From Axe-Fx II Wiki
The information on this page supplements the official manuals.
Delay: supported by which Fractal Audio products?
- Axe-Fx II: yes.
- FX8: yes.
- AX8: yes.
Delay and X/Y switching
- The Delay block in the Axe-Fx II, AX8 and FX8 supports X/Y switching.
Delay Type and Config
- The Delay "type" is just a "meta-parameter" that sets the values of other parameters.
- Config is the critical parameter in terms of specifying the base algorithm.
Time and Tempo
- There are two ways to set the delay time:
- Enter a specific delay time in milliseconds.
- Set the tempo in relation to the global preset tempo (Tempo button), say 1/8 or 1/8 Dot etc.
- Important: if you use the Tempo method, the menu won't let you enter a delay time in milliseconds anymore. To do that, first set Tempo to None.
- The Delay block contains a two-band parametric EQ for the wet signal with low cut and high cut with adjustable slopes for the cut filters. The EQ stuff is on a separate GUI page with a graphical display.
- Tutorial: setting up an analog sounding delay.
- The Master feedback goes to 200% for oscillating delay effects.
- Self-oscillating preset
Effect on trails only
- To add an effect to the delay trails only, not to the direct tone, place the delay in a parallel row and add the effect after it. See Effects routing: series or parallel.
- When the parameter Auto Delay in the Tempo menu is set to “ON,” any delay blocks that are bypassed will become active whenever a tempo is tapped in. This allows you to set the tempo and un-bypass your delay block(s) from a single footswitch. See Tempo and Metronome.
Muting the Delay with trails fading out
- By attaching an external controller (connected to a pedal or switch) to Input Gain, you're controlling the delay level at the input stage. This will make delay trails fade out nicely when muting the delay.
Maintaining unity gain with Delay
- Axe-Fx II firmware prior to v11: when using Mix to control the volume level of the delay, the volume level of the dry signal is affected also. In other words, when turning up the delay level, the dry signal's level decreases. To deal with this: turn up Mix to 50% and set Level to +6dB. Or put the Delay in a parallel row, see Effects routing: series or parallel.
- Axe-Fx II firmware 11 and later, and FX8: the behavior described above has changed. Release notes: "Changed mix law for Delay block. The dry signal now stays constant at unity until Mix reaches 50% then decreases linearly to zero. Conversely the wet signal starts at zero and then increases linearly to unity when Mix reaches 50%. This eliminates having to compensate for decreased dry signal when increasing the mix".
Delay and CPU usage
- The Tape and Ambient delay types require more CPU cycles than the other types.
Delay Drive parameter
- The Drive parameter allows adding distortion to the echoes when using the block before an Amp block.
True Tape Echo emulation with Delay
- Axe-Fx II firmware 4.00 added a "true" Tape Echo mode to the Delay and Multi Delay blocks. It's mono only (the Stereo Tape is the same one as in previous firmware). From the release notes: "Added Tape Echo algorithm to Delay and Multidelay blocks. This algorithm simulates a tape echo where modulation occurs due to tape speed variation. In the Delay block the algorithm is implemented as a two head monophonic tape “deck”. The Time/Tempo parameters set the distance between the record and first playback head. The Ratio parameter sets the relative distance between the record and second playback head as a percentage of the first playback head. The Multidelay block is implemented as a monophonic deck with four independent heads. See the updated manual for full details."
