Hello. I'm using a Jab5 4x100 dsp amp board on a project. The SQ is acceptable for the use even if there is some background tweeter hiss. The fan noise is the real issue. I'm wondering if anyone has had any long term experience running the board with the fan disconnected and/or removed. Has it lasted without the additional heat dissipation? Also contemplating adding a resistor to reduce the fan output.
I don't have any experience with the jab 5 but have used resistors to quiet fans down in other amplifiers. Sometimes I use a lower voltage like 8v for a 12v fan of possible as well. You could also possibly find a quieter fan too as I'm sure the one that comes on the board is just a cheap loud fan. I have a wondom/sure bdm8 which is a 2 channel tpa3255 board and it doesn't have a fan but I added one because the heat sink gets so hot even idle. The enclosure the tpa3255 is in in also have a 48v smps with a fan and the enclosure has a fan in the back to vent warm air out. The enclosure fan and amps fan run constantly and I can't hear them ever. If it's really quiet in my room I can hear the power supplys fan kick on but I haven't changed it or tinkered with that one.
Cheers. I'll try dropping the voltage first and see if that's acceptable. I ran it without the fan for a little whlie and the heat sink did get quite hot. I'd rather not go buying some other fans and hope they are quieter than this one. Incidentally the fan is quiet when held in free air and only produces noise once butted up against the heat sink. If only Radioshack was still in business to pop down and pick up a few resistors...
Maybe you could try putting some nylon washers between the fan and heat sink to create an air gap. That would quiet it down if it's louder when you install it. You'd want the fan to blow air onto the heat sink rather than pull it away if you tried that. Just have to experiment and see what works and what doesn't. At least that's all just time.