arcam alpha 7 amp

[stand]

the fuse keeps blowing ,what seems to be the problem needs help ...thanks

 

[AndrewT]

Hi,
the problem is no sound.
Try a six inch nail to replace the fuse and make a good job of it. Now you'll hear a sound!

Seems like you need the help of a technician to sort this out.

 

[stand]

thanks for your kindness ..i just want to know the honest answer for this...so if you dont know dont answer..

 

[Netlist]

stand,

We need a bit more info is what Andrew meant.
What fuse is blowing, the mains- or, if any, the output fuse? How does the fuse look? Blackened, or is the wire just melted?
Some history would be nice too. Did you party with the amp? Was it lying there for years unused...
What have you already done and do you have some basic measuring instruments available?

/Hugo

 

[jaycee]

At a guess, the output mosfets have blown on one channel. This seems to be a common thing to happen to these amps, especially if pushed too hard or abused. However that's not a definite solution as this amp has only the mains fuse protecting it, so a fault anywhere in the amp could cause the fuse to blow.

If you have some experience with electronics, then we can suggest a few things. If however, you don't, then I advise you send it back to Arcam for repair.

 

[stand]

sorry about that....i just had this amp for about a week and using it for about 10 minutes when it happens ...i used to build my own gear just amp and pre amp (tubes) with diagram,i also do some minor troubleshooting.,,,in my country (philippines).you can easily get spare parts i dont know here in england.

 

[pinkmouse]

Drop an email to Arcam customer support. They are very friendly and helpful, and will send you the schematic for free and/or give you a quote for a factory repair.

 

[stand]

does anyone knows where to get this IRF 540 FETs ,and do i need to replace all of it? ....

 

[AndrewT]

Hi,
does the Arcam Alpha have an Nchannel quasi complementary output stage using irf540 vertical FETs?

If the answer is yes, then these are the cheapest and easiest to obtain FETs around.
And a second YES, replace all those in the dead channel.

 

[big jim]

Hi you can get the fets from maplins

i have many times

good luck. jim

 

[jaycee]

You can get them from Maplin but it depends what branch of Maplin you go to - they will also want too much money, IMO.

The last time I repaired an Alpha 7 I bought my IRF540's on eBay. You can also get them from Rapid.

AndrewT, yes the Alpha's are all pretty much the same... rather flimsy heatsinking too if you ask me. I've got the service manual if you'd like it.