 Re: LFR1100 Actives hum
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Joined: Jul 2006
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OP
Founder, Axiom Upgrade Club shareholder in the making
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Isn't it strange, that with your AVR and DSP off, and the ADA to DSP cable connected, the hum is still there? But when you remove the ADA to DSP cable, the hum subsides. Oh, this is why I thought I should clarify. When you first said amp to DSP cable, singular, I assumed that meant the cable from the AVR to the DSP, since there are five cables connecting DSP to ADA. Let me try that out as well, disconnecting at the DSP all of those cables, and I'll report back.
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Re: LFR1100 Actives hum
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Joined: Jul 2006
Posts: 12,077 Likes: 7
Founder, Axiom Upgrade Club shareholder in the making
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OP
Founder, Axiom Upgrade Club shareholder in the making
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When you first said amp to DSP cable, singular, I assumed that meant the cable from the AVR to the DSP, since there are five cables connecting DSP to ADA. Let me try that out as well, disconnecting at the DSP all of those cables, and I'll report back. Yes, unplugging all of the DSP to ADA cables at the DSP gets rid of the hum completely.
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Re: LFR1100 Actives hum
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Joined: Jan 2007
Posts: 10,490 Likes: 116
shareholder in the making
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shareholder in the making
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You could unplug just one and the hum for that channel disappears. My theory stands.
House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated
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Re: LFR1100 Actives hum
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Joined: Jul 2006
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OP
Founder, Axiom Upgrade Club shareholder in the making
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The theory therefore is a parasitic, common mode noise source in the ADA that arises from the ADA's input power and is somehow impressed on one or both of the ADA's input signal lines. Is there something in the design that could solve this issue? I just know that the hum I was getting before introducing the line filter was significant, but I could live with it, while this new level of hum is going to take away all of my home theater joy until I get it resolved.
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Re: LFR1100 Actives hum
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Joined: Jan 2007
Posts: 10,490 Likes: 116
shareholder in the making
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shareholder in the making
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I really have no idea why the addition of Emotiva's filter created more hum. Did it further exacerbate the problem through some type of interaction with the ADA?
If my theory is proven true, there is definitely something in the design causing the issue and therefore when that design is improved, the issue will go away. Not a good answer I know but the first step is to investigate the theory.
House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated
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Re: LFR1100 Actives hum
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Joined: Sep 2009
Posts: 1,898 Likes: 101
connoisseur
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connoisseur
Joined: Sep 2009
Posts: 1,898 Likes: 101 |
CV are you using balanced cables?
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Re: LFR1100 Actives hum
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Joined: Jul 2006
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Founder, Axiom Upgrade Club shareholder in the making
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OP
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CV are you using balanced cables? Yes and no. I'm not getting the benefit of balanced connections since my AVR only has RCA connections. That's one reason I want a pre-pro. I do have the DSPs and ADAs connected via XLR.
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Re: LFR1100 Actives hum
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Joined: Jul 2006
Posts: 12,077 Likes: 7
Founder, Axiom Upgrade Club shareholder in the making
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OP
Founder, Axiom Upgrade Club shareholder in the making
Joined: Jul 2006
Posts: 12,077 Likes: 7 |
I really have no idea why the addition of Emotiva's filter created more hum. Did it further exacerbate the problem through some type of interaction with the ADA? I'm not sure. The first things I connected to the line filter were the DSPs, and the louder hum was evident with that first step. Next I tried the ADAs, then the AVR. Ever since the first connection to the DSPs, the hum was louder and hasn't gone down since. I think something happened, but it's not like I heard anything or saw anything disturbing when hooking it up. The only evidence I have that something happened is the louder hum.
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Re: LFR1100 Actives hum
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Joined: Jan 2007
Posts: 10,490 Likes: 116
shareholder in the making
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shareholder in the making
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Charles, I would try connecting the same channel's DSP and ADA to the filter. That way, they will both be supplied from the same potential voltage.
House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated
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Re: LFR1100 Actives hum
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Joined: Sep 2009
Posts: 1,898 Likes: 101
connoisseur
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connoisseur
Joined: Sep 2009
Posts: 1,898 Likes: 101 |
How is the sub connected? To dsp or AVR? By xlr or rca?
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