Film-Tech Forum ARCHIVE: Crown Amplifier Problem

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Posted by Chris Daigle (Member # 7347) on 04-04-2013, 12:51 PM:

I was hoping someone here could help me figure out whats wrong with a Crown CE1000 amp. In this particular auditorium, when I first turn on the amps at the beginning of the day, instead of just getting the 4-second flashing of the fault lights and then hearing the clicking as the lights go out, one of the amps has the CLIP lights on both channels light up solid while the fault lights blink for 4 seconds. After 4 seconds, the fault lights go out but the clip lights stay on for about 30 seconds after which both clip lights then slowly just fade out. We haven't had any issues with playback at this point, the CLIP lights don't come on at all during playout and everything sounds OK in the auditorium, but I'm worried that this may turn into a bigger problem soon. I've already swapped input/outputs between this amp and a different Crown amp in the rack, but the problem stays with the amp. Any ideas?

Posted by Tony Bandiera Jr (Member # 2365) on 04-04-2013, 08:01 PM:

Yeah get rid of those piece of shit Crowns and get QSC. [Smile]

Seriously though, take that amp completely out of service and have it repaired right away, before it takes out the speakers when it finally fails. [thumbsup]

Posted by Randy Stankey (Member # 64) on 04-04-2013, 10:46 PM:

It all depends on how your theater is set up and the arrangement of your amps but you can often shuffle amps around, temporarily, until you can get the bad one repaired.

Can you, for instance, unhook one of the amps for the subwoofers then put it in place of the bad one which powers the left, center or right channels? This is how I used to do it at Cinemark when amps went bad. They didn't have spares in the theaters. I had to call in to have another amp shipped in then send the bad one back for repair but it often took a week or more. We couldn't have a theater down for that long so I just swapped amps around until the replacement arrived.

If you do this, be sure that you are swapping in the same model of amp and be damned sure that the settings and switches are set right.

This was possible at Cinemark because there were ten or more theaters with similar or even identical setups. It wasn't a problem to take the subwoofer amp out of a small house and put it in place of the bad one in another house. If you are in a small theater, it might not be possible. If you can get a replacement in a short time, it might not even be worth it. You might just be better off to limp along until the replacement arrives. This assumes you order the repair/replacement right away and it arrives in a few days or a week.

Tony is right. I have seen many Crown amps fail. A few of them went up in smoke. Depending on budgets and politics at your theater, you should use this as a reason to push for replacement of those amps. At very minimum, get yourself on record as saying that those amps are on their last legs and should be replaced as soon as possible or else, as Tony says, those amps will fail and take the speakers with them.

You know that Murphy's Law predicts those amps WILL fail and, when they do, it WILL happen on a busy Friday night in a packed house showing the premiere of the most popular movie of the season! [Wink]

Posted by Monte L Fullmer (Member # 2797) on 04-05-2013, 12:39 AM:

Now, CROWN has those DSi amps that uses a switching PS inside and I wonder on the reliability of these units.

Posted by Richard Fowler (Member # 893) on 04-05-2013, 01:57 AM:

The protection circuits tend to get wonky with age, low voltage or loose connections. Better to save up for new gear since I have stripped out a couple of multiplex cinemas of this model due to the amps eventually start having speaker problems.

Posted by Paul Mayer (Member # 355) on 04-05-2013, 10:18 AM:

Old joke - how the Crown DC300 (remember those?) got its name - that's how many amps it presented to the speakers when it died. [Smile]

Posted by Marco Giustini (Member # 4544) on 04-05-2013, 12:05 PM:

I have a very limited experience with Crown, but as everybody here says, QSC - whith which I have plenty of experience - is much better. Seen several Crown exploding in a cloud of smoke bringing the speaker with them. Never seen that with QSC and failures are usually quite low.

Posted by William Kucharski (Member # 7246) on 04-10-2013, 01:35 AM:

Hmmm, I would think a better joke would be that DC300 stood for the DC voltage sent to the speakers when it failed. [Big Grin]

Posted by Tony Bandiera Jr (Member # 2365) on 04-16-2013, 09:14 PM:

Paul and William are both spot-on. [Smile]

Actually, the Crown DC series amplifiers were originally designed not for audio use.....but to drive the magnetic drivers used for "shaking tables" in labs, production lines and product testing.

