When was the last time you had the opportunity to choose how many filters you wanted on your synth, or the number of envelopes you could use when designing a sound? These features and many more are available with CreamWare's new Pulsar DSP sound engine-a single-slot PCI audio card for Windows computers.
The Pulsar is no ordinary sound card. It has 20 discrete channels of audio input and output and enough onboard DSP horsepower to handle real-time mixing and effects. With extensive signal-routing capabilities, MIDI-based control, and excellent onscreen graphics, the Pulsar can easily assume the role of an audio traffic controller in a complex studio.
As an added bonus, Pulsar throws in software synthesis capabilities. Included in the Pulsar package are excellent analog emulations (along with a roll-your-own modular synthesizer), an FM-based synthesizer, sample players that load Akai programs, and even a vocoder. You won't find all the features that exist in some dedicated software synthesis programs, but there is plenty of power to play with. And Pulsar's excellent graphics play a big role in making the synthesizers easy as well as fun to use.
The Pulsar card draws its power from four onboard Analog Devices SHARC DSPs. A cable assembly connects to the card and has MIDI In, Out, and Thru ports (only one of each, unfortunately). Four channels of audio I/O (two channels of stereo analog and two by way of S/PDIF) are provided on the cable assembly through RCA connectors. Pulsar converts digital audio to analog with 24-bit resolution and converts analog to digital at 20 bits. Sample rates up to 96 kHz are supported.
Sixteen channels of audio I/O are provided with two sets of ADAT Optical connectors. These four connectors are mounted directly on the Pulsar card but aren't labeled; I had to dig into the manual to figure out which cable went where. The card has no word clock or 9-pin ADAT sync connectors, so you have to synchronize your ADAT audio using the optical signal itself.
OUT OF THE BOXI installed the Pulsar into a 400 MHz Pentium II machine with 128 MB of RAM. Hardware, software, and drivers all installed free of incident. I ran the Pulsar software in Windows 95, but it also supports Windows 98. The product does not, however, support Windows NT. (In fact, it might even prevent NT from loading on a dual-boot, dual-processor machine, as one of EM's editors experienced. No other users have reported this problem to CreamWare, though.)
The Pulsar software gives you everything you need to control the card's capabilities in a Windows environment. And like most similar products, Pulsar provides no audio recording or MIDI sequencing functions on its own; you're free to choose your favorite programs for these capabilities. When you launch the Pulsar software, you're presented with a cool-looking application work space (see Fig. 1) that contains a Project window and a File Browser. (In Pulsar-speak, a Project represents a complete description of all Pulsar connections, synthesizer settings, and effects.)
Pulsar's File Browser shows all of the Devices and Modules that you can use in your project. The distinction between Devices and Modules is somewhat blurry. Generally speaking, however, Devices are software synths, mixers, and effects with control surfaces; Modules usually have no control surfaces. The Pulsar's analog outputs and MIDI input are examples of Modules.
CONNECT THE DOTSThe procedure for putting Devices and Modules to work is very intuitive. Choose one or the other in the File Browser, drag it to the Project window, and connect it up. You connect the inputs and outputs of Pulsar objects using "virtual" patch cords. These connections can represent either MIDI or audio data. Each Pulsar Device has a control surface, which is accessed by double-clicking on the Device in the Project window (more about this later).
You can get a different view of your Pulsar connections by opening the Rack window. This window shows each Module and Device stacked one on top of the other as if in a rack (see Fig. 1). The inputs and outputs for each object are clearly labeled with a text description that indicates what each Module or Device is connected to. Oddly enough, you don't have the ability to open a Device's control panel from this window.
Other windows in the Pulsar environment include a DSP Load window, which shows how much of your available processing power is currently in use. A Sample Rate Settings window lets you establish the Pulsar's sample rate and sync source for digital audio. As a master, the Pulsar can operate at 32, 44.1, 48, or 96 kHz. It can also slave to S/PDIF or either of the ADAT inputs.
THE OUTSIDE WORLDPulsar is well suited to coexist with other audio and MIDI applications. Each physical connection (MIDI, analog audio, S/PDIF, and ADAT) has corresponding "source" and "destination" modules that can be placed and connected in the Project window.
