Which dimmer pack?

[Mal]

Hi all,

 

Following previous advice I received here before, I'm now looking at getting a 4 channel DMX dimmer pack. Or 2 if we can find the cash for it.

There only really seem to be about 3-4 different ones, assumming that some are rebadged by other distributors. Are there any opinions for which of these "are better", if it's possible to quantify?

 

All seem basically the same: 4 channel, 1000W DMX controlled dimmer packs; so by my limited understanding are all doing the same thing, and all about £60-£75.

 

1. soundlab/Transcension CDP405/EDX4.

2. Showtec Multidim/QTX4-4/ADJ SP4

3. NJD DPX4/10.

 

The basic differences I can see are:

Soundlab may have minor connection problems which can easily be solved on first use. But the CDP/EDX4 seem to be ok (?)

Showtec Multidim/QTX has 2 sockets for each channel. Possibly helpful, but certainly not a "must have".

DPX4 would normally need a greater supply that I can (officially) come up with and don't really need 10A/channel anyway.

 

Is there any reason to choose one over another? Have I missed any important other differences?

As I'm operating on a very limited budget, is there anything wrong with going for the cheapest - which in this case seems to be a QTX4/4 for £62 incl delivery?

 

Cheers,

 

Mal

[KevinE]

This is going to be a matter of opinion of course. The ones you have mentioned are 'disco' grade dimmers, and as usual, you get what you pay for. I doubt there's much difference in quality at this price point.

 

If I were you I'd look for a second hand or refurbished 'better quality' brand like Anytronics, Mode, Zero 88, Pulsar etc. Customer support will usually be better as well.

[TonyMitchell]

+1 for what Kevin's said - avoid the disco grade toys.

 

You can often pick up Pulsar 2U and 4U 6-channel packs for very reasonable prices secondhand (near-on giveaway prices, when you look at what they originally cost). The older ones will be 0-10v analogue, so you would need a demux to use with DMX. The Pulsar version is called a "Universal Interface" and comes in 18 and 36 channel flavours.

 

Also look out for secondhand DMX Betapacks.

 

You'll get top notch support and service from both of these UK companies.

[dbuckley]

3. NJD DPX4/10.

 

This unit is different to the others, it is of British origin, and the NJD 4x10A dimmer has been manufactured in one form or another for yonks, albeit DMX capability being a relatively recent addition. The old +10V model is the DP1000, and I have a couple of these. NJD are primarily known as a maker of disco gear, and these dimmers are usually used installed, though there is a version with plugs and sockets on.

 

They also are built with easily replaceable triacs from the outset...

 

And they are designed for the outset so you can with a quick bit of rewiring use them as low voltage dimmers.

 

So, most of the time, I'd take the NJD over the standard Chinese four channel dimmers every day of the week. In fact, as an owner of a couple of the standard Chinese four channel dimmers, I'd swap them for the NJD in a heartbeat. Stranger than that, I'd swap one of these outwardly-identical Chinese dimmers for another of the other in a heartbeat too; one is well built, the other is really shoddy with a bent PCB and missing screws, things that don't line up, great quality assurance...

 

Why only most of the time? The drawback with the NJD is that it is a lid-off operation to set the DMX address. So you will lose the lid screws over time.

[TonyMitchell]

3. NJD DPX4/10.

 

This unit is different to the others, it is of British origin...

 

Is that still the case?, since NJD has AFAIK for the past ten or so years been *just* an Electrovision brand, rather than the former Nottingham based manufacturer it was when it was Kevin Hopcroft's business, for several decades prior.

[Mal]

Thanks Kevin and Tony.

I'd seen a couple of Pulsar units already, but they're slowly heading out of budget. So now I'll put them closer to the top of the list.

 

Considering I'm unlikely to be putting more than a couple of amps on any channel as it is and we currently plan to use them for just 2 performances a year (plus a couple of rehersals), what "extra quality" do you get with a pulsar or zero88 etc?

Better reliability of components (triacs etc)? a better designed DMX interface that doesn't hang up during a show? higher grade connectors that don't wear as quickly? Apart from the background of the maker, how is the product itself better when I get to use it?

