Basics: Five Questions About Using Stompboxes with SONAR

by Craig Anderton

Plug-in signal processors are a great feature of computer-based recording programs like SONAR, but you may have some favorite stompboxes with no plug-in equivalents—like that cool fuzz pedal you love, or the ancient analog delay you scored on eBay. Fortunately, with just a little bit of effort you can make SONAR think external hardware effects are actually plug-ins.

1. What do I need to interface stompboxes with SONAR? You’ll need a low-latency audio interface with an unusd analog output and unused analog input (or two of each for stereo effects), and cords to patch these audio interface connections to the stompbox. We’ll use the TASCAM US-4×4 interface because it has extra I/O and low latency, but the same principles apply to other audio interfaces.

2. How do I hook up the effect and the interface? SONAR’s External Insert plug-in inserts in an FX bin, and diverts the signal to the assigned audio interface output. You patch the audio interface output to a hardware effect’s input, then patch the hardware effect’s output to the assigned audio interface input. This input returns to the External Effect plug-in, and continues on its way through the mixer. For this example, we’ll assume a stompbox with a mono input and stereo output.

3. What are correct settings for the External Insert plug-in parameters? When you insert the External Insert into the FX bin, a window appears that provides all the controls needed to set up the external hardware.

• Send. This section’s drop-down menu assigns the send output to the audio interface. In this example, the send feeds the US-4×4’s output 3. Patch this audio interface output to your effect’s input. (Note that if an output is already assigned, it won’t appear in the drop-down menu.)
• Output level control. The level coming out of the computer will be much higher than what most stompboxes want, so in this example the output level control is cutting the signal down by about -12 dB to avoid overloading the effect.
• Return. Assign this section’s drop-down menu to the audio interface input through which the stompbox signal returns (in this example, the US-4×4’s stereo inputs 3 and 4). Patch the hardware effect output(s) to this input or inputs.
• Return level control. Because the stompbox will usually have a low-level output, this slider brings the gain back up for compatibility with the rest of the system. In this example, the slider shows about +10 dB of gain. (Note: You can invert the signal phase in the Return section if needed.)

4. Is it necessary to compensate for the delay caused by going through the external hardware? Yes, because the output has to go through a converter from digital to the audio interface’s analog input, then come back into the system through the audio interface’s analog-to-digital converter. If the stompox is digital, it will introduce further delays. Clicking in the Delay field causes SONAR to measure the amount of delay, and compensate automatically (in this instance, the delay is about 9 ms).

The compensation isn’t always perfect, because an external effect like chorus has a varying time delay—so there’s no way for SONAR to know the “real” delay. One solution is to bypass the external effect when you click on the delay field, but this won’t help if the effect introduces a delay when enabled. If needed, you can trim the offset manually in the “Offset (Samples)” field to tweak the timing.

Because you can save the External Insert settings as a preset, you can save time if there’s some piece of hardware you use a lot.

5. If the external hardware has a MIDI input, can I control it by sending MIDI control signals? That depends on the interface and the external hardware. Many processors have 5-pin DIN MIDI connectors; fortunately, the US-4×4 and US-2×2 offer 5-pin DIN MIDI connectors for input and output, so you can patch its MIDI output to the effect’s MIDI input. However even if MIDI control isn’t available, several External Insert parameters are automatable (Send Gain, Return Gain, Phase Invert, Left Mute, Right Mute, and Mono, which sums the right and left signals together so the same signal appears at the left and right hardware interface outputs). So, as one example, you can vary the input going into a distortion effect to change the amount of “drive,” and automate the output coming back from the effect to compensate for level changes.