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Author Topic: UX 8800 and ITECH problems  (Read 3510 times)

Teddy Murphy

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UX 8800 and ITECH problems
« on: April 08, 2012, 09:10:49 am »

Ok, last night was the first time I got to use my ITECHs with my KF850's and my UX8800.  I had some issues getting the settings in Pilot to send to the ux, when it finally did, it seemed as though the limiters weren't engaging.  So, we went and to the limiters on the ITECHs on the front panel with some program music playing really low and notice that the amps on occasion would go from -20 to clip without any spike in the music even with the clip limiter on.  So here are both of my problems:

1: what might be causing my ux8800 not to limit properly.  I do know that it is not on the current firmware, but I still have the same greybox settings that I had been using on my Macrotech's and the limiters worked fine on them.

2: What could be causing the clip light to come on like that.  The amp's were not hot, but I also had no way to check the thermal limit settings because I didn't have a laptop with SA on it with me.  Do the clip lights come on when the limiter engages on the amps?? 
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Dana Sampson

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Re: UX 8800 and ITECH problems
« Reply #1 on: April 08, 2012, 10:51:54 am »

Regarding the UX8800, there was a bug in build 114 of the firmware released in 10-2011, but it supposedly only affected the high pass and low pass filters, not the limiters.  Which version of firmware are you running?  Which version of Pilot?

I'd suggest, for now, to just double and triple check the UX8800 settings making extra sure the amp gain and voltage is set correctly.  Which i-tech are you using?
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Iain.Macdonald

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Re: UX 8800 and ITECH problems
« Reply #2 on: April 08, 2012, 10:54:02 am »

Ok, last night was the first time I got to use my ITECHs with my KF850's and my UX8800.  I had some issues getting the settings in Pilot to send to the ux, when it finally did, it seemed as though the limiters weren't engaging.  So, we went and to the limiters on the ITECHs on the front panel with some program music playing really low and notice that the amps on occasion would go from -20 to clip without any spike in the music even with the clip limiter on.  So here are both of my problems:

1: what might be causing my ux8800 not to limit properly.  I do know that it is not on the current firmware, but I still have the same greybox settings that I had been using on my Macrotech's and the limiters worked fine on them.

2: What could be causing the clip light to come on like that.  The amp's were not hot, but I also had no way to check the thermal limit settings because I didn't have a laptop with SA on it with me.  Do the clip lights come on when the limiter engages on the amps??

http://forums.prosoundweb.com/index.php/topic,3639.msg19887.html#msg19887
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Teddy Murphy

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Re: UX 8800 and ITECH problems
« Reply #3 on: April 08, 2012, 11:03:09 am »

http://forums.prosoundweb.com/index.php/topic,3639.msg19887.html#msg19887

I have seen this mentioned on other forums but it is always only concerning the HD models.  Mine are ITECH 6000's.

I have the update that was released in October.
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Justin Myers

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Re: UX 8800 and ITECH problems
« Reply #4 on: April 08, 2012, 10:42:28 pm »

Hello,

I don't know if this applies to your case but I have encountered similar symptoms.

If I use 4 core speaker cable on speakon output 1 into a speaker that has a switchable active/passive crossover built in, the clip light comes on and the amp becomes unhappy. It isn't apparent at low level. It turns bad all of a sudden and the clip lights come on with an increase in level.
Speakon 1 is wired to both sides of the amp using all 4 pins so the switchable crossover on the speakers I have mustn't open pins 2+ and 2- in passive mode.
Maybe there is a short or something happening across the speaker outputs somehow. Is there an exclamation mark in the middle of the screen on your Itech?
« Last Edit: April 08, 2012, 10:46:50 pm by Justin Myers »
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Tim McCulloch

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Re: UX 8800 and ITECH problems
« Reply #5 on: April 09, 2012, 05:28:30 am »

Ok, last night was the first time I got to use my ITECHs with my KF850's and my UX8800.  I had some issues getting the settings in Pilot to send to the ux, when it finally did, it seemed as though the limiters weren't engaging.  So, we went and to the limiters on the ITECHs on the front panel with some program music playing really low and notice that the amps on occasion would go from -20 to clip without any spike in the music even with the clip limiter on.  So here are both of my problems:

1: what might be causing my ux8800 not to limit properly.  I do know that it is not on the current firmware, but I still have the same greybox settings that I had been using on my Macrotech's and the limiters worked fine on them.

2: What could be causing the clip light to come on like that.  The amp's were not hot, but I also had no way to check the thermal limit settings because I didn't have a laptop with SA on it with me.  Do the clip lights come on when the limiter engages on the amps??

Crown says the clip lights will come on at the "onset of audible distortion at the output" or if the thermal limiter is engaging.  IIRC the front panel clip light will come on when the peak voltage or RMS limiters are more than 3dB into level reduction, but I can't find a citation for that.

That said, at "low volume" you shouldn't see a sudden rise on the LED meters.  Did you hear a level change that would be consistent with a 20dB bump?  10dB?

What voltage or RMS limits did you come up with?  IIRC, you can't enter any attack or release parameters from the front panel, only voltage threshold.  The same is true of setting the RMS limiter, only wattage can be specified.

None of this explains what you were seeing with the LED meters, so I suggest you go into the I-Tech's front panel "monitor menu" and see how many CLIP events you had.

Tis a puzzlement.
« Last Edit: April 09, 2012, 05:30:08 am by Tim McCulloch »
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Kyle Kinda

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Re: UX 8800 and ITECH problems
« Reply #6 on: April 09, 2012, 10:06:57 am »

ITechs have the option of monitoring various parameters and give you error reports. One of the things I found out when we got our first IT 8000's was that if you have the load monitoring on, it can use the clip light as an error indicator. It is an option that I didn't know was turned on and I was wondering why I was getting constant clip indications in the error report list (before I got into the program and properly set the impedance limits so it wasn't constantly going past the upper and lower limits). Anyhow, this was a few years ago and I was using IQWic before SA. Since moving to SA I haven't really looked for that feature, but I would assume it is in the load monitoring section. There is also the possibility you can have other errors report with the clip light, but I have only had experience with the load monitoring. Sounds like that might be whats happening with yours.

Kyle
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Teddy Murphy

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Re: UX 8800 and ITECH problems
« Reply #7 on: April 09, 2012, 12:03:31 pm »

I set the RMS limiters on the amps at the Continuous wattage ratings that EAW had published.  I turned on the Clip limiter so that it wouldn't clip and guessed at the voltage peak.  The Highs were 50 volt, the mids at 80 volt and lows at 90 volts.  I didn't know if you could set the clip light to show other errors or not.  I didn't have an exclamation point at any point.  I was running the amps at 8/10 ohm (the HF is 10)
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ProSoundWeb Community

Re: UX 8800 and ITECH problems
« Reply #7 on: April 09, 2012, 12:03:31 pm »


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