pecci, again thanks a lot for the link and your detailed description!
BarG01, many thanks for the hint!
Greetings all. i have had my dam1921 going for about 1.5 years now. Everything has been great until a few days ago. i will be sitting there listening to music when all of a sudden the music drops out. it is heard very faintly and highly distorted. Its like the dac looses the timing latch. Anyone got any ideas? i am feeding the dac via Roon Nucleus using USB. It also glitched out when i tried to feed it using RPI3 B through digital coax.
Would anyone know what would be the best way to add a second pair of outputs to connect to a second set of amplifiers?
The idea is that the normal balanced outputs would connect to my power amplifier and that the second set of outputs would be connected to amplifier modules that reside in my speakers to power the bass drivers.
The idea is that the normal balanced outputs would connect to my power amplifier and that the second set of outputs would be connected to amplifier modules that reside in my speakers to power the bass drivers.
If you only need bass the best is to use the dedicated sub woofer output of your main amplifier 😉
Another solution cascading from your amp is to use speaker out and build low pass filter .... to feed your module.
Ultimately you have to use another DAC dedicated to bass with active filter see minidsp threads.
If you want to keep it too simple by just using SE for bass and Balanced for AMP this can work but not being optimal due to power/volume mismatch between frequencies.
Another solution cascading from your amp is to use speaker out and build low pass filter .... to feed your module.
Ultimately you have to use another DAC dedicated to bass with active filter see minidsp threads.
If you want to keep it too simple by just using SE for bass and Balanced for AMP this can work but not being optimal due to power/volume mismatch between frequencies.
I’ve been using computer transport for 10 years or so and it seemed to work well. Last year, out of curiosity, I hooked up CD Transport and was pleasantly surprised: it sounded different, smoother and more analog like.
So CDT sits permanently in my system now and I basically don’t listen to computer at all. Recently, I’ve been experimenting with input interface on a DAC.
The Murata pulse transformers there are pretty good and both the Lundhal 1572 and Newava S22100 didn’t seem much of an improvement. I ended up with Newava S37211 and it seems just right when combined with Caddocks MK132. As pulse transformers have been criticized by some, I tried coupling capacitor on the other input and here I have Teflon V-Cap 0.01uF with nude Vishay. At the moment I didn’t make my mind what sounds better, on certain albums capacitor is better, on some other I think I prefer the transformer. Capacitor provides slightly better resolution and immediacy, transformer is a bit more coloured, but creates this impression of rounder, more organic sound.
The original transformer and resistor in a DAC is not bad at all, but it sounds more flat and less interesting.
I must say that I’ve been enjoying this DAC a lot and I never thought I’ll be going back to CDs, but here we are, I’m browsing discogs and getting more titles every week 😉
So CDT sits permanently in my system now and I basically don’t listen to computer at all. Recently, I’ve been experimenting with input interface on a DAC.
The Murata pulse transformers there are pretty good and both the Lundhal 1572 and Newava S22100 didn’t seem much of an improvement. I ended up with Newava S37211 and it seems just right when combined with Caddocks MK132. As pulse transformers have been criticized by some, I tried coupling capacitor on the other input and here I have Teflon V-Cap 0.01uF with nude Vishay. At the moment I didn’t make my mind what sounds better, on certain albums capacitor is better, on some other I think I prefer the transformer. Capacitor provides slightly better resolution and immediacy, transformer is a bit more coloured, but creates this impression of rounder, more organic sound.
The original transformer and resistor in a DAC is not bad at all, but it sounds more flat and less interesting.
I must say that I’ve been enjoying this DAC a lot and I never thought I’ll be going back to CDs, but here we are, I’m browsing discogs and getting more titles every week 😉
Attachments
Yup. Despite FIFOs and other buzz words a computer transport requires an incredible amount of work to compete with a good optical transport 🙂
Please define "computer transport'. Is is a Windows pc also used for audio playback or is it a dedicated computer only for audio playback (using all resources for audio and a "just enough" OS)? That is quite a difference IMO as the latter win from CD players hands down in general.
Many a "media player" (as the dedicated computer now is called) is optimized for audio playback in high resolution with ultra low jitter either from network or from a local SSD. This is such a large difference with CD that comparing is dishonest in itself. Only nostalgia comes around the corner 🙂
Many a "media player" (as the dedicated computer now is called) is optimized for audio playback in high resolution with ultra low jitter either from network or from a local SSD. This is such a large difference with CD that comparing is dishonest in itself. Only nostalgia comes around the corner 🙂
Last edited:
Interestingly, i am not so sure. What i use is by all definitions a dedicated transport. Minimised, stripped down OS, linear regulators for all rails, passive cooling. In another system i have a Rpi used as dumb network client.
Still, a transport of the quality PD uses, actually the same one as i get to listen to one occasionally, seems to do some things like pace, timing, rhythm, image density and general liveliness a bit better. Would i ever consider going back to optical devices? No way, but the odd comparison is still interesting.
Would not even discuss what office type PCs sound like when trying to perform transport duties.
Last edited:
Red Book 16/44.1 versus high res... but often comparisons are made with 16/44.1 material on both with only slight differences when high quality CD players/DACs are used (standard old ones are simply too jittery)... Maybe it would be wiser to compare 16/44.1 on CD to 24/96 on a high res platform. Why would one limit a device to a lower standard while the device is capable of stuff?
I don't know the CD player in question but I take it is a polished type with low jitter clock etc?
