I may have to try this new DAC for Rasp. Pi or Tinker Board. I wonder if it is microphonic?
DACBerry NTB - OSA Electronics
DACBerry NTB - OSA Electronics
This is more of a joke product. Of course there are many cases where a nutube rocks. First of all As preamp, but also to replace an output stage and add the „tube like“ kind of distortion, but here it is more of a joke. The used DAC chip, the PCM5142 has an integrated output stage and does not need any kind of opamp or tube at its output. Second problen is, that the 5142 is a 2$ chip that sounds very bad compared to Sabre or PCM179x series for example.
Its like putting ferrari wheels on a fiat and expecting it to be fast like a racing car. Just a marketing joke, nothing more.
Better buy a DAC that is not based on this cheap IC. It sounds very flat, digital and you will have more fun if you buy something with a better chip and linear psu. But the real joke is the price. The nutube is worth 50$, so they think that their 5142 implementation WITHOUT any kind of isolation is worth so much ? Very, very, very sad that companies do jokes like this.
Its like putting ferrari wheels on a fiat and expecting it to be fast like a racing car. Just a marketing joke, nothing more.
Better buy a DAC that is not based on this cheap IC. It sounds very flat, digital and you will have more fun if you buy something with a better chip and linear psu. But the real joke is the price. The nutube is worth 50$, so they think that their 5142 implementation WITHOUT any kind of isolation is worth so much ? Very, very, very sad that companies do jokes like this.
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I am really surprised about how people like to blame on products, designs or whatever, without really testing them or having and idea about them.
This is my first and my last post probably here, because I do not like to enter on that kind of discussions. You may like or you may don't like my work/designs, but please, try to be more polite. This free attack by your side to my designs talks by itself.
The PCM5142 is a really nice DAC, and as you like to do comparisions, it is not about if it id a Ferrari or not, my old 90's BMW can beat you Ferrari easily 😉
Try to be constructive with your comments and not attacking this way.
Best,
Oriol.
This is my first and my last post probably here, because I do not like to enter on that kind of discussions. You may like or you may don't like my work/designs, but please, try to be more polite. This free attack by your side to my designs talks by itself.
The PCM5142 is a really nice DAC, and as you like to do comparisions, it is not about if it id a Ferrari or not, my old 90's BMW can beat you Ferrari easily 😉
Try to be constructive with your comments and not attacking this way.
Best,
Oriol.
Yeah if your sensitive to being butt-hurt this might not be the place to post, you were getting sound if not sarcastic advice about the technical flaws or limitations based on design of your proposed product. Since the nutube itself is a $50 device the dac hat created for it better be a tech marvel or why both?
I know the PCM51xx series very well. They sound nice, yes if you consider, that they are a 2$ product. I know a lot of implementations of this chip and also tested it often by myself (even much more complicated designs, to try to overcome its flaws, like galvanically isolated, lifepo4/adm7150 powered). This chip is intended for low segment hardware like mp3 players and more like TV sets.
Why using the nutube AFTER the PCM51xx output stage ? Take a current out DAC and this makes sense, take a low voltage out DAC and it makes sense, but here its just nonsense. The PCM51xx peoblems are mostly because of its simple implementation. It is a ready to go product, that gives you not much freedom for improvement.
If you want to stay with cars, it was wrong what i said. Giving the PCM51xx a tube output stage is like having a car with four wheels and mounting four more.
Please tell me, why you chose this IC ? It has full 2V output, no need to amplify the signal at output stage. So the nutube is just a marketing thing. Something like „look, it has tubes, it must be good“.
Tubes are best used in certain places, like input stages of amps and i/v conversion of DACs, or V amplification if your DAC has low voltage output. But here. What a joke.
Subtract the nutube that is worth under 50 bucks and you have a very normal rpi DAC hat with the chip, that everybody uses, just for a premium price, that i cant explain.
Instead of trying to make your product more advanced, like isolating it from the very bad Rpi signals (and that would be easy as hell for example with a il715e) you just choose the easy way.
After a lot of experiments i found out, that this IC sounds best if run in master mode, like you do, but isolated (this made the background much better) with lifepo4 supply and supercaps very close to the voltage inputs.
But even if operated like this, the IC is garbage. Its what its price is, a 2$ product. Yes, i know your audience is the everyday joe, so it doesnt care, but if i compare the PCM51xx DACs to my other DACs here, they are simply trash. They sound harsh and digital compared to PCM179x or many Wolfson and Sabres. I dint want to compare it to my aD1865s and PCM63, because this is not another league, its a complete different game.
Sorry, im sad, but just because someone uses here standard components worth pennies, adds a good tube, but one that is misplaced here and wants a premium price.
