Dear all,
good afternoon, I'm Matteo, I wrote in this forum a couple of years ago, when I restored a wonderful AU-X11, which is being used on a daily basis since then.
I thought you might be interested to a last work I did; since 1 year, the amp developed the following issue (well, I'd say 'warning'): when powered on, led protection blink for 4-5 secs, then speaker relay click. After that, speaker relays disengage, and engage again, sometimes with annoying popping noises also; all this for about 2-3 minutes, when the amp finally settles correctly and plays music.
I found that this was due to the power relay (it's a 2-channels 24V - 250V), which is mounted in the 'power supply - protection' board (power relay, not speaker relays). The board is on the bottom of the amp, it's necessary to put the amp upside-down in order to access it.
As contacts were dirty (or maybe relay mechanics was not in full working order, also), it was taking a while to fully engage with low resistance between contacts; meanwhile, each and every fluctuation of voltage, due to contacts settling, resulted in protection to disconnect / connect speakers. I remember I cleaned those contacts 2 years ago with sandpaper; this demonstrates that it's far better to replace the relays, than trying to clean them: it won't last for long.
So, one of the few items which I didn't replace when I restored the amp was faulty
After I replaced the relay, everything is going wonderfully and smootly ! I replaced the HA12002 integrated circuit also, but this was not the cause of the malfunction.
That's all ... thank you very much to everybody !
Matteo
good afternoon, I'm Matteo, I wrote in this forum a couple of years ago, when I restored a wonderful AU-X11, which is being used on a daily basis since then.
I thought you might be interested to a last work I did; since 1 year, the amp developed the following issue (well, I'd say 'warning'): when powered on, led protection blink for 4-5 secs, then speaker relay click. After that, speaker relays disengage, and engage again, sometimes with annoying popping noises also; all this for about 2-3 minutes, when the amp finally settles correctly and plays music.
I found that this was due to the power relay (it's a 2-channels 24V - 250V), which is mounted in the 'power supply - protection' board (power relay, not speaker relays). The board is on the bottom of the amp, it's necessary to put the amp upside-down in order to access it.
As contacts were dirty (or maybe relay mechanics was not in full working order, also), it was taking a while to fully engage with low resistance between contacts; meanwhile, each and every fluctuation of voltage, due to contacts settling, resulted in protection to disconnect / connect speakers. I remember I cleaned those contacts 2 years ago with sandpaper; this demonstrates that it's far better to replace the relays, than trying to clean them: it won't last for long.
So, one of the few items which I didn't replace when I restored the amp was faulty
After I replaced the relay, everything is going wonderfully and smootly ! I replaced the HA12002 integrated circuit also, but this was not the cause of the malfunction.
That's all ... thank you very much to everybody !
Matteo