As if that will be the reason to explain it sounds better 🙂
So a higher distortion is better you think? Certainly for DAC's i don't agree at all. For (pre)amps a touch of low order harmonic distortion can do magic, but not in a dac that should translate the digital to analog as precise as possible, not colour the sound with distortion.
Both distortion levels are also so low (125dB vs 140dB sinad) that they are undectectable for our ears. So they sound the same. The human ear has a very limited Sinad of arround 95dB average. Everything over that (count maybe 10dB margin to be safe) is unhearable. That is what science says.
Both distortion levels are also so low (125dB vs 140dB sinad) that they are undectectable for our ears. So they sound the same. The human ear has a very limited Sinad of arround 95dB average. Everything over that (count maybe 10dB margin to be safe) is unhearable. That is what science says.
Try OPA1642 with e.g. AK4499 and you'll see why your sweeping statement is false. OPA1642 simply doesn't cut it unless you enjoy noise and distortion.
Regarding spureous noise spikes in DAC:
An example of stepped response measurement.
Takes about 4 hours to be done
0.1 dB step. 88kHz bandwith, 1k sin
If there were spurious noise spikes at some point during the measurements the noise measurement should also have a spike. But it does’t.
And that is really impressive!
An example of stepped response measurement.
Takes about 4 hours to be done
0.1 dB step. 88kHz bandwith, 1k sin
If there were spurious noise spikes at some point during the measurements the noise measurement should also have a spike. But it does’t.
And that is really impressive!
It does cut it in many cases and many applications and seems to be a general good workhorse but not in all would be a better description. Even at first glance it would not be the first choice as first opamps after todays RF spewing DAC ICs with MHz clocks but previous workhorses also weren't. Audientid14 also wrote "at the output stage"......
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that is why they invented the lpf filter on the dac output. That is a non existing problem that you and others always mention to defend your love for old coloured dac's. And those MHz frequencies are centainly not in our hearing passband that goes from 20 to 20kHz in the most optimistic scenarios.
I said it doesn't cut it with AK4499. So not in all cases.
I/V is part of the output stage.
Its a well known problem which has to do with demodulation of RF in semiconductor junctions.
The demodulated RF then gets intermodulated with audio signal, which occurs in the audio passband humans can hear.
BTW, this is very old news. There are app notes on the problem, PMA posted a thread at ASR on it, etc.
OPA1612 is the most tolerant opamp of the RF, which is why it is most common I/V opamp in use. However, some of the RF is at much higher frequencies than OPA1612 can amplify. Therefore the RF may pass by OPA1612 through the I/V feedback cap and be partially absorbed by the open loop output Z of the OPA1612 output. Any RF not absorbed there may pass into following output stage opamps.
Therefore subsequent processing in the output stage after the I/V stage, such as balanced MFB filters, often benefit from some additional passive filtering after the I/V stage to help attenuate remaining RF before the audio signals are further filtered and processed.
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But it's also so low in level that humans can't hear it, so it's not relevant in reality. But if you prefer the other opamp, feel free to use it and feel better.
But if the noise of that modulation would be on a level that we can hear it, it, it would be visible in the general disortion measurements. If all distorton is so low (below -100dB) in level that it's below our hearing treshold, how can that distortion impact the sound we hear?
Ahem, please consider to read up on the subject. RF may be one of the most defining influences on audio performance today. In various possible ways, coming from either within or from the outside, with various possible influences depending on amplitude and frequency. I dare to say it is one
of our mightiest enemies.
BTW no love for old/colored DACs. I love young colored women but that is another subject.
of our mightiest enemies.
BTW no love for old/colored DACs. I love young colored women but that is another subject.
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I am not aware of any published research supporting your claim.
Not necessarily true if its correlated with the audio signal. In that case you may only see it as spectral line noise skirts (which are a measurement but a nonquantitative one).
To stick with subject of the thread which chinese DACs suffer from RF? A while back you supported replacing OPA1612 with OPA1642 even though the former is among the best opamps for dealing with RF. So why do that if RF is the most defining influences on audio performance today?
https://www.itu.int/rec/R-REC-BS.1116/
This article references some studies.
https://www.audioholics.com/room-acoustics/human-hearing-reprise-part-4?utm_source=chatgpt.com
You could also do some of the distortion tests on Klippels site and get an idea what your threshold is for different types of distortion (spoiler, your hearing isn't as good as you think it is).
I don't have access to AES papers anymore (as i'm not in the bussiness anymore i did not prolong my subsription), but this subject was already known in the late 1970's by an paper about the hearability of noise and THD. If you got a subscription, i'm sure you can find it.
But i could also reverse the question, can you show us a study that says that it's hearable? I'm not aware of one and the general consensus is that it's not below 100dB SNR
But i could also reverse the question, can you show us a study that says that it's hearable? I'm not aware of one and the general consensus is that it's not below 100dB SNR
So any op amp/device which measures better in this parameter will be the same for human ears you claim or I can't understand your idea ?
Published thresholds are for the average ear. Think of something like the center of a bell curve. Despite that, some people still believe thresholds are hard limits (which they are not).
Also, studies done on old equipment from decades ago may not replicable today, and may not hold up if following something like ITU guidelines. For one thing, it the old days it was common practice to discard outliers. Today that would be considered pretty unacceptable.
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The info I linked seems more than adequate in establishing audibility thresholds, maybe I'm just gullible ¯\(ツ)/¯
Have you considered funding your own studies? It doesn't seem like any currently accepted information on the topic would satisfy you. I mean, this stuff has been studied for decades and there's plenty of studies out there if you just use google. I'm curious what evidence you have to suggest that everyone else is wrong?
I checked out the Nitsch Pietus Maximus. That is no longer a cheap DAC, and it is also a headphone amplifier. I don't need a headphone amplifier, and $849 for the multibit DAC + headphone amp is too much to qualify as 'cheap'. I think the Magni Piety is a headphone amp only. I already have a (single-ended triode) headphone amp I built, so I'm not in need of another headphone amp. But thanks for the recommendations.
I would be most interested in the Schiit Modi ($129), since it's in the same general price category as the Topping E30 II Lite or the SMSL SU-1.
The main difference I see between the Modi and the Modius ($229) is that the former uses an ES9018 DAC chip and the latter uses an ES9028. I'm sure the Modius has a more refined power supply too... Or at least I hope it does.
Perhaps if I get curious enough to pay double the money, I might try the Schiit Modi Multibit ($299). If that sounds undeniably, noticeably better than the Topping E30 II Lite then I guess I'd keep it. If it sounds pretty much similar, I'd probably return it.
It seems these go on ebay for $300 to $450 USD. No longer cheap in my book. Would that really sound 300% better than a Topping E30 II Lite? Maybe it does. I don't know.
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