Keep it cool and actively ventilated

Gunther16

Recently after modification to my vintage Polks I found that my Krell amplifier bit the dust. On analyses by Krell it cost me $861.00 to get it fixed. Major culprit "HEAT". Now I know heat kills electronics but thought that since they had wide openings on 2 sides inside cabinet that this was sufficient, I was wrong. Internal temperatures during operation exceeded 125deg Farenheit. Since then I added active ventilation to cabinets and now internal temperature does not exceed 83deg under the most demanding situations. Invest in an active ventilation system to save those expensive electronics.
Words of wisdom learned the hard way!

vmaxer

Wow, hate that happened to you.

Gunther16

Came as quite a surprise Vmax. Thanks to looking ahead I still had an adcom in reserve so I could "burn in" the modified Polks. Adcoms did ok but Krell was the icing on the cake!

DaveHo

Could you post some pics of your fan setup? I have my amp in a similar cabinet, but there is at least a foot of space above it. It is designed to run hot, but have felt some forced cooling would be good. Curious how you positioned things.

Gunther16

Will do. Ventilation cost was less than 80 bucks and made a huge difference. I did have to block one side as the active ventilation airflowwas bypassing the amps ventilation openings.

SCompRacer

Which Krell amp do you have? The 3250? My old KSA-250 idles at 79C (173-174F) out in the open.

: 0

Gunther16

Just think if it was in a cabinet! Cook you a burger/steak! Yes Krell 3250 and it gets too hot to touch when pushed. I talked to Krell customer service who advised me to actively ventilate if installed in cabinet as there would be only minimal air movement although both front and rear were open. Obviously the rising air just sits on top of the amp and gets progressively warmer. Customer service said that actively ventilating is recommended as it removes the excessive hot air but does not affect the internal temperature requirements of the unit when operating. I do not measure the actual temperature of the unit itself but the ambient temp in the enclosure. To the touch it is much warmer than the mentioned 83 degrees. The active ventilation just removes the excess accumulated heat.
Nice setup you have I bet it sounds sweet

EndersShadow

DaveHo wrote: »

Could you post some pics of your fan setup? I have my amp in a similar cabinet, but there is at least a foot of space above it. It is designed to run hot, but have felt some forced cooling would be good. Curious how you positioned things.

@DaveHo

You could always use a laptop cooler with a large fan to pull their up and through the amp.

I keep meaning to get one of the Thermaltake ones for my B&K and another for the Denon AVR.

D'prived

A few years ago the wife and I bought a new entertainment center and my Marantz receiver and Yamaha power amp were going to be behind doors in an enclosed area. I purchased several of these fans and installed them in the back of the entertainment center to pull the heat out.

http://www.amazon.com/AC-Infinity-AIRPLATE-Cooling-Cabinets/dp/B009COQYA0?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

Then I bought two of these Antec coolers and placed one on top of the Marantz and one on top of the Yamaha. They have two fans on the bottom that draw the heat from the unit and vents it out the back.
http://www.amazon.com/ANTEC-Notebook-Cooler-V-COOLER/dp/B000QJ4ZE2?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o08_s00

Works really well.

Gunther16

Awesome!

EndersShadow

The only thing I've read about those Antec's is that they don't pull a ton of air out.

Here is one option I've been looking at. IIRC the LED's can be turned off too



Also there is a company called "Coolerguys" that specialize in this type of stuff.

They have both cabinet kits, and kits for between components

leftwinger57

This is interesting to me. Having a Krell w/ no load idle at 173* seems way high to me but never owning any amp besides the Adcom 555 maybe it's normal. All I do know is the heat sinks in the rear of the Adcom rarely even get warm and once I had of all my sets going at one time for a minute or 5 and still it only got warmer but never hot to the touch. My Yamaha is entirely a different story, the louder it goes it gets considerably hotter. I like that flat fan.

Footnote; I have to admit I was a tad tipsy that night and never run multiple speaker sets as a practice.

Gunther16

Krell equipment in general runs quite hot although I agree that 173 deg at idle seems excessive. My 3250 does not come close to that at idle but really pumps out the heat when asked to push.

Gunther16

Pics of fan location and controller, guess I should have rotated them first. Still haven't figured out how to get them to just show in the body of the text?

pitdogg2

this might go without saying but it you put a fan on top always pull air away not blow into the amp etc.

DaveHo

Thanks for the pics. The orientation of the pics is throwing me off. You have one set of fans in the Krell bay & one in the Adcom bay? Looks like the back of your cabinet is closed as well so it's forced to draw air from the front? Where'd you source the parts from? I really like the look of the controller.

Gunther16

Yes Dave one set of fans in the Krell Bay and one set in the Adcom bay. The back on both bays has openings and draws the air. I need to keep the front doors closed (which I really love) as the fans draw from there when open and bypasses the unit ventilation openings. I purchased them from Amazon.com and they are AC Infinity Airplate S5 Quiet Cooling Fan System 8" with speed control at $24.99 each and AC Infinity AI-ATC, Fan Thermostat and speed Controller at $26.99 for a total of $76.97. The control unit is not really necessary as one can manually operate the fans but I like the convenience of setting a temperature and the controller operates the fans as required adjusting fan speed as needed. Kind of set and forget! I have only had them a week so cant say a lot about the longevity but so far they are doing exactly as advertised. You need to be the judge on what you need as there is a variety of cooling units and sizes available out there.
Hope this helps. One tip I can give you is not to make the air intake too large and if you use these units be sure to use the included templates and cut the openings for the fans and controller EXCACTLY to size. Location of the Fans is really up to you and dependent on configuration. I had to vent to the side but they can go anywhere you deem best.

heiney9

Depends on the design and the wattage. My Aleph 30 which is a single ended class A amp run full all the time (hence the single ended design) at idle all the power is dissipated as heat. The fins are too hot to touch for more than 6-8 seconds. Funny thing is, if you make it work hard it runs a tad bit cooler because full power is no longer dissipated on the fins, but through speakers.

It's designed this way and is totally normal and I have had zero issues with it out in the open. If I were to put it in an enclosed space it would need active ventilation. It also has a thermal cut off if it reaches 167*F on heat sink temp.

H9

P.s. The output transistors are run at 1/3 the maximum safe operating temp. So there's still plenty of room up the temp scale before failure in this case.

SCompRacer

leftwinger57 wrote: »

This is interesting to me. Having a Krell w/ no load idle at 173* seems way high to me but never owning any amp besides the Adcom 555 maybe it's normal.

Nope, 173F is normal. It pulls over 10 amps at idle, normal too. Stable to 0.5 ohm.

EndersShadow

What pictures you WONT SEE is that Rich got rid of his furnace and stove.

Nothing like making your morning Omlett on your amp.

Gunther16

SCompRacer

LOL funny Dan.

Jasper uses it to keep warm during winter months. Sometimes to heat up his....

posterior.