Effects Technology - Analog, Digital, and Software Modeling
By Chris Loeffler |
Effects Technology - Analog, Digital, and Software Modeling
You have choices ...
by Chris Loeffler
A number of technologies can process tone electronically, and the options have expanded as digital technology in general lurches forward. Let's examine the pros and cons of each type of technology.
Rise of the machine. The earliest days of attempting to add effects to instruments involved physical mechanisms such as mechanically driven rotating speakers, specialized physical spaces to create ambience, running the signal through springs to create reverb, leveraging vibrations in oil to create delay, physically recording the signal to tape and playing it back, passing the electric signal through a physical plate, and even placing a thumb on a playing tape’s flange to create flanging. These inventive approaches helped build the expectation of what an instrument could sound like once electrified, but they were often bulky, expensive, required maintenance, and were not always useable in a live situation.
Analog electronics. Solid-state analog electronics started replicating many of these sounds in a smaller format, making many effects available to the average player in a compact, easy-to-use format. LEDs, FETs, and operational amplifiers (op amps) were put into service to recreate the amplification and distortion characteristics of a traditional guitar amplifier, while analog “bucket brigade” delay (BBD) chips like the Reticon SAD-1024 and Matsushita MN3005 allowed players to begin experimenting with time—it became possible to create true echo repeats, replicate the sound of multiple instruments playing the same piece, and create resonant, sweeping modulation.
This excerpt from the Reticon SAD-1024 analog delay data sheet shows how it was used in a variety of audio applications
Analog devices are prized by many musicians both for their being such an intrinsic part of electric instruments’ sound in popular music over that last 50 years, and because of their organic response to electric signals.
Digital’s Debut. Digital technology came into its own in the early 80s, and converted the electronic instrument audio into 1s and 0s to apply the effects via digital hardware. Digital technology brought with it digital controls and storage, which opened up a world of presets and complex, multi-effect routing. As a result, players were able to dramatically increase the number and types of effects they could use at once, and switch them simultaneously. Digital technology also allowed delay and reverb effects to become longer and more complex. Whereas the typical analog delay effect could accommodate 300-600 ms of delay time, digital quickly took that to several seconds, added the ability to run multiple delay lines in parallel or series, and even assign digital targeting of expression pedals to different effects parameters like feedback or delay time.
While the newfound freedom digital technology offered resulted in a proliferation of expanding rack setups and effects-drenched tones, many manufacturers at the time were dealing with inferior ADA (analog-to-digital-to-analog) converters that could degrade the incoming signal and add noise. Additionally, compared to today’s digital technology, resolution and processing was relatively rudimentary and wasn’t able to capture the full frequency of the input signal, sometimes creating thin-sounding delays or reverbs.
The Line 6 Helix is an example of a digital unit that achieves an "analog" sound quality
Digital technology has matured to where effects and recording are processed at a level of fidelity beyond the human ear’s ability to perceive the differences, meaning a well-designed digital circuit can meet or even exceed the audio quality of its analog counterpart.
The virtual effects world of computers. As computer technology grew to a point where much of the work being handled by physical digital components was moving to software, effects manufacturers began creating modelling and sampling algorithms that either replicate signal chains in a software environment or process pre-recorded sounds to extrapolate how those effects would react to an analog signal. The resultant, pure software technology entirely removed physical formats from the effects process, other than controllers or graphic user interfaces. Furthermore, as RAM became less expensive and computers started measuring RAM in gigabytes, it was possible to reach another level of complex processing.
Native Instruments' Guitar Rig is one of many popular amp and effects simulators for Windows and Mac
Software effect technology is often found as plug-ins for DAWs, independent apps or software instruments, and in tradition effects formats like stomp boxes or rack units. They require a digital processor to run the modelling software, but the software, not the physical components, do the sonic processing and effects creation.
And the winner is… All of the above. All these technologies continue to coexist and thrive, with none poised to overtake the others anytime soon. In fact, there’s an expanding attempt to overlap the technologies to get the best of all worlds, with analog effects makers using digital controls to attain the flexibility of digital routing and presets with the familiarity and sound of analog circuits, and digital effects introducing analog parallel paths to avoid ADA conversion of the dry signal.
But remember that technology is just a means to accomplish your tone, so identify which options provide the most benefits (and fewest drawbacks) for you. Keep an open mind, and use your ears to judge what’s best.
Chris Loeffler is a multi-instrumentalist and the Content Strategist of Harmony Central. In addition to his ten years experience as an online guitar merchandiser, marketing strategist, and community director he has worked as an international exporter, website consultant and brand manager. When he’s not working he can be found playing music, geeking out on guitar pedals and amps, and brewing tasty beer.