They were deliberately designed to have useable output from DC (0 hz) up to the top end, which IIRC was 40khz.

Only the input stage is designed to limit frequency response (and supposedly later serial numbers are rumored to have input stages designed to do "only" 20hz-25khz), but from the driver stages on out they are still capable of full power DC output.

Common failure mode was the driver transistor's "pre-driver" stage, which frequently shorted the driver transistors which then sent the full DC power supply rails out to the speakers, with predictable results. [Eek!]

The DC Series should never have left the labs they were designed for.

As for the rest of the Crown line, candidly I have never found any of their amps to be reliable or safe to operate compared to other brands. I too have seen way too many Crowns of all vintages go up in smoke in "normal" operation.

Posted by Louis Bornwasser (Member # 3063) on 04-18-2013, 11:42 AM:

While certainly not my favorite amplifier, you are too hard on the Crown. The DC-300 was the only decent amplifier during the early days of Dolby. There was no alternative. I installed many that are still in service in small theatres. Only failure mode I saw was dc from the Dolby frying all of the surround speakers (Altec 312s)

I also installed DC300 in both sides of the Century Plaza Twin in L.A. back in 1980. 6 channel 70mm, passive crossovers with Altec A4x. First film was Ghandi for Tom Ogbourne (operator). (was supposed to be the world premiere of Heaven's Gate, but that was cancelled.) Louis

Posted by Victor Liorentas (Member # 5272) on 04-18-2013, 12:11 PM:

What do you guys think of the XLS 602 Crown amps? Mine are 8 years old without any problem but I would love to upgrade when we can afford to.
If the threat of taking out our speakers is likely...then the time may be soon.

Posted by Richard Fowler (Member # 893) on 04-18-2013, 02:07 PM:

Crown XLS is fine...I have many in operation. I find some units have a higher noise floor and on one install I went through eight amplifiers to find a noise match for the five installed.

Posted by Tony Bandiera Jr (Member # 2365) on 04-18-2013, 07:54 PM:

Louis:

After having to replace dozens of Crowns and too many drivers to count I don't think I am being too hard on them. Crown is one of those brands that has some sort of time-warped brand name mystique that the product has repeatedly failed to live up to. To whit:

quote: Richard Fowler
......I find some units have a higher noise floor and on one install I went through eight amplifiers to find a noise match for the five installed.

Richard, if you had to go thru that just to match the noise floor that is NOT FINE!! That is unacceptable and shows a serious lack of quality control on Crown's part.

Overall, Crown is overpriced, overhyped, unreliable [bs]

. ANY amplifier whose repeated failure modes include severe speaker damage and/or smoke and flames (seen that a lot on Crowns too) is NOT a "fine" amplifier. (I have never been impressed with their sound quality either, and that opinion was formed BEFORE I encountered the other problems.)

How's that for being hard on them Louis? [evil]

Victor: You would be wise to upgrade to QSC's or some other amp before you start to have problems. Most Crown failures that take out speakers happen without any advance warning and have happened even when the amp is "idling".

Posted by Rex Oliver (Member # 7593) on 04-19-2013, 02:49 AM:

Crown power amp
I have used these in a Broadcast enviornment-studios and transmitter sites.Had a spectacular Crown failure at a transmitter site-amp was used to power a pair of JBL speakers for the FM monitor system.Site is unmanned at nigh-was in WashDC area-summer night bad thunderstorm at night.I worked the morning AM transmitter sign on shift.As I walked inot the transmitter building-found both JBL speaker grilles on the floor-then looked up and saw the woofer cones hanging down by their leads.The Crown DC150 amp had both channels blown from the lightening.Got out the old Electro Voice Sentry mon speakers and a kit built Op-Amp labs amp.Built the thing while manning the site.Crown amp-was decided beyond repair-so supplier provided another one.Was able to get the JBL woofers rebuilt at Veneman Music.For broadcasters the Crown amps were reliable-but could fail without warning and blow speakers.Used BGW as an alternative.Liked those better.There was another Crown 150 amp used for the AM monitor.One channel for the site control room JBL speaker-other thru RF chokes-for the tower base monitor speakers.Somehow got 2 old drive in theater speakers and used those at the tower bases for monitoring program for base current readings-a remote audio mutre allowed the person taking readings to mute the audio for a base current reading.With the Delta RF ampmeters that was no longer required.That Crown amp survived the storm!Weird!

