Chauvet Stage Designer 50

    Analysis of hardware and operation

  In the realm of small and inexpensive lighting desks, the Stage Designer 50 is notable because it can handle 48 channels in a very small physical footprint and has some really useful and intuitive features.  It also has some subtle gotchas that can take the novice or unwary operator by surprise, and a couple of minor hardware annoyances that in this case needed to be fixed before being placed into live operation.

The user manual for the console is readily available online, but is rough going in spots where functionality is not explained as clearly as we'd like.  Near the end of this page are some clarifying points that may help to understand the operational quirks and how to get this unit to behave to our liking.

[Images here are linked to larger copies.]
LEDs are way too bright What we notice first on power-up is that the red and yellow LEDs are *very* bright -- so bright that they interfere with being able to see the labeling on the panel.  The green ones are okay; the blue channel-output indicators are fairly bright but tolerable since when they're on, presumably the stage is lit at the same time producing more ambient light in general but even then, not necessarily in your dark little booth!  Still, investigating any possibility of making them dimmer is one motivation for opening the board up for a look at the insides.

Board opened up Disassembly is straightforward; the main body of the desk is one big circuit board mounted on standoffs under the top panel.  The power supply regulator and various I/O are on a separate part mounted into the back panel, with a fairly minimal cable running between.  The case is all steel and seems quite sturdy.

A nice feature immediately noticed is that the slide pots all have dust guards, which should help them resist getting crapped up inside.

Control section, and SIP resistor packs All the chips are socketed DIP, which gives us a hint as to the vintage of the design but also makes parts easy to replace if needed.  Unfortunately the dropping resistors for the LEDs are in the form of hard-soldered SIPs and all 220 ohm, meaning that specifically dimming the red and yellow LEDs by changing a few separate resistors is out of the question.  So we'll do what everybody else does with these boards -- slap pieces of tape over the stupidly bright ones and get on with life.

Disabling the FULL ON button In most settings there is absolutely no need for an "everything on instantly" button, which is too easy to hit by mistake.  If we need all channels at full, we can easily program a scene for that [perhaps as a preheat?] but in the meantime this button has to *go*.  A little cut through the relevant circuit trace permanently disables it.

  After receiving the unit, I spent a few days playing with it and putting as many features as possible through the paces.  I had immediate questions to direct to Chauvet's technical support staff, who said they'd welcome any feedback on the operational aspects.  The result was a monster three-part opus sent via email, albeit probably kidding myself about any hope of ever being able to try revised firmware.  Without trying to write the complete "missing manual for the SD50" from scratch, here are some of the relevant points from that series to help clarify what the given manual leaves sketchy or leaves out.  Additional motivation for providing this came from finding this thread at Controlbooth on the subject, in which a new user worked through much of his own early-on confusion and even remedied some of mine.

  • DMX output:   The 5-pin and 3-pin output XLRs are wired in parallel and there is no internal bias or termination on the transmitter.  This means that the desk can sit in the middle of a network that runs in two directions away from it, provided that each leg gets properly terminated at the end.  This may enable some network topology optimizations using a minimum of hardware.  Also, the desk only sends a short 48-slot DMX frame on the wire, yielding a rather high overall refresh rate.
  • Startup defaults:   The board always powers up in "blackout" mode.  Besides turning that off, some default settings are useful when starting to build a show -- mixed-chase mode, speed slider on "instant", step time slid down to "show mode", and both masters at their respective maximum.  Quick mnemonic for master faders is up, down, up, down, down, like in the first picture.
  • Single channel park:   The AUX knobs are about the closest thing to a "park" facility, good for only one channel apiece.  A channel assigned to them in mode 2 becomes truly isolated, controlled only by the knob, and doesn't get recorded into scene memories at all.  The blue channel-mimic LED will NOT follow the AUX, however, and will no longer indicate the channel's true output.
  • No useful patching:   The "fader reassignment" mechanism under password 666 isn't really that useful, as you can't patch to more than 48 DMX addresses anyway.  If you really want to group up channels without writing a scene, go ahead, but things can work in a somewhat confusing way thereafter especially when channel-bank switching.  See the Controlbooth thread linked above for hints on how do that across high/low channel ranges if you need it.
  • Nomenclature:   The word "page" is horrifically over-used in the manual, to mean both the 4 groups of scene memories *and* the A/B bank switching between high and low channels.  I prefer to refer to the channel ranges as "banks", even when the board's display is sitting there saying "RUNNING PAGE A".
  • Record mode:   It's useful to make little paint dots or something next to buttons 1,5,6,8 on the top row, for instant visual location when typing in that silly record-mode password.
  • Scene/memory building:   Always remember to "record" a look into temporary step memory before saving it to a scene, even for a single static look.  Otherwise, no content gets saved to the scene-slider.
  • WARNING:   If you try to run scenes while swapped to bank B, the high channels, you will run into the bug described in the email and have spurious low channels coming up.  Always bank-swap back to "RUNNING PAGE A" before attempting anything like sane playback.  The four *real* pages of scene memory work in a straightforward and correct way, and scenes will "hold over" on a page change until the slider is dropped to 0 and brought back up like you'd expect from any other board.  This means that it's not easy to build scenes from components on multiple pages if they happen to use the same sliders, but as the board operates in a straightforward HTP way, spare scene sliders can be creatively used as temporary accumulators to build into.  Plan your page/scene allocation accordingly.
  • Chases can be cue-lists:   Every "scene" is really a chase with one or more steps, all subject to the global playback fade time.  [Should we call it a "chene"?]  With careful planning, a multi-step chase can be run as a manual set of cues using the STEP button.  Different crossfade times would still have to pre-set with the fade slider before execution, but once set, the board handles it pretty smoothly.  Chases always restart at their first step when the scene is brought up off 0, and STEP indexes any chases that happen to be active.
  • Editing sucks:   The mechanism for changing channel values inside a scene is klunky, and it may be easier to just re-record the memory in question.  If it's a multi-step chase you can't tell what step you're in from the board, you just have to look at the rig and count STEP button presses.
  • Chase tempo caveats:   The SPEED slider has to be up away from its "show mode" infinite setting, even if a manual "tap sync" timing is in effect, before recording a "beat" tempo to a chase.  Once a speed is recorded, that chase runs completely independently of the master step-time slider, and can thus run out of sync with other chases.  This is useful for offset-time sequences or building that "fire flicker" effect across some red and amber lights, where two chases with subtly changing levels and slightly different timing can run against each other and produce a nicely randomized output.  The fade-time slider still affects everything running.
  • More nomenclature:   The ADD KILL button really should be called SOLO, because that's what it does when a bump button is pressed -- solos up the item and knocks out everything else.
This board is remarkably similar to the Elation Scene Setter, with virtually the same physical layout but different firmware.  As one might expect, behind it all is a typical sad tale of engineering staff parting ways with one company and taking all the intellectual property with them to a competitor or spinoff, and by now they're probably out of that development cycle entirely.  So the noted problems with the board are not likely to get fixed any time soon, but we can hope for at least a little better support from Chauvet on this one.  In the meantime, it is hoped that the info presented here will help owners of the Stage Designer 50 get the most from their thankfully modest investment.

_H*   160229