synergistic research orange blue fuse direction.


Hi, I have two 611s, one 302 and one 452 McIntosh amps, and I just purchased three Synergistic Research (SR) Orange fuses. I also received one SR Blue fuse free with the purchase of the SR blue receptacle. Would someone advise me with some specificity on the directional installation of the Blue and Orange fuse. Again all the amps are McIntosh.

Thanks.
Guy
guyt

Showing 2 responses by cheeg

OK, I’ve been waiting for someone else to ask the obvious “dumb” question, but since none of you are volunteering, here goes: if it’s an AC signal, why does the directionality matter?
millercarbon:

Okay so well first off in a house wired 120v the panel has 240v coming in with the breakers on the left connected to one 120v leg, the breakers on the right connected to the other 120v leg… But what about 240v...Well the answer is even then the power coming in one wire is positive, the other ground or negative. In any case the AC coming into all components, the first thing it does is go through a transformer (to get whatever voltage the component uses) then to some diode rectifiers and then to some power supply caps. Because all components, even though plugged into AC, they all run on DC. But you knew that, right? ;)
 

Thank you for responding to my question, but the way I see it, it shouldn’t matter whether you’re getting your AC from the right or left side of the panel; both sides are supplying a 120v, 60Hz sine wave (I'll save the 240 discussion for another day). If you put your fuse on the incoming signal, the field across the fuse will change from +120v to -120v every cycle, so the current in the fuse will flow first in one direction, and then in the opposite direction, 60 times a second. At that point in the circuit, the amplitude is the same in both directions, so the current will spend just as much time flowing in one direction as the other.  I don’t see how the directionality of the fuse could affect the downstream signal, unless you’re suggesting that the fuse passes more current on the positive side of the cycle as the negative side (or vice-versa). We can come back to that later if you like, but for now I’ll assume that is not what you meant.

Now, you say, let’s look at the signal after it’s been rectified and stored in a capacitor; that’s fine, because then you would be dealing with DC, and directionality of the fuse could definitely make a difference. But my understanding is that these fuses are located in many different places within the amp, and the recommendations I’ve seen on Agon say it’s best to replace ALL the fuses with Synergistic Orange (or Blue). Are they saying that ALL the fuse locations in a power amp are only passing current in one direction?  That seems really unlikely. I can see how some of the fuse locations could be limited to DC, and would be affected by directionality, but for the ones that are passing AC, the direction of the fuse should make no difference.