New Crown - thermal shut down - Boo!

[robertbartsch]

OK, so I have been using a Crown XLS 800D in one HT for eight months or so and it has run cold as ice and without incident. The fans were really loud so I turned them off.

Anyway, I liked the Crown amp so much I recently purchased another one of the same make and model for the basement. Since I did not have any thermal issues with the first unit, I turned the fans in the new unit off too.

Apparently, this new amp wants more cold air as it shut off twice during its very first playing session at moderate levels.

I was driving a single set of 8 Ohm 4312s at the time. One of the speakers is 60 feet away and I am using thin speaker cable, however. The amp was mildly warm to the touch which surprised me. My first Crown amp is NEVER warm to the touch irrespective of the power I apply.

Anyway my questions:

1. Is the thin speaker wire in the basement application a reason that the new amp might run hotter than the same make and model amp runs in the TV room?

2. Is it possible that two Crown amps of the same make and model would run at different operating temperatures both driving a single set of 8 ohm load speakers in a home setting?

3. I'm sure I can stop the thermal shut down of the new amp if I turn on the fans but they are noisy; can I use a less noisy pancake fan or is there another potential solution to thermal meltdown?

[BMWCCA]

I'm sure I can stop the thermal shut down of the new amp if I turn on the fans but they are noisy; can I use a less noisy pancake fan or is there another potential solution to thermal meltdown?Try better wires but maybe you should just hook up the fans and put the amps in another room. I used to keep my first D150 in the closet since it was sold without even a faceplate. Did you at least have it up in the air where it could get circumferential cooling?

[mikebake]

How exactly did you turn them off? Were they designed to be able to be turned off?

[robertbartsch]

...new amp is sitting in an open glass shelf rack that was built for HT components - 6 inches of open space above and open to the sides and back. Rack is not against the wall.

Both amps are "B" stock inventory which is either (1) slight damage to the case or (2) a return amp that has been factory reconditioned.

I guess the Crown amps have good protection circuits like DC shut down and thermal shut down which is a good idea, I suppose. Anyway, putting units in separate rooms is not an option for me, however.

[mikebake]

Back to my question................

[BMWCCA]

Back to my question................I'll answer: The fans are on all the time unless you pull their power. The amp is a high-power DJ PA amp designed for a working rack where the noise won't be heard over the system. It's a nice design but very light with little heat-sink area or cooling fins. Made in China so maybe a better-quality whisper fan could help the problem.

Here's a shot of the guts of another Crown XLS model posted on another site which might give you an idea why it needs the fan:
http://www.linaeum.com/computerspeakers/crown_xls202d_internal.jpg

[mikebake]

Okay, so what we have is "New B stock Crowns -Thermal shutdown-boo! I didn't turn them off, I opened the case and unplugged the fans that are designed to cool it and not meant to be unplugged by the consumer and now it is shutting down- boo!"
I got it.............

[Robh3606]

Geez that will do it. Not a lot of heat sink area for just convection cooling. With the old Crowns the whole case including the faceplate was a heatsink. Are those tied into the bottom of the housing at all??

Rob:)

[Mr. Widget]

Sounds like the wrong amps...

For sub duty I use a JBL badged QSC. The JBL MPA 660... it is large and heavy. It is rated at ~600wpc and the fan never comes on. I guess it would driving a Vertec Array in a large venue.


Widget

[Oldmics]

Disconnecting the fan circuitry is a bad idea.

It will eventually cause catastrophic failure of the amp.Not immeadently but it will happen.

The energy destined to go to the fan once the demand to turn the fan on has to be dispersed in some fashion.

That rampant,unterminated electrical energy will cause overheating of the terminated electrical componets through out the entire fan circuit.

I would hook the fans back up or increase your homes fire insurance.

Oldmics

[hjames]

If it were me, I would hook the fans back up, sell the PA amp,
and get something more in line with your needs for home audio use.

Surely there must be something better suited for your use?

[robertbartsch]

Yeh, Ok I will re-connect the fans. Thx....

I have several large consumer amps including Adcom, Denon, Onkyo, Sub plate amps, etc. None of them touch the Crown in terms of shear performance characteristics. These amps are very powerful and natural sounding big mothers! Trully hard to beat at $300 for a NEW 500 WPC stereo amp (includes current factory rebate of $100)

I've had several issues with old electronics recently, so I would rather not buy more OLD stuff.

Anyway, the picture above must be a smaller Crown 202D amp since it only has about half the output transisters that my unit has.

Question:
Is it possible that a factory defect would casue the new "B" stock unit to run really hot?

I ran the old Crown 802D last night in the TV room at very high SPL and it was cold as ice.

This morning I ran the new Crown 802D in the basement and it was warm to the touch at very low SPLs.

