I'd imagine all the AC input stuff has just been left to provide input power polarity protection and local decoupling. But then, knowing it is clean DC incoming, it means all the the local regulators can be optimised for clean DC stepdown rather than heavy filtering of ripply rectified DC.
Hi guys, I need some help, please. Yesterday I upgraded a dam1021 rev6 board to the 1.23 firmware. The u manager gave me the correct messages, but when I powered on again, the only thing I hear was a loud hiss coming out from the loudspeakers. What could be happened? The only thing I can say is that before upgrading I was on the 1.21 firmware and some months ago I installed a digital filter that I downloaded from another dedicated thread, but I don't remember which one. What can I try to fix?
Thank you,
Gaetano.
Thank you,
Gaetano.
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Thank you guys, yes, I'm sure that I installed the correct firmware, 1.23. The wrong one is the 1.24, which is for the rev7 boards. I think that somehow (correct me if I'm saying nonsenses) perhaps the filter I installed on the 1.21 firmware could be incompatible with the new 1.23 firmware. Might it be? If I downgrade to 1.21, should I return to Soeren's original filter?
Gaetano.
Gaetano.
Okay, so if I use WASAPI output, the clipping/crackling noise is greatly reduced (you can tell that I've stopped worrying about "sound quality" a long ago...). And the noise actually almost goes away if I toggle the output level in FB2K to -30db (in addition to the -17db on the dam1021). I can't get the dam1021 to lock on to a x8 signal, however. Maybe it's just the Amanero that's broken since the situation improves with a smaller signal from the Amanero and the fact that I'm not getting the same distortion from I2S/SPDIF?
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That certainly sounds most likely. You are going to have to try feeding with a different source. Do you have any source handy where you can pull a SPDIF or I2S signal?
Yea I have toslink/coax input options in my build, and it was the first thing I tested last night. Problem is the signal locks on just fine up to x8 sampling frequency, yet there's nothing in the output (compared to the clipping noise with I2S input option). It could be that the Amanero is contaminating the input section, but I don't see how that would work either... The voltages on the 3.3v and 5v rails of the PSU powering the isolated input section look just fine.
The fact that the only thing leading up to the fault that might've triggered it is an EMI spike/static discharge makes it more likely that it damaged the Amanero which is fed by a long cable from my PC. I also lifted the shield pin on the Amanero USB connector (though it should still be grounded on the other end), so maybe that contributed as well. Again, with my limited knowledge in electronics I don't see how it could've happened.
Edit: Looking more closely at my build, it seems unlikely that the problem is isolated within the Amanero - it's powered by the external USB, so it should've been completely off when I tested the toslink/coaxial, and is only connected to the dam1021 via FSCLK, BCLK, DATA and GND.
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The dam1021 module is also behaving erratically. I removed all inputs but the dam1021 is still able to "lock on" to an I2S 44.1Khz signal... The isolated section is only grounded via the USB input, I believe. Maybe there was an EMI spike that fried some components in the isolated section of the dam1021? Is there a way for me to ascertain the problem? Is this covered by any warranty?...
Edit: If I toggle input method to coaxial or toslink, it doesn't lock on without a signal, and it does lock on to a real signal and display the right sampling frequency, there's just no sound. But if I toggle to I2S, it locks on to 44.1khz without a real signal present (and the Amanero is powered off...). Same thing happens with auto when coaxial and toslink (spdif 1 and 2) are disconnected - it locks on to a fake 44.1khz i2s signal... The indicator light does blink occasionally (loses lock) when this happens.
Edit: If I toggle input method to coaxial or toslink, it doesn't lock on without a signal, and it does lock on to a real signal and display the right sampling frequency, there's just no sound. But if I toggle to I2S, it locks on to 44.1khz without a real signal present (and the Amanero is powered off...). Same thing happens with auto when coaxial and toslink (spdif 1 and 2) are disconnected - it locks on to a fake 44.1khz i2s signal... The indicator light does blink occasionally (loses lock) when this happens.
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I do feel like I implemented everything right. The same problem could theoretically happen even with the dac2541 since the USB interface is also powered externally, I think? If I were to repair or replace the dam1021 I need to make sure that, at the very least, the same problem won't happen again. In any case, I do have to say that I am still shocked at the fact that the dam1021 sounds so much better and cleaner than the E-MU 0404 powered by a delta-sigma chip. I honestly didn't believe that I would hear any difference... Anyone has similar experiences with other DACs?
@soekris why keep the bridge rectifier/5v LDO on rev7 if you're already asking for a DC feed? Doesn't that add a ton to the PSU impedance? Or is it negligible taking into account the impedance of the opamp vref? What's your reasoning here? I know you must have one...
@soekris why keep the bridge rectifier/5v LDO on rev7 if you're already asking for a DC feed? Doesn't that add a ton to the PSU impedance? Or is it negligible taking into account the impedance of the opamp vref? What's your reasoning here? I know you must have one...
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I used the Amanero in my build and it ran flawlessly for 3ish years. But I think it just fried my dam1021 during a static discharge in my room (I was taking off a polyester jacket in a very low humidity environment...). Until someone figures out what went wrong in my build, I would recommend using something less electrical like a toslink optical connection... The USB cable I used is about 3m but high quality and definitely well-shielded. It also has a couple of ferrite rings but that didn't save me either. Toslink (S/PDIF) will only get you to x4 sampling frequencies compared to x8 on the Amanero, but it should be plenty.
