Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

Heat Sinks for Power Tubes....

7/1/2003 5:22 AM
Heat Sinks for Power Tubes....
Hey guys.  
in my homebrew i have 540V going onto the plates of a pair of 5881's. so they get hot. the back panel is starting to get a little crispy.... so i was thinking.... are there heat sinks for power tubes?? could you wrap a spiral of wire around a tube (not touching it but close) and connect taht to a heat sink to dissipate it?? ideas, comments, concerns. thanks.
7/1/2003 9:21 AM
steve conner

I think some old tube radio transmitters did enclose the tubes in holes in an aluminum block. The problem with this approach is that not all tubes are the same diameter, some are crooked, and if they were a tight fit for good heat dissipation, they might expand with heat and shatter. You could smear the tube with heatsink compound before sticking it in the block, so you could use a loose fit and still get conduction.  
But really nothing beats a fan. One of those little computer fans circulating air around the tubes will make a huge difference.  
Remember though, the tubes themselves don't mind the heat, they can happily operate above 200 degrees C, it's the other components in the chassis that suffer :(  
Steve C.
Book Of The Day The Ultimate Tone, Volume III by Kevin O'Connor
Have you ever wondered if there is a better way to build a Bassman, Champ, Plexi, an 800, AC-30, Bulldog or Portaflex? Or you wanted to build an SVT with off-the-shelf parts? How about a master-volume amp that doesn’t change tone with the master setting? Everything you need to know is right here, including: proper grounding techniques, wiring methods, and mechanical considerations. Eighteen chapters cover the “iconic” amps everyone knows and loves, with schematics and layouts for each, along with the technical history of the product. Eyelet-board and chassis-mounted tube socket construction is used throughout, for easy servicing and modding. TUT3 is very accessible even if you cannot fully read a schematic and is a "must have" if you are going to build an amp for your self.

Note: The Ampage Archive is an Amazon Associate site. A small commission is paid to the site owner on any qualified purchase made after clicking an associate link such as the one above.
7/1/2003 9:54 AM
Le Basseur
No computer fans,please read my comments in this section on Ampage about this,it's the "Horizontal KT88???" thread.  
If cooling output tubes is a priority for you,try using Pearl Coolers (or make yourself some).  
7/1/2003 12:20 PM
steve conner
pearl tube coolers... hmmmm
I had never considered Pearl-type tube coolers (they're for hi-fi guys... not musicians... right?) but it seems they actually work better than fans:  
They are not too expensive (about the price of sovtek tubes) so might be worth a try. They just cool the tube envelope, though: If you want the chassis of your amp to run cooler, you'll still require more ventilation holes or a fan.  
Steve C.
7/1/2003 4:20 PM
Le Basseur
"I had never considered Pearl-type tube coolers (they're for hi-fi guys... not musicians... right?) "
Wrong,they're for everyone who wants to cool down a tube;)
   Page 1 of 1