[BMWCCA]

Yeh, Ok I will re-connect the fans. Thx....Take a picture of the inside while you're there, OK?




Question:
Is it possible that a factory defect would casue the new "B" stock unit to run really hot? Find out after you reconnect the fan. ;)

[clubman]

Don't get me wrong, Crowns are good amps. But there is nothing speacial about the XLS series. I have had issues with that line in the past.

[BMWCCA]

Don't get me wrong, Crowns are good amps. But there is nothing speacial about the XLS series. I have had issues with that line in the past.We discussed this when Robert first had the idea. This was pretty much an experiment on Robert's part which worked well with his first unit but apparently not so well with the second. We had discussed all the potential issues such as the Chinese-build-quality, the fan, and the sound-reinforcement versus home-use intent of the design. I appreciate Robert letting us know how it all worked out and perhaps he does just have a defective second unit.

If he hasn't already, maybe Robert could swap the amps and see how each perform in the other's position? ;)

[Mike Caldwell]

First those amps are pushing it to even be called a Crown....just my opinion!

As others have said I would not recommend disconnecting the fans, however have you tried swapping the amps from one system to the other and see if the problem stays with the same amp or is related to the system that it is connected to. Maybe you have an extremely low impedance load on one channel of the basement system.

Mike Caldwell
www.mikecaldwellaudioproductions.com (http://www.mikecaldwellaudioproductions.com)

[mech986]

Also Robert, if you think the one amp is running too hot or not functioning correctly like the other one, you should then have it checked out by a Crown Service station or send it back to Crown. You should mention that with the fan running, the unit seems warmer than the other one (almost cold) and you're concerned with the fact that if its getting warm with the fan, if you have a, ahem, fan failure, there could be a problem with the unit overheating (as you found out).

Even out of the box, electronics can have problems and they sometimes need to be readjusted for bias, offset, or other parameters. Even with B stock, run-in or operation for the first 90-120 days can reveal some early component problems. While we would love to have all our stuff work from day 1 (Quality control), it just isn't always that way. And when stuff is made offshore, well there can be more problems unless the manufacturing and QC process is very good.

Seems to me if there is a warranty, now would be a good time to use it.

Those heat sinks are only there in sizes and orientation for use with forced air cooling so it's not surprising to see they're quite small. I can only imagine what the higher power amps look like with all those TO3 spaces filled and 3 or 4 more sinks that need more air. Would there be multiples of fans installed?

Bart

[SMKSoundPro]

I agree with Bart and ask some of the same questions.

Is it possible to stand the amp on its face to utilize convective air currents to cool without a fan? Not attractive I'm sure seeing an amp on its face.

That sure seems to be an over-worked fan for a "pro" amp. If the other TO3 were full, how could there be enough cooling power for the one fan.

In the Macro Tech series, the chassis is designed for serious cooling. Even in a Mackie amp, they use a T style of air current where the fan forces air across all of the output devices. Could be a better amp, but at least they got that part fairly right.

From the internal view of this amp, I can assure you that one of these "crowns" will not be in my kit, no matter the cost.

scotty.

ps. try an old battle tested Yamaha amp like Bart and I are using. P2200 or 2201, 2002, or any othe other 250w/ch. offerings. They are a bargain!

[mech986]

Hey Scotty,

Now I know what the pic of the heat sink reminds me of - those same types of sinks are in computer swithching power supplies and fan cooled too!! Most if not all use plastic power parts though, not TO3 based transistors.

Otherwise, shhh! about the Yami's, we don't want the whole world to know about it. OTOH, if he can find them reasonably priced locally so not have to ship, they are truly a bargain.

Regards,

Bart

[robertbartsch]

I was thinking of swapping the location of the two amps too; good idea.

Anyway, I'm somewhat skeptical about the new amp simply because it is new and is a "B" stock item.

[subwoof]

B stock means the box has been opened for *any* reason and therefore cannot be sold as "new". Crown will pull an item at random from inventory and test it to confirm proper operation - this is the most common form of QC any manufacturer has and it is reliable.

Crown also has a "C" stock - look at their website or call them to get the correct explanation.

You bought the cheapest, lowest power crown that you could find that was meant for the lowest grade PA application and assumed that it would work for your high-end home system.

You defeated the REQUIRED cooling method ( fans are cheaper than metal heatsinks ) because you know better and now wonder why they run hot. Gee.

Now that you have baked one of these cheapo chinese toys it appears to run hotter - of course without measuring ambient temps before and after, line and load currents, duty cycle and a host of other variables you have *diagnosed* the ailment.

Have you measured the bias voltages? CFM of the fans? Impedance plots of your loads? Measured for RFI infiltration?

Simply making guesses and putting them into print is a sure way to have someone else find a google snippet of this and the adage "I saw this once on the internet so it must be true" becomes reality.