There are other modules that bring signals into and out of the Pulsar environment but are designed for use within your computer. Both 16- and 24-bit Wave modules appear as audio drivers in Windows, which allows you to record Pulsar synth output to your hard drive. First connect the synth to a Wave Destination module in Pulsar, then record the synth by choosing one of the Pulsar's Record sources from within your audio program.
To play back audio "through" the Pulsar, choose one of the Pulsar Play drivers in your audio program. These drivers appear as Wave Sources in Pulsar, so audio is sent directly to one of the card's audio outputs or to an effects module. You can do similar things with MIDI sources and destinations. By default, Pulsar sets up two audio and two MIDI drivers in Windows. You can add more in the Windows Control Panel if you need them.
If you have a particular Pulsar configuration that you'd like to use each time Windows starts up, just set it up and click the Save Project as Windows Standard button. (It's in a Settings dialog box.) This is a nice feature, because it lets you automatically configure the basics for system sounds or simple sequencing without having to fire up the whole Pulsar Project environment. You can also save a default configuration that comes up every time you do run the Pulsar environment.
Steinberg Cubase users will appreciate the inclusion of 16- and 24-bit ASIO modules, which can be configured to carry 2 to 32 channels of audio. Pulsar also includes modules for sending audio to and from a standard Windows sound card and for accepting audio from programs that use Microsoft DirectSound drivers.
SYNTH-O-RAMAPulsar is loaded with software synthesis capabilities, and this is by far my favorite aspect of the Pulsar experience. The program has several analog synths, each of which varies in capabilities and DSP processing load. A few have the look of classic models from days gone by. To work with a synth, open its control surface from the Project window. You are then presented with an impressive display of graphics, knobs, switches, buttons, and faders.
The BlueSynth is one of the more powerful models (see Fig. 2). This device has three oscillators per voice; 4-stage envelopes for pitch, filter, and amplitude; and four LFOs that can sync to incoming MIDI clock. (Handy clock dividers are available if you want to group pulses into metrically useful divisions.) Velocity, Aftertouch, and the LFOs can modulate the filter, the amp, or any oscillator.
Although the BlueSynth is useful, it lacks portamento or a noise generator. If you want these things, however, check out the miniScope. This synthesizer, which looks suspiciously like a Minimoog, has three oscillators per voice, a noise generator, and six LFOs.
Pulsar also includes EZSynth, which has only a single oscillator and filter; distortion and chorus are available to fatten up the sound a bit. EZSynth is a good choice when you want to use a minimum amount of DSP power. Another option, Inferno, is also a one-voice synth, but it provides a more capable oscillator (including a fixed-ratio suboscillator) and more control over the amplitude and filter envelopes than EZSynth. Like EZSynth, Inferno includes chorus and distortion and also offers a ring modulator and Velocity sensitivity.
U KNOW 007, presumably an emulation of a Roland Juno-series synth, has a sawtooth oscillator, a pulse oscillator, a square-wave suboscillator, and a noise generator. U KNOW 007 also gives you a high degree of control over the phase relationships between the two main oscillators. The synth includes niceties such as a spread (detuning) control, a highpass filter, delayed onset of LFO modulation, stereo chorus, and an ability to link the amplitude and filter envelopes.
ALTERNATE MODESIf analog emulations aren't your bag, Pulsar offers several alternate functions. Among these are the Sample Players, which can layer up to four Akai-format programs. The Sample Players have only minimal editing capabilities (one model offers transpose and amplitude envelope offsets; the other adds filter offsets as well), so your best bet is to create your Akai programs elsewhere, or choose from a variety of sounds on the included sample CD.
Another module is a monophonic FM synthesizer, with lots of graphical parameter screens for editing waveforms, envelopes, and operator algorithms. I don't have much use for the sounds that monophonic FM synthesis can create, but Pulsar's intuitive user interface provides an excellent medium for learning and experimenting with this complex method of synthesis.