Not sure if it's a good idea to use an AC supply. Get a decent regulated DC supply. I'm using UltraBiB which might be overkill, but you can build it yourself so it's inexpensive. I think my transformer is 25VA iirc. I also added a mu-metal shield around the toroidal - no mains noise in my measurements. In comparison, the square E type or whatever transformer that came with the audiozen control unit produces a lot of measurable EMI, but since I was running it in dual-mono, it basically cancelled out that noise too. I planned to replace it with a toroidal anyway since the blue square transformer ran too hot and I wanted minimal noise, but never got around to installing the component because, well, I probably wouldn't hear the difference....
As someone who stopped believing years ago that the R2R DAC I spent countless hours putting together and perfecting every implementation detail actually made a difference in sound quality (not to mention its $1k price tag), only now to be surprised by the dramatic (without being dramatic) difference that I hear between the r2r and d-s EMU0404, I can say with some confidence that it's probably worth it for you to build with the dam1021.
I also like to add that I think it's more than a difference and subjective preference. Haven't been to a live concert in a while, but I remember clearly that even my EQed HD800 and dam1021 sounded too soft and wasn't clear/transparent enough compared to real instruments in a real concert hall. People say the HD800 is too harsh (it does have a balance issue around 6khz) and the dam1021 is "digital", but compared to the real world I think they're still too "analog". The E-MU 0404 sound is even further from real instruments, as was the HD650 that I used to listen to before getting the HD800 (but that was a much greater difference). I can see how some people might prefer the softer/warmer sound, but it's probably flat-out wrong.
I think the dam1021 also sounds a lot smoother despite being "clearer" at the same time. Less sure about this one since it wasn't the first thing that jumped out at me, and I haven't bothered to think about SQ in a long time. Real instruments also have that smoothness despite being sharp and transparent.
Maybe my E-MU 0404 is just broken. It's almost "unlistenable"...
I think the dam1021 also sounds a lot smoother despite being "clearer" at the same time. Less sure about this one since it wasn't the first thing that jumped out at me, and I haven't bothered to think about SQ in a long time. Real instruments also have that smoothness despite being sharp and transparent.
Maybe my E-MU 0404 is just broken. It's almost "unlistenable"...
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Well, I've made faulty observations in the past, as is well documented in this thread. One time I think I was under the illusion that a 1M tap linear filter sounded smoother than a regular one. I upsampled the same track to x8 using filters with different lengths, and I couldn't pass an ABX test in fb2k. That one made me think twice about making any claims about how one thing sounds different or better than another.
When I first completed my build, I did also hear a difference between the dam1021 and onboard PC (I remember the onboard chip to sound a little muddier/softer with worse soundstage etc). I also thought that I heard a difference between balanced and SE output, with the balanced output sounding more spacious. I knew that it could've just been another hallucination, and I had no easy way to conduct a level-matched double-blind test, so I just decided to forget about it for that reason among others.
I also felt that I heard a difference in a replacement HD800 cable, when the rubber sheath cracked on the original. The cables were supposed to be the same minus any difference that could've resulted from the soldering when I converted the stock SE connector to balanced XLR. The replacement is a secondhand HD800s cable in good conditions. I thought that the new cable sounded slightly harsher than the old one, but I don't think I was able to confirm my observation after I swapped back to the original cable. The important thing is I had no reason whatsoever to think that the two cables would sound different, so I just convinced myself to stop worrying.
Fast forward, it took a while for me to get the EMU 0404 to work because of outdated drivers. But I'm pretty sure I had fully expected it to sound exactly the same as the dam1021 and prove to myself yet again that there is no audible difference between the two systems, or any two systems that are within spec in terms of THD, FR etc. Now, the main reason I broke out the EMU 0404 was to test the SPDIF inputs on the dam1021 (it'd still be more convenient to use even if it doesn't sound any better than anything else, if I could salvage just the SPDIF inputs). One could argue that this is like when I swapped out the HD800 cables, that I didn't expect any difference but might've been somewhat attached to the original cable despite the cracked rubber sheath. But I was genuinely looking forward to proving to myself that the EMU 0404 would sound exactly the same and not any worse than the dam1021 which I've invested so much in. It's been years and I've fully accepted the fact (or so I thought) that all DACs sound the same and I wasted my time for no real gain in sound quality. I was totally fine with it and even told many of my friends about my error in judgment without feeling ashamed or anything, and I was happy to keep using the dam1021 because it was convenient to use and looks great in my room. But if anyone told me that my dam1021 sounded better than any other system, I would probably laugh and explain to him that he's likely mistaken. Yet, despite all this, and the fact that it would be more of a loss for me if the dam1021 that had just been fried is actually better, I could immediately tell that the EMU0404 sound is qualitatively different in a number of ways, and none of it good.
I think I have to say that the dam1021 is better. But even now I'd be happy to prove myself wrong if I can get an ABX test. It is what it is. I'm almost certain I'd pass the ABX test, but it's odd that no one else has had concrete ABX results proving that DACs sound different. How could it be that hard?
I've never been a hardcore skeptic of SQ differences in DACs to the point where I would viciously attack those who think otherwise, but I've had a number of reasons to doubt people's claims and felt that it was wiser not to bother. Another thing that makes this so bizarre is the fact that I've listened to other people's fancy portable equipment, some of which looked very nice and were very expensive, but I didn't like the colored sound signature of the earphones at all, which is probably easy enough to prove with measurements. The two times that I'm pretty sure I was hallucinating (one with the length of filters, the other with headphone cables), the differences that I thought I heard were both pretty subtle - one being "smoother/better" or "harsher/worse". I think I can believe that those were just the result of my preconceived biases. But this seems totally different...
I don't mean to insult anyone's opinion on how different devices sound different or don't. I tend to overthink a bit as usual, so please ignore my post if you're not interested.
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