How many fuses in a McIntosh MC275?


Hello.

I have upgraded the main fuse in my MC275 mk IV, the one that can be replaced from the outside, a 200 mA slo blow. But I keep reading about several fuses in amps, some for the speaker outputs...I don't know if mine has. Does anyone know?

Thanks!
lewinskih01
No, they are OK. Actually, I had an upgraded fuse (the main, external fuse), and it was taken out by a defective tube. You might have seen my thread a while back. Replaced the tube and used a generic fuse and all is working ok.

Now I'm in the process of getting a quad of new tubes, replace the fuse that went, and thought it was the right time to consider upgrading other fuses, should there be any more, should they make a difference, and should it not require disassembling the whole amp to do so.

Can you elaborate on you first post, dude?
WOW No way! Fuses are usually visible and sometimes resistors are set to work as a fuse. Upgrading or replacing fuses is the most ridiculous upgrade you'll ever get.
I see...fuses are a ridiculous upgrade to you. Yet I heard improvements every time I upgraded from a std fuse to an audiophile fuse.

Why do you waist time trying to convince me of something I did not even ask about? You are surely waisting my time trying to honestly understand if you had something to say...oh well...

Thanks
Are you sure it is a 200mA? From what I see in the service menu, the main power fuse is 250V 4A slow-blow and two more inside for speakers output are 250V 2A slow-blow. You can download a service menu from here.
you can only prove hearing improvements on the blind a/b tests. blind tests is where all audi'o'philes fail to ID stock fuse from aftermarket and other silly unnecessary stuff.
as you know, fuses tend to blow and usually are all visible on the pcb or direct wiring. the improvement you've heard is possibly from the quality of the contact so all you need to do is to clean fuse terminals with qtip and contact cleaner.
I read the schematic and found that the two fuses inside are actually for filament heaters, not speaker outputs.
Nothing wrong with blind tests per se but it's certainly a mistake to think that if someone cannot hear a fuse or whatever in a blind test that the fuse or whatever doesn't work in other systems. There are many reasons why audiophiles get null or inconclusive results with some tweaks. You know what I'm talkin' about.
Marakenetz, do tell of your experiments with blind tests of standard and audiophile fuses. Of course it would be disingenuous to suggest someone's direct experience was to be false or untrue due to an improper scientific method if you had not rigorously proven the null hypothesis yourself (adjusting for clean contacts and such).
Hififan: my mistake; it's a 2 A fuse because my amp runs on 220 V (it was not 200 mA).

Thanks for the link to the service manual. You mean the two fuses called F1 and F2 on page 8, right? So if they are on the filament heating circuit...should I expect them to improve sound?

Thanks for the input!
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