Hello to everyone. I'm having troubles with an old Rega Elicit MK1. It sounded so nice and it was a robust system, since it met my grandfather. Actually not himself, but his illness. He's not able to remember things, he probably made a misconnection... so, I thought, that's a bit of a complex repair... and I'm not sure if it's possible... but I'd like to make him listen to his collections again, and here I am.
Diagnosis: The amp was dead, no power. So I opened it, and found blown fuses, and quite some damage.
I took a photo of the incriminated section, which is on the power side of the left channel. Ouch!
Following the schematics I made some basic tests with a multimeter and a transistor tester. I've found and replaced a list of parts that were damaged, which include the finals (2SC2922 and 2SA1216), the BD139 and 140 which were totally blown (T14, T17, T18, T13, T21, T22) as the 100uF capacitor C30, the big resistors R11 and R12 (blown!) as well as R18, R36, and R49, and some zener diodes. T48 on the -39.5V was also tested bad, but with no visible damage.
I remade some tracks that were vapourized (ouch), I tested the other small transistors too (only in the amplification section of the board), and they were all good.
Feeling quite confident I powered on the amplifier, and there was life. Connecting a speaker (the right one) revealed sound! I did a rough impedance test, I swapped the channel, it sounded amazing. hooray! You might think... 🙂
Because after some time... a POP was heard! But the amp was still on, so no fuse was triggered. I power cycled it, giving some time to cool down, thinking it was the thermal protection.
Nevermind, the music played again.
Remember I did the test in mono, because I had only the right speaker at that time. Later inspecting the other speaker (left) I found one woofer's coil stuck upwards, cooked to perfection. Replacement of the woofer done, but the internal connection of the loudspeakers' crossover was not clear to me. The loudspeakers are the Rega XEL. I can provide more detailed information if needed.
Anyway, the first stereo test was made...
Sure enough, after less than 2 minutes, there was the POP disconnection sound, much louder at the left speaker (the one that I repaired), and the sound went mute. Power cycling the system "resetted" the protection (the DC one?? I've read that the thermal protection turns the "Elicit" front LED red, but I'm not sure about more localized protections, if that was a protection at all) but the issue persisted, so I opened it again and found R36 and R49 burned again, on the left channel. Was that for the impedance of the left speaker, the one that was blown and repaired, not being high enough? Was it the crossover's fault, or the amp still has some issues?
And that's where I'm now. I also found a cold solder at LED3. That is to see the +39.5V, and it's the only led that turns on slow and turns off fast. Maybe that was only that solder joint that triggered T25, which caused the pop?
There are some big capacitor which hold a lot of charge, and don't think they'll discharge after days, like I did: you need to discharge them, I learned the hard way 🙂 but when holding charge, the finals show short?? I don't know.
Your help is very much appreciated; I'm absolutely no audio technician or expert, forgive me for the technical mistakes I made, and thank you for your patience reading all of this.
Ciao!
Diagnosis: The amp was dead, no power. So I opened it, and found blown fuses, and quite some damage.
I took a photo of the incriminated section, which is on the power side of the left channel. Ouch!
Following the schematics I made some basic tests with a multimeter and a transistor tester. I've found and replaced a list of parts that were damaged, which include the finals (2SC2922 and 2SA1216), the BD139 and 140 which were totally blown (T14, T17, T18, T13, T21, T22) as the 100uF capacitor C30, the big resistors R11 and R12 (blown!) as well as R18, R36, and R49, and some zener diodes. T48 on the -39.5V was also tested bad, but with no visible damage.
I remade some tracks that were vapourized (ouch), I tested the other small transistors too (only in the amplification section of the board), and they were all good.
Feeling quite confident I powered on the amplifier, and there was life. Connecting a speaker (the right one) revealed sound! I did a rough impedance test, I swapped the channel, it sounded amazing. hooray! You might think... 🙂
Because after some time... a POP was heard! But the amp was still on, so no fuse was triggered. I power cycled it, giving some time to cool down, thinking it was the thermal protection.
Nevermind, the music played again.
Remember I did the test in mono, because I had only the right speaker at that time. Later inspecting the other speaker (left) I found one woofer's coil stuck upwards, cooked to perfection. Replacement of the woofer done, but the internal connection of the loudspeakers' crossover was not clear to me. The loudspeakers are the Rega XEL. I can provide more detailed information if needed.
Anyway, the first stereo test was made...
Sure enough, after less than 2 minutes, there was the POP disconnection sound, much louder at the left speaker (the one that I repaired), and the sound went mute. Power cycling the system "resetted" the protection (the DC one?? I've read that the thermal protection turns the "Elicit" front LED red, but I'm not sure about more localized protections, if that was a protection at all) but the issue persisted, so I opened it again and found R36 and R49 burned again, on the left channel. Was that for the impedance of the left speaker, the one that was blown and repaired, not being high enough? Was it the crossover's fault, or the amp still has some issues?
And that's where I'm now. I also found a cold solder at LED3. That is to see the +39.5V, and it's the only led that turns on slow and turns off fast. Maybe that was only that solder joint that triggered T25, which caused the pop?
There are some big capacitor which hold a lot of charge, and don't think they'll discharge after days, like I did: you need to discharge them, I learned the hard way 🙂 but when holding charge, the finals show short?? I don't know.
Your help is very much appreciated; I'm absolutely no audio technician or expert, forgive me for the technical mistakes I made, and thank you for your patience reading all of this.
Ciao!
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Hi edomobius,
Now you know why good technicians exist. While I applaud people doing things they understand how to do, and have the right equipment and tools, you're trying to do things beyond your abilities.
I'll ask a simple question. Do want this unit to work reliably again - to spec? If so, take it to a known good technician that has the right equipment and uses parts from authorized sources. If you would like to increase the service bill, give it a shot. You may end up with e-waste and that would be a shame. You have already erased the clues they needed, and maybe used fake parts that will cause problems in the future.
Up to you.
Now you know why good technicians exist. While I applaud people doing things they understand how to do, and have the right equipment and tools, you're trying to do things beyond your abilities.
I'll ask a simple question. Do want this unit to work reliably again - to spec? If so, take it to a known good technician that has the right equipment and uses parts from authorized sources. If you would like to increase the service bill, give it a shot. You may end up with e-waste and that would be a shame. You have already erased the clues they needed, and maybe used fake parts that will cause problems in the future.
Up to you.