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I have mcintosh amp (4 x100) and I wonder what do you guys recommend for the fuse size (e.g. 30, 40, etc) for this amp. Also, can someone educate me what is the different the fuel size can do your amp? thanks in advance
 

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do you mean the fuse for the amp itself or the fuse that come after the battery? if its the fuse that come after the battery... i tink i was once told to use the same or something little bigger. EG. 40 on the amp, you should use 40-50 in the fuseholder after the battery. If you asking for the fuse on the amp itself, you should refer to the instruction to the exact amount required.
Hope this helps..
 

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Fuses placed by the battery do nothing in actuality to protect the amplifier - they are there to protect the power wire instead. But it is a good idea to keep the fuse selection close to that of the maximum current draw of the amplifier.

A good rule of thumb is to take the fuse ratings of all amplifiers and components off of that run of wire and add them up. Then select the power wire diameter based on that current draw and the length of the run.

Another way to determine your amplifier's current draw is to take the outut of the amplifier...in this case a potential of 800W (if you bridged all the channels), then multiply that number by 2 - amps are really only 50% efficient - half of the current put into them are lost as heat. So in actuality, you need to give this thing 1600W. That power is delivered at somewhere between 12V and 14.4 V.

Divide the 1600W by 12, and you get a MAXIMUM current draw of 133A divide by 14.4, and you get about 110A.

Now if you are going to use that amp in just a four channel mode at 4 ohm - you onlyl need about an 60A fuse, if you wanted to run it mixed - bridged to a sub lets say and to a pair of components, I'd fuse it around 80 or 100A.

One thing to note is that these calculations are very conservative and err on ths side of over-estimating the current draw. Due to the duty cycle of music, rarely if ever would you hit the maximum current draw for an amplifier - it just doesn't happen....

Hope that helps you out....
 
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