If none of the ready-made Pulsar synths suit your needs, then you'll appreciate the ability to "roll your own" modular synthesizer (see Fig. 3). There are 80 synth modules in all, and each can be added multiple times to your onscreen modular creation. You'll also find plenty of oscillators (including two wavetable oscillators from Waldorf), filters, envelopes, and LFOs. Rounding out the toolkit are audio mixers, signal switches, MIDI manipulators, and effects.
To create a modular synth, add the modules you want and patch them together. Each module comes with a variety of ports, which might carry frequency, gate, or envelope signals. Others offer MIDI, audio, or a DC offset. Two clicks of the mouse is all it takes to place a patch cord from one port to another. I routed signals and twiddled knobs for hours and came up with all sorts of interesting sounds.
All Pulsar synths are monophonic by default, but that doesn't mean they have to stay that way. With the exception of FM One, each synthesizer can operate with up to 16 notes of polyphony. (I found it interesting that you can do polyphonic FM synthesis with the modular synth.) And if that's not enough, just add more copies of the synthesizer to your Project work space. More polyphony carries a cost of greater DSP consumption (as does synthesizer complexity), so there are limits to what you can do. I was able to easily create a 16-note EZSynth, but I ran out of DSP power when my U KNOW 007 synth exceeded 13 notes.
EFFECTIONATELY YOURSPulsar includes a decent set of effects, which you hook up in the Project window. Included in the effects palette are delay, chorus, flanging, phasing, and dynamics processing. You also get a 4-band parametric EQ, a 4-pole filter (with a built-in LFO), stereo chorus, and a nifty 11-band vocoder. No reverb is offered currently, but one is in the works.
With the exception of the vocoder, the effects are divided into aux and insert effects. Both types can be hooked up in the Project window, but insert effects can also be dropped into an effects slot on the Big Mixer (described shortly). Most inserts are mono, but stereo versions of the compressor, limiter, and 4-pole filter are available.
The aux effects include stereo versions of delay, chorus, flanging, and phasing. Everything but chorus is also available as a mono insert effect, and in a "cross" version that applies the left channel effects to the right channel output and vice versa. All of the aux effects can operate in a mono-in/stereo-out configuration.
The vocoder stands on its own and has audio inputs for analysis and synthesis. It includes a built-in frequency analyzer and all the tools you need to map 11 bands of input frequency to the output signal. Move over, Alan Parsons!
All of the effects have graphical control surfaces and are easy to use. I particularly like the dynamics processing (see Fig. 4), which shows a gain reduction curve and real-time meters for input, output, and gain reduction. You can adjust the effect's settings by turning knobs, by entering numbers directly, or by manipulating the gain-reduction curve with the mouse.
All of the effects sound great to me, and I noticed no unpleasant artifacts during the course of the review. I particularly enjoyed making low-budget- sci-fi sounds with the 4-pole filter. (I'm easily entertained.)
MIX IT UPWith so many places for audio to come from and go to, you definitely need mixing capabilities, and Pulsar gives you two mixers to choose from. The Dynamixer can be configured to accept 1 to 16 inputs and offers bare-bones mixing (as well as bare-bones DSP consumption) to a stereo output. Each input channel has gain, pan, and mute controls, as well as a channel fader and meter. Separate, linkable faders and meters are provided for the two output channels.
If you need more mixing flexibility, bring in the Big Mixer (see Fig. 5). This is a 32 5 16 5 2 configuration with dedicated outputs and submix strips for the 16 buses. Each of the 32 input channels has a gain control, a phase- inversion switch, a separate stereo send to the monitor bus, six mono aux sends, and up to four insert effects.
Mute, solo, pan, prefader listen, and a 4-band parametric EQ round out the offerings for each channel strip. Each of the sends, EQ, and effects can be configured to operate pre- or postfader, and each channel's level meter can monitor the input or channel level. You can assign each channel to one of six mute groups and to 2 of the 16 buses. Or, if you prefer, you can send the channel directly to the main stereo bus.
The Big Mixer provides stereo returns for each aux send. You connect effects to the aux buses by patching Pulsar effects in the Project window. External effects can also be used by connecting the Pulsar's audio ins and outs to these buses instead. The Big Mixer has master aux send and return controls, and each return can be fed into buses 1 through 16, the main mix, or the monitor bus.
