[ahpook]

Hi all, long-time AVA fan but first time poster.

I have a ~12 year old Omega III 200 CA integrated amp, driving Paradigm Studio 20 mk5.

A couple of years ago the main fuse (just inside the power line) blew and since then the replacements have gone every couple of months. The fuse always blows at the same time: right as I flip the power switch on.  I have been replacing them with RadioShack 250V 5A Fast Action fuses as that was -- I believe -- the original fuse.

My questions for this august body are thus:
- are these the right fuses to use? or did I misread/misbuy the first replacement and all the subsequent ones are blowing because they are the wrong capacity or fast instead of slow?
- is this common and expected, or is it indicative of something deeper wrong with the wiring that would require a repair session?

Thanks for any advice.

[Lefty052347]

The AC fuse is normally a slo blo.

Speaker and B+ / B- fuses are quick blo.

If the fuse is in line between the power cord and the switch it should be a slo blo. 

I can check in the morning for the proper value.

Feel free to call us in the morning if you have more questions.

Regards,
Dean

[avahifi]

The main AC fuse should be a 3AG 5 amp slo-blow fuse.  A quick blow fuse used here will blow often due to the current inrush surge as the main power supply capacitors charge at turn on.

"3AG" identifies the fuse physical dimensions.  5 ampere is the rating, slow blow tells that the fuse will withstand a substantial overload for a short period of time before blowing.

Quick blow fuses are used for the power supply and or speaker fuses as they need to blow quickly from a sudden overload before the speakers or circuit parts are overloaded and blow.

Frank Van Alstine

[ahpook]

Awesome info, thanks very much Frank and Dean.