Vintage HiFi Audio Forum

Audio Discussion => DIY => Topic started by: bearjew on November 28, 2014, 03:17:20 PM

Title: Rack Cooling
Post by: bearjew on November 28, 2014, 03:17:20 PM
Ok, so as I am currently finishing up a bunch of various projects, I am about to start my biggest one to date.  I will be building three Nelson Pass amps.  Building the amps isn't the part I need help with though.  I am going to be putting these three amps in a rack when it's all said and done, and they apparently idle at 140 degrees.  I have done a ton of reading, and it's totally fine for them to run at 140, but I imagine they'll live significantly longer if their asses aren't on fire all the time.  anyone familiar with any rack cooling methods that don't destroy your wallet?
Title: Re: Rack Cooling
Post by: Sir Thrift-a-Lot on November 28, 2014, 03:36:08 PM
Set em on laptop coolers.
Title: Re: Rack Cooling
Post by: bearjew on November 28, 2014, 04:42:23 PM
i thought about that, but i'd like to get actual rack mountable stuff to keep everything... um... clean?  plus, those laptop coolers aren't as effective as i'd like them to be
Title: Re: Rack Cooling
Post by: Sir Thrift-a-Lot on November 28, 2014, 04:57:49 PM
Still cheap and quiet, you could mount similar computer fans into a wooden panel and mount that at the back of your rack.   It could be done very discretely if you are careful.
Title: Re: Rack Cooling
Post by: ataudio on November 28, 2014, 06:10:09 PM
What type of rack?   Closed, furniture style or open rack like Salamander brand?
I have used computer fans very effectively.  To keep noise down I run them at reduced voltages.
A 12v fan (or several of them) are very very quiet when run off 5 volts or so.  A long time ago I ran
A 240 volt (yes, 240 volt fan off enterprise IT hardware) off 120 volts and it was super quiet.  I used this in an old
fully enclosed furniture style cabinet.  I have several computer fans and many wallwart power supplies if you want to
experiment.  I just left them run all the time....never an issue.
Title: Re: Rack Cooling
Post by: schwarcw on November 28, 2014, 06:45:46 PM
Check out these, made specific for racks of various size and cooling capacity.  Not cheap, but professional all the way made for what you want to do.  If your going to put the blood, sweat, tears and money into building some Nelson Pass design equipment, don't cheat yourself on the cooling.

http://www.coolcomponents.com/rackcooling (http://www.coolcomponents.com/rackcooling)

Title: Re: Rack Cooling
Post by: F1nut on November 28, 2014, 07:37:04 PM
I would place them side by side.
Title: Re: Rack Cooling
Post by: bearjew on November 28, 2014, 07:44:07 PM
Check out these, made specific for racks of various size and cooling capacity.  Not cheap, but professional all the way made for what you want to do.  If your going to put the blood, sweat, tears and money into building some Nelson Pass design equipment, don't cheat yourself on the cooling.

http://www.coolcomponents.com/rackcooling (http://www.coolcomponents.com/rackcooling)



wow that site is brilliant.  i'm definitely not cheaping out on these amps; i'm just trying to make this Pass project fit into my budget... i know, "Pass" and "budget" have never been in a sentence together before.

I would place them side by side.

i would love to, but i currently will not have the space to do that.
Title: Re: Rack Cooling
Post by: papabearjew on November 28, 2014, 08:02:29 PM
Immerse in nitrogen bath like they do with super computers. At least Cray used to.
Title: Re: Rack Cooling
Post by: ataudio on November 28, 2014, 08:15:49 PM
Maybe  you can use oversize the heatsinks.  Start with good passive cooling. 
Title: Re: Rack Cooling
Post by: bearjew on November 28, 2014, 08:18:06 PM
the chassis are going to have 40mm heatsinks already haha
Title: Re: Rack Cooling
Post by: ataudio on November 28, 2014, 08:26:56 PM
A really good ballbearing fan run on reduced voltage can move enough air to work. Since your amp is spec's to run as is a simple fan setup would probably work just fine.  I've only borrowed a couple of class a amps.  One was a Sumo and one was a Pass amp of some forgotten
flavor.  I remember liking them both...but both out of my price range at the time.  Good luck on such an adventurous project.
Please keep us posted.
Title: Re: Rack Cooling
Post by: bearjew on November 28, 2014, 09:38:52 PM
A really good ballbearing fan run on reduced voltage can move enough air to work. Since your amp is spec's to run as is a simple fan setup would probably work just fine.  I've only borrowed a couple of class a amps.  One was a Sumo and one was a Pass amp of some forgotten
flavor.  I remember liking them both...but both out of my price range at the time.  Good luck on such an adventurous project.
Please keep us posted.

