ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Lounge FUD Forum Archive => Topic started by: Roger Johnson on October 13, 2009, 11:56:52 PM

Title: Crown I-Tech 6000 Temperature
Post by: Roger Johnson on October 13, 2009, 11:56:52 PM

Just wondering how hot i-techs run for others... I've got an itech 6000 that seems to run very hot, regardless of the load it's pushing.

Pushing subs or idling, the fans cycle regularly on the unit.  If an XTi 4000 was doing the same job, the fan wouldn't even come on.  

There always seems to be a steady stream of hot air coming out of this amp, and I don't have another to compare it to.  Does anyone notice that the itechs run hotter than other amps, even if idling?

Thanks for the help!

Title: Re: Crown I-Tech 6000 Temperature
Post by: Tim McCulloch on October 14, 2009, 01:20:31 AM

Ours cycle, too, but I'd not call the idle temps "very hot."  At idle the IT6k runs hotter than MacroTech 5002.  Hotter than our old iron Crests.  But not what I'd call "hot."

Do you have a way to measure the temp?  Have you gone through the "Monitor" menu and checked for thermal or input voltage errors?

Tim "inquiring mind" Mc

Title: Re: Crown I-Tech 6000 Temperature
Post by: Roger Johnson on October 14, 2009, 07:34:50 AM

I looked at the menus, and no thermal, load, or clip, errors.  The amp only has 50 hrs on it.

It just seems like its running too hot.  It has a certain smell that I wouldn't expect from a power amp.

Title: Re: Crown I-Tech 6000 Temperature
Post by: Adam Schaible on October 14, 2009, 01:44:19 PM

My fans kick on for about 1/2 second every once in a while.  I wouldn't worry about it.  It does tell you a thermal "percentage" of max, so you could look at that.

Title: Re: Crown I-Tech 6000 Temperature
Post by: Jeff Wheeler on October 14, 2009, 04:02:45 PM

I know the XTi will display several internal temperature readings on the front panel if you hold the three buttons down for a moment to go into some special mode.

Title: Re: Crown I-Tech 6000 Temperature
Post by: Jeff Wayne (J.W.) on October 14, 2009, 09:11:37 PM

  When I bought my first batch of I-Techs I set a few of them up at home so I could play around with them.  I noticed that the fan in one of them (an I-Tech-6000), would swing into high speed with no signal present.  After several minutes it would die down to a low and quiet speed.  Then it would repeat the process.  Again, with no signal present, and all faders down.  In the quiet of the room I was working in it was very noticable.  It was in a rack with two other I-Techs, which were quiet unless I pushed them.

 I don't know about any specific temperatures that were present, but I think fan speed is governed by temperature.
 
 I sent it to Crown and they fixed whatever was wrong with it and had it back to me within a week.  I remember being impressed at the turnaround time.  They made a note about replacing an input section or something.  Whatever was wrong with it might have been commonplace with those early I-Techs.  That's just a wild guess, based on the fact that they fixed it and had it back in route to my shop on the same day.
 That was quite a while ago and I haven't had any trouble with it since.

 The amp was doing it's job, but I knew something wasn't right with it.  I wanted to take advantage of the warranty while it was still covered.  As it turns out there was indeed something wrong with the amp.

 I hope this helps.  Take care.  Jeff

Title: Re: Crown I-Tech 6000 Temperature
Post by: Silas Pradetto on October 15, 2009, 10:16:40 AM

I own a few Itechs myself, and I always seem to have one that does that. I think I've figured out why. The PSU and output device fans are linked, so if the output devices are not being used (no signal) but yet the amp is on (PSU is making heat) the fans will spool once in a while to keep it low. I know the Itech HD has separate controls for the two fans.

