advertisement


Dead Amplifier

J

jimmymcfarrell

pfm Member
The A&R Cambridge A60 that I use on a 2nd system with my computer has just given up the ghost. It was serviced with Arcam around 5 years ago and has performed faultlessly pretty much daily ever since. I know I could send it back toArcam and they'll be able to fix it, but I expect this will be the same price as the service and as I remember this wasn't at all cheap.
I changed the 3.15a fuses (the amp has 2 pairs of quick blow fuses, one pair had gone) thinking it was going to be an easy fix and that I just left the volume control cranked up and switching the amp on had taken out the fuses. Wrong; it made a very brief noise (i mean split second here) and lo and behold the same pair of fuses went again. Now it doesnt make a sound, no hiss when I turn it up really loud, no headphones but the LED power light comes on and I got voltage at the output of the transformer. Any ideas anyone where I should start looking. Also can anybody recommend anyone who may be able to repair it for a more reasonable price than Arcam, I live in the South West but dont mind posting it.
Many thanks in advance.
 
Output transistors short cct by the sound of it. Better get a professional to have a look.

Richard
 
when the output stage goes on an a60 everything else goes too.

change every transistor and electrolytic in the output stages because its easier and quicker (and cheaper) than working out which 80% has actually gone whumpf.

also keep your eyes peeled for charred resistors.
 
Replace it with another decent integrated - I recently picked up a slightly battered Technics SUV550 for £35ish, in a second hand shop in Leeds. This was a £500 integrated in its time, it works a treat and will last a few more years. Sorry to be a bit defeatist but some of this stuff is only worth mending if you want to DIY.
 
I'd have a go at it myself , its broken so have a look inside , replace what ever you can with modern equivalents output devices , transistors and capacitors etc, you could probably source all the parts for less than a repair by a so called professional. I did a similar thing with an old pioneer tuner , replaced all the caps and some other parts , sounds really good now.
 
An amps output stage is not quite as simple as a tuner though. I wouldn't really advise it for a beginner, especially if David's statement is correct - basically, if you miss one failed component during the replacement exercise you run the risk of blowing the whole stage again... There will likely be a few charred resistors that need replacing too - meaning you either need a cct diagram or ability to identify value from the good channel.

Richard
 
I have successfully repaired an A & R Cambridge A60 with blown output transistors and a small signal transistor in the past. It is not a difficult job, but it requires electronic knowledge and right equipment. Don't forget to adjust the bias after repair. A competent electronic technician should be able to repair it. Search the web and you will find information about the A60 including the circuit diagram. The main output transistors can be obtained from RS or Farnell. The small signal transistors may not be available, but you can find equilvalent easily. Good luck.
 
hifienthusiast said:
I have successfully repaired an A & R Cambridge A60 with blown output transistors and a small signal transistor in the past. It is not a difficult job, but it requires electronic knowledge and right equipment. Don't forget to adjust the bias after repair. A competent electronic technician should be able to repair it. Search the web and you will find information about the A60 including the circuit diagram. The main output transistors can be obtained from RS or Farnell. The small signal transistors may not be available, but you can find equilvalent easily. Good luck.
Click to expand...

OT, but, Hon, where's your onix page gone? I had that bookmarked... :)
 
well you can actually source all the parts for a A60 for less than £100 ,those that actually need replacing ..... about £20. I doubt the repair bill will be less than that.
 
its a bit special this A60, its an AP spec one, pre out / power amp in connections via aux socket to enable it to be used with external power amps, active crossovers etc. I've got the matching SA60 power amp with active crossover board and the correct ARC speakers; and as Ive only seen 1 AP spec one for sale in the last 5 years I'm going repair it. I've got the service manual and a mate whos a bit handy at electronics so I should probably give the repair a go. But maybe it was about time it had a service............
 
...and dodgy electrolytics may have helped it to fail :)

Good luck, try and post some pictures of the internals!

Richard
 
You must log in or register to reply here.


advertisement


Back
Top