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Post by sycraft on Jun 15, 2016 15:04:31 GMT -5
Do you get better SNR on the balanced or unbalanced inputs?
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Post by garbulky on Jun 15, 2016 15:11:49 GMT -5
The gen 3 isn't a fully balanced amp. So some of the distortion reductions don't occur in this. But balanced XLR is the superior connection. Not sure if you'll notice an audible difference.
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Post by Gary Cook on Jun 15, 2016 15:43:15 GMT -5
In the real world it depends on how much of the N is getting into the amplification circuit via the interconnect. A balanced interconnect might help, particularly if it's a long run and/or it's a noisy (electronically) environment. If it's a short run and not a lot of interference present then my experience has been that there is no discernible difference.
Cheers
Gary
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Post by AudioHTIT on Jun 15, 2016 15:45:18 GMT -5
The gen 3 isn't a fully balanced amp. So some of the distortion reductions don't occur in this. But balanced XLR is the superior connection. Not sure if you'll notice an audible difference. Or put more accurately, the single wide blades currently available for the Gen 3 are not fully balanced. |
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Post by sycraft on Jun 15, 2016 17:23:27 GMT -5
On the Gen 2 the XLR inputs have audibly more noise than the unbalanced inputs. Wondering if it is the same here, particularly since they state SNR on the unbalanced inputs.
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Post by garbulky on Jun 15, 2016 18:29:04 GMT -5
On the Gen 2 the XLR inputs have audibly more noise than the unbalanced inputs. Wondering if it is the same here, particularly since they state SNR on the unbalanced inputs. What do you mean audibly more noise? Something tells me it's your XLR cables here. Sometimes some cables do worse than others. Some orientations of cables also do worse than others. Like if they are layed a certain way on top of each other. The XLR inputs on say an XPA-1 gen 2 is pretty quiet. I don't think there is a case where the connections themselves yield worse noise compared to RCA. |
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Post by sycraft on Jun 16, 2016 0:11:38 GMT -5
I mean I have very sensitive speakers, which I'm very close (4 feet) to, and I can hear noise at idle, even with no input hooked up. When I flip the switch to unbalanced, the noise level drops a bit, 3dB maybe. This happens cables, or no. I do not have audible noise from my Rotel RB-1050 which is unbalanced only. An XMC-1 is what it gets hooked to.
With regards to cables I use Belden 1505F for unbalanced cables, EWI Starline for balanced. Three feet long from the XMC-1 to the XPA-5 and RB-1050. I do not think they are an issue, particularly since the noise is present with inputs disconnected.
I'm looking at a Gen 3 to try and solve the noise issues. This was a general technical question, more for the Emotiva people since they list the SNR specs on the unbalanced inputs.
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Post by goodfellas27 on Jun 16, 2016 0:31:26 GMT -5
I don't have noise problems with xmc and xpa7. I am using XLR since you get better VRMS and better noise tolerance versus RCA.
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Post by Gary Cook on Jun 16, 2016 0:35:29 GMT -5
Since you have an XMC-1 as the source I'd strongly suggest utilising a quad discrete power amp with balanced (XLR) interconnects, that will give you a fully balanced circuit all the way through. At the moment in the Emotiva range that is limited to XPA-1 Gen 2's.
Cheers
Gary
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Post by sycraft on Jun 16, 2016 1:12:40 GMT -5
Their monoblocks are beyond what I am willing to pay for amps. Were I to pay that much, I'd get Rotel or ATI amps since both of those I've verified as quiet.
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Post by Gary Cook on Jun 16, 2016 1:48:37 GMT -5
I'm having a feeling that we have had this discussion before, I can verify that my XPA-2, XPA-3, XPA-5, XPA-1L's and XPA-100 are all quiet too. Dead quiet, even with an ear up to the speaker. Not sure why yours isn't. That's was with a USP-1 with short (750 mm) RCA interconnects and now an XSP-1 with long (5 metre) XLR interconnects.
After all you have an XMC-1 that features quad differential and balanced circuitry and utilising XLR connections to a power amp similarly endowed would complete a technically noiseless system. Worth keeping in mind that power amplifiers last for years, decades even, as they don't go out of date, get superseded by technology etc. So I have always spent more on my power amplifiers than I have on processors which have to be replaced far more frequently.
Cheers
Gary
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Post by Axis on Jun 16, 2016 4:23:37 GMT -5
I know this is off topic but there were many critics of the Gen 3 power supply before it's release.
Are there any reports of the Gen 3 switching power supply creating radio frequency noise ?
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Post by dwaleke on Jun 16, 2016 9:09:21 GMT -5
I mean I have very sensitive speakers, which I'm very close (4 feet) to, and I can hear noise at idle, even with no input hooked up. How sensitive are your speakers? |
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Post by Axis on Jun 16, 2016 9:59:03 GMT -5
Do you get better SNR on the balanced or unbalanced inputs? Waiting on KeithL to answer this. I have a feeling that the answer may be yes but not that you will hear it on Emo gear.  |
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KeithL
Administrator 
Posts: 10,273
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Post by KeithL on Jun 16, 2016 11:36:41 GMT -5
As far as the XPA Gen3 amplifier itself, the unbalanced inputs are a few dB quieter than the balanced inputs (because the balanced inputs are going through one more stage on the way in). However, the difference is only a few dB - and both inputs are pretty quiet - so most people may not notice the difference. However, as a few people have already noted, your results may depend on other factors. (Balanced connections are much more immune to picking up noise so, if you're in a noisy environment, or have very long cable runs, then balanced connections may end up being quieter for you.)
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Post by Axis on Jun 16, 2016 14:15:09 GMT -5
Ask again, is there any noise from the XPA Gen 3 ? I bet they are dead silent for both outputs just like every Emotiva amp made and that switching power supply that was said to be a source of noise that would be the end of Emotiva amps is not even there. I remember all kinds of folks saying they would never own a XPA Gen 3 because it would have noise. Where are all the reports of noise from the new power supply ?
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Post by gzubeck on Jun 16, 2016 15:06:03 GMT -5
Axis, most people were concerned about the longevity of a switching power supply versus the linear. If the linear will last 10-15 years on average versus 5-7 years for switchable then why would i want to buy that. If emotiva wants to warrantee their product for ten years on the switchable power supply then thats what will produce real sales. I have no problem buying their products with the linear power supplies. The switching power supplies would make me want to be cautious to hear about the failure rates first.
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Post by sycraft on Jun 16, 2016 15:14:02 GMT -5
I would hope the new PSU would lead to less noise. SMPSes are very low noise when done right. That aside, the lowest noise amp in history, the Benchmark AHB2, uses a SMPS. I don't need to drop the noise level much from the Gen 2, it is audible, not loud, but it is audible. So I'm hoping the Gen 3 is quiet enough to be totally perceptually silent.
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Post by gzubeck on Jun 16, 2016 15:21:53 GMT -5
I would hope the new PSU would lead to less noise. SMPSes are very low noise when done right. That aside, the lowest noise amp in history, the Benchmark AHB2, uses a SMPS. I don't need to drop the noise level much from the Gen 2, it is audible, not loud, but it is audible. So I'm hoping the Gen 3 is quiet enough to be totally perceptually silent. Use a smaller transformer and use a larger array of panasonic caps(more capacitence) in the power supply and it will be quiet quiet quiet..... |
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Post by Gary Cook on Jun 16, 2016 15:37:03 GMT -5
In the quest for an answer, maybe we should get more specific. What frequency is the noise that you hear?
Cheers
Gary
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