Shez

I'm looking to commission the construction of a replacement prop but as this is somewhat outside of my usual sphere, I'm a little short of ideas of companies to approach. (Basic prop details below). I'd be grateful for any recommendations of companies that might be able to undertake this.

It's essentially an OSC controlled paper thrower. It has to drop single sheets of A4 paper from over stage - one sheet per OSC "fire" command. Sometimes single sheets, sometimes flurries. We get through nearly a ream of paper in each performance. The current version is built from the innards of a laser printer with a new speed controlled stepper motor to drive the rollers and a solenoid to kick each sheet to the rollers. There's a mac mini attached (slight overkill!) to receive OSC and control an arduino that drives the mechanics. It's several years old now and is starting to become unreliable / worn out.

On cameras with built-in IR LEDs, if positioned above audience e.g. on a balcony front, it often looks like it's snowing upwards. Whilst in IR mode, dust rising up, carried by the heat from the audience is lit very brightly by the LEDs and becomes very visible. A separate IR floodlight, positioned slightly away from the camera, reduces that effect.

Two cameras, one permanently in IR mode, feeding two monitors is a good solution. Single cameras take time to switch modes which is rarely ideal if you need to see what's happening immediately after a B/O.

On 11/17/2021 at 10:22 PM, Bryson said:

I'll be honest, this doesn't sound like something I would even attempt without at least a practice run, and certainly not with mere minutes to execute!  How is the amp configured right now?

I enjoy a challenge 😉 Plus I did my homework - I seem to be increasingly expected to use kit I've not used before so I'm well versed in learning the essentials before arriving on site. I also took along a four channel amp of my own just in case. I always have contingency plans.
The amp was hired so just on reset factory settings from the hire co.

On 11/17/2021 at 11:46 PM, Stuart91 said:

Are you sure you have the correct login/password to access the amp?

Default login. I had the hire co's phone number just in case. And a laptop so I could access it directly if needed.

On 11/18/2021 at 8:27 AM, adamburgess said:

Is it not worth putting an extra amp on the kit list to hire before the gig?

Then at least you can test things (to make sure noise comes out) with anything you have lying around?

I didn't have access to the venue or the hired kit until I arrived there. Not ideal but it was a fairly unique situation.

All went well in the end. Easy to access the amp via wifi with a tablet and all settings pretty much as I'd seen in Armonia. A bit more fiddly to set up the crossover using a touchscreen than a mouse & keyboard but perfectly manageable. Everyone was very impressed with the power and DSP in a box that small!

Any users of Powersoft's X series who could help steer me in the right direction? I have a gig coming up where I'll need to get a PA up and running within a matter of minutes - two tops, two subs, one X4 - and I won't have access to the amp in advance to configure it.

I've installed ArmoniaPlus and had a look through the virtual web interface for it. Am I right in thinking that I can just connect a tablet to the amp's WiFi network and access enough parameters through there to configure all the important settings? Inputs (two analogue), matrix routing (One input to two amp channels, the other to the other two channels), speaker selection (there are presets present for the speakers in question), and crossover (there are curves within the presets although presumably designed around individual speakers rather than specific combinations as they overlap considerably). Is there any means of linking channels so that what you configure for the left sub & top will copy over to the right channels too or is that a manual job?

I'm sure I could save a setup within Armonia but I don't really fancy battling with potential network connectivity issues if it's easier to just use the amp's WiFi.

You'll also usually have a "blinder" - a full black cloth - immediately upstage of the gauze to completely block the view through it and prevent any projection passing through it and hitting the set behind it. That would be flown out just before any reveal through the gauze needs to occur.

 

Many gauzes are printed with their show logos rather than projected but unless you can find an appropriate one to hire, that would be an expensive undertaking.

File system and size are the key factors. FAT32 and sub 32GB should work fine.

As you've discovered, older sticks tend to meet those requirements whereas newer ones are often larger and tend to be hit or miss. For saving scenes, you only need a tiny stick so dig out an old one and you'll be fine.

I'm fairly sure that desk has pins 2 and 3 swapped on the DMX output

Sorry - I must have missed my cue here Tony ;)

 

I don't have any experience of arena scale sound - I'm wondering whether the designers / specifiers of that type of system are quite a different breed to theatre sound designers. In theatre, a key driver is making the PA transparent - i.e. you shouldn't know that it's there (for spoken word at least). That often means keeping levels low enough that they don't draw attention to the PA. Like Tony, I don't think I've seen any high level theatre shows with distorted or excessively loud sound. It's interesting to note that there is a very small number of theatre sound designers who between them seem to have the West End / national touring market almost completely cornered. Perhaps that helps to keep standards as high as they are.