For the PCM51xx its better to improve the psu and isolation, than to make a second output stage, that is nit really needed. It has its own one, that is trash enough.
Why using the nutube AFTER the PCM51xx output stage ? Take a current out DAC and this makes sense, take a low voltage out DAC and it makes sense, but here its just nonsense. The PCM51xx peoblems are mostly because of its simple implementation. It is a ready to go product, that gives you not much freedom for improvement.
If you want to stay with cars, it was wrong what i said. Giving the PCM51xx a tube output stage is like having a car with four wheels and mounting four more.
Please tell me, why you chose this IC ? It has full 2V output, no need to amplify the signal at output stage. So the nutube is just a marketing thing. Something like „look, it has tubes, it must be good“.
Tubes are best used in certain places, like input stages of amps and i/v conversion of DACs, or V amplification if your DAC has low voltage output. But here. What a joke.
Subtract the nutube that is worth under 50 bucks and you have a very normal rpi DAC hat with the chip, that everybody uses, just for a premium price, that i cant explain.
Instead of trying to make your product more advanced, like isolating it from the very bad Rpi signals (and that would be easy as hell for example with a il715e) you just choose the easy way.
After a lot of experiments i found out, that this IC sounds best if run in master mode, like you do, but isolated (this made the background much better) with lifepo4 supply and supercaps very close to the voltage inputs.
But even if operated like this, the IC is garbage. Its what its price is, a 2$ product. Yes, i know your audience is the everyday joe, so it doesnt care, but if i compare the PCM51xx DACs to my other DACs here, they are simply trash. They sound harsh and digital compared to PCM179x or many Wolfson and Sabres. I dint want to compare it to my aD1865s and PCM63, because this is not another league, its a complete different game.
Sorry, im sad, but just because someone uses here standard components worth pennies, adds a good tube, but one that is misplaced here and wants a premium price.
For the PCM51xx its better to improve the psu and isolation, than to make a second output stage, that is nit really needed. It has its own one, that is trash enough.
As I previously said, I do not want to enter onto a discussion, but would be nice if people thinks twice before writting bad things on internet.
You actually don't know the exact specifications of the board, I have not even yet shipped any unit because it is still on pre-sale.
This board was designed in early 2018 and is has not even yet introduced at all because as you said, Nutube brings some problems like microphonics. More than 7 revisions were needed to bring the final product, and the boards have traveled thousands of miles between Spain and Japan, because this is a collaboration between OSA and Korg. In fact, this board has been shown in Berlin IFA 2018, in the Korg stand:
I know that other dac could be used, I know the PCM5142 is not the best one probalby to be with the Nutube, and what I learned using it a lot in other designs is exactly why you said, this DAC does not work pretty well in slave mode and having the Pi as a clock source is not the best deal, and this is why this board uses master mode and low jitter clocks. But you are wrong regarding isolation, the i2s signals are isolated.
If we choose this dac it is because it's widely used and because I re-designed many times the design arround the PCM51XX to achieve the best result possible. Also the Pi market is very special, you cannot ask 500 Euros for Pi DAC boards, using a better DAC will increase the cost, and we were already happy with this combination result. The board is intended to act as a "headphone amplifier" not as a simple DAC, despite you see the RCA output. Here is why the use of the Nutube, or you want that I bring the 2Vrms output of the DAC directly to the 600 ohm headphones?
And now I am going to talk about why I feel this way bad with you, and why you should take care about what you write:
I quit my job and invested my savings from last 10 years to create OSA and design my own products. I have my own SMT line, with it's stencil printer, SPI, pick and place, reflow oven and AOI. Do you have an idea about how much this cost? Oh, and forgot to mention all the lab equipment, of course. Also as you can imagine I do not have all this stuff at home, so I need to pay an office rent, etc. And do you work for free? Because I do not. Do you? Have you ever tried to run a business?
Do you really think 150 Euros is a premium price being said that? All my boards are made in house, with EU or US components from authorized distributors like Arrow or Mouser. If you prefer to purchase a Chinese product because it's cheaper, go ahead, but do not understimate the work of the others.
It's funny to see how many European and US manufacturers have did their designs in China and tell that it has been made by themselfs.. I am tired to see many "Nuvoton" microcontrollers everywhere, on every audio board. But hey, they have a Sabre.. so people think they are good! When probably impelementation and components are crap.
My job is my passion, and I am pretty sure you don't like to see how people talks bad about your job, when they do not even know anything about it. Don't you?
Why people only see the components costs all the times? Do you know what engineering cost is? And many other things that are reflected in the final product price? Do