How To Calculate Delay Times (Part 1)

This is going to be a very interesting post. I’m pretty sure not a lot of people actually understand what’s going on with delay times; I have to admit I was one of them. The reality is that having a strong notion about how to calculate delay times and how you can apply that to your playing can make you a better musician, and overall, it can give quality to your whole mix. The goal of this post will be to understand these concepts and for that, a little bit of math and music theory will come in handy, but don’t worry; it’s not going to be boring, I promiseJ.

Milliseconds into BPM

First we have to address the issue that delay times are generally expressed in milliseconds (ms).When you for instance want to know how much delay time a certain pedal has, the manual will normally state that in ms. For instance, Maxon (a famous Japanese effects pedal manufacturer) states on their website that their AD-999 Analog Delay goes up to 900 ms of delay time. Another example; if you go to EHX’s website and take a look at the Deluxe Memory Man, you’ll see again that they state the delay time in ms, in this case the Deluxe Memory Man 550-TT has a maximum time of 550 ms.

You sure get the idea by now, and if you are following the train of thought then, you know what we’re getting in to: songs are expressed in Beats per Minute (BPM) not ms. For instance, the song by Mike Oldfield, Man in the Rain (it was the first example that crossed my mind right now :)) it’s about 128 BMP. What happens then if you want to adjust you delay pedal to play in-sync with the song? Well, you have to convert your ms into BMP and adjust the time knob accordingly.

In order to do so, we need to have the equivalencies, and it is the norm to use 1 minute as the anchor concept for the calculation. So, 1 minute has 60 seconds; 1 millisecond is the 1000th part of a second, so, if you multiply 1000 x 60, you get the quantity of ms in 1 minute, which will be 60.000.

So first, we have that the amount of ms you can have in 1 minute are 60.000, or stated similarly, you have 60.000 ms in 1 minute. From here the process is fairly simple, you just have to apply this formula and you will have the ms according to the BMP of the song:

60.000/BMP = One Beat in Milliseconds

Going back to our song example (yeah, Man in the Rain), we saw that it is in 128 BPM. Applying the formula we get:

60.000/128 = 469 (it is actually 468,75 but I decided to round the number ;)).

With that information, you can start adjusting the time knob on your delay and it will be in-sync with the song. But again, we have an issue here. Often times, delay pedals do not have their time knob segmented by ms. This means you have to make a best guest for this. Nonetheless, it’s easier if you can segment the time by yourself. Let me see if I can explain this in the most simplest of terms. For instance, the Memory Boy has up to 550 ms of delay time. With this in mind we can imagine the time knob divided in something like this:

So, we have the time knob divided in 8 quadrants sort to speak. We know the maximum delay time is 550 ms, right? So, if we move the knob all the way to the right, we get the max delay time available in the pedal, this is represented by the blue line. The yellow line represents the minimum delay time available; this varies according to each pedal (usually around 0-30 ms), but for the purpose of this example it will be 0 ms.

With this we have the full range of the pedal to operate, from 0 to 550. So, following the reasoning, how much time in ms should we get if we put the knob in the middle? Well, the calculation should be easy: 550/2, and this gives us 275 ms. But, I think there’s a more “accurate” way of doing this and I’m going to show you how to do it and why.

First, l think it is better if we divide the time knob in degrees or even better, in percentages, so, we start with 0% (0 ms) and then we go all the way to the right to 100% (550 ms).

According to this reasoining, putting the knob in the middle will give the 50% of the allowed time of the pedal. So, 50%*550, gives us, yes, 275, the same result from above, but here’s the catch: have you noticed that the knobs in the pedal do not start or end in the middle of the range? If we would divide the pedal in quadrants, the calculation of the rest of the delay times between the initial and middle position of the knob will not get the number correctly (the grey lines); that’s why it is better to think of the positions in percentages. This way, you can divide the range in 6 parts, each part consisting in approximately 16,7% of the full range.

Now, we can multiply the % by the total amount of ms in the pedal and this will give us the approximate delay time in that position! In this case, the segments will be labeled like this: 0% – 16,7% – 33,4% – 50% – 66,8% – 83,5% – 100%.

I know what you’re thinking, “hey I did the math, it should be 50,1% in the middle and 100,2% in the last one!”. And my answer is yes, you’re totally right, for simplicity reasons I just decided to leave it like that so we don’t have to count all the decimals (100% divided the 6 quadrants actually gives you 16,66666666666667%, but it is easier if you just round the number :)).

So finally, in ms, the approximate range of the pedal looks something like this:

To finally apply everything, let’s go back to our Mike Oldfield example. If you recall it correctly, the song was in 128 BPM and by using the formula we got that in ms (and rounding the number) that is 469. From here it should be pretty straightforward; we find the spot in the time knob that is closer to that number and that’s it, with some fine tuning you should have your delay repeats in sync with the song; in our example it would be positioning the knob a little bit beyond the sixth position.

So know you may be wondering this, “I’ve noticed that some players tweak their delay settings to quarter notes, triplets, eights, dotted eights, etc. How do I do that?”. That’s a topic we are going to be discussing in the next post, but for now, I can give you a hint: delay times are by default usually expressed in quarter notes.

One Final Thought

I think this method of calculating the approximate delay time works best on simple pedals, especially analog. The reason for this is that normally, analog units do not have long delay times. The longer the delay time, the more sensitive the pedal is to the change in the time knob so; it is kind of hard to do it manually or on the fly.

That’s why for instance, if you look in the way the DD-3 works in adjusting the delay time, it’s just brilliant; the pedal has a dedicated time knob and a more general time mode selector, so for instance, in the first time mode, the pedal goes from 12.5 ms to 50 ms max and then you fine tune the delay time with the dedicated time knob in between that range. The same is true for the DD-5, DD-6 and DD-7.

So that’s everything for now. As I mentioned before, we’re going to be talking about delay time sub-divisions in the following post. I hope did find the information here useful. Leave a comment and let me know your thoughts about everything we’ve discussed so far.

Until the next time,

M.M