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Post by rockguitar on Jun 16, 2010 8:00:51 GMT -5
If the XDA-1 DAC is also used to replace the USP-1 pre-amp (as is in my setup) I would connect my computer via USB. What would be the best way to connect the Emotiva ERC-1 CD player to the XDA-1?Computer source - USB input to DAC ERC-1 CD - ?? input to DAC Mike I believe that Coax is better than Optical, but know nothing about XLR or what so ever..... Any other thoughts by the more technical forum members / experts ? Hard to say what’s better without testing it. For the ERC, there's only coax and optical digital outputs. The XLR would only be relevant if you are connecting that to a separate pre-pro. Optical has the advantage of electrically isolating the components from each other, so you prevent ground loops -- you know that sound like humming. But I've had good success with making my own coax cables. Optical -- I buy. Based on what Wes Philips, Stereophile writer [former??] and web reviewer, has written about on the past, you may notice a difference in the sound based on the length of the cables, either optical or coax, with longer sounder better, paradoxically. The argument for the longer cables, other than making the cable companies more money, is that the reflections of the signal are supposed to be reduced. Wes recommended using 2 meter (6 feet) long digital cables as a good choice. I have not tested this recommendation -- so I am just letting you know what's been written about it. When I had a Benchmark DAC1, I compared different cables and did not notice much difference between coax and optical when the cables were decent – though I did not try the pricey ones. I have heard differences between grades of optical cable -- the cheapo optical cables did not fair too well -- they are usually made of plastic. If you go the optical cable route, I highly recommend getting glass fiber optical cable with polished ends. I bought mine on ebay. Coax cables have the advantage of being easy to make and a decent coax cable can be made relatively inexpensively.
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Post by rockguitar on Jun 16, 2010 8:27:56 GMT -5
Guys, I just saw this posted on the www.emonatics.com/XDA-1.shtml" Output voltage: 1V nominal, 12V peak
A little more detail from Lonnie regarding the quality and finesse of the XDA-1 design: The DAC used in the XDA is the AD1955 which is the same DAC as used in the ERC-1, But the real magic is in the analog drive stage after the DAC. In the ERC it has a single stage drive where the XDA uses a Dual Differential input stage with cross linked current sources, Darlington VAS stage and Darlington output stages. The discrete output stage can easily produce in excess of 2 amps of current and swing in excess of 12v. So it will completely take all cables out of the equation. Smiley Face" It wasn't it in the earlier post that pasted from the Emonatics site. Thought it would be interesting. By taking all the cables out of the equation, that purple highlight should only refer to the cables from the DAC to the pre-amp or amp. Based on the specs I highlighted in red, it looks like it should have plenty of ability to directly drive an amp -- though that 12 Volts looks like a peak voltage, not RMS. Note that it only takes about 1 Volt RMS to drive an amp to full rated power. For comparison, the USP-1 outputs up to 9 Volt RMS, so it can drive the input of an amp with well more than enough voltage.
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Post by sanjaygolf on Jun 16, 2010 8:41:45 GMT -5
"The discrete output stage can easily produce in excess of 2 amps of current and swing in excess of 12v. So it will completely take all cables out of the equation"
Is this why I hear no difference between cables using my ERC-1?
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Post by jasonb on Jun 17, 2010 1:30:45 GMT -5
"The discrete output stage can easily produce in excess of 2 amps of current and swing in excess of 12v. So it will completely take all cables out of the equation" Is this why I hear no difference between cables using my ERC-1? What I make out of this is that the XDA-1 is a serious "stand-alone" pre/pro that directly can connected with amp(s) with enough power(voltage).... edit: but it's possible that I did not understand it (can somebody explain if I am wrong) ? IMO when you connect it with the analog input of a preamplifier there will be differences using different cables. Using the ERC-1 as transport to a DAC/processor I do not know if there will be a difference....
