This is a decidedly niche. A fuse blew in the Dac I use in conjunction with my headphone amp. It occurred after restoring power to it after I had disconnected it to install some new feet to it’s underside to increase the air flow around it as it gets rather hot after an hour of use. Anyhoo I found the fuse next to the power inlet on it’s rear and discovered that the manufactures had supplied a replacement fuse inside the case for such an eventuality so I swapped them out and all is now fine and dandy once more. However being someone whose default position is to worry I would like to buy in a small supply of replacement fuses in case it decides to throw another wobbler. This begs the question that I hope some kind individual on here can help me with namely which fuses do I buy? I know the fuse is a fastblow glass fuse measuring 5×20 mm and around one end of it is embossed the following F200mAL250/ this means bugger all to me so can anyone interpret this in a way I can understand.
Also are nutjobs who replace fuses in audio kit with stonkingly expensive audiophile grade ceramic jobs as completely insane as I suspect they are?
Ta.
ATM. Glass fuses.
by 73 Comments
Hi Mr Squeezer – available from Amazon and eBay, amongst others. I’ve been trying to post a link and failing, for reasons not clear to me. Search for fastblow F200mAL250 and you’ll find them – different sizes, so check for 5x20mm
Diolch butties.
I took a look on Amazon and being confronted with a bewildering array of choices my mind flipped daddio and instantly froze that’s why I am reluctantly seeking advice here. My main concern is that if this occurs again that I would in my ignorance install the wrong fuse and end up bricking the Dac. It wasn’t cheap and not easily replaceable for me.
https://www.ebay.co.uk/itm/123470676635
This looks like the thing – fast blow, correct size, 200mA
The very ones. I shall see if I can find them on Amazon as I have an unreasonable dislike of ebay. Ta.
As Fitz says cannot post a link. Most odd.
I’ve had the same problem with Amazon links.
If you have a Prime account you need be logged out to post links.
I think it’s to do with your account security.
Sold in packs of 10 fuses. Should last you far longer than your DAC.
The ebay price is good. Slightly cheaper than Amazon.
If the fuse keeps blows one more time you need to get the amp looked at Peter otherwise bad things could happen.
Thankfully Richie my amps are seemingly fine and this particular Dac evidently has a propensity to blow this fuse if it’s powered up and down too much so my experience isn’t unknown as other owners of the same Dac have reported the problem. As I mentioned to Dai I keep my amps and Dacs permanently powered up and had only powered down this Dac and the headphone amp it’s hooked up to so I could mod the feet on it to get more air around it to help with heat dispersion. It’s fine again now and I’ve ordered some replacement fuses which I hope I never find a use for but I’ll feel happier knowing I have some to hand.
Fair enough Peter, from what you say it sounds like an intrinsic fault with the DAC.
I now keep my amp powered up but I didn’t at one time. I was in the Netherlands town of Delft visiting friends and we were in this hi-fi shop were I was buying some headphones (Grado). I got talking to the shop owner and it was he who advised me to keep my amp powered on, it does make a difference even to my ears.
👍
Found the wee blighters. Pack of fifteen for £5.99.
👍😎
Fuses only blow for a reason, so it may happen again. May be worth getting your DAC checked out to see what caused it.
Thanks Dai. After digging into this on other forums such as Head-fi and Audio Science Review it seems this particular Dac has a propensity for blowing this fuse if the power supply to the device is switched on and off too often. As I as matter of course leave my Dacs and amps powered up I hadn’t experienced this problem until I undertook this simple mod. Evidently it can be rectified with an online upgrade to the firmware but as I am sans computer nowadays I’ll just keep it powered up and keep a supply of replacement fuses handy.
Ok good
Fuses can, like any electro-mechanical device, suffer from fatigue.
“Interestingly”, the 3A fuse in the mains plug is there to protect the mains cable, not the device, from catching fire. The 200mA fuse in the DAC is to protect the primary windings of the mains transformer as per BS EN 62368-1:2014 clause 6.4.2, probably.
Interesting use of the word “interestingly…”
Clause 6.4.2 has me transfixed.
Well yes, recently I had a vintage Sony receiver that blew a fuse (after some use), I bought the correct fuse on Amazon and replaced it and it blew again immediately. Tried a 3rd one, you can guess the rest
No we can’t, stop being a big tease and cough.
Did you dim the lights?
Here’s a decoding of Fuse coding:
https://www.swe-check.com.au/pages/learn_fuse_markings.php
So “F200mAL250” means
F = Fast-blow
200mA = 0.2A hold capacity (i.e. it should pass 0.2 Amps without blowing)
L = Low Breaking Capacity (i.e. will blow at not much over 0.2A)
250 = 250 Volts (i.e. suitable for mains power)
Don’t ever swap a glass fuse for a ceramic, as the ceramic material delays the blowing. Damage to the connected equipment and/or fire could result.
Thanks Steve. You are a living breathing Rosetta Stone for this kind of arcane knowledge. It now makes sense where before all was befuddled.
When faced with these kinda situations I always replace like for like as I figure the manufacturers have done what they have done for sound reasons so mucking about with potentially risky alternatives isn’t gonna happen.
If I’m honest, that was a bit boring.
Edith. This was my hilarious reply to Fenton not Mr Squeezer.
I’ll be fu*ked if I’ll let Fents take credit for the entirety of the ennui generated by my enquiry. I demand to be considered equally boring.