 

Six is an interesting hybrid in that it sits somewhere between theatre and rock gig. Chatting to the fit up crew, one of the aims of the design of that show was to recreate the sound of the original album of the show. That means there's a lot of compression and other processing going on with the vocals to get that "studio" sound. A lot of additional instrumentation on track too. An almost silent band with all performers on IEMs helps keep the sound very clean. It was loud enough to be powerful and punchy but not in any way too loud. It was the usual d&b line arrays plus assorted fills & delays configuration that most shows on this circuit use, albeit rigged in slightly less common positions.

I have a pair of Turbosound IQ10s which are pretty nice. They also do an IQ8 which is even smaller.

Is wireless control essential? I know trusting cast members to operate props correctly is a whole other discussion topic but it would be vastly cheaper if it was feasible.

At the moment, EVERY page I try to go to on the Blue Room is giving me a "This is an insecure site/page - are you sure?" message.

The certificate has expired - see some other current threads about that.

I had a deleted topic called "circus accident". I can say with pretty much 100% certainty that I never posted a topic with that title. I assume some spamming was going on somewhere. Any security issues we should be aware of? Worth changing passwords?

Pre-heating the gobo in the couple of cues before it's needed is a good idea to lower the thermal shock it experiences if subjected to a sudden 100%.

Have a look at the BMD Web Presenter and the Epiphan Pearl Nano.

If you want web browsers to easily pick up a stream, you may need a web server running on the network. NGINX is small, free and great for streaming.

Worth checking the supply voltage in the venue if you can. If it's at the higher end of the tolerance, it'll stress the (24/7) PSUs more than if it was a bit lower.

I can't help thinking this is like inventing the wheel when all of the assembly work and hardware is available ready made for not many pennies in the form of a small 12V floodlamp previously linked to.

I've ordered a couple to experiment with. Also spotted this flexible LED tape which would be a neat solution for folding tape back and forth in a confined area.

I think that the simplest and most reliable solution would be to use the 3 volt LED filaments as sold on ebay.

I've yet to move into 3D printing but imagine it should be reasonably simple to construct a frame that would hold half a dozen filaments (by their connecting wires) in a visually pleasing pattern. Assuming they don't kick out too much heat of course!

The best thing is to find lamps, tape or filaments which use resistor-dropper control and drive them with a PWM dimmer

That's the golden goose. Sadly when it comes to lamps, it's not a feature that anyone advertises. Fleabay seems to have a reasonable supply of bare 3V filaments - useful if constructing ones own DIY lightbulbs was a thing?

 

 

As an experiment I've connected non dimmable MR16s and "kitchen bulb" capsule lamps (G4?) to a PWM dimmer and they stay on at full brightness down to about 30% then flash until they snap off at about 10%

I've just tried a "non dimmable" MR16 too (an "Aurora Enlite"). Slightly better results - from full downwards: a bit of a step down from 100-90%, smooth dimming down to about 20%, bit of strobing down to about 10% then snap off. At a couple of narrow levels in the smooth dimming range, there was a bit of slight strobing. Still unusable in this application but nicely demonstrates the unpredictability of these things.

I don't think it's counter intuitive at all, back when such foots were in use they were as likely to be on a blackout switch as a dimmer.

Just to clarify, I do want them to dim. What I'm wondering is whether lamps marketed as non-dimmable might actually dim better with the type of dimmer I plan to use than those marketed as dimmable for use with a different type of dimmer.

It might be worth considering the use of LED "filaments" rather than ready made LED bulbs. These can be driven from a suitable DC supply via a resistance dropper, and dimmed via PWM..

I've been looking at some of the filament lamps - Big Clive has dissected a couple - one with a simple resistor dropper and one with a more complex driver. But I'd not seen the bare filaments so that's another interesting possibility. I've also seen some G4 discs that look like they're just a collection of SMD LEDs but like most of these things, may or may not contain unhelpful drivers.

 

 

If you are building your own dimming circuit with an Arduino, remember that 8-bit dimming is rubbish with LEDs and you need a 16-bit PWM to get a good curve.

Only for testing purposes before I invest in a proper dimmer of one kind or another. I would imagine the curve obtained from PWM would immediately be quite different to that from a triac dimmer - electrically linear - but I don't know how that then translates to perceived brightness from an LED.

 

 

Mikelectricstuff sells a trailing edge dimmer suitable for LED lamps on his White Wing Logic website that can be used to dim 8 or 16 channels of mains LED lamps. Might be another possible solution to your problem? My link

Good shout - thank you - I'd not seen those dimmers before.

