FLASH Noise Free 4 X 1 Stereo Switcher with Passive Mixing and MIDI from Uptown Technologies
by Jerry Vigil
This month's Test Drive is on a box mentioned in last month's interview. We wanted to know a little more about this thing called "Flash," so we contacted Uptown Technologies and the brightly colored unit arrived within days. What is Flash? As the labeling on the front panel states, Flash is a "Noise Free, 4 X 1 Stereo Switcher with Passive Mixing and MIDI." At first glance, the unit appears to be nothing more than a simple stereo switching device with four stereo inputs and one stereo output, but Flash is far more than just a four-input, one-output stereo routing switcher.
To begin with, this switcher is absolutely noise free. Many signal routers will give you a pop or a click when you switch from one input to another, but Flash makes the transition as smoothly as a digital edit. Added to this noise free switching is a noise floor of -108dB. That's quiet, folks.
Okay. So you have a box that will let you switch between four different stereo sources, but you can also have more than just one of the inputs going to the output. Flash lets you output all four of these inputs simultaneously, or any two stereo pairs, or any three. So, Flash is also a mixer, a passive mixer to be precise. What is a "passive" mixer? Consoles utilize amps and other circuits that are "active," and signals flow through these circuits on their way to the console output. Flash, on the other hand, has no active circuits in line, and the result is a mixer that can claim a noise floor of -108dB. There is no addition of "console" noise when Flash is used as a mixer. Another characteristic of passive mixing is a drop in audio when the inputs are mixed. The 10dB drop in the output level of Flash when used as a mixer is compensated for by simply increasing the level at your console or wherever you end up sending Flash's output. Four trim pots on the front panel let you adjust your inputs for the proper layering of audio, or you can bypass the trims and set levels at the input source.
Mixing or layering audio through a passive mixer such as Flash offers something else. In the world of audio in the nineties expect to hear more and more about psychoacoustics, the study of audio perception. The manual states that mixing two sounds on a standard console gives you a "mixed" sound, while mixing those same two sounds with Flash results in a "merged" sound. This merged sound is a psychoacoustic effect -- it is a perception. If you mix a voice track with some music on a Pacific Recorders ABX console then do the same mix using Flash, you may be hard pressed to tell the difference. On the other hand, if you're mixing two very pure sounds from two very nice synthesizers, a trained ear may well be able to distinguish the difference. We ran the A/B tests doing a console mix of a voice track on R-DAT with music on CD then mixed again using Flash. Just knowing that the Flash mix was supposed to sound "merged" tended to solicit agreement that it did. It definitely sounded clean. Then again, maybe our levels on the Flash mix were just a little different than our levels on the console mix, and the Flash mix simply seemed better for that reason. If someone were to present a mix done with Flash and ask the listener (who has no knowledge how the audio was mixed) what was unusual about the mix, I doubt the individual would say it sounds "merged" rather than "mixed." (Psychoacoustic effects -- What'll they think of next?) Now, when the day comes when we're all producing for digital radio stations, the high fidelity and psychoacoustic effects of Flash's mixing abilities may be a bigger consideration, but for now, if you're just going to take Joe Bob Store Manager and mix his voice over some music for a spot, you can safely perform your mix on a console without worrying about how the audience is going to perceive Joe Bob in relation to the music under him.
Psychoacoustics and high fidelity set aside, the mixing aspects of Flash in radio production do offer several pluses. If your studio has acquired additional pieces of outboard gear over the months or years, and you didn't have a large console to begin with, Flash makes for a nice, and very flexible, "sub-mixer." If you've added CD players and R-DAT machines but don't have enough inputs on your console, Flash is an ideal unit to expand your console with. These digital machines will retain their full quality while passing through the Flash to your console, and you'll have some very interesting mixing and switching options at your disposal.
As an audio switcher, we have yet to hear of a box that has the power of Flash. This is where the MIDI features of the unit come in. On the left side of the front panel are four buttons with accompanying LED's. You can switch from one input to the other and layer inputs using these four buttons, or you can send MIDI program change messages to Flash for MIDI control of the switching and layering. Using the buttons to switch and layer manually gives you up to sixteen different combinations to choose from -- input 1 with 3; 2 with 3; 1 with 2, 3 and 4; etc.. Using MIDI, you are given up to 256 different combinations. This is because, with MIDI, left and right inputs can be selected individually. For example, you could have a mix that is comprised of the left channel of input 1, both channels of input 2, and the right channel of input 3. Consider also that the four stereo inputs can also be treated as eight mono inputs going to two mono outputs.
Now comes the kicker. Let's say you have all four stereo inputs in use. With MIDI program change messages coming from a sequencer, Flash can switch from one input to another as fast as one hundred times per second, NOISE FREE! You can have, let's say, a stereo music bed going through input 1, and various sound effects going through inputs 2, 3, and 4. You can do a mix with the music playing steady while the sounds on inputs 2, 3, and 4 switch from one to the next to the beat of the music and have them bounce back and forth between the left and right channels. Think about that for a while and consider all the possibilities for some fun on a slow day. We played around with this for some time but had some difficulty getting the internal sequencer of an Ensoniq SQ-80 to shoot out program change messages as fast as the Flash could receive them. Nevertheless, we sent them fast enough to come up with some interesting results. It may have been lack of knowledge about the SQ-80's sequencer or limited abilities of the sequencer itself that prevented us from sending program change messages at a rate of one hundred times per second, but anyone with a computer based sequencer should have no problem getting things at full speed.