....another fustrated EE

[Allanvh5150]

That is quite possibly the worst heatsinking that I have ever seen in a power amp, period!:blink:

Here's a thought, fill the rest of the spaces with the same as what you already have there. Then it will probably run cool.

[BMWCCA]

That is quite possibly the worst heatsinking that I have ever seen in a power amp, period!:blink:What do I know? It's probably more than sufficient when used as designed, which means with a fan. However, that is a a photo of a 202, I believe. Current Crown info on-line show two fan openings on the 2-RU XLS amps, whether or not both are used on all models I can't tell from the specs. Can't wait to see Robert's shot of the guts of the 802D.

Interesting chart on the XLS-series heat dissipation is here (http://crownaudio.com/pdf/amps/139718.pdf). They also provide data for air-flow volume requirements per-minute: 80.15 ft³. :dont-know

[JBL 4645]

Whoops!

I’ve been telling most now place these fan type amplifiers in different room and isolate the noise from the living room or home cinema to keep the fan noise and mild transform hum as stacks of them will produce a mild humming sound due to the transformer.

I plan at some stage to place my non-fan Alesis RA300 and more when I get around to it and fan type for to run the JBL 4545 more efficiently in the bedroom.

Just drill a hole in the lower part of the skirting-board place a few plastic tubes in the hole and glue it up and then feed the cables and wires though it no big deal and then you can run the fans as loud as you want!:)

All you need is the basic AVR to control the volume or switch to other modes sod the amplifiers keep the in another part of the house. There more annoying than a computer pc fan blaring away!:banghead:

You’d never ever hear the stacks of Crown amps at the Empire! The stage amps for five-screen and subs are placed behind the THX baffle wall. The surround amps along with the dbx 4800 are all housed up in the projection booth along with two other racks 4 in all.

[Mike Caldwell]

For a higher powered Crown amp that does not need a fan look at the K1 or K2. They are discontinued now but can be found used.

Mike Caldwell

[robertbartsch]

Well, I've acquired several big consumer amps and other electronic equipment over the years and recently.

Frankly, I fail to see the value in these components since I have not had good luck at all. These old electronics can fail and the cost to repair them is usually more than they are worth.

Yeh, the Crown XLSs are dirt cheap but they are constructed from new components, are powerful as hell so I did not mind taking a chance that the fan mod would void the warranty.

At a cost of $300 bucks for a 1000 watts of power into 8 ohms, that is high value to me. Generally, I try to avoid stuff made in communist China but this is an exception.

There are lots of stamps inside that say "Mex" so I assumed the manufactur was Mexico not communist China.

[mikebake]

At a cost of $300 bucks for a 1000 watts of power into 8 ohms, that is high value to me.
Doesn't sound like it worked out all that hot to me.
One of my biggest complaints with audio forums, starting with my early years on Audio Asylum and going on from there, is the incessant striving for/belief in the free lunch.
It may be high value to you, but to me it looks (and apparently acts) like a $300 amp. I think you just made the wrong choice here, over-heating or not. But, it's your money.
Sometimes the strategy is to take stuff you aren't using/don't really need and turn it into cash so you can get a really good piece of gear that will serve you reliably for years.

"Well, I've acquired several big consumer amps and other electronic equipment over the years and recently.

Frankly, I fail to see the value in these components since I have not had good luck at all. These old electronics can fail and the cost to repair them is usually more than they are worth."
Then stop buying them and get quality new stuff; that may be the best value in the long run. I happen to like QSC in the pro amp category. Very good experiences with them.

[Mr. Widget]

I happen to like QSC in the pro amp category. Very good experiences with them.Me too, and Bo seems pleased with his as well, however QSC and Crown both have gone all Guitar Center on us... you need to buy the right models.
First those amps are pushing it to even be called a Crown....just my opinion!Both Crown and QSC are producing amps that are semi-pro at best and I'd be surprised if 20-30 years from now they'll still be around, while the old school Crowns are still in service.


Widget

[mikebake]

Yes, you have to buy in the upper 1/2 -1/3 of their offerings to get the proper ones, not their cheaper entry level stuff. No different than JBL JRX gear, I guess.

[Mike Caldwell]

I used both, QSC PL2 series amps and Crown Macro Tech 3600's. The entry level QSC RMX series is really pretty good, far better than the Crown entry level low end amps.
The only problem with the Crown Macro Tech's is the weight! I've been think about selling them and looking into the Crown I tech or the QSC PL3 series.

Mike Caldwell

[BMWCCA]

Both Crown and QSC are producing amps that are semi-pro at best and I'd be surprised if 20-30 years from now they'll still be around, while the old school Crowns are still in service.If you look at Crown's amp application chart, they break their applications into five categories: installed sound, portable P/A, touring, recording/broadcast, and Cinema. The XLS series is suggested for portable P/A and Cinema, only. Only the Macro-Techs and I-techs are listed for touring and installed sound. I suppose that says something, though the CDi, CTs, and Commercial Audio Series are also listed for installed sound, just not touring. Something for everyone and I guess Cinema needs must be far different than touring.

