I had to change the fuses on my amplifier recently and written beside the fuse holders is ''only use f4r q8 fuses''.
I pulled the fuses out of an old Cambridge Audio amp that were the same value and size and put them in temporally, the amp works OK but does anyone know what f4r q8 means?
I pulled the fuses out of an old Cambridge Audio amp that were the same value and size and put them in temporally, the amp works OK but does anyone know what f4r q8 means?
This is likely a spare parts code, no? So the brand/model of the amp you are puzzling over would thus make help here possible - i.e. to look up any on-line copy of the user manual or schematic and find that it may simply mean no more than a particular standard fast-blow fuse, perhaps as your replacement probably is. Let's be certain though.
You can usually check these matters out simply; there may even be a thread for your amp here, so do try the search button, using the brand/model as key words.
You can usually check these matters out simply; there may even be a thread for your amp here, so do try the search button, using the brand/model as key words.
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Sorry for the late reply , the amp in question is a wharfedale 2050a, not much about them on the net I'm afraid. It seems to be working OK with the new fuses but I just wanted to make sure.
OK, Plan B:
Look carefully at the fuse. I'll take a guess that it's a standard glass tube type with a fine wire up the middle, soldered to each plated end cap. This a standard type and measures either 1.25" long by .25" diameter (3AG type) or 20mm long by 5mm diameter (M205 type) These are typical types found in audio and general electronic equipment everywhere.
However, occasionally , designers fit exotic varieties of these with little beads of alloy metal on the wire or wriggle wire to slow the failure or a little spring inside to tension the wire and make it fail more rapidly. These are not normally seen but you never know what was the plan and these can be hard to find. The point is, that if your fuse was rated 3 amps with a fast blow type, it could act like anything from a 2 -5 amp rating if not of similar plain construction.
Having said all that, what did you find of the original type and your replacement that looks different? Next, the obvious question, because everyone wants to know what caused the fuse to fail in the first place. Usually it indicates misuse of the amo or it's past the electrolytic capacitor life span and major problems are starting to appear.
This calls for replacements and these add up to quite a cost.
Look carefully at the fuse. I'll take a guess that it's a standard glass tube type with a fine wire up the middle, soldered to each plated end cap. This a standard type and measures either 1.25" long by .25" diameter (3AG type) or 20mm long by 5mm diameter (M205 type) These are typical types found in audio and general electronic equipment everywhere.
However, occasionally , designers fit exotic varieties of these with little beads of alloy metal on the wire or wriggle wire to slow the failure or a little spring inside to tension the wire and make it fail more rapidly. These are not normally seen but you never know what was the plan and these can be hard to find. The point is, that if your fuse was rated 3 amps with a fast blow type, it could act like anything from a 2 -5 amp rating if not of similar plain construction.
Having said all that, what did you find of the original type and your replacement that looks different? Next, the obvious question, because everyone wants to know what caused the fuse to fail in the first place. Usually it indicates misuse of the amo or it's past the electrolytic capacitor life span and major problems are starting to appear.
This calls for replacements and these add up to quite a cost.
The new fuses have a bead on the fuse wire, I am not sure about the old ones, they might have been just plain wire.
I can remember checking the fuses and there was no visual sign that the fuses had failed, the wire within the glass case was not , or at least did not look as though it had been damaged.
The fuses blew because my daughter turned the volume up full when the amp was switched off then my wife decided to play a record without checking the volume first, the result was a loud noise then nothing.
I can remember checking the fuses and there was no visual sign that the fuses had failed, the wire within the glass case was not , or at least did not look as though it had been damaged.
The fuses blew because my daughter turned the volume up full when the amp was switched off then my wife decided to play a record without checking the volume first, the result was a loud noise then nothing.
Ah, well things may be ok for now, considering the technology change from modern memory setting type volume controls to the older manual style.
I assume you have access to an electrical parts store where you will find single or 5 or 10 packs of plain fuses. It's a 50W amp from what I read on the web and these would probably use a 3 amp type. Just don't use a higher rating by more than 10% if it comes to availability options. Go with the plain wire type and enjoy, but consider the electrolytic cap condition as a project soon. It's cheaper to replace them now than have to do them. plus sundry burnt semis and resistors - maybe even bin it because its all rather hard to follow. Good luck doing it that way.
I assume you have access to an electrical parts store where you will find single or 5 or 10 packs of plain fuses. It's a 50W amp from what I read on the web and these would probably use a 3 amp type. Just don't use a higher rating by more than 10% if it comes to availability options. Go with the plain wire type and enjoy, but consider the electrolytic cap condition as a project soon. It's cheaper to replace them now than have to do them. plus sundry burnt semis and resistors - maybe even bin it because its all rather hard to follow. Good luck doing it that way.
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