Also controllable via MIDI is the muting function of Flash. There's a mute button on the front panel that will noiselessly mute the output of the unit when pushed. When controlled by a sequencer, the Flash's output can be muted then turned back on at a rate of one hundred times per second. Done to the beat of a piece of music, you get an effect used on a lot of "Euro-disco" type of music.
With both the input switching and muting functions there are two "modes" of operation available, LATCH and PUNCH. When switching inputs in the LATCH mode, an input will turn on when the button is pushed and remain on until the button is pushed again, even if you hit another input button. In the PUNCH mode, hitting another input button will automatically turn off any input previously turned on. With Flash in the LATCH mode, the MUTE button mutes the audio when pressed, then un-mutes it when pressed again. In the PUNCH mode, the output is muted only while the MUTE button is depressed. Switching from LATCH and PUNCH modes is done with one of several DIP switches on the back panel.
So, you can switch audio inputs and mute things in some pretty fancy ways, but this is hardly all that Flash can do. Remember that the unit uses "passive" circuits. Yet another characteristic of a passive mixer is that signal flow can go either way. What we've been referring to as inputs and outputs on the back panel are actually bi-directional jacks labeled GROUP A (four stereo pairs) and GROUP B (one stereo pair). You can input a signal into GROUP B (normally the mixed output) and send the signal to the four pairs of jacks that are GROUP A. All of a sudden you have a distribution amp of sorts. You can send a voice track to the left side of GROUP B and send four signals to four different effects boxes using the four left channels of GROUP A. Taking this bi-directional aspect of Flash a step further, you can take the four outputs of these four effects boxes, send them as inputs to the right channel jacks of GROUP A and output them as a mix on the right channel jack of GROUP B. Give that one some creative thought.
The more we got into the unit and the manual, the more applications we found. In fact, the 138-page manual contains some forty pages of applications, several of which are better categorized as effects rather than audio routing applications. Something else worth mentioning is that several Flash units can be chained together to give you switching and layering power over a large number of sources.
The passive circuitry and special opto-isolated switching resistors of Flash let the unit handle more than just audio signals. Flash can do its thing with control voltages and straight power of up to fifty volts and one-tenth of a watt. With some relays and a power supply, this box becomes an on/off controller for anything that runs on AC power -- lights, fans, baby bottle heaters, toasters, and EKG machines, just to mention of few of the items suggested by the manual. Flash can also deal with SMPTE code, PCM audio, and other digital bitstreams with some limitations.
The unit is (here comes that phrase again) "designed for musicians" and has numerous applications for use in live performance as well as in the studio. (The applications for live performance are so many that no musician should be without Flash on stage with them.) As is the case with many pieces of gear designed for musicians, Flash still offers many functions that can apply to the radio production studio environment. The ideal hookup in the production room would be to have all ten jacks on the back panel appear on your patch bay. This way, you can easily play with the many configurations available. If you're one of the few MIDI wizards in a radio production room, you'll be able to do a large number of interesting things using a sequencer to send program change messages and volume messages to the Flash. The program change messages select the different combinations available on the GROUP A jacks. The volume messages turn the MUTE on and off.
As you might have gathered by now, the more proficient a person is with MIDI, the more they will get out of Flash, but many of the applications don't need MIDI control. For example, to switch between two inputs to the beat of a piece of music doesn't necessarily require syncing Flash to your multi-track and a sequencer with SMPTE time code. If you have one ounce of rhythm, you can simply push the buttons on the front panel to the beat, though you will be limited by how fast you can push the buttons, and you won't be able to access programs that use only the left or right channels of an input. (You could just unplug the patch for a channel you don't want, however.)
Other non-MIDI applications include layering the outputs of effects boxes to mix, let's say, reverb with a pitch shift. You can split a stereo signal, send one pair into GROUP A-1 and the other pair to GROUP A-2 with the left and right channels reversed. Selecting input 1 then input 2 swaps the stereo image quickly and is a simple but interesting effect on music or anything that has a lot of left/right separation. Because the box is so versatile, the many things you can do with it will largely depend upon your studio setup and the amount of time you have to get creative.
On the MIDI application end, the possibilities seem to be endless. Synced to a multi-track machine and a sequencer, Flash becomes an automated noise gate to turn unused portions of tracks off then back on when audio is present. Split a signal and send it to Flash, using the trims to slightly vary the levels of the two splits. Switching rapidly (up to one hundred times per second) from one to the other gives you the "shimmer" effect found on some effects boxes. Again, Flash is a powerful tool for the live performer, being able to quickly and quietly switch from instrument to instrument, amp to amp, or effect to effect. Synced to a sequencer playing live on stage, the switching can be automated.
Flash lists for $499. This is the price of a good semi-pro effects box. If you don't have an effects box, get it first. If your studio is already equipped with the basics, take a look at Flash. Getting creative with effects boxes results in new and different sounding delays, reverbs, etc.. Getting creative with switching, layering, and muting puts you in another area of special effects altogether. Have a sequencer and know your MIDI, otherwise, you'll be limited to those functions available on the front panel.
Specs for the techs include the previously mentioned noise floor at -108dB and -112dB with the mute engaged. The frequency response is 20Hz to 20kHz. Crosstalk is -96dB at 1kHz. Connectors are the ¼-inch type for both GROUP A and GROUP B jacks. You have the standard MIDI IN, OUT, and THRU connectors on the back panel plus 8-pin DIN remote control connectors on both the front and back panels for the optional footswitch. For more information about Flash contact Uptown Technologies in Whitewater, Wisconsin at (414) 473-1088.
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