Insert effects get dropped into a channel strip from the File Browser, and from there you can open the effect's control surface to adjust it. You can also drop up to four insert effects onto the master output section.
Speaking of which, the master section has linkable faders for the left and right channels, as well as separate level controls for the control-room and monitor outputs. The control-room outputs can contain the main mix, the monitor mix, or the prefader listen signals. A convert-to-mono switch, a 4-band EQ, and a talkback circuit round out the master section. A Big Mixer, indeed!
MORE CONTROLEvery Pulsar device has an associated Presets list, which lets you store a snapshot of each device setting. Presets are particularly important for the synthesizers, because they let you get back to a particular sound with ease. But presets are also useful for quickly changing the configuration of a mixer or effects device. You can export preset lists to separate files, and thereby keep different sets of presets for particular projects.
Most of the synthesizers come with a ready-made collection of useful presets (synth patches, for example). Unfortunately, none of the effects has such a collection. I'd like to see a set of commonly used settings for each of the effects devices.
Pulsar offers extensive MIDI control over the synth and mixer settings. A simple right-click on a Pulsar control is all it takes to open a MIDI controller assignment window. Once there, Pulsar can autodetect incoming MIDI messages to make the controller assignment a breeze.
Pulsar's MIDI controller assignments have some powerful features. You can automate entire mixes by linking each fader in a mixer to the MIDI stream from a sequencer. You can control fat filter sweeps from a breath controller. I only wish that Pulsar's effects had the same capabilities. Having external control over delay time or chorus depth would be nice as well.
PULSE CHECKThat the Pulsar system offers an extensive set of features should now be obvious. I should note, however, that you can't use all of the features simultaneously. The Pulsar card provides a fixed amount of DSP processing power, so you have to choose among the available Pulsar devices.
So just how much power is there? One of the Pulsar demo Projects uses most of the DSP power, so I'll describe it here as a representative example. This particular project has a BlueSynth, a Modular Synth, an EZSynth, and three sample players. The six sound generators all feed from the same MIDI source, and between them they contain 11 notes of polyphony.
One synth feeds into a stereo delay, and another feeds into a stereo phaser. Everything goes into an 11- channel Dynamixer. The output of the Dynamixer goes through a stereo compressor on the way to the analog outputs. As you can see, a significant amount of Pulsar's capabilities can be used at the same time.
The question of latency always comes up in discussions of software-based synthesizers. I'm happy to report that Pulsar performs admirably in this regard. Notes sounded as soon as they were played, and the effects of moving an onscreen slider or knob could be heard in real time. I did notice a tiny delay when playing a piano program with a Pulsar sample player, but this wasn't a problem for me.
Pulsar's graphics are impressive, but applications that replace or remove standard Windows functionality always bother me. Pulsar's windows can't be resized from the top, which makes it impossible to shrink a window that extends below the bottom of the screen. Other annoyances include menus that don't close when they should, cursors that don't change shape when they ought to, and scrollbars that can't be moved in certain ways. The main application work space can't be resized with the mouse-you have to open a dialog box to do it.
The Pulsar environment is stable, for the most part. I did, however, experience a few nonrepeatable Pulsar crashes during the review period, and these usually meant I had to restart Windows before I was up and running again. I also found some user-interface quirks, which indicate that Pulsar isn't completely polished yet. But this technology is new and very complex, so a few quirks are understandable for now. Overall, I was satisfied with the performance of the product.
Most of the documentation is onscreen in PDF format, which is undesirable for those who like printed manuals. Nonetheless, the documentation is thorough and well organized. Unfortunately, no context- sensitive help is available.
Overall, this is a great product and a great platform. Where else can you get lots of software synthesis, mixing, I/O, and effects for under $1,300? The sound quality is excellent, and the product's usability is superb. If you want to add some fat analog emulations to your sonic arsenal, or if you'd just like to add some DSP horsepower to your PC, you should give Pulsar a thorough test-drive.
Allan Metts is an Atlanta-based musician, software/systems designer, and consultant.