Mod Old Fan Cont. -or- Get New One?

[DedEmbryonicCe11]

I'm still running the old Vantec Nexus 205 3.5" bay device. It's supposed to put out a range of 7V-12V to the four ports. It was good enough for me way back when I got it however I've found the control lacking with higher RPM fans and was planning a little work to make one or two of the ports go lower. I bought a tiny SPDT switch from Radioshack with a center off position so that I could add at least a full off ability and possibly use the bottom position for an alternate circuit with something to drop the power a bit more. After spending a few days worth of spare time trying to learn a little about resistors and LEDs and such I got to actually testing the device and found the big problem with it. The voltage adjustment range for each port appears to be entirely based on the current draw of the fan(s) connected to the port! To clarify:

12.08V at molex connector power source
Voltage ranges from Min-Max
#1  9.49V - 12.00V  driving 0.25amp fan
#2  9.45V - 12.00V  driving 0.25amp fan
#3  7.58V - 11.93V  driving 0.46amp fan
#4 11.64V - 12.04V  No fan connected

As you can see it only seems to work to spec when it has roughly 0.5amp connected!
So the question is, would there be anything worth the time/money I could do considering how it shouldn't cost more than like $30-40 for a better device? Bear in mind I'm definitely no electrician so any solution would have to be somewhat simple. I still have the receipt for the switch but that was only $3 and I'm considering keeping it either way in case it comes in handy. Otherwise I'd kind of hate to spend a bunch fixing this controller when the faceplate barely has room to either side for the tiny switches next to #1 and #4.

 

[MisterSparkle]

The fan controller is probably using plain old potentiometers to adjust the speed, which don't work very well with unknown fans, since, as you said, there's a big difference between your fans of different power. What you could do, is wire up a switch so that when you toggle it to a certain position, you add a number of diodes in series with the fan output. Each diode in series will drop the voltage by close to 0.6volts.