- Cliff's comments:
- "The algorithm is a single tape with one record head and two playback heads. The signal from each head can be fed back (Feedback) and panned and leveled. Head 1 Time sets the delay time of head #1 when the Motor Speed is 1.0. This is analogous to the distance between the record head and the playback head in a tape deck. As you increase the time you move the heads apart and vice-versa. Whatever the time is set to is the delay time when the Motor Speed is 1.0. As you increase the Motor Speed the tape moves faster so the delay time decreases and vice-versa. The relative position of the heads do not change. Ratio sets the delay time of head #2 as a percentage of head #1. If you set Ratio to 50% then the delay time of head #2 will be half that of head #1. This is analogous to positioning head #2 exactly half the distance as head #1 from the record head. In brief: Delay Time = distance between heads, Motor Speed = tape speed. The LFOs modulate the motor speed. Modulating the motor speed (which changes the tape speed) is a very different effect than modulating the delay time. You can hear the difference between by varying the Motor Speed manually and the Head 1 Time manually. In a typical tape deck the tape speed is not constant. In the days of tape recorders much effort was expended on trying to keep the tape speed as constant as possible. This included periodic maintenance. However, when applied as a delay effect, the variation in tape speed could create a desirable modulation. Tape Echos, in particular, were built to cost points and suffered from considerable tape speed fluctuation. The two primary components of speed variation were termed "wow" and "flutter". Wow arises due to low-frequency variations in the tape speed. This is typically due to variation in the speed of the motor itself and/or eccentricity of the pulleys. Flutter is a high-frequency modulation and arises due to eccentricity of the capstan and pinch roller." source
- "The LFOs actually modulate the tape speed. It’s the same as attaching a modifier to the tape speed. This is because in an actual tape deck the tape speed is what is typically subject to variation. Wow occurs due to variation in motor speed (or belt/pulley, etc.) and flutter is due to capstan and pinch roller. Wow varies the tape speed slowly, flutter is a high-frequency variation in speed. The actual delay time is very stable since the heads are stationary and the tape is taught between the heads. Delay modulation due to tape stretching is negligible."
- "Originally all the delays "chirped" when changing the tempo (like many other effects processors). I rewrote the primary delay types so it cross-fades between tempos when you tap a new one to avoid this. The tape delay type doesn't do this so that you can use it as you would an actual tape delay and get all those cool effects by changing the head position or motor speed." source
- "That algorithm does not support bit reduction." source
Delay block position and Reverb
- Cliff: "If there isn't distortion or modulation in the delay/reverb then the order is irrelevant since they are then Linear Time Invariant (or shift invariant in digital parlance). If there is a small amount of distortion or modulation then the order is probably still irrelevant. If there is a lot of distortion or modulation then the order may make a difference. However, typically the biggest difference, as noted above, is series vs. parallel since h1(t)*h2(t) is not the same as h1(t)+h2(t). If LTI h1*h2 = h2*h1. It may seem counter-intuitive that the order doesn't matter but try it and you'll be surprised." source
- The Time Offset parameter (mono delay only) allows adding up to 100ms of delay to the right wet signal which can be used for widening effects.
2290 Delay not audible?
- The 2290/mod delay type has Phase Reverse set to Right. Because of this you'll hear no delay when the signal is summed to mono (for example when placed before the Amp, or when using a mono cab), due to phase cancellation.
Fixed number of Delay repeats
- Use Band Delay or Tap Ten Delay in the MultiDelay block to specify an exact number of repeats.
- Also known as: backwards delay. It's a setting in the Delay and Multidelay blocks. You can also use Pitch Crystals or Plex Shift, with pitch set to 0.
- Check the Axe-Fx II stock presets "bass ackwards" and "regnalf esrever".
Delay for leads
- For a lead tone with ambient delay, try this: Stereo Delay, Tempo 1/4, Right Time Ratio 61.8%. You can use these settings with a stereo or mono rig.
More Delay information and tips
- Forum member and effects wizard Simeon provides a load of magnificent delay effects. Leave a donation if you use them!
- Scott Peterson's tutorial.
- Premier Guitar: How To get The Most Out Of Your Delay Pedal.
- Cliff: "IMO, what people like about analog delays are the narrow bandwidth. The noise, aliasing and crud is debatable. The early analog delays typically used fixed anti-aliasing and reconstruction filters. These filters were designed for the worst-case scenario: maximum delay time. Typically at maximum delay time the clock frequency was only 4-5 kHz IIRC which means the filters need to be < 2 kHz. One popular pedal had the filter at 1.75 kHz. They filters also have a very steep cut-off, typically at least 4th-order but usually 6th order. The slope is given by order x 6 so for 6th-order you would set the slope to 36 dB/oct. For those who are interested there's a paper on DAFX about it." source
- John Petrucci's delay settings.