Title: Re: Crown I-Tech 6000 Temperature
Post by: Moby (Mike Diack) on October 15, 2009, 11:54:49 PM

What you need to determine is if the i-tech has overactive fan syndrome or if it is getting too hot (and protecting itself).
OFS is usually caused by one of the four thermal sensors (NTC thermistors) giving a false low resistance reading. This is quite a common fault - there are 2 on the output devices and 2 on the PSU heatsinks. Usually it is one of the PSU ones that go bad. They can be checked in circuit by comparing one with t'other. If the thing is getting genuinely too hot in a quiescent situation, there are channel overlap/underlap pots which can be twiddled - this is well documented in the service notes and should not be attempted in the absence of these notes.
You should be running the latest firmware revision (Crown tweek the fan algorithms from time to time). The itech thermal management system is a beast of amazing complexity.
M

Title: Re: Crown I-Tech 6000 Temperature
Post by: Bob Lee (QSC) on October 21, 2009, 08:38:59 PM

One thing to be aware of is that compared to class AB, class D amps tend to run warmer at idle and low signal levels but much cooler at moderate and high levels. If that's what you're experiencing, it might just be normal.

Title: Re: Crown I-Tech 6000 Temperature
Post by: jason burk on October 23, 2009, 05:49:05 PM

Jeff Wayne (J.W.) wrote on Wed, 14 October 2009 20:11

When I bought my first batch of I-Techs I set a few of them up at home so I could play around with them.  I noticed that the fan in one of them (an I-Tech-6000), would swing into high speed with no signal present.  After several minutes it would die down to a low and quiet speed.  Then it would repeat the process.  Again, with no signal present, and all faders down.  In the quiet of the room I was working in it was very noticable.  It was in a rack with two other I-Techs, which were quiet unless I pushed them.  I don't know about any specific temperatures that were present, but I think fan speed is governed by temperature.    I sent it to Crown and they fixed whatever was wrong with it and had it back to me within a week.  I remember being impressed at the turnaround time.  They made a note about replacing an input section or something.  Whatever was wrong with it might have been commonplace with those early I-Techs.  That's just a wild guess, based on the fact that they fixed it and had it back in route to my shop on the same day.  That was quite a while ago and I haven't had any trouble with it since.  The amp was doing it's job, but I knew something wasn't right with it.  I wanted to take advantage of the warranty while it was still covered.  As it turns out there was indeed something wrong with the amp.  I hope this helps.  Take care.  Jeff

i just got my itech 6000 in the mail today. it was bought used. 3172 hours on it. but i got it from arik who's selling these and a few other itechs they have in stock so they can upgrade to the hd's. i plugged it in to the system architect and updated the firmware to the latest. v2.1.2.2.

its been running on idle for about 3 hours now. just been lookin at it and messing with the architect on it. just about 5 minutes ago, that same fan problem happened to me. went on full speed, then calmed down after about 5 minutes.

i bought this amp to have my little rig ready for a show nov.6th.

this amps not going to shut down on me in the middle of the show is it?
thx!

Title: Re: Crown I-Tech 6000 Temperature
Post by: Tim McCulloch on October 23, 2009, 06:40:06 PM

You should be fine.  We've had a couple of 6000s that rev up to full speed at idle but System Architect doesn't show them anywhere near thermal limit.. maybe 20%?  Then we pound them.  No thermal shutdowns, no thermal errors.

I'll have to put a sticker on them so I can follow more closely, but in the 15 months we've had our I-Techs, we've only sent in 2 for service (warranty) and that was for the sputtering, frying bacon sound on channel 2.  That, apparently, is a ribbon cable issue.  And we just bought 4 more...

We've taken the Sound Image approach:  we send out *1* spare ITech with every rig.  Just 1.  So far I've never had to replace an amp at a gig, but I've used the spare to power a wedge for a VIP area several times.

With 3000+ hours, I'd say Arik's amp is broken in, not broken.  If you're really concerned call Kevin Gring at Crown's Elkhart factory and get his opinion.  He might have you run a couple of diagnostics before he can say "don't worry" or "send it in."

Have fun, good luck.

Tim Mc