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why do hi-end fuses keep blowing, while std don't?

I've had my McIntosh MC275 for several years running flawlesly. Up until last Nov I was using stock KT88 and rolled small tubes and had a Hi-Fi Tunning fuse without issues.

In Nov-13 I upgraded the KT-88 to Psvane black bottles measuring 60mA plate current. A few power-ons after I rolled the tubes, I turned on the amp to let it warm up, but returned to a blown fuse. I thought a tube might be bad so used a std fuse, but never had a problem again.

Two months ago I bought a new high-end fuse, replaced it, and soon thereafter the same happened: blown fuse. I replaced it with a std fuse again, which is still running.

So I want to upgrade the fuse, but chances are if I use the 2A fuse it will happen again. Yet I don't want to use a higher value fuse. I'm thinking the Psvanes might be drawing significantly more current than the stock KT88 and the Hi-Fi Tunning fuse might have a tighter spec, driving said fuses to fail while the std ones survive. Would you agree?

Suggestions as to how to resolve this?

thanks much!
lewinskih01
lewinskih01 OP
909 posts
 
Thanks for the update.
So you keep you amp switch in the on position and turn on/off by turning the isolation transformer? Interesting.
My balanced power conditioner trips if I do that, but will keep it in mind.
Which isolation transformer are you using?
summercrema
5 posts
 
I bought it from them Tortech,  https://www.tortech.com.au/product-category/isolation/

it is available on ebay.com.au
 ISO600VA.

My tube amp is only 6 months old, manufacturer will no commend on third party hifi fuses and fuse manufacturers will say anything either.
After googling few hours Isolation Transformer  came up few times and found out Tortech has a soft start circuit to to limit inrush current problem.

Actually I turn on the ISO600 before I turn on Tube Amp.  
summercrema
5 posts
 
correction I mean to type $160 not $120.
Post removed 
geoffkait's avatar
geoffkait
23,365 posts
 
In the long history of audio there has never been a single documented and verified component damaged by a high end fuse. If anything, by blowing too quickly they prevent damage to equipment. What a load of horse hockey! 🏒 Are some audiophiles really that superstitious? First they complain audiophiles fuses blow too fast. They must have got bored with that approach and complain they don’t blow fast enough. 🎻
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