Sadly enough, I'm building these strictly based on the reputation of Nelson Pass.  I have never had the luxury of hearing any Pass amps, but I have a gut feeling that these could be end-all amps for me... unless i'm a millionaire, then i'm going to make them out of 24k gold...
Title: Re: Rack Cooling
Post by: GraphicFX on November 28, 2014, 10:09:51 PM
Ok, so as I am currently finishing up a bunch of various projects, I am about to start my biggest one to date.  I will be building three Nelson Pass amps.  I am going to be putting these three amps in a rack when it's all said and done

When you say rack, are you talking about 19" front mounting? If so, there are tons of rack mount cooling fans everywhere. Fairly cheep and look way cool.  My rack, Contains 4 old school crown amps, Behind the rack (hidden) I use a 7inch desk fan. plugged in to a power strip. When the party gets cookin', I just flip the breaker and on she goes. I only use it when I'm playing my system at just below clipping. At that volume, you can't hear it.

It's primitive but cools things in a hurry.
Title: Re: Rack Cooling
Post by: schwarcw on November 29, 2014, 12:19:55 AM
These are a pair of Pass Labs 600 wpc mono blocks.  I heard these at the Chicago Audio show earlier this year.

(http://i126.photobucket.com/albums/p97/schwarcw/P4250146.jpg) (http://s126.photobucket.com/user/schwarcw/media/P4250146.jpg.html)

Pass Labs link:  https://passlabs.com/products/amplifiers/point-5/x600.5 (https://passlabs.com/products/amplifiers/point-5/x600.5)

Title: Re: Rack Cooling
Post by: schwarcw on November 29, 2014, 12:35:17 AM
Those can be yours for $22,000 a pair.  The 1,000 wpc monoblocks are a measly $34,100/pair.  I don't know if you can 10% off at Acoustic Sounds this weekend.  LOL! 
Title: Re: Rack Cooling
Post by: bearjew on November 29, 2014, 08:12:11 AM
Ok, so as I am currently finishing up a bunch of various projects, I am about to start my biggest one to date.  I will be building three Nelson Pass amps.  I am going to be putting these three amps in a rack when it's all said and done

When you say rack, are you talking about 19" front mounting? If so, there are tons of rack mount cooling fans everywhere. Fairly cheep and look way cool.  My rack, Contains 4 old school crown amps, Behind the rack (hidden) I use a 7inch desk fan. plugged in to a power strip. When the party gets cookin', I just flip the breaker and on she goes. I only use it when I'm playing my system at just below clipping. At that volume, you can't hear it.

It's primitive but cools things in a hurry.

19 inch is exactly what I'm talking about.  I see some fans that apparently only get to about 30db, but they seem to be expensive.  I definitely have time on my side right now, so I will have to look further into it.  I also don't really know how to set them up.  Do I just want fans in the back pushing out?  Or should I have ones in the front pushing in, and ones in the back pushing out?


These are a pair of Pass Labs 600 wpc mono blocks.  I heard these at the Chicago Audio show earlier this year.

(http://i126.photobucket.com/albums/p97/schwarcw/P4250146.jpg) (http://s126.photobucket.com/user/schwarcw/media/P4250146.jpg.html)

Pass Labs link:  https://passlabs.com/products/amplifiers/point-5/x600.5 (https://passlabs.com/products/amplifiers/point-5/x600.5)

don't get me wrong, i would kill to have those, and they are some of the best looking amps i have ever seen, but those ones are AB, and the ones I'm building are just class A, which is why i'm investigating the cooling stuff.
Title: Re: Rack Cooling
Post by: MacGeek on November 29, 2014, 08:30:01 AM
BJ-I suggest putting fans in the back and pulling the cooling air through the rack.  Be sure to occasionally clean the fans and gear; fans pulling air may increase the dust factor.
Title: Re: Rack Cooling
Post by: schwarcw on November 29, 2014, 03:23:43 PM
If you want pure Class A, take a look at these:  https://passlabs.com/products/amplifiers/xs/xs-300

In reality, 50 wpc Class A is probably more than you'll ever need.  Unless you have some inefficient speakers.
Title: Re: Rack Cooling
Post by: Reverend on November 29, 2014, 07:06:05 PM
How about something like this?  http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=7737987&Sku=C13-2110 (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=7737987&Sku=C13-2110)
Title: Re: Rack Cooling
Post by: bearjew on November 30, 2014, 09:46:50 AM
If you want pure Class A, take a look at these:  https://passlabs.com/products/amplifiers/xs/xs-300 (https://passlabs.com/products/amplifiers/xs/xs-300)

In reality, 50 wpc Class A is probably more than you'll ever need.  Unless you have some inefficient speakers.

oh yeah, i know about those.  this thread just got even more expensive haha


How about something like this?  http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=7737987&Sku=C13-2110 (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=7737987&Sku=C13-2110)

i'm actually running that in my computer right now.  It's not rack mountable, and I have no idea how i would set that up.