Life of KT88's

[Black Stuart]

Philip,
just a thought - if you could build these into an amp, you could only use them with that one amp.

By making them totally independant of the amp, they can be switched from one amp (power) to another (head/amp) - just a thought.

[Dik Dolan]

A quick google search found this
http://www.primecooler.com/index.php...ewp&idprod=272
"Operation Voltage 6V-14V, Starting Voltage 6V"
The same site also lists 5v fans, i'm sure there are lots of others out there- pc cooling is big business

[pre65]

Hi-i saw this on e-bay.Seems well priced !

http://cgi.ebay.co.uk/Hi-Fi-Cooling-...QQcmdZViewItem


I like the idea of 3 speed settings,and mains operation.Saves the cost of an extra transformer.


Philip

[Tourmaline]

Originally Posted by Dik Dolan

A quick google search found this
http://www.primecooler.com/index.php...ewp&idprod=272
"Operation Voltage 6V-14V, Starting Voltage 6V"
The same site also lists 5v fans, i'm sure there are lots of others out there- pc cooling is big business

Beware of less good or smaller fans. They make alot of noise. The best fan's are 12 cm fans since they don't have to make much cycles to make the same airflow.
In other words; a good 12 cm fan, like the papst fans(they are one of the best around)don't make as much noise as a smaller fan at the same voltage!

At 7 volts, a 12 cm isn't even there and still has better air displacement then any other fan! For long lifety buy only the best fans around, like Papst. They don't cost much extra but give you a long time of secure cooling.

I see the papst doesn't need as much juice as that fan, costing less for cooling(lol). wattage for that fan is quite high. Seems like a decent fan though.

[Tourmaline]

Originally Posted by pre65

Hi-i saw this on e-bay.Seems well priced !

http://cgi.ebay.co.uk/Hi-Fi-Cooling-...QQcmdZViewItem


I like the idea of 3 speed settings,and mains operation.Saves the cost of an extra transformer.


Philip

I wouldn't use 6 cm fans. 12 cm fans make much less noise at the same voltage yet yield much more airflow. And there is a reason this guy also uses papst fans; they are almost indestructable and run forever.

Furthermore, i rather like direct cooling underneath instead of blowing air underneath.

At 12 volts, those 6 mm fans make more noise then a 12 cm fan! I don't like that design either, it's ugly.

6 fans x 28db a piece is about 28 + 5 x2-3 db = about 40db of sound, comming from those fans. 2 x 12 cm fans only make about 28db combined.
For every fan extra installed you need to add 2-3 db extra for sound production. So, 6 fans will make a hell of a noise, bad design concerning cooling and styling.

Thus, if you use this baby at 12 volts, you have to play very loud to be able to hear any music.

The way i and Black stuart are making the cooling is much less noisy and more versatile! I can even switch the polarity so they can suck instead of blow.

oh and eh, there's a transformer build in....a 14 volts fan won't run on 230 volts.....he's using a pot type of speed control while stuart and i just have to flip a switch on the converter to have 3 to 12 volts operation. even more versatile. Papst fans can also run on 14 volts. But then the fan would cross the line i would find acceptable in a living room for noise production.

[Black Stuart]

Tourmaline,
quite right, it is the direct cooling that is so important. Am I wrong or is the cooling with this multi-fan system horizontal, not what's wanted at all, it has to be a vertical air change to be really effective.

Tourmaline's principal is correct about all fan structures, ie. the longer a wind turbines blades the less wind it needs to start producing electricity and the bigger bladed turbines produce less noise as well.

But none the less, we can all see now that fan assisted cooling is something that should have been explored a long time ago by commercial cos.

Could part of the reason be that components would last that much longer (not to mention better sonics) , so making the market smaller and less profitable - built in short life. This happens with many pieces of equipment and is not confined to hi-fi.

[Dik Dolan]

Fan life might play a part too. As they get older they also get noisier.

[Black Stuart]

I can't accept that at all.

Fan noise is determined soley by the blade design and the rpm - nothing else.

[Tourmaline]

Originally Posted by Black Stuart

I can't accept that at all.

Fan noise is determined soley by the blade design and the rpm - nothing else.

I am with stuart on this one. A good designed fan doesn't have dust problems.

[Tourmaline]

Originally Posted by Black Stuart

Tourmaline,
quite right, it is the direct cooling that is so important. Am I wrong or is the cooling with this multi-fan system horizontal, not what's wanted at all, it has to be a vertical air change to be really effective.

Tourmaline's principal is correct about all fan structures, ie. the longer a wind turbines blades the less wind it needs to start producing electricity and the bigger bladed turbines produce less noise as well.

But none the less, we can all see now that fan assisted cooling is something that should have been explored a long time ago by commercial cos.

Could part of the reason be that components would last that much longer (not to mention better sonics) , so making the market smaller and less profitable - built in short life. This happens with many pieces of equipment and is not confined to hi-fi.

Probably. They don't make stuff as good as they used to do! Making sure lifecycle is shorter.

Active cooling, especially for mosfets and tubes is important! It raises the level of sound considderably and gives as a bonus longer life! Especially expensive tubes could benefit from this, like powertubes as the 300b etc. or the more exotic driver tubes. Tubes become more and more rare and more expensive.