I don't know the CD player in question but I take it is a polished type with low jitter clock etc?
Last edited:
My computer transport was described here: https://www.diyaudio.com/forums/ven...24-bit-384-khz-dac-module-39.html#post6011242. The OS is Windows Server 2019 with Audiophile Optimizer, files sourced from NAS. I downloaded quite a few so called high resolution files, but they never sounded better than my personal 16/44 rips.
The CEC TL0 has been slightly modified, with output cleaned out by removing coupling caps and SC coupling transformer. Also, a dedicated umbilical cord from PS replaces standard cable.
I’ve been thinking about touching that subject a while now. We’ve been discussing this DAC for years, but nobody really mentions the transports, and this DAC is only as good as the source.
The CEC TL0 has been slightly modified, with output cleaned out by removing coupling caps and SC coupling transformer. Also, a dedicated umbilical cord from PS replaces standard cable.
I’ve been thinking about touching that subject a while now. We’ve been discussing this DAC for years, but nobody really mentions the transports, and this DAC is only as good as the source.
Maybe a streaming device or media player of quality specifically designed for audio would make the difference between 16/44.1 and high res more clear (after all this IS a 24 bit DAC 🙂). If done right it has low jitter, separate power supplies for each section etc. When keeping stuff in one casing I2S and short cabling can be chosen which is the weapon of choice for best results. Attempts with pc's, SPDIF so 2 box approach etc. are nice but will rarely reach the full potential compared to a device that has I2S and built in DAC.
Just suggestions. What I see in practice is that the choice is defined by choosing an external DAC that must be used for more than 1 device. Therefor the less optimal interfaces are often chosen and comparisons are a little compromised sometimes giving biased findings.
True.
Just suggestions. What I see in practice is that the choice is defined by choosing an external DAC that must be used for more than 1 device. Therefor the less optimal interfaces are often chosen and comparisons are a little compromised sometimes giving biased findings.
True.
Last edited:
If your CDT source clock is way better than the PC source clock (which I assume it is), then your observation seem to confirm the other hot topic here questioning the DAM clock implementation, allowing source clock issues to flow through into the DAC.
It is an interesting observation.
Implementation of the clock in TL0 is actually very simple, I talked about it here: https://www.diyaudio.com/forums/audio-sector/160373-cd-transport.html#post2068996
Did you ever try a recent dedicated computer? In other words a known good low jitter source of today to drive the DAC?
Last edited:
This discussion fits this particular thread because the dam is supposed to be insensitive to input jitter. And it might be. Jitter propagation is just one hypothesis on why transports sound different.
And anyway what does a "low jitter" computer mean? Low lattency OS? In the case of USB i would imagine a dedicated card using a high precision oscillator and clean power. Not sure how this translates to SPDIF.
Hi I just mean that if one wants to get the most out of an external DAC the source must be of lowest jitter possible despite the DAC being known as insensitive to jitter. In my experiments with external DACs known to be insensitive to jitter the results were improved by concentrating/focussing on using a better source. I never tried a DAM DAC FWIW but still. Even if the DAC would be perfect then using the best source won't harm anything 🙂
The external box approach has already a disadvantage from the start.. the interface. Or, better said various commonly used interfaces all with their specific issues. Most will acknowledge that a DAC type X may perform excellent on coax SPDIF but less good on Toslink while DAC Y does it vice versa. Plus: no feedback of the clock signal to the source. Plus: various conversions in the digital signal path. An approach could be to use a source connected by I2S in 1 box thereby omitting conversion in the source to SPDIF and reconstructing clock and signals at the receiving end. That would save 2 conversions. If done like this results can be very good and the source previously not the best performing may now be the best performing.
* I already described what a low jitter computer is, a media player designed/built for ultra low jitter playback of audio. The more and more common source of today.
The external box approach has already a disadvantage from the start.. the interface. Or, better said various commonly used interfaces all with their specific issues. Most will acknowledge that a DAC type X may perform excellent on coax SPDIF but less good on Toslink while DAC Y does it vice versa. Plus: no feedback of the clock signal to the source. Plus: various conversions in the digital signal path. An approach could be to use a source connected by I2S in 1 box thereby omitting conversion in the source to SPDIF and reconstructing clock and signals at the receiving end. That would save 2 conversions. If done like this results can be very good and the source previously not the best performing may now be the best performing.
* I already described what a low jitter computer is, a media player designed/built for ultra low jitter playback of audio. The more and more common source of today.
Last edited:
Dirty grounds or noisy power supplies outside the DAC can also be the cause.
I once could hear the SMPS PS of a network switch through my speakers.
Now I've galvanic isolated the network connection of my media PC.
I once could hear the SMPS PS of a network switch through my speakers.
Now I've galvanic isolated the network connection of my media PC.
I believe most of the "transport effects" are due to common mode and radiated noise.
Ethernet is galvanically isolated by default, isn't it?
Ethernet is transformer coupled by design,
but that is not as efficient for suppressing noise as total galvanic isolation through fiber with optical converters.
but that is not as efficient for suppressing noise as total galvanic isolation through fiber with optical converters.
Yes, SMPS garbage, wireless, cell phone, Bluetooth signals, LED lighting current regulators/SMPS, frequency converters as used in industrial devices creating noise and other RF everywhere too. A one box device with separated sections and linear PSU's with I2S to the DAC and a low jitter clock is the means to what is possible in digital audio. The 2 box approach is way harder to get right, maybe except for the shielding.
Last edited: