin after striking a key (attack), if the note will fade a bit (decay), how loudly the note will ring out (sustain), and how long the note will fade after releasing the key (release).

If you have a very short attack, the note will begin instantly, which is similar to plucking a guitar string. If you have a very long attack, the note will slowly fade in, which is similar to a slowly pulling a bow over a violin string. The Moog can have an attack of 0 seconds all the way up to 10 seconds!

After the initial attack, the note might Decay to a lower volume. Going back to the guitar, the initial pluck is quite loud, but the sound of the string ringing out afterwards is generally softer. The time it takes to get to that softer ringing out is our Decay length. Just like Attack, this can be 0-10 seconds in length.

Once the Decay has occurred, the note will continue to Sustain as long as the key is held. So the value of the Sustain knob is not about time (unlike Attack and Decay). Instead the Sustain knob dictates how loud the sound will be after the first two stages of the envelope. If the Sustain knob is all the way down, the sound will fade away to nothing after the Attack and/or Decay. If the Sustain knob is all the way up, the sound will never Decay at all and will remain at full strength after the initial Attack.

Lastly, we have the Release. This is the amount of time it will take the sound to fade away once you release the key. Once again, we have a large range of options given that the release can last 0-10 seconds. You may want the sound to cut off instantly, you may want a bit of a taper, or maybe you want some epic, trippy space sounds that seemingly last forever.

To better demonstrate all of this, here’s a video exclusively on the Volume Envelope.

Right next door to the Volume Envelope is the Filter Envelope.

The same picture from above applies, but this time, going up and down on the picture represents how open or closed the filter is (if you missed the last post on Filters, I highly recommend checking that out first before proceeding).

A. D. S. and R. all work exactly the same as on the Volume Envelope. We’re just choosing how quickly to open and close the filter. The Sustain decides how open or closed the filter will wind up after the initial Attack and Decay, and the Release will fully close the filter over a certain amount of time.

Side-note: the Volume and Filter envelopes are independent of each other, so you could have two radically different envelopes going on at the same time, which enables you to create some wonderfully unique sounds.

The only unique item on the Filter Envelope is the knob called “Amount to Filter.” Unlike most knobs that proceed clockwise from least to most, this knob is “off” at the 12 o’clock position. When turned to the right, it has a positive effect on the envelope, and when turned to the left, it has a negative effect on the envelope.

When in positive mode, the envelope matches the picture above. The filter starts off closed and opens as it increases in strength.

However, when in negative mode, the envelope becomes a mirror image (flipped upside down) of the picture above. The filter starts open and closes as it follows the Attack, the Decay opens it back up, etc.

Once again, a video will do wonders to make all of this clearer.

One other item in the Envelope section that wasn’t touched upon today was the Envelope Gate. We’ll cover gates in a later post and will come back to this. For now, this post is under the presumption that all notes are activated via a keyboard.

With that all said, we’ve covered the main components of making sound on a synthesizer! Next time, we’ll get into how we can start to really modify and tweak our sounds via the LFO (Low Frequency Oscillator) and Modulation Busses. Things are about to get wild!