 

Don't get me wrong - I'd much prefer to use a better quality product if I can. But if I'm unlikely to reach the "limit" of a disco dimmer, then I have to think carefully about how best to use the few pennies I've been provided.

[dbuckley]

Is that still the case?, since NJD has AFAIK for the past ten or so years been *just* an Electrovision brand, rather than the former Nottingham based manufacturer it was when it was Kevin Hopcroft's business, for several decades prior.

That is a jolly good question. Certainly, Electrovision do distribute a lot of kit that you've seen somewhere else, but the NJD dimmers still look like they always did, and there isn't anyone else that I know of that flogs stuff that looks the same. NJD on their website still claim to be a manufacturer. So I dunno.

 

UPDATE - from the NJD website

 

Part of the Electrovision Group, NJD designs, manufactures and sells a range of speakers, lighting equipment, cases and metalwork. All items that we manufacture are conceived and designed in our UK offices before being sent to our factory in Shenzhen for final manufacture. Our 20,000 sq/ft factory has full manufacturing facilities including wood working, metal working painting and PCB assembly

 

So designed in Blighty, manufactured in China.

[Mal]

Interesting, thanks - now also moved close to the top of the list.

Helpfully, also a little cheaper than the others.

 

Any historical reason why the triacs are easily replaceable? the only manufacturer (at that end of the market) that openly acknowledges that triacs fail, and it's better to make them easily replaceable with less risk of damage by the user?

Or, a company that has poor reliability, and it was easier for them as well as the customer?

 

Lid off isn't an issue, neither is missing screws. Just gives them a bit of character.... :)

 

 

 

 

 

[david.elsbury]

Cheap dimmers tend to have poor dimming curves, which can matter (or not) depending on preference, and if they are alongside other more expensive packs.

[Mal]

Thanks, poor in this context means non-linear?

 

 

 

[niclights]

I'm sure the Showtec's will be fine for you. Yes, it's true that some budget dimmers have awful, almost unusable, curves (more like suddenly on/steppy rather than non-linear), but I've got one of the Showtec's in a small room and it doesn't seem that bad. I wouldn't use it for 'pro' applications but it's quite acceptable. Similarly, it's true that packs like the Pulsar's are totally rock-solid and work forever, whereas I've seen triacs go on the showtec following a blown lamp. But given you're not looking for the absolute best and don't need 6x10A or similar you could buy a spare Showtec for a great deal less.

[KevinE]

If you're driving incandescent lamps, then a blown filament will sometimes blow the triac..meaning that channel either sticks on, or remains permanently dead. Sometimes the channel can go 'half wave' which makes a lamp flicker, and can burn-out anything with a motor or transformer (pinspot, disco light).

 

If you're only going to use it lightly in a mobile disco/small band situation, any unit will be fine. The 'quality' ones have already a proven track-record in contract installs in pubs and clubs, theatres and cinemas, and can be picked up cheaply as venues convert to LED/intelligent fixtures. They are designed for continuous use and the quality shows. Uprated triacs & firing circuits, better casings, quality connectors, fuseholders & construction, better quality control.

 

As an example, some cheap dimmers only have internal fuses and their triacs are soldered in, often requiring removal of the whole pcb just to change it.

 

I am of course viewing it from a repair guy's point of view <_<

[top-cat]

To be honest I've had no issues with the Showtec multidim dimmers in a club-venue environment, perfectly good and reliable.

[Gerry]

Dimmer pack choice also depends on are they for a fixed or portable rig, your budget, where you will be using them, how often you will be using them.

I use 13 Multidim racks for about 4 X 1 week amateur events a year.

No problems, except had 4 triacs blow so far, but fairly easy to replace.

Cheers

Gerry

[GR1]

If you are only using the stuff a couple of times a year I would rent better quality kit when you need it. You don't have to worry about storing it or, PAT testing it and in 3 or 4 years you will probably want to do something different - with a hired set up you can change as often as you like. The benefits of ownership don't usually kick in unless you use the kit quite often.