 

 

I'm now wondering whether, slightly counter-intuitively, a non-dimmable fixture might actually be better in this application. The dimmable ones often seem to contain drivers to cope with the unhelpful phase control dimmers that they're expected to be used with so perhaps the non-dimmable ones are more simple and hence easier to PWM? Lamps with a simple dropper resistor won't dim with a triac dimmer but are perfect for PWM. Is my thinking way off here?

Yes, but most LED lamps sold these days contain a switched mode power supply and not a simple resistive dropper.

That's my main concern at the moment. And that's the one feature that suppliers don't advertise and are unlikely to even understand. I've been looking at options on Alibaba but I suspect I'd have little chance of explaining clearly enough exactly what I'd like. A tear-down of some samples would quickly reveal their secrets but what are the chances of being able to order more of exactly the same product that hasn't been "improved" in the meantime...

LV LEDs that use only a resistor to manage LED current will dim quite happily on CV PWM dimmers

It's good to get confirmation on that as I thought it should be the case.

 

I'm ordering a few bits & bobs (including MOSFETs to hook up to an Arduino as a crude PWM dimmer) so we'll see what happens.

The ones I linked to are 12v-24V and for size the same width as a passport: https://photos.google.com/u/1/album/AF1QipMQvwTveON-V9XRKVjruUS7sGSdvRZZQbl2Ukcl/photo/AF1QipO54zRLBTc4GAahSALZfEteuaCq7YH_3tOBkH4w

The driver (for what it's worth) is very easily bypassed to run on an external dimmable driver.

Ah, that's interesting then. Something with a built-in bracket would certainly help with mounting! Skipping the existing driver would also be good.

 

 

The truth is that even suppliers of so-called dimmable LED lamps are cagey about whether they will actually dim satisfactorilly in many cases.

I'm aiming for PWM dimming as I think conventional phase control will always be a non-starter for LEDs. I've just been browsing Big Clive's Youtube channel; he has a nice tear-down of a 12V filament E27 bulb that simply has a resistor inside - no driver, and dims well to zero. Ebay suggests that all of China is out of stock of the 12V version at the moment but I'm sure there'll be some somewhere! That would be a very nice looking solution if I can find stock.

So in the same spirit - Brass batten lampholder, 240v 60-100w GLS Clear.

That option certainly isn't off the table! I'd prefer to keep mains and glass away from people's feet if possible but I agree it wins on light quality and simplicity.

 

 

Most 12V LED lamps (including MR16s) won't dim, or won't dim very well, even supposedly "dimmable" types, due to the internal driver electronics.

This is exactly where I'm struggling to find concrete information. What exactly is inside these bulbs - and what's the difference between a dimmable and non-dimmable one? I've also considered a bare COB - no built-in driver to cause issues so I can pick/design a dimming circuit that works properly.

"onsolar" offer a range of ELV LED Lamps. One style has two switch selectable output settings. 0.5 watts or 2.5 watts. Use of these lamps would give several brightness settings.

I'm very much hoping to be able to dim. I haven't completely ruled out tungsten (the aesthetic I'd really like) but LED would seem sensible for many reasons.

 

 

A 12V MR16 would give you a bit more punch (and directiivity) if you can derive a suitable way to make it stand up (back end of a PAR16 and ignore the nose?)

This might be the way to go. Keeping it all 12V is a big plus. In an unrelated thread I saw a suggestion of SORAA lamps being a very good choice for tungsten replacement and good dimming, albeit at a price. DMX 12V CV dimmers are a thing and I'm led to believe that they'll drive such 12V LEDs which removes the need for transformers too. You're absolutely right that mounting will be the biggest issue though! Might have to experiment with some diffussion too as 36^o seems to be about as wide as they go which may be a tiny bit less wide than ideal.

 

 

If the lamps won't be visible, how about making up a flat plate covered in LED tape? You could use RGB or white tape, and there are plenty of low voltage LED DMX-able drivers out there.

That's an interesting idea! With pixel tape I could control each shell independently very easily and just daisy chain power & control. Although I'm really looking for a tungsten aesthetic, the possibility of RGB certainly opens things up a bit.

 

 

Will small LED floodlights fit in the clamshells? https://www.ebay.co....h0AAOSw79JgPLUR

I don't have one in front of me to check dimensions right now but I suspect it might be a squeeze. Also mains & non-dim which is less ideal.

 

 

It would be a help to me understand your needs if you said whether you wanted the Clamshells to look like the genuine article light-wise or whether you have another aim.

The shows they'll be used for have quite a vintage aesthetic so I'm aiming for something reasonably authentic looking from the audience perspective. I think how they look on the performer side is less important as long as the light output is warm and smooth. I suspect most in the audience won't have seen the genuine article in use so there may be an element of hitting an expectation rather than being completely authentic.