I have received the ddx boards a week ago, and have been trying out one. I must say that I really like the sound of it. It feels like it plays very loud, even when the volume is not very loud, the music stands out clear and loud. I guess it sounds a bit more neutral than TK2050 (which add's a bit of magic in the mid). But it is not a "cold digital" type of neutral. It sounds full and neither warm or cold, just clear.
I have tried it on both my DIY speakers and on my Hifiman HE-5SE headphones (yes those headphones sounds very good on speaker amps, been using them with the T1 amp for a while), and I think this amp is the most exciting that happened in my hifi life since discovering the direct-out DAC mod and of course the Tripath amps.
However, I've been having some noise issues from time to time. It is most easily heard with open, clear music, like a dry sounding bass drum in the left channel, will make the right channel play a higher pitch sshh kind of sound that follows the bass drum rhythm. It sounds a bit like the bass drum was resampled into very low bit resolution (like 4 or 2 bits).
It is not there all the time, so it is a bit difficult to look into it. When it is there it stays for the rest of the listening session normally. But then I was trying to record this noise to show yubing, it was gone.
I'm still trying to discover if it could be something else with my setup/source, but I have heard it both from coax and opt input, so I doubt so.
Any ideas about this noise would be appreciated.
I have tried it on both my DIY speakers and on my Hifiman HE-5SE headphones (yes those headphones sounds very good on speaker amps, been using them with the T1 amp for a while), and I think this amp is the most exciting that happened in my hifi life since discovering the direct-out DAC mod and of course the Tripath amps.
However, I've been having some noise issues from time to time. It is most easily heard with open, clear music, like a dry sounding bass drum in the left channel, will make the right channel play a higher pitch sshh kind of sound that follows the bass drum rhythm. It sounds a bit like the bass drum was resampled into very low bit resolution (like 4 or 2 bits).
It is not there all the time, so it is a bit difficult to look into it. When it is there it stays for the rest of the listening session normally. But then I was trying to record this noise to show yubing, it was gone.
I'm still trying to discover if it could be something else with my setup/source, but I have heard it both from coax and opt input, so I doubt so.
Any ideas about this noise would be appreciated.
I (mis)understand this as the distortion figures being higher? Usually how I can tell that a system is high grade is that you play at higher volumes than you should because there is no distortion to tell your ears/brain that this is loud. Adding distortion, be it a cheap amp or cheap'ish speakers tend to bring the sound more forward at lower volumes in my experience, but louder volumes unbearable.
Hi Nick,
I have not ordered the amp yet, but might do so soon.
Just to let you know I did encounter distorted digital sound ( I am presently using miniamp and minidisp) before when using with my LG blu ray player as source. In the end I traced it back to the player. I switched the player off and on again and it was gone. Might want to try that with your player...
Oon
I have tried different sources, all the same.
I did discover that it dissapeard (and stay away) after a restart (cut power) off the amp.
Nick,
A quick question. I apologize if this has been addressed previously.
Does the cross-over setting affect both the low pass for the sub AND high pass for the satellites, or just low pass for the sub only with the satellites always running full range?
Thanks,
Duc
EDIT:
Never mind, I see that the satellites are running full range, practically.
A quick question. I apologize if this has been addressed previously.
Does the cross-over setting affect both the low pass for the sub AND high pass for the satellites, or just low pass for the sub only with the satellites always running full range?
Thanks,
Duc
EDIT:
Never mind, I see that the satellites are running full range, practically.
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I assume the first wave of units has shipped? Has anyone received theirs yet?
If the noise has disappeared, then the unit might just have needed some time to break-in.
Hi Hifimediy,
I find the DDX320 concept _very_ interesting but the crossover range you chose is quite a deal-breaker for me. Would it be possible to order a custom version with a different crossover range?
IMHO, but I think 99% of diyaudio will agree, a 80Hz-360Hz crossover range for a subwoofer makes no sense: Anything above 80Hz for a subwoofer start to be a compromise, and I don't think even the cheapest/smallest satellite speaker would need a subwoofer going above 100-120Hz, which leaves very few settings actually usable. Beside, since there's no high-pass filter, the crossover point needs to be adjusted to the satellite speakers, and 20Hz steps are huge.