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Post by rockguitar on Jun 17, 2010 7:52:41 GMT -5
"The discrete output stage can easily produce in excess of 2 amps of current and swing in excess of 12v. So it will completely take all cables out of the equation" Is this why I hear no difference between cables using my ERC-1? Assuming you are referring to the RCA or XLR cables only, the ERC-1 doesn't have as strong of an output stage as the XDA as quoted above. If I remember correctly, Lonnie stated before it can swing 1 amp of current and 7 volts, that's quite a bit lower than the 2 amps of current and 12 volts of the XDA. So if you are going to apply that kind reasoning to the ERC-1, it would raise the question whether it would have more cable interactions than than the XDA. To be honest I don't think Lonnie's explanation was complete. I think what he was getting at is that the output stage of the DAC was designed very robustly and thus any losses in the signal due to the cables will be minimized. I don't really like to discuss cables much on forums because that's one where I've seen flames start up. But there are measurable differences in cables and I've heard differences in cables but a lot of times it depends on the resolution of the system. If anything in the system hides or masks differences in the final sound, then you are going to hear less differences with cables. I keep referring back to the Benchmark DAC-1, but that's when my stereo system was the simplest and had the DAC-1 connected directly to the power amp. In that scenario, I clearly heard differences between using DIY silver interconnects and regular copper interconnects. The DIY silver ones stayed, because they were the most transparent sounding. I refer you guys to for a highly developed description of cables here www.hometheaterhifi.com/cables-products-menu-column3-48/749-emotiva-x-series-av-cables.html?start=2The silver interconnects were my slightly modified version of the original of the Chris Venhaus DIY design. www.venhaus1.com/diysilverinterconnects.htmlThese sound great to my ears and I should get around to build a few more pairs, as soon as I recover from being sick.
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Post by BillBauman on Jun 17, 2010 15:08:03 GMT -5
I think what Lonnie is saying about taking cables out of the equation is a bit overstated. He's saying that the preamp section, or the analog output phase, is capable of driving enough current that it doesn't matter how you plan to implement the XDA-1. It doesn't mean that it equalizes all cables to being identical. I'm in agreement with rockguitar that discussing cables gets to be a hot subject sometimes, so that's all I'll say, just to clarify my view on Lonnie's comments.
As far as digital vs. coax, that's been discussed on another forum post. If you can find it, I did a write-up on the merits of both and why I'm generally, unless massive interference is an issue, a supporter or coax over most consumer-grade optical implementations.
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Post by khonfused on Jun 18, 2010 15:57:52 GMT -5
So I could use the xda-1 as a pre/pro and connect it directly to my Xpa-5. How would I integrate the xternal dac into my existing HT setup? I am using an avr as processor connected via preouts to the xpa-5 right now. The main speakers would be used for 2ch music listining with the xda/xpa combination and also as main speakers in the ht setup.
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Post by Topend on Jun 18, 2010 16:11:58 GMT -5
So I could use the xda-1 as a pre/pro and connect it directly to my Xpa-5. How would I integrate the xternal dac into my existing HT setup? I am using an avr as processor connected via preouts to the xpa-5 right now. The main speakers would be used for 2ch music listining with the xda/xpa combination and also as main speakers in the ht setup. Connect the DAC to an aux in RCA on your receiver and leave the volume on the DAC at max.
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Post by khonfused on Jun 18, 2010 16:32:41 GMT -5
yes, that's one possibility. but it is not the supposedly best connection regarding sq according to Lonnie, which is the direct connection to the amp. Won't the avr in between have a negative effect on sq?
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Post by ajani on Jun 18, 2010 17:12:11 GMT -5
yes, that's one possibility. but it is not the supposedly best connection regarding sq according to Lonnie, which is the direct connection to the amp. Won't the avr in between have a negative effect on sq? I'd connect the DAC to the XPA-5 via balanced and connect the AVR to the XPA-5 via RCA. That way the DAC's sound is not degraded by passing through the AVR.
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Post by Topend on Jun 18, 2010 17:19:15 GMT -5
yes, that's one possibility. but it is not the supposedly best connection regarding sq according to Lonnie, which is the direct connection to the amp. Won't the avr in between have a negative effect on sq? I'd connect the DAC to the XPA-5 via balanced and connect the AVR to the XPA-5 via RCA. That way the DAC's sound is not degraded by passing through the AVR. That is a thought. In my case I will connect the XDA-1 to my UMC-1 so I play listen either in my main room or outside with zone 2. When I do get the XDA-1 I will test it connected directly to my XPA-2 to hear how good it sounds through my main speakers. Cheers, Dave.
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Post by Topend on Jun 18, 2010 17:20:14 GMT -5
yes, that's one possibility. but it is not the supposedly best connection regarding sq according to Lonnie, which is the direct connection to the amp. Won't the avr in between have a negative effect on sq? Yes I know, I was just addressing the question.
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Post by rockguitar on Jun 18, 2010 19:45:08 GMT -5
yes, that's one possibility. but it is not the supposedly best connection regarding sq according to Lonnie, which is the direct connection to the amp. Won't the avr in between have a negative effect on sq? I'd connect the DAC to the XPA-5 via balanced and connect the AVR to the XPA-5 via RCA. That way the DAC's sound is not degraded by passing through the AVR. That sounds like a pretty good plan to me. The only thing is if the amp receives a signal on both the RCA and XLR inputs at the same time, what happens? Which amp input is the default? It shouldn't be a big deal as you can always turn off whatever input you are not using. When you compare an AVR preamp section vs. the DAC directly to the amp section, you should see a much bigger gain in clarity and transparency via the DAC directly. Most AVR's don't have a great stereo preamp section in comparison. From Lonnie's previous comments he was taking aim at bettering the performance of a well known DAC, unnamed of course, so my hopes are high as to what the XDA can do.
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Post by rockguitar on Jun 18, 2010 19:49:15 GMT -5
You could also do it the hard way, plug in whatever you want directly into the amp It's really too bad the HT bypass didn't make it into the design. One last option is to use right in front of the amp that allows you to select between sources (one for the receiver, one for the DAC). This could be done e.g. with a passive preamp that switches between sources.
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Post by Topend on Jun 18, 2010 21:02:16 GMT -5
That sounds like a pretty good plan to me. The only thing is if the amp receives a signal on both the RCA and XLR inputs at the same time, what happens? Which amp input is the default? There is a switch on the back of the amp to select balanced or unbalanced. You would have to switch between the two. Dave.
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Post by orangeLollies on Jun 19, 2010 0:13:43 GMT -5
That sounds like a pretty good plan to me. The only thing is if the amp receives a signal on both the RCA and XLR inputs at the same time, what happens? Which amp input is the default? There is a switch on the back of the amp to select balanced or unbalanced. You would have to switch between the two. Dave. Hey guys, just thought it worth pointing you toward this post I started a while back regarding integration of the XDA-1 into an HT setup... there's no real 'answer' given, but ya may be interested in the read... emotivalounge.proboards.com/index.cgi?board=preamps&action=display&thread=11034Switching your L&R amp(s) between XLR & RCA is one way to do it for sure...if ya can be bothered getting in behind your gear every time
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jlafrenz
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I don't want to jump in, unless this music's thumping
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Post by jlafrenz on Jun 19, 2010 0:42:25 GMT -5
This could be done e.g. with a passive preamp that switches between sources. Bingo! I use a passive preamp with my DAC and phono stage so that it feeds the amps directly and never touches my processor. My processor also feeds into the passive preamp. I just turn it all the way up so the signal is not attenuated and that acts just like a bypass.
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Post by khonfused on Jun 19, 2010 14:04:57 GMT -5
This could be done e.g. with a passive preamp that switches between sources. Bingo! I use a passive preamp with my DAC and phono stage so that it feeds the amps directly and never touches my processor. My processor also feeds into the passive preamp. I just turn it all the way up so the signal is not attenuated and that acts just like a bypass. Could you point us towards some suitable passive preamps? Any links? Switching between balanced and unbalanced inputs would be possible in my setup, but still not very comfortable.
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Post by rockguitar on Jun 19, 2010 16:55:54 GMT -5
Passive pre recommendations? There are lots of good ones, but their retail price will be about the same as the XDA or higher. Not exactly a budget solution for most people considering the XDA if you buy new. You could always look for a used one on Audiogon There are also either stereo switchers or a/v switchers on the market. I have my doubts about their quality for the cheap ones, but they start around $10 and up. The Goldpoint SW4 or the Sumiko Por-Ject Switch box can also do the trick for just switching inputs. www.goldpt.com/sw4.htmlwww.amazon.com/Sumiko-Pro-Ject-Switch-Box-Silver/dp/B001NAC8XIIf you can solder, for about $20-30 in parts, you should be make a quality switch.
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jlafrenz
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Post by jlafrenz on Jun 19, 2010 18:43:35 GMT -5
Rockguitar is right. Many are more expensive than you would think for what they are. In my case though, I think it was worth it and I am very pleased with it. Sometimes you have to spend a little money to get the sound your looking for. Here is the one I have www.goldpt.com/sa4.htmlA couple others that I looked at www.ciaudio.com/www.creekaudio.com/products/obh22.phpMcCormack Micro Line - not in production, but can be found used.
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