Long-time troller of this forum, first-time poster. At the risk of repeating a previous thread (I did my best to search previous posts first), I’d like to hear some first-hand experiences with bypassing the fuses in your Magnepans. I’ve read threads in other forums on this topic, and I’m aware of the risks and the consequence of having the warranty voided. Before I perform surgery on my 20.7’s I’d love to get input from fellow tinkerers who have actually done it. Are you experiencing better sound, expanded soundstage, etc? Has anyone (with responsible care) blown their tweeters? Have you used fuse bypass kits or did you rewire and bypass the fuses entirely? Is there any other advice that you can give? Thanks for your input.
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Welcome!
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I’ve used fuse bypass kits (loaded silver fuse-sized pieces) to bypass both low/mid and tweeters on my 20.7s. Then I decided that the risk was too great, so I put standard fuses back into the tweeters, but not the low/mids. But they weren’t the expensive kind of fuses that @aangen seems to loathe. 
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That’s a good idea…to bypass the mids only. What fuse bypass kits did you use? The 11Audio kits have been out of stock for quite some time. What replacement fuses did you use for the tweeters?
In general, fuses in the audio path are a bad idea. Things like polyswitches can be better but there is still a degree of nonlinearity.
If I were magnepan, I would use a steeper filter on the tweeter (and no feed as much LF into it). As it stands, it is such a gradual filter, it isn’t doing much to attenuate the midrange from the tweeter. This also causes somewhat more uneven coverage through the crossover range.
Danny Ritchie shows a little bit of this in some of his measurements (I think he had a 1.7 or something he was looking at).
I know that they are trying to keep costs low, but a few more good quality crossover components and getting rid of those fuses would be a signifcant step up for them in performance, I think.
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I used Mikey’s kit. And I used stock fuses on the Tweeters.
There’s always a “but”. Of course they could use better quality components, but in all their history, they haven’t, and likely never will.
It is up to us…
About three years ago I bypassed the fuses in my .7s with ¼ inch Super-Conductive 101 Copper Tubes from McMaster Carr and heard an immediate improvement in the highs.
Interesting. Curious, what’s the best way to cut a 1/4" copper tube? Thanks for the reply.
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Why are you guys trying to put ‘lipstick on a pig’ by replacing the fuse with a thick jumper? Have you seen how cheap the fuse holder is with its riveted wire connectors? The cheapest and best solution is to bypass the fuse assembly entirely by wiring directly. Very simple to do after removing the plate.
For some people…
I used one of these.
I have run my original MG-iiis (1st gen with ribbon tweeters) for 20 years without the fuses with no issues. My understanding is that the fuse is there to interrupt lengthy exposure to high volume/high wattage listening sessions that literally overheats the wires glued to the Mylar film and risk damaging the adhesion. That is why it is a slow-blow fuse. My recollection is that I was provide this information when I was discussing the crossover upgrade with Magnepan directly. My first act whenever I get a new pair or Maggies is to remove the fuse. The difference is dramatic. Not only is a whale lifted but a great white shark, 3 dolphins and 5 sea lions. 
Seriously, not just a veil but a velvet curtain is lifted. MUCH better clarity and sparkle. Once you hear it you won’t go back. At least I won’t. Admittedly all my Maggies have been used without warranty, so I can feel your pain.
I (like anabellebachoy) also recommend bypassing the entire fuse system behind the plate. (others argue to get ride of the plate and the poor quaility connectors as well). Definitely wire out the tweeter attenuater, too, as it is more junk in series with the tweeter. You can always restore it back to stock anytime you need to.
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I am not advocating what I have done, but, inspired by some of the upgrade kits, I have replaced the fuses on my LRSs with cut pieces of solid copper core rods (bought inexpensively from the big online store). I have excellent results. The highs are more natural and extended, especially for the classical music I love. Of course, I have to be careful but I don’t play music very loud anyway and I have never clipped or blown any of the speakers I have ever owned.
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I’ve used Mike Powell’s silver replacement jumpers and fuse replacement - low cost and great results…
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