Adding extras to echo.

Adding damping to the echo.

The first addition to echo which goes a long way to creating a more natural sounding effect is damping. What exactly is damping?
When we hear echoes in a large room, hall or any large space, especially if there is an audience or any form of furnishing, is that the higher frequency sounds tend to get absorbed, and reduced in level. We can emulate this easily with a 1 pole LPF, the frequency of this can be varied creating a variable amount of damping. We just need to set up a feedback loop with a Feedback – Volts module, our 1 pole LPF, and a Level Adjust module.

It’s not “All about the Bass”.

Sometimes (well quite often) we don’t want too much bass entering an echo as it can make the sound “muddy” and even overpower the higher frequencies. Adding a simple 1 pole HPF on the input of the Delay 2 module can help greatly with this by cutting out those troublesome lower frequencies

Getting a “Tape Echo” sound.

What is Tape Saturation?
It’s a subtle effect that occurs as the magnetic particles in a recording tape (remember reel to reel recorders?) are asked to record too higher signal level it introduces a slight harmonic distortion, and a soft clipping effect. What some would refer to as a “warm analogue sound”. Used sparingly it can add to an effect such as echo to reproduce some of the old tape delay effects units.
Examples of these were Roland Space Echo, Korg Stage Echo, and the famous Watkins WEM “Copycat”.
The distortion in these machines was a result of several factors:
The design of the amplifiers
The amount of tape “bias”
The type of recording and playback heads
The type of tape
The amount of feedback used.

Getting the “saturated tape” effect.
This can be done by adding a subtle distortion using the TanH formula. I have used a Waveshaper 2, for a tape effect it only needs to be a subtle amount, and nothing too harsh, so TanH is the ideal formula for imitating a soft tape saturation effect. An example of a TanH curve is shown below (full formula 5*tanh(x) along with the effect on a sine wave (yellow is direct from the oscillator).

We can soften the effect more by a simple modification of the formula to 5*tanh(x/2)

Or the distortion can be increased by changing to 5*tanh(x*2)

The depth and harshness of distortion is directly related to the multiplier or divisor vale for x. The greater the divisor the softer the effect, the greater the multiplier the harsher the effect. My suggestion would be to use a formula along the lines of 5*tanh(x/3), or for an even more subtle effect 5*(tanh/4)

The Finished “Tape Echo”

Here is the final version. I tested a few modules for the saturation effect, and found the best sounding one seemed to be the stock waveshaper 2 using the formula tanh*(x/4).
The X Mix module on the waveshaper output is to give control over how much of the distorted and undistorted sound is used in the feedback loop.
Note: Don’t forget to set the feedback level on the Delay 2 module to 0, as we are using an external feedback loop.
Creating a stereo Echo is as simple as duplicating the effect and using the same controls for both channels. I containerized the Waveshaper 2,and left it as a non-visible module so that it’s not shown on the panel layout, and therefore not available to the used to change the saturation formula in the waveshaper.