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28-Jan-2018, 16:03
(This post was last modified: 29-Jan-2018, 11:13 by SquiggFSM.
Edit Reason: Clarification
)
Hi Folks
I’m getting loud electrical hum from the sub pre out while the unit’s are in standby mode, loud enough to trigger the sub to turn on, and stay on. When you turn the units on, the hum goes away. It’s the same for the master and the slave outputs. Anyone got any thoughts?
440 Pro Core Infinity
2.1.0 + 12.1.2
PowerSoundAudio S3000i Sub
Thanks in advance
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Well DOS 2.2.0 beta12 + 12.2.6 didn't fix anything, still got the same problem
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What happens if you unplug the cable at the amp end when you have hum? Does the hum go away?
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Roon, ROCK/Audiolense XO/Music on NAS/EtherRegen/RoPieee/USPCB/ISORegen/USPCB/Sound Devices USBPre2/Tannoy GOLD 8
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I had exactly the same problem that you described. Devialet on - no hum from the subs, off - hum from the subs. Also, no ground pin on my subs.
To cut a long story short, I noticed that moving the interconnect going to the subs changed the volume of the hum from the subs. These are good quality $600 interconnects (Zcable Live5) I had used with a lot of different gear and never had such an issue. I'm quite certain that these interconnects are not shielded.
I changed them to coaxial interconnects from Canare (and since then Oyaide) and the hum is gone for good. The first interconnects definitely picked up the noise, I just don't know why that didn't happen when the Devialet was on. I have a strong feeling that it is the same problem in your case.
Win10/HQPlayer / Roon - Uptone Audio Etherregen switch / SOtM-SMS-200 ultra with clock input - Mutec REF 10 clock for the switch and the streamer - Denafrips GAIA DCC - Devialet D800 - YG Acoustics Carmel - Dual Elac SUB-2090
power supplies: Uptone JS-2, SOtM SPS-500
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10-Feb-2018, 23:40
(This post was last modified: 10-Feb-2018, 23:54 by ogs.)
If this is 'normal' hum, then it is because the cable (and hence the subwoofer input) is not grounded when the Devialet amp is off or in standby, i.e. the Devialet disconnects ground of the RCA rather than creating a short between signal and ground. If you disconnect the cable(s) and touch the signal pin without touching the sleeve of the plug you'll probably get a similar (not identical) hum in the subwoofer. As soon as you touch the metal on the sleeve hum will be much weaker or go away completely.
The other type of hum can , as zdenes says, be created by the cable itself. The input circuit of the subwoofer is then triggered into an unstable mode. This is actually not hum, but a sort of oscillation in the input circuitry where the cable acts as a kind of antenna - when it is unterminated at the amplifier end. A different cable can help here.
EDIT. keeping the ground connected and disconnect the signal pin in the amplifier could also work. Either way it is something Devialet needs to fix
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Roon, ROCK/Audiolense XO/Music on NAS/EtherRegen/RoPieee/USPCB/ISORegen/USPCB/Sound Devices USBPre2/Tannoy GOLD 8
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Were you getting the hum before the CI upgrade?
Roon, Rega P9 + Dynavector XX2Mk2 > 440 Pro > Sonus Faber Guarneri Evolution
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I think zdenes above is using the D800. He also describe hum in his post. So yes, the hum is probably there even before the Pro upgrade
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Devialetless!
Roon, ROCK/Audiolense XO/Music on NAS/EtherRegen/RoPieee/USPCB/ISORegen/USPCB/Sound Devices USBPre2/Tannoy GOLD 8
250 Pro CI, MicroRendu(1.4), Mutec MC-3+USB