[peter4jc]

For the last 2.5 years I've used my monoblocks to drive a pair of Philharmonic Audio HT Towers.  Frank and PA's head honcho, Dennis Murphy, were long-time friends; in fact, Frank was the one who directed me to Dennis for speakers when I spoke with him about updating my electronics in '23.  Some of you might know it was a joint venture at Axpona where the two companies exhibited together.

Anyway, yesterday, I was listening at a moderately loud volume, close to 90dB measured with a phone app (so who knows).  My left channel went silent, and after a bit of sleuthing, it was determined to be one of the speaker fuses on the back of the amp.  I was relieved to find it was nothing of consequence, and after a search online for the fuse and a 2min. drive to my Ace Hardware, I was back in business.

My speakers are rated at 4ohms minimum, and conservatively at 90dB sensitivity.  So, even at that volume, I doubt the amps were working very hard - they barely get warm when driven like that, and only if it's for an extended time.

I'm curious to learn about the conditions that would blow a fuse like that?  Were the speakers actually drawing more current than I think?  Maybe it was simply an aging fuse? 

Thanks for any thoughts/feedback.

[Dart87]

From Google AI:

Yes, electronic fuses can wear out over time due to operational stress, thermal cycling, and environmental factors, even without a major overload event. Repeated heating, cooling, and high inrush currents cause the internal metal element to oxidize, weaken, or experience fatigue, potentially leading to premature failure.

[danielgk]

The fact that you have been using it for 2.5 years tells me that you are not close to the speaker fuse limits.  The fact that the M225 is not getting hot tells me even more that you are not close to the speaker fuse limits.

Rule of thumb:  First fuse blown always gets a new fuse and a "re-try".

I'd definitely chalk it up to a bad fuse...they do go bad with age and repeated use.


Dan

[peter4jc]

The fact that you have been using it for 2.5 years tells me that you are not close to the speaker fuse limits.  The fact that the M225 is not getting hot tells me even more that you are not close to the speaker fuse limits.

Rule of thumb:  First fuse blown always gets a new fuse and a "re-try".

I'd definitely chalk it up to a bad fuse...they do go bad with age and repeated use.


Dan

Thanks. 

Maybe I'll put a pair of earplugs in and blast away to see if I can re-enact a 100dB scenario. 

I read in the manual that we can go up to an 8amp fuse if 5's blow too often, but based on what you're saying that won't be necessary. 

Thanks again.