Hi,
SX-590 receiver works perfectly in every way other than when set to phono.
With nothing connected other than power and speakers, when phono is selected I get hum when I turn the volume up (it is silent with volume at minimum) and when I turn it up more than a quarter of the way around, the woofers in the speakers start to pulsate.
When a turntable is connected it is exactly the same and when I am listening to music through the turntable, the sound is good but you can hear the hum in the background or when the song ends.
So, this is definitely a problem with the phono part of the receiver which needs repairing. All controls have been cleaned so it will be components replacement that's necessary.
Is this a known fault? Does anyone know which components will need to be replaced? Any help much appreciated.
Thanks,
Geoff.
SX-590 receiver works perfectly in every way other than when set to phono.
With nothing connected other than power and speakers, when phono is selected I get hum when I turn the volume up (it is silent with volume at minimum) and when I turn it up more than a quarter of the way around, the woofers in the speakers start to pulsate.
When a turntable is connected it is exactly the same and when I am listening to music through the turntable, the sound is good but you can hear the hum in the background or when the song ends.
So, this is definitely a problem with the phono part of the receiver which needs repairing. All controls have been cleaned so it will be components replacement that's necessary.
Is this a known fault? Does anyone know which components will need to be replaced? Any help much appreciated.
Thanks,
Geoff.
Seems like a bad electrolytic capacitor, probably in the shared power supply for the phono stage
Agreed. I would replace C219? (47µ/50) in the phono pre (maybe 47µ/63, and if you can fit a 100µ/63 that won't hurt), as well as C404-406 in the responsible power supply section (220µ/50, which is a bit tight for some of them - I would use at least a 63 V part). As always, use some decent quality caps.
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Hi,
I have the same problem, but I also had a 33 ohm resistor that was broken in the 41V power part. Right now the amplifier is "motorboating" if I turn up the volume when in Phono mode. I have exchanged a lot of capacitors in the left channel, because it is only in the left channel where I can trigger the problem by tapping at different solder points on the PCB.
My next step is to exchange all 200uF capacitors, because they are actually dealing with 51V and they are only specified 50V. The motor boating is in both channels.
I have the same problem, but I also had a 33 ohm resistor that was broken in the 41V power part. Right now the amplifier is "motorboating" if I turn up the volume when in Phono mode. I have exchanged a lot of capacitors in the left channel, because it is only in the left channel where I can trigger the problem by tapping at different solder points on the PCB.
My next step is to exchange all 200uF capacitors, because they are actually dealing with 51V and they are only specified 50V. The motor boating is in both channels.