PLUG-INS (DIRECTX, SAW)

Power Technology started out creating hardware based DSP cards for Windows. But as computers have gotten more powerful, they ported their effects into the DirectX plug-in format. Like many competing plug-in products, DSP-FX is a suite of plug-ins (11 in all) that work with DirectX-compatible host programs. Unlike most others, though, DSP-FX plug-ins allow stand-alone operation (start the plug-in application, open a WAV file - no host program necessary - then tweak the controls manually if you need to, in real time, as the program writes the processed file to disk). You can also adjust each plug-in's controls via MIDI in real time, which in conjunction with a hardware processor - a most welcome addition for those who still feel that creating music involves interaction with an artist, not just "set and forget" presets.

The DSP-FX Virtual Pack has continued to evolve over the years, with the company making free updates available to registered owners and releasing new plug-in packages to current owners for $99. The latest additions are a new reverb with a distinctly "Lexiconish" vibe, a limiter/ditherer for increasing average levels and dithering high resolution digital audio down to 8, 12, 16, or 20 bits, and an aural enchancer that adds controlled distortion to create brightness without EQ.

Installation
Installing the program is painless: When you run the installation program, Windows automatically registers the effects as plug-ins, and you're done.

The copy protection method is novel. The programs will run for a seven-day evaluation period, after which you must register. Running the included registration program analyzes your setup and produces a machine ID based on your motherboard and CPU combination. You then email, fax, or phone the CD's product ID along with your machine ID to Power Technology, and they return a password (within minutes, if you're using email) that unlocks the application for unlimited usage of your machine - no dongles and no hard disk authorizations. The same password and ID combination also provides access to updates.

If you upgrade your hardware, all you need to do is re-register. (Given that I'm using a lowly 200MHz MMX Pentium with 32Mb and plan to upgrade soon, this was good news.) One benefit of this copy-protection method is that you can reinstall on your existing hardware at any time (e.g., in the event of a hard disk crash or Windows reinstallation) as long as you know the password and product ID.

But what happens if the company goes out of business? (Of course, problems can happen even with companies that still are in business; just try getting an original Sound Designer key disk out of Digidesign.) Even though Power Technology is diversified beyond the music business and doing just fine, they have assured me that contingency plans are in place if they are bought out, exit the music business, etc.

Interface
Most windows are similar (See Figure 1), consisting of buttons, knobs, a graphic display, input and output metering, level sliders (if applicable), and MIDI options. Common controls (for instance master output level) appear in the same places, and respond to the same MIDI controller numbers, for all plug-ins.

You turn the "knobs" by clicking on them with the mouse and rotating, or simply move the mouse up for "more" and down for "less." The graphic displays are more successfully implemented; they convey at-a-glance, graphic-intensive information about multiple parameters, and are extremely useful once you understand the concept.

Multiple-element plug-ins, like multiband parametric and tapped delay, use color to differentiate among the various elements (see Figure 2 on page 94), as well as knobs that have dual functions. For example, a "delay time" knob may control a global delay time multiplier of the delay time for individual taps. When controlling a global parameter, the knob turns light brown; when controlling an individual tap, it takes on the color associated with that tap.

At first, this seems like color overkill. But once you get used to it, you wonder why more plug-in manufacturers don't use color more creatively. On the downside, the plug-ins look somewhat "klunky" compared to recent plug-ins from other manufacturers who are heavy into industrial design.

Operations
The plug-ins can work on individual tracks in a multitrack system or stereo files; you can also chain them together with Sound Forge's Patch Chainer (although my machine ran out of processing power before hitting the eight-effect limit indicated by Power Technology). In addition to being able to load and save presets, you can select five "greatest hits" presets that show up a separate, easy to access menu.

While the plug-ins can write processed files to disk in stand-alone mode without a host program, they also work live, sending sound-card input signals directly to the outputs through the selected processing. How realtime this is depends on your computer; minimum latency is about 100ms, but that increases if you need to augment the buffer size to accommodate a slower machine.

The Effects
I was deep into creating a loop library when I started working on this review, and that gave me plenty of material for testing. Many of the tweaks ended up being "keepers." Below are my subjective comments on each plug-in. The numbers in parentheses indicate approximate CPU loading with my 200 MHz system; these numbers would drop dramatically with more powerful machines. (Ed. Note: Power Technology tells us their figures for a 200 MHz MMX computer are lower in some cases than those reported below -- 22% for the Acoustic Verb, for example).

Optimizer (25%): Intended for mastering, this look-ahead limiter with dithering raises the overall average level of material so it sounds louder. The Optimizer was ideal for some drum loops that needed more punch. Note that it works best on material that hasn't been already compressed. Controls include threshold, maximum output level, release time, dithering (three times), and quantization (the word length to which you're dithering).

AcousticVerb (30%): Of the two reverbs, this is the more natural, roomy-sounding type, although it also has a slightly metallic timbre. Pay careful attention to the all-important first reflections. Dense reflections work well on drums, but not as well with voice; lesser densities cause drums to sound spiky, but keep vocals airy. Of course, you can always just call up the presets, but tweaking for specific program material yields great results. I used this reverb on several drum, organ, and guitar tracks.

SudioVerb (25%): This is a denser, airier, more transparent reverb that is outstanding on synthesized timbres (such as brass), vocals, and lead guitar. Both reverbs are excellent (I especially appreciated the lack of graininess in the reverb tails), but this one is killer.

