7volt mod the safe way?

[Slickone]

Also can I use one resister but run several fans off of that?

 

[Slickone]

If I have six 80mm fans running the 7V mod [off a 400W Antec PSU], could I have problems?

 

[Navid]

Originally posted by: Slickone
Also can I use one resister but run several fans off of that?

Each fan has an effective resistance. By running them all off of the same resistor, you are placing the fans in parallel. So, as long as you take that into account in your calculations, you will be OK. HOWEVER, if you remove one fan from such a setup, you change the setup and increase the RPM of all the remaining fans.

It is better to have one resistor for each fan. The best setup is to use a fan controller (something like this), which places variable resistors in series with each one of the fans that it controls. Most fan controllers control 4 fans. The advantage is the flexibility you get in controlling the RPM of each fan.

 

[Slickone]

Yeah I was just trying to get around a fan controller for a couple reasons.
BTW, is that particular controller variable? It lists the voltage as 5V or 12V, so seems not. And couldn't you control 2 fans on 1 channel, so more than 4 total?

I wouldn't mind using the Fanmate mentioned earlier, but as I said it's powered by a 3pin connector and asked if there was something like that that uses a 4 pin, for hooking several fans to it (if possible). I guess I could get a 3 to 4 pin converter.

Also I wondered if Spire Dual Speed mentioned earlier could support several fans (3 or 5) on one side, so I could hook my CPU fan with RPM monitoring to the other side. And I didn't know what kind of connectors it had.

 

[professor1942]

I picked up the Vantec NXP-205 3.5" controller yesterday and am quite happy with it... basically you just turn the fans down enough that the vibrating & humming stops (it doesn't take much, just a few volts less).

 

[Navid]

Originally posted by: Slickone
BTW, is that particular controller variable? It lists the voltage as 5V or 12V, so seems not.

I have the controller that I linked to. It has 4 knobs that you can use to adjust the speed of 4 fans. The 5-12 you see is the range, which by the way is wrong. It is more like 7-12.

And couldn't you control 2 fans on 1 channel, so more than 4 total?

You can always do that. But, you give up flexibility. I like to find out which fan it is that makes the most noise and quiet that down first. I keep doing that until I am happy. If you hook up two fans to the same controller (resistor), it is quite possible that one of the two makes more noise. You need to reduce the RPM of that one. But, you will reduce the RPM of the other one more than you need to in this configuration (shared series resistor or controller).

 

[vanvock]

Since I'm just after 1 fan I picked up a 3w, 25ohm variable resistor at RadioShack & gonna give that a whirl(pun intended).