The good-old D-Series is the only amp suggested for broadcast and recording duty. :D

[allen mueller]

I used both, QSC PL2 series amps and Crown Macro Tech 3600's. The entry level QSC RMX series is really pretty good, far better than the Crown entry level low end amps.
The only problem with the Crown Macro Tech's is the weight! I've been think about selling them and looking into the Crown I tech or the QSC PL3 series.

Mike Caldwell

I'm with you on the RMX, I like better than the entry level Crown. I use a PL325 on my LSR 6332's and love it. My setup is in a finished basement and I keep the amp on the utility side, so fan noise is not a problem.

Allen

[robertbartsch]

....So the 40 year old Crown DC300s were orginally designed for touring bands and cinema but many are used today in home theater and other home sound applications....

I guess that something too....

[BMWCCA]

....So the 40 year old Crown DC300s were orginally designed for touring bands and cinema but many are used today in home theater and other home sound applications....I don't know about that. I bought my first Crown D150 over 35 years ago and they were a staple at a high-end stereo shop that was a JBL and McIntosh dealer. I'm pretty sure Crown started making amps to provide sound systems for churches and PAs after successfully producing reel-to-reels built for use by missionaries. I guess that's "touring". Doesn't sound like there was much competition then, or else the DC300 was just that far ahead of its time.

I don't know too many people still relying on their original DC300s in their primary systems today. There are quite a few using the developed versions, DC300A, Series-II, and the PS-series amps though. Just like I've been doing for over 35 years. Doesn't mean Crown's other stuff won't work at home, if you use them properly. They just may not be the best tool in the drawer. And all tools are not equally well made!
http://trxblue.at.infoseek.co.jp/images_tools/400_trx850_04020616.jpg

[dj jason]

i run my crown ce2000 on my 4648 cabs in my theater room and i can run it all day playing club music to move watching and the fan hardly ever turns on . it is my frist crown amp and i have been very happy with it . the only time the fan well run for along time is if i run it full range . but as a sub amp it does a great job

[robertbartsch]

I've been away in Detroit on business for 5 weeks or so. I did get a chance to come home for the weekend, however.

So I installed a variable speed pancake fan on the back of the unit and ran it at moderatly high volume for a few hours without issue.

I suppose I'll try a few other things, but for now, I guess I can conclude from this brief test that the unit needs some air flow to stay cool enough to avoid thermal shut down.

[Allanvh5150]

I don't know about that. I bought my first Crown D150 over 35 years ago and they were a staple at a high-end stereo shop that was a JBL and McIntosh dealer. I'm pretty sure Crown started making amps to provide sound systems for churches and PAs after successfully producing reel-to-reels built for use by missionaries. I guess that's "touring". Doesn't sound like there was much competition then, or else the DC300 was just that far ahead of its time.

I don't know too many people still relying on their original DC300s in their primary systems today. There are quite a few using the developed versions, DC300A, Series-II, and the PS-series amps though. Just like I've been doing for over 35 years. Doesn't mean Crown's other stuff won't work at home, if you use them properly. They just may not be the best tool in the drawer. And all tools are not equally well made!
http://trxblue.at.infoseek.co.jp/images_tools/400_trx850_04020616.jpg

If you are refering to the notches in the spanner as being of poor manufacture, there are a few manufacurers that do this on purpose. When you need to pull on the spanner, the notches don't allow the spanner to slip off the nut. I have a set that look like this as well and I was pissed when I got them home until I red the blurb and tested it for myself. They have saved my knuckles on more than one ocasion.:)

[BMWCCA]

If you are refering to the notches in the spanner as being of poor manufacture, there are a few manufacurers that do this on purpose. When you need to pull on the spanner, the notches don't allow the spanner to slip off the nut. I have a set that look like this as well and I was pissed when I got them home until I red the blurb and tested it for myself. They have saved my knuckles on more than one ocasion.:)Quite the contrary. That's a Snap-on Flank Drive wrench. I may be a cheap bastard on many things, but I won't use cheap tools. My hands deserve it, as does my patience.

http://www.aolcdn.com/channels/09/06/4795a5ac-0036b-0230e-400cb8e1

[mikebake]

Snap On, I called it.
Trivia;
I bought the Snap On guys trade-in. What kind of shape do you think it was in?

[BMWCCA]

What kind of shape do you think it was in?The shoemaker's kids?

[mikebake]

The shoemaker's kids?
Nope. Perfect.

[robertbartsch]

I have Snap-on tools - great stuff.

Their new stuff grabs the heads in the center not the edges....