Correct me if I am wrong, but I thought that blowing air onto hot tubes can result in "microcracks" and is not recommended. |
That's what it says in my Jadis manual as well. However, ARC does use fans in some of its models (I think my M-300/Classic 150s had them; that I can't recall entirely will testify that their noise was not intrusive), and I believe they make them for installation in enclosed rack/cabinet enclosures. You might want to check with ARC about this--what model amp do you have, anyway? You could ask ARC if a fan is really necessary for your application as well. |
My VT100s have fans in them. Fairly quiet ones, too. Given the cost of retubing one of those guys, I hope I'm not developing "micro cracks!"
Might check an electronics parts outfit, the fans look like the 5 1/2" ones found in computers. I think they make "whisper" versions that are pretty silent. |
I put a Radio Shack fan on top of my Audio research VT 100 MK II and put a variable speed fan potentiometer from Home Depot. This lowered the fan speed and also the noise from the fan. This profect only cost me around $20.00. I put the fan so it blows across the amplifier to circulate the warm air away from the unit. Not blowing directly onto the tubes.
Hope this helps
Kevin |
Kevyo is right. You want a low-speed one for two reasons: prevent problems with tubes and low noise. Rogue uses one that is amazingly quiet and you may be able to find out from them what brand it is. And don't blow it direct on the tubes. |
Do not allow the fan to blow directly onto the tubes as this will cause microcracks. Place the fan's exhaust away from the amp, which will allow the cool air to be "drawn" into the amp, thus enhancing the natural cooling convection effect to take place. |
Yes definitely draw the heat away vs, blowing air into any component, tubed or not. A variac will reduce line voltage to slow down & quiet that fan, but don't use an SCR dimmer (even one for motor control) because they're typically electrically noisy. Lutron may be the exception but I've never tried one. |
I don't get it. ARC's VT100 mk2 has a fan mounted inside the chassis. It's on the bottom of the amp, and I haven't checked to see if it is blowing up or down. However, what IS that fan doing besides bringing new air into the chassis for cooling? Is the VT100 mk2's design flawed in that respect? |
I actually have my fan behind my rack circulating the air away from the rack. But I need a totally silent fan. |
As for quiet fans, I found this site a while back that sells ultra quiet fans for PC's. I've never dealt with them so I can't attest to the quality of their service, but you might check out their catalog and see if there are products available that fit your needs.
http://www.endpcnoise.com/
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i have an ARC fan set-up with a vent sytem -rack mount in their aluminum finish. USed for my old ARC tube amps- no scratches on it.
Stuart Kishner
skyg@ica.net |
cooling fan with no noice........take a so great possible fan and reduce the rotation speed
works verry well
succes
henk |
See Recommended -> Recommended Fans.
-O |
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Usually the higher priced squirrel cage fans seem to be more durable as well as quieter. I've used these in high power HF tube amplifiers. In this case the bottom of the cabinet is pressurised and the air moves through a ventilated tube socket,up around a chimney enclosing the tube then out the top of the cabinet. This seemed to keep very big and very $$$$$ tubes happy. |
Get a cheap very quiet mini desktop fan 4" dia. at target for $8.00 will do you just fine!! it's very very quiet |
Whether the air is 'forced' across the tubes or 'drawn' across the tubes makes no differnce since it is the temperature of the air that makes the difference and it is the same in both cases.
At any rate, if you can't hearthe fan then the amount of air flowing isn't high enough to be any 'danger' to the tubes, forced or induced.
Salut, Bob P. |
Vornado Zippi totally silent. I was using it when I was keeping a tube amp in a rack with somewhat limited shelf space. I had the fan blowing upwards over the top of the amp so the heat would blow out the side of the rack and not heat the upper shelf too much. Worked perfectly. |
I find pro cool fans are very quiet.
Some assemblies have a thermostat so she'll kick in at a certain temp and off as well at a certain temp.
I use two and I can't hear either of them.
Also there is a temp display. |
Try End PC Noise for a wide selection of quiet fans. I have one I got from them mounted to the back panel of my HT system cabinet running 24/7 and it is inaudible. I power the fan with a 12V wall wart. Two cable boxes in the cabinet alone generate a substantial amount of heat around the clock, and with closed cabinet doors, I need to get rid of the heat buildup.
http://www.endpcnoise.com/cgi-bin/e/std/category=Quiet_Case_Fans.html
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A comment that uses extreme brevity and a hint of irony is a "micro crack". Also, fans have been cooling tube amps in one way or another (suck? blow?) seemingly forever, and this is the first I've heard of micro cracks...I'm suspicious...I'm going to be looking for these everywhere now..."Hold still Marge...you could be standing near a tube with MICRO CRACKS"... |
