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electronicsuk

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  1. electronicsuk

    Zero Ohms

    From the patent application: They go on to say: The patent author(s) appear to state that because the amplifier's output voltage remains broadly the same when the lower impedance load is connected via their circuit, the amplifier can be prevented from going into protect. The tests are done at 1V nominal into a 0.47 Ohm load, so about 2.5W RMS. This doesn't represent the power levels typical of a large PA system. Looking at the measurements, there are figures presented at 2 Ohms both with and without the circuit. It's a strange omission to only include the with-circuit measurements for the 0.47 Ohm load. I'd like to see how they compare to the same load without the circuit. The patent application also seems to state that because the amplifier's internal impedance remains unchanged (I'm not sure how this is being measured), this negates any issues with the load impedance. I don't understand how this conclusion was drawn as I'd expect the amp's output impedance to remain relatively low, with respect to the design load impedance, regardless of what impedance is presented at the output terminals. It'd be interesting to see how it scales up. The specs state power handling of up to 4K RMS. The test results in the patent application seem to suggest that the current at the output terminals remains largely unchanged, whether the load is connected directly or via the circuit. With a 0.47 Ohm load at 4K, that's a peak current of sqrt(4000/0.47) 92 Amps. The same 4K into a more typical 4 Ohm load would be about 32 Amps peak. That's a big difference as far as the output and protection circuitry of the amp is concerned. Unfortunately, as the current is being measured at the output terminals of the multiplexer and not the amplifier, you can only draw conclusions about the current at the amplifier's output terminals.
  2. You're using the term RCD and Circuit Breaker interchangeably so it's hard to tell what you're actually asking. If you want to know whether or not it's worth protecting the supply to your amps with an MCB when they're fed off a 13A plug then no, there's no benefit to doing that. If the question is specifically about RCDs, the majority of 13A sockets these days will already be protected by an RCD somewhere in the distribution system. Having your own plug-in RCD isn't bad idea for those occasions where the socket isn't already protected, more for the protection of you and the public than that of your amps. You can also test your RCD and be confident that it works, whereas you might not have access to the distribution cabinet where the RCD feeding the 13A sockets is located. If you're running from a diesel generator of a decent size supplied by a proper hire co with power distribution then whatever you plug into will already be protected. If you're running off a small stand-alone generator of your own then it may well have a floating earth, in which case an RCD may or may not operate in the event of a fault. TL;DR: Using a plug-in RCD would have little downside and some potential benefits.
  3. P.S. If you used a regular monitor wedge instead of your amp then you could use the Kemper's direct out into your mixer and have the guitar through your vocal wedge, which is one less cabinet to carry around . That's assuming you carry your own gear and have the time to practice and get used to the different tone that it would provide.
  4. That's fair enough. Just wanted to make sure you weren't under any illusions that your driver will sound the same in a different cabinet. You might be better off just putting your existing amp on a tilt stand in front of you. Otherwise, your best bet would be to find a cheap used 12" coaxial monitor, as it's not as if you need the space for a horn. If you aren't fussed about the cab being a little larger (it isn't coax) then you could buy a brand new 12" monitor for barely £75 from Thomann and swap out the driver.
  5. Ok, I'll bite. Why would you want to purchase an unloaded cabinet and replace the driver with one which will, in all likelihood, be an inferior match to the cabinet than the driver it was originally fitted with? I'm guessing you're thinking about removing the driver from a guitar amp, but this seems pointless if you're using a profiler. You'd do much better to just buy a complete wedge fitted with the original driver.
  6. I'm still not sure I understand. If you want to use the same lighting state multiple times then you can go into your cue store and copy the same cue into multiple different positions in your cue stack. All you need to do then is set fade time and press go every time you want to move on to the next cue. If you really insist on jumping back and forth in the cue stack then you can select the cue you want, press the 'preload cue' soft button and then the preloaded cue will release next time you press go. If you've set a fade time then this will still work with preload. However, it seems like a lot of unnecessary work.
  7. I can't personally vouch for them but there are a few people on eBay running repair services where you can ship the amp module to them and (hopefully) get back a working one. At least one of them specifically mentions HK in the listing title.
  8. Exactly. Just set to cue timing, set a fade time and step through the cues. I'm assuming they're in a cue stack already. If they aren't, they probably should be. EDIT: Sorry, I just noticed you clearly said they were in a stack. So yes, all you need to do is set fade times. If you need to adjust fade times on the fly then you can use the crossfader.
  9. I heard that they had an issue with the winches that meant that couldn't manipulate a huge portion of the set that was rigged on the rear with LED panels. Wouldn't want to have to try and re-design all that at 24 hrs notice!
  10. I'm surprised that nobody ever answered this one. On paper it isn't too difficult, and in fact it has been asked before. Your mileage may vary - I haven't ever tried it myself.
  11. RS232 requires an extra interface card. I haven't seen one fitted before but your interface doesn't look to have any additional 'bits'. I suspect you don't have the RS-232 interface and will need to program from the outstations. The RJ45s are for DMX and the RJ12 on the card is a DALI interface.
  12. From what I can recall the entire fixture runs on a single 48V PSU, so if pan/tilt are working fine then it's probably not worth spending much time on the PSU. The LED driver board on the back of the head is pretty easy to get to, just four screws to remove. From there it should be pretty easy to ID the power to the driver board from the cable size (I believe the cores are orange), so check that you've got 48V there to rule out any cable breaks. Like most heads, there are lots of connectors on the boards so probably worth re-seating the ones that are easy to get to and see if this helps. As already stated, check that the fan that cools the LEDs is working and clean. The plastics are also pretty hopeless on these heads, so make sure you haven't got any screws floating about inside the units that could be causing problems. If you go into the service menu then you should be able to get the fixture to "lamp on" without any DMX connected, which would rule out a control issue, however unlikely.
  13. Telefunken have plenty of them freely available on their site.
  14. Check your AES50 clock settings in Setup > Config tab. I've never tried to link two consoles this way but I guess the X32 will need to be set to use AES 50 port A for synchronisation rather than the default setting of internal clock.
  15. Just for the record, nothing to do with me! I can't say I approve much of the idea of running them on mains without making any effort to waterproof them. I'm not sure why anyone would do it this way when the passive version of the same cab is about half the price and would be a lot safer in the rain.
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