I had a party on Friday and my beloved Cambridge Audio A5 Amplifier died. it got very hot so i turned it off and left it, now it wont turn on at all. i opened it up checked the fuses they all seem to be fine apart from a few, which have a squiggly shaped wire? however this could be what it should look like i have no idea. please help your sincerely Holden Wright
Cambridge amps are not party amps unfortunately. They have poor protection circuitry and inadequate heatsinking.
If there is no signs of life at all then I concur with Sakis, the transformer has probably packed in.
The official service agent for these amps in the UK is Richer Sounds. You may find they charge more than it is worth, however...
If there is no signs of life at all then I concur with Sakis, the transformer has probably packed in.
The official service agent for these amps in the UK is Richer Sounds. You may find they charge more than it is worth, however...
A new transformer will be between £12 - £15 from Rapid Electronics or similar. However if you have no experience of electronics then you may be safer to get some who does know to replace it. But you need to test it first or you may waste your money. It could be something else.
Pity I am not nearer Brighton, I would have offered.
Pity I am not nearer Brighton, I would have offered.
i tested it using a multimeter, it is the transformer
from your advice i found this on rapid electronics
http://www.rapidonline.com/Electron...mers/Encapsulated-toroidal-transformers/72657
however this only has 4 out put wires mine has 6, also i would have no idea whether this transformer meets all the right criteria.
from your advice i found this on rapid electronics
http://www.rapidonline.com/Electron...mers/Encapsulated-toroidal-transformers/72657
however this only has 4 out put wires mine has 6, also i would have no idea whether this transformer meets all the right criteria.
Unfortunately the schematic I have is for the A500 and doesn't show how the primary side of the transformer is connected.
If you can take a picture of the unit with the top off that would help. Also measure the original transformer's diameter and height. If memory serves they're only 120VA units in these amps.
The original transformer should have a total of 5 wires - 2 primary wires which are blue and brown, and 3 secondary wires coloured red, yellow and orange. (it's possible the colours of the secondary wires are different)
The type of transformer Cambridge use is called a centre-tapped secondary. This is why there are only 3 wires - the wire that goes to the middle of the capacitors is the centre tap. The transformer you are looking at on Rapid has two seperate secondary windings. This can still be used, all it means is that two of the wires must be joined to form the centre tap.
If you can take a picture of the unit with the top off that would help. Also measure the original transformer's diameter and height. If memory serves they're only 120VA units in these amps.
The original transformer should have a total of 5 wires - 2 primary wires which are blue and brown, and 3 secondary wires coloured red, yellow and orange. (it's possible the colours of the secondary wires are different)
The type of transformer Cambridge use is called a centre-tapped secondary. This is why there are only 3 wires - the wire that goes to the middle of the capacitors is the centre tap. The transformer you are looking at on Rapid has two seperate secondary windings. This can still be used, all it means is that two of the wires must be joined to form the centre tap.
the picture you posted is not from any a5/500 or an a300/a4 not sure about the a1 but i doubt it,that i've ever seen, jayce is right the a5/500 has got a center tapped transformer to replace it with the one from rapid you need to take the power amp board out look at where the center wire of the 3 that connect to the power amp board then look for a solder sealed hole that is on the same trace as the middle wire which is 0v or ground(should be right next to it) and solder the second 0v wire from your transformer to there.
that is if you have an a5 which by the picture it dosent look like you have, im inclined to think that it is one of there later amps? or someone's taken the innards out of a newer cambridge and put it in an a5 chassis.
on further reflection of the provided picture, on the very right hand side of the picture there are 2 components with six pins each that i can see, near the top, and one at the bottom, does anyone else think that these are chipamps?
chris
that is if you have an a5 which by the picture it dosent look like you have, im inclined to think that it is one of there later amps? or someone's taken the innards out of a newer cambridge and put it in an a5 chassis.
on further reflection of the provided picture, on the very right hand side of the picture there are 2 components with six pins each that i can see, near the top, and one at the bottom, does anyone else think that these are chipamps?
chris
Could be LM3886 based. Here is a link to the 340A amp. Scroll down to get pics.
However, whatever the chips are doesn't get over the problem of identifying where he should connect the secondaries.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=131847&perpage=25&highlight=&pagenumber=3
However, whatever the chips are doesn't get over the problem of identifying where he should connect the secondaries.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=131847&perpage=25&highlight=&pagenumber=3
This isn't an A5 then
If I had to guess, the 6 taps mean there is a 35-0-35 winding for the power amp, and a 15-0-15 one for the preamp (there appears to be two voltage regulator IC's at the bottom).
At any rate, the transformer is a custom part. You won't be able to get one from anywhere other than Cambridge Audio. On the other hand, I would be very surprised if the transformer is actually faulty.
If I had to guess, the 6 taps mean there is a 35-0-35 winding for the power amp, and a 15-0-15 one for the preamp (there appears to be two voltage regulator IC's at the bottom).
At any rate, the transformer is a custom part. You won't be able to get one from anywhere other than Cambridge Audio. On the other hand, I would be very surprised if the transformer is actually faulty.
A300 Transformer - temperature fuse
Had a Cambridge A300 pack up. Primary transformer coil was open circuit. Ordered a new one from Richer Sounds, cost £28 incl VAT and delivery.
Got curious so took the old one to bits to find where the open circuit in the primary windings was. Found it quite quickly. To my surprise (I'm a noobie to this stuff) I found a 136 deg C one-time thermal fuse in there. Clearly it had got quite hot and given out.
Works nicely now with the new transformer.
Had a Cambridge A300 pack up. Primary transformer coil was open circuit. Ordered a new one from Richer Sounds, cost £28 incl VAT and delivery.
Got curious so took the old one to bits to find where the open circuit in the primary windings was. Found it quite quickly. To my surprise (I'm a noobie to this stuff) I found a 136 deg C one-time thermal fuse in there. Clearly it had got quite hot and given out.
Works nicely now with the new transformer.
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