How’s this for exciting, then, eh?
https://www.bbc.co.uk/news/uk-politics-66375185
You do know that I have made paintings utilising internationally accepted ideographs so that surpasses exciting and smoothly glides into the realms of the downright sexy.
I found the (somewhat belated) fit of common sense on the part of the UK government on this issue somewhat gratifying. My former employer made diesel generators, and we exported all around the world. My area of responsibility was designing the control panels, and at one stage we had three different versions of essentially the same panel, to conform with CE, CSA (Canada) & UL (USA) requirements. As you can appreciate this was a royal PITA when it came to either new product, or engineering changes to existing designs, as it basically tripled the amount of work required as three sets of drawings had to be created/amended. This was the kind of scenario facing any UK company which made products both for export & domestic consumption. They would’ve had to have their product approved twice to get CE & CA markings.
I found it both interesting and comforting. Try reading it in a shipping forecast voice. You see?
If you read it in a gruff but rotund Welsh accent you run the risk of summoning up the disgruntled shade of Richard Burton.
Too late.
Oohh I like that as well. And the The War Of The Worlds music kicks in. Marvellous.
Apprentice Borer?
I’ll take that.
An internship.
Yes, apprentices have to be paid. I only dull for free.
Free ennui! Get it while it’s dull!
Let’s kick rampant ennui and boringlessness aside.
Gaze on the beauty of the valve.
That is a trouser botheringly hot photograph.
I can feel a thread about tube rolling just aching to be unleashed.
Tubes rolled on the thighs of Cuban maidens.
Oooof!
Maybe, just maybe, reading about a blown fuse could prevent the reader from blowing a fuse themselves, albeit a metaphorical one, if they were on the verge as it were. Overcome with boredom instead. Overwhelmed with soporific waves.
Makes me wonder why Gwinny Paltrow isn’t offering up Goop certified fuses for $500 a pop. It’s a holistic wellness meditative goldmine.
How do you know she hasn’t? She probably has them in a “warm place”, waiting for the right entry to the marketplace.
Ooof! Again!
Is it a lemon entry?
A niche area, certainly…as Mr Squeezer suggested.
Thank you Dr Watson
There is, of course, the traditional solution of replacing the broken one with a bigger one which definitely won’t blow. When mains fuses used wire, a small nail could solve a number of problems.
Just wrap the blown fuse in some silver paper from inside a fag packet.
This has become very Peter Belt. Should I also offer up prayers to Yog-Sothoth whilst hopping widdershins around a small cairn constructed from magpie beaks at midnight on Walpurgisnacht?
Perhaps I should throw cats at it or only ever use it when it’s stashed in the boot of a Hillman Imp.
I think even Mr Belt drew the line at the Hillman Imp idea. Think of the length your cables would have to be…
Cables fashioned in complete darkness from mermaid’s hair by a pooka wearing sandals constructed from the bubbles found in a shot of crème de menthe.
Now, those ARE fancy cables – are they infinitely thin?
Only if you shut your eyes when eating French onion soup.
Hoffmanites scream in the darkness about capacitance.
I wondered what that racket was. I was listening to Echoes by Fire! Orchestra and wasn’t entirely certain if it was part of the musical landscape or not.
Oh, good lord, Peter Belt. Have you tried sticking half a post-it note to one of your curtains?
My curtains are entirely comprised of post-it notes. It’s so effective as a room treatment I can hear seraphim breaking wind.
I hope you have an odd number of curtains, as Mr Belt didn’t like even numbers. Although, presumably, he had two ears like the rest of us.
An old mucker of mine tried removing one of the feet from his amp and swore blind that he could hear a definite improvement but he was a Genesis fan so we made allowances.
I would draw the line at foot removal – but I have heard definite (if subtle) improvement in perceived sound quality if I stand on one leg.
If I stick a small square of foil to the boot still in contact with the earth, the difference is night and day!!
Which leg?
The big one.
I knew nothing of Peter Belt so looked him up. Instead of buying new fuses why not just put the old one in the freezer overnight or use one of his paperclips?
I’ve adhered one of his paperclips to my manly chest with nano tape as an alternative pacemaker. As I am still here I can only assume that it is working just fine and dandy.
On reflection: “Glass fuses” is a very short sentence.
Back in the old Fred Flintstone days, my first proper job was in Control Systems for steelworks. A months after successful commissioning, we had a callout from the customer, annoyed that the fuse kept blowing on one of the panels in the new system that we had installed.
I gathered together the As Built drawings, a set of spares, some fuses, and went to site to investigate.
The root cause analysis was simple – the customer had wired some extra equipment into our panel (and it looked like he had hired a plumber to do it). This was causing our fuse to blow, because it was designed to handle the power and headroom for our system, not these extras.
To get around the annoyance, they had taken the clever step of replacing the fuse with a bolt. I got the Shift Manager to come and look at it, then phoned my boss, who explained the problem back to the customer, who then removed the additional equipment and went back to the rated fuse.
As you know my old friend I live in a post-Steelworks town and I can assure you that that kind of problem solving is pretty much applied to everything from filling in potholes to child rearing.
I am glad that you did not apply the same solution to your DAC – it sometimes has unintended (if entirely predictable) consequences.
Only because I didn’t have a bolt handy. 😉
@fitterstoke you are John Wayne and I claim my £5.
I gotta big dilemma…