Posted by Richard Fowler (Member # 893) on 04-19-2013, 08:19 AM:

The client has scores of other Crowns in their building and the XLS where picked for a price point on their budget for upgrading their cinema rack section in a multirack set up. QSC RMX are working that price point as are other brands. The room is used for many premieres and one visiting studio technical engineer has done the same swap out of XLS to get the results he wanted in his situations.
I was one of the first people to test DC300 for use in amusement venues and after blowing a couple of drivers in the shop we sourced from another company...at the time there where very few power options. The CE series I am not in love with after replacing 50 units in a year....QSC USA went in their place.

Posted by Richard Hamilton (Member # 321) on 04-20-2013, 09:22 AM:

Rex
.--. .-.. . .- ... . / --.- ..- .. - / ..- ... .. -. --. / -- --- .-. ... . / -.-. --- -.. . / .- -. -.. / - .-. -.-- / .--. ..- - - .. -. --. / ... .--. .- -.-. . ... / .. -. / -... . - .-- . . -. / ... . -. - . -. -.-. . ... .-.-.- / .. - / -- .- -.- . ... / -.-- --- ..- .-. / .--. --- ... - ... / . .- ... .. . .-. / - --- / .-. . .- -.. .-.-.-

Translation:

please quit using morse code and try putting spaces in between sentences. it makes your posts easier to read.

Posted by Tony Bandiera Jr (Member # 2365) on 04-21-2013, 10:47 PM:

quote: Richard Fowler
The client has scores of other Crowns in their building and the XLS where picked for a price point on their budget for upgrading their cinema rack section in a multirack set up. QSC RMX are working that price point as are other brands. The room is used for many premieres and one visiting studio technical engineer has done the same swap out of XLS to get the results he wanted in his situations.

So the client has a hard-on for Crown and you didn't persuade them to dump them for an amplifier that actually works and will not leave their speakers at risk? [Big Grin]

And I'm sure the visiting engineer was favorably impressed by the fact he had to also play the amp swap caper to get acceptable results.... [Roll Eyes]

quote: Richard Fowler
I was one of the first people to test DC300 for use in amusement venues and after blowing a couple of drivers in the shop we sourced from another company...at the time there where very few power options. The CE series I am not in love with after replacing 50 units in a year....QSC USA went in their place.

Yeah back then there weren't a lot of options but there were still others out there as you discovered.

50 units out of how many? I'm betting oh, 50 or so.... [Big Grin]

Posted by Sam D. Chavez (Member # 1841) on 04-21-2013, 11:10 PM:

Tony says,

"So the client has a hard-on for Crown, etc.."

So who has the hard on? You are starting to sound like Mark Gulbrandsen with all the negative comment.

Actually, Kintek was a good sub in its time, just did not get loud enough for digital. The cabinets were pretty well built and the self powered amp limited the output to prevent speaker damage. They did have their problems for sure.

Crown is a perfectly good amp these days, but QSC is hard to beat. Back in the day there were all sorts of mediocre amps, Gromes, Magowan (sp), TOA, to name a few.

DC300's sounded pretty good with solid bass.

Posted by Richard Fowler (Member # 893) on 04-22-2013, 12:08 AM:

Grommes Precision....classic P.A. Legacy amplifier...they did the Cinemeccanica amplifier clone for Xetron. We used Yamaha amplifiers for power until the early QSC amps came on the scene.

Posted by Steven Cutting (Member # 5803) on 05-04-2013, 05:28 AM:

Ouch,
I bought a Crown Ce2000 second hand a year ago. The ad read " Very little use" when it arrived I poped off the lid to see how much dust was inside and could see that it had recently been repaired. Most of the transistors looked to have been replaced...........Still working though.

Posted by William Kucharski (Member # 7246) on 05-07-2013, 07:42 AM:

Well hey, it could have had "very little use" because it was in the shop often. [Big Grin]