New Crown - thermal shut down - Boo!

[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

[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!

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!

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. 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!

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