possibilities for increased ventilation on small hybrid amp.

[tonequester]

tonequester here.


I have a Blackstar Ht-1R which has 8 small "slits" in the sheet metal back for ventilation. The back of the p.c. board faces the vents. All tubes and circuitry is on the othe side of course. I have wondered if adding a small computer fan to a couple of the vents, forcing air into the amp might prevent heat build up, and it's consequences, especially to the s.s. circuitry in close proximity to the two tubes. I haven't Googled sources yet, but I believe that even battery powered fans like these are available. I also do not know if the tone would be affected by cooling the tubes or not. Any opinion would be appreciated. The first of these amps "died" at six months, perhaps do to overheating. I stress perhaps, as they don't fix these under warranty, they replace them, so I don't know for sure what happened. Any opinions or experience with doing something similar is appreciated. There seem to be mixed feelings
when Googling this,mostly opinions from other forums. Thanks very much. tonequester.

[Enzo]

perhaps do to overheating

DO we have ANY evidence there is a heating problem? I forget from your other threads just what the problems were with your earlier units, but were any of the symptoms things that seeemed thermal related?

If we don't know what we are trying to fix, then random efforts are usually a waste of time. Like adding a fish sonar to a pickup truck.

[tonequester]

tonequester here.


Thanks for the reply Enzo. I have no evidence of anything concerning the Ht-1R other than what I,'ve seen. Absolutely shoddy lack of craftsmanship. The amp that I am now keeping, came with a speaker that was connected by one "screw" to the baffle-board, out of the 4 that should have been used. The first amp I did not open, because at that time I wanted to
avoid voiding my warranty. It just died 2 seconds after turning it on. The fuse that I could check was good. There was no feedback on either amp that went to a tech, because they apparently don't do much more than return them to Blackstar to be replaced. I do know that heat is one of the worst enemies of electronic components. I fixed my first stereo after a too busy tech told me what to check. He said the Sansui I owned was notorious for poor heat-sinking, and that I'd probably find a burned out power transistor, which I did. I remember it well because the part cost me less than $18.00. Hell, I'm just speculating. I had heard of computer fans being used to increase ventilation to increase tube life. I did not even intend to make this
any part of the amps circuitry, That's why I mentioned battery powered ones. I'm sure it could have been a bad part, bad soldering,bad fuse(the one on the board), or maybe it just doesn't like the way I play. I've had it with their warranty replacement. I get the pleasure of having an amp 6 months out of the year. It may be entry-level, but thats just an excuse for the kind of poor quality Americans have come to expect. I should have saved the $300.00 until it became $900.00 and bought a hand-wired American amp. The whole thing has been a great learning experience. That's all there is and there ain't no more. Thanks again for the reply, I'm a speculatin' kind of guy. tonequester.

[Austin]

I use a fan on one of my amps. The fan came from a microwave oven. I just like the way it looks but it does keep everything nice and cool.

[tonequester]

tonequester here.


Hey Austin ! Good to here from you. I never thought about a micro-wave fan. They move a considerable amount of air. I take it you don't notice any detrimental effect to your tone. That little HT-1R of mine gets pretty warm to the touch, and the vents are blocked off by the p.c. board. I think I'll give it a try forcing air into the bottom vents. The convection should carry the heat out of the top vents. I'm more worried about the s.s. components having to take the heat than the tubes themselves, although I have read that tube coolers and forced air can extend tube life-span. Thanks for the affirmation on giving your amp a little breeze. Who knows, it might even help get rid if some of the dust that can build up on electronics. Have a great day ! tonequester.

[Enzo]

It keeps your amp cool, AND it reheats your macaroni and cheese in only 60 seconds.

[tonequester]

tonequester here.


Greetings Enzo ! An "A" for an orininal idea, and an "A" for an original reply. I'm not much of a "mac 'n cheese man, but the notion of defrosting a steak for supper WHILE you play had crossed my mind. In all honesty, I'm taking the advice that you alluded to. This one ain't broke, it would be all to ME, to screw it up with the intention to improve it. After looking it over a little closer, I believe that they have a convection thing going on with their vent placement. I think it cools in the way that a good chimney works, by drawing in air at the bottom and letting the heated air exit the top vents. Somebody that has more education than me undoubtedly designed that feature using some mathematical formula for air flow and heat displacement. Like you've said before, if it ain't broke, don't fix it ! Thanks for keeping me grounded. One can speculate too much. One can even speculate so much that they don't accomplish anything but speculation. Have a great day Enzo. Sincerely, tonequester.

[Enzo]

A lot of amps do rely upon the lid/cover. With it in place, there is a natural convection path that draws air across the hot parts. In those amps, taking the lid off actually makes them run hotter, because now air just wafts away without flowing across the heatsinks.

[tonequester]

tonequester here.


Thanks for further clarification on the cooling issue. I'll admit that I got worried feeling the hot air coming out of the top vents. What I didn't notice until later was that the bottom vents gave off no heat. My old wood stove came to mind. Open up the lower "vents" and when you opened the doors, no smoke would even come out into the room. it was all sucked
up through the chimney. I guess you could say that tube amps have a draft. Thanks for clearing the air of all smoke. tonequester.