So, if possible without modifying the PCB, I would be very interested with a custom version with a 40Hz-110Hz crossover in 5Hz steps. Is this possible?
And, if it can be done without modifying the PCB, I think most will agree that it should be the crossover range of the version 1.1.
And maybe a high-pass filter for the satellite in the 1.2 version?
I find the DDX320 concept _very_ interesting but the crossover range you chose is quite a deal-breaker for me. Would it be possible to order a custom version with a different crossover range?
IMHO, but I think 99% of diyaudio will agree, a 80Hz-360Hz crossover range for a subwoofer makes no sense: Anything above 80Hz for a subwoofer start to be a compromise, and I don't think even the cheapest/smallest satellite speaker would need a subwoofer going above 100-120Hz, which leaves very few settings actually usable. Beside, since there's no high-pass filter, the crossover point needs to be adjusted to the satellite speakers, and 20Hz steps are huge.
So, if possible without modifying the PCB, I would be very interested with a custom version with a 40Hz-110Hz crossover in 5Hz steps. Is this possible?
And, if it can be done without modifying the PCB, I think most will agree that it should be the crossover range of the version 1.1.
And maybe a high-pass filter for the satellite in the 1.2 version?
True, not many people need a 320hz crossover. However, some smaller speakers - like desktop PC speakers, or wall-mounted home theater satellites - will still require a higher crossover of 160hz or even 200hz for optimal results. A crossover range of 40hz-200hz or thereabouts seems like the sweet spot.
10hz increments are probably enough for most people. 5hz steps would be overkill for all but the most sensitive audiophiles (would you really notice the difference?).
The cable was actually a software update. I did it and haven't experience any of the noise issues after that. still trying it out. Will update the other boards I have and should be ready to send out soon.
So this board has firmware? Interesting. Do the updates come from the manufacturer?
Also - how do you update the board if it doesn't have a USB port?
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This one time update was to fix this fault. it was done by powering the board on with another small board containing the update connected in place of the control board.
Updated after it's sold is not possible.
Still problems..
The update did not fix the noise problem.
The problems is that on each start up the amp will either work fine on 44 to 96khz, or on 176-192khz, but not on both. And it switches randomly (on each boot up) between the two. It will continue working if you don't turn it completely off, but keep it in standby. We haven't been able to find a solution to this problem.
The amp can be used (as I do now) if you keep it on standby after it boots into the non-problem mode. If anybody would like to try it with this defect PM me.
Still trying to sort it out, but no idea how long that could take.
The update did not fix the noise problem.
The problems is that on each start up the amp will either work fine on 44 to 96khz, or on 176-192khz, but not on both. And it switches randomly (on each boot up) between the two. It will continue working if you don't turn it completely off, but keep it in standby. We haven't been able to find a solution to this problem.
The amp can be used (as I do now) if you keep it on standby after it boots into the non-problem mode. If anybody would like to try it with this defect PM me.
Still trying to sort it out, but no idea how long that could take.
Sorry to hear that this bug has turned out to be a showstopper.
It might be a hardware issue, but if the problem is in the software then fixing it could be difficult.A question: if the DDX chip uses firmware, then is it possible to use a USB or serial cable to connect to it, and read the output as it boots?
Discount
As we are not able to find a solution to this now, we will sell the current small batch with a very high discount. If we find a software solution we will sell the (hardware cable) update at a resonable price.
The amp can be used as explained above, and I think it sounds amazing. But still it's not a good solution with the problems, so I hope we are able to fix this soon!
Hifimediy DDX320 digital amplifier 80W+80W @8ohm and 100W@4ohm|Hifimediy
Sorry to hear that this bug has turned out to be a showstopper.
A question: if the DDX chip uses firmware, then is it possible to use a USB or serial cable to connect to it, and read the output as it boots?
As we are not able to find a solution to this now, we will sell the current small batch with a very high discount. If we find a software solution we will sell the (hardware cable) update at a resonable price.
The amp can be used as explained above, and I think it sounds amazing. But still it's not a good solution with the problems, so I hope we are able to fix this soon!
Hifimediy DDX320 digital amplifier 80W+80W @8ohm and 100W@4ohm|Hifimediy
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