Multi-Tap Delay (23%): This provides up to eight taps with the usual delay, feedback, and pan controls, but these dual-function controls can also affect all taps globally (increase all delays by a factor of 1.2 , for example, which is fabulous if you want to use the same preset with spongs that have different tempos.) It takes some time to set up all the parameters, but the sound is excellent. Unfortunately, there are no high-cut filters in the tap feedback paths, which would help keep older echoes from "stepping on" newer ones.

The maximum delay time per element varies from 2.9 seconds for a single tap to 360ms if you're using all eight taps. Considering the amount of RAM in the average computer, that's not much delay time, but the folks at Power Technology tell us they don't get many requests from their users for long delays. (ed. Note: A fully functional free version of the Multi-Tap Delay plug-in is included in the downloadable demo version of the Virtual Pack.)

Multi-Element Chorus (32%): Using four voices can give very lush, dense chorus textures. Generally, I'm not a big fan of chorusing on dance-oriented loops, so this effect didn't get used a lot in my project. Nonetheless, it works just fine. Like the delay, it has global and individual controls, although, again as with the delay, there's no way to instantly set all values for a group of parameters to the same value.

Flanger (25%): This contains two independent flanger elements, allowing relatively complex effects. There is a manual control for realtime flanging, which like all the controls in the Virtual Pack can be used for realtime mixdowns or in stand-alone mode. The flanger was okay, but in my usage it seemed best at more radical, somewhat metallic flanging effects, not for subtle, organic sounds. Also, the lack of a modulation depth parameter is limiting, as there's a brief "buddy" effect at minimum delay times.

Aural Activator (21%): This effect adds controlled distortion, then sends it through a highpass filter (with a tunable frequency) to add a blend of odd and/or even harmonics. It works best with the same type of material as other exciter-type devices: digital audio produced with low sampling rates, analog tape, vocals recorded with dynamic mics, or other material that lacks sparkle. This effect is more for fixing problems than for sounding cool, but is a very handy addition to the plug-in toolkit.

Auto-Pan (12%): I don't use this type of effect often (I've probably listened to too much '60s music in my lifetime, with all its gratuitous panning), but it definitely does the job if you want sounds to fly back and forth in your speakers. It has a different auto-pan element for each channel, which I found useful. I tried autopanning the right channel between center and right, and the left channel between center and left, at different rates. This added lots of motion while retaining most of the stereo imaging-try it!

Tremolo (13%): Surf's up, so grab that Fender Jazzmaster and do some tremolo. With hardware models difficult to find, this is one convenient way to get that cool pulsing sound. The algorithm features different tremolo elements for left and right channels and works very well.

Pitch Shifter (17%): The only real question about a pitch-shifter is how badly it messes up the sound when you do extreme transposition. Shifting downward does an amazingly good job and is very usable; shifting up dosen't fare as well, due to sort of shuttering echo effect. However, this algorithm is great for weirdo processing with MIDI control - crank up the feedback, change the pitch, mess with the pre-delay, and get some really astounding sound effects. It also excels at thickening up drum sounds.

Parametric EQ (12%): Standard issue, except that it has eight bands (plus high and low shelving), goes up to 30dB of boost or cut, and has fine-tuning controls for frequency and bandwidth. If your EQ problem can't be solved with this module, then you have a really serious EQ problem.

MIDI
The first 128 presets in the preset list are selectable with MIDI program change commands, but the real action is with a MIDI fader box: I configured a Peavy PC 1600 and had a great time manipulating multiple controls in real time. In either stand-alone or DirectX mode, the controls are surprisingly responsive, and the parameters are very good about not being glitchy. Even changing reverb size is relatively well-behaved, unless you have multiple effects chained together. You can also use MIDI to pseudo-sync pan and tremolo rates to the music by judicious use of the LFO reset and hold parameters.

Best of all, MIDI response can either be absolute (the value corresponds to the current fader position), icremental (fader changes add to or subtract from the existing value), or "catch" (the MIDI value has to match the existing value before the fader can start to change values.) MIDI control is one of the niftiest surprises in this package, and is the most welcome. In fact, DSP-FX has now spoiled me to the extent that I miss this kind of control on other plug-ins. Don't underestimate the importance of the interactivity that this stellar feature provides.

You can also drive the MIDI parameters with a sequencer running concurrently with the program; this requires installing a small MIDI patcher utility provided with the software.

Pros: Good variety of effects. Excellent reverbs with low CPU loading. Usable on relatively slow systems. Responsive, real time parameter control via MIDI. Stand-alone operation for processing files without a host program. Cost-effective. 32 bit floating-point processing. Native versions included to SAW.

Cons: No keyboard equivalents for functions such as selecting different elements in multi-element plug-ins. No filtering on delay taps. Effects with modulation and delay don't respond to MIDI clock.

Bottom Line: In the competitive world of plug-ins, DSP-FX Virtual Pack has some very strong points especially at under $30.00 per plug-in. Many of the effects have become my "first-call" plug-ins because they sound great and don't burden my underachieving computer. It would be nice if these plug-ins were also available in VST format. Some of the effects lack imagination. There's no filtering for delay feedback paths, no MIDI clock sync for effects with modulation, and no envelop-based modulation. Because these plug-ins are so good at realtime parameter manipulation, one hopes that future updates will put back some of the control we've lost in the transition from analog to digital processing. All in all, for the bucks, you can't go wrong. A hardware reverb that sounds as good as the Studioverb goes for a lot more than the price of the entire package, which is quite a statement in itself.