Amplifier heat...help!


Hi all, 

Working on a system for a small 9 by 11 listening room.   I have narrowed it down to two small speakers: Falcon Acoustics Ls3/5a (15 ohm, 83 db) or the Airtight AL-05, also called Bonsai II (4 ohm 89 fb).

Tha amplifier will go in a cabinet.  I have about 14 inches between shelves and I always play music with the doors open.  I would love to use a tube amplifier but worry about heat.  So I am wondering if readers think something like a Line Magnetic 211ia could work in this configuration, or if it produces too much heat?   I have also been thinking about the tube -like  solid state Sugden A21Se, but have a similar question about its temperature.   Another cool (literally cool) option would be the Vinnie Rossi LIO, an amp I love but that is conisiderably more money.

Are there other options for relatively  compact tube amps (i.e.: . I have 17 inches of depth inside this cabinet including power cords so unit cannot be more than 14 inches deep) that do not produce a lot of heat (relatively speaking?).  Or is there really no tube amp that would work well in this scenario?

thanks!
mcanaday
Tube amps have been in stuffed into cabinets for decades. However they tend to use small power tubes like EL84s. As long as you have thru ventilation and a small amp you should be okay. Perhaps use a small fan mounted at the back. There are server rack fans with built-in thermostats. If it's a large octal amp, I would not advise you to put atube amp in a cabinet.
Hi Noromance,
Thanks very much for your response.  Can you suggest an EL84 type amp?  It is not one I have heard of.  And what is an octal amp?  Finally, does anyone have suggestions for quiet fan that could work well in this application?
This is very helpful!  Thanks,
Margot
Have you thought about putting in a sliding tray that could be used to pull the amp out of the cabinet when in use?
Your speakers are pretty inefficient to drive so will not go very loud with low-powered amps. Octals are the larger tubes like EL34/KT120 etc.
The sliding tray is a brilliant idea.  I will investigate that.  (I guess it does leave the question of what a tube amp is going to do to the overall temp in a small room, but that might be secondary concern.)

And does that mean the Line Magnetic 211 is out?  It is an el34 but a smaller one...

thanks!

If you get the amp in free air, you can use whatever you prefer. Both your speakers choices require some thought. The 3/5 need a 15ohm tap on the amp...not that common. The Bonsai need a 4 ohm. Both need a decent amount of watts if you want to go loud although the Bonsai should be okay. Also they may not sound their best in a small room if they are up against the wall rather than well away from walls.
Many thanks!

Let us know how it turns out!
I have my Quicksilver mono amps with both Kt88 and El34 tubes in a cabinet with no clearance on the sides and 6" on top. I've used it this way for over seven years with no problem.
Thanks, Yogiboy.  That is encouraging!  Do you use a fan?

No fan needed. I called mike at Quicksilver and told him it gets about 130 degrees and he told me that is not a problem. I really would not worry about it!
Great.  Thanks!
I never found my LM 211 to give off much heat. I'm sure this is not the case when you get up to their 218/518.  I think Tone Imports may have picked up Sugden. If so, that may be a question to toss their way. With that in mind, the Leben 300 is the only EL84 amp that comes to mind, though I'm sure there are several.
hey haven't you seen console stereos before? They're all cabinette based and as I've been diggin' for tubes, I was able to still find good tubes from 40's 50's inside there.
If you find used Quicksilver M60(EL34 based), they do not run hot and run tubes super safe
130deg F is 30deg C increase above ambient temperature.  Life of electrolytic caps is reduced 2x for each 10degC increase.  In that case it will be 2x2x2=8 times.  It will reduce 8x life of all capacitors in this cabinet.   Sliding tray or fan or both !!!
Lots of good advice!  Thanks again to all...

mcanaday,
I auditioned the Sugden on the same day and same system as the Line Magnetic 518, and I was really impressed with it. It is a great integrated. Really good music coming from it. You should seek it out to listen if you can. I would consider buying it, but I am obsessed with the Line Magnetic 219, which WOULD be a heat problem in your room.
Hi Roxy54,
So glad to hear this rave review of the Sugden!  That is really good to know.  And the 219 looks amazing.  I hope you are able to get it!
thanks, Margot

McCanaday ...

Double click on my avatar and you'll see an enlarged picture of my equipment rack. The ARC REF-75 is on the bottom shelf. I just measured the clearance. There is exactly two inches of clearance between the top of the KT-150 power tubes and the bottom of the shelf that resides over the amp. Granted, the shelving is an open design, but there has never been a problem with overheating in the many years I've had this rack.  Prior to the REF-75, I had an ARC Classic 60 in its place. No problem there either. The Classic 60 has a fan, but I kept it disconnected for lower noise. The REF-75 has  no fan.

OP
Rx for the Cheap Fix...computer fans.  Quiet, low power, inexpensive.  I've been using them on my equipment for years.  As noromance noted 10/30, you could opt for a server rack frame.  If installing into a cabinet, just allow for an intake and use the fans as exhaust out the back.  Easy to 'scale up' if you feel you're still running too warm...I mean your amp...

Oh, and if you're running hot, take 2 aspirin, rest in bed, and don't call me in the morning...I'm not a 'morning person'....*S*
Oregonpapa and Asvjerry-

Thanks!  I am feeling more confident that I can manage the heat issue, whichever amplifier I select.  Thanks very much!

Margot
I had a mother in law who drank a half bottle of whisky a day and smoked a pack a day. Lived to be 87. Invoking the exception to a rule that hard liqor and smoking are bad for your health would not make sense. Best to adhere to best practice. Lots of heat in an enclosed space is not a good idea either for the electronics or the building.
Whoa, whoa, whoa! Tube amps in confined spaces is a big no-no in any users manual. You're sure to forget to turn the amp off some night....not good. (Sugden amps do sound good but run way too hot as well.)
Beyond that, tube amps like to have speakers with at least 8 ohms. and should be fairly efficient. Your speakers don't fit that bill.
You need to re-think this from the start.
(Put that hatchet down, Eugene!)



If the Sugden is Class A it will run as hot or hotter than a lower powered tube amp, and will do so whenever it is plugged in, regardless of whether it is turned on.  As far as an EL-84 amp that puts out more power, try the RAM RM-10.  No idea of your budget, but another tube amp that runs cool is the Berning ZOTLs.
Okay, thanks guys.  The Sugden is hot when it's off but plugged in???  Why would that be?

Thanks! 
I solved this with computer cooling fans installed in back of a completely enclosed antique Chinese cabinet.  I drilled air intake holes on the back toward the bottom. Then I installed four 92 mm computer case cooling fans from Noctura on the back toward the top. These are 12 V DC fans that I plugged into a transformer (one of those black plastic plug-in things) on a lamp dimmer. Totally quiet except on full speed and no discernible sound on the speakers.  
I have a Magnum Dynalab 209 and a Manley Chinook inside. Temperatures were above 110 before. Now it remains room temperate.