roggom wrote:
santik wrote:
so, you are saying that the MOSFETs should be as cool as possible in order not to induce distortion? and some FETs will definitely make this sound?
I have noticed that Mosfets found in power supplies IRF 530 630 and so forth will exhibit the quick hiss and also have a worse response curve. I am not 100% sure what is going on, just think it is something intenal to the mosfet to prevent thermal runaway. If you are experiencing more than one hiss an hour then heatsinking is in order. It does not have to be fancy, I have used washers before.
For your power supply question download PSUD2 and design for least amount of ripple.
http://www.duncanamps.com/psud2/index.html Some RC LC theory
http://www.play-hookey.com/ac_theory/ps_filters.htmlNow the only issue with low voltage power supplies is to really make them clean you will need very low value resistors, in turn they draw some current.
Other than that you can look up some 12v power supply projects by Ti Kan (AMB)
http://www.amb.org/audio/sigma11/the MOSFETs are heatsinked... and I noticed... if I fan the heatsinks... it gets cooler and sounds slightly better...
I am presuming the hissing does come from the power supply... I am thinking of making it away... I guess it is ripple in the supply... how do it away if it is ripple? I have 1000uf 50V capacitors in hand.
are you suggesting I put a very low value resistor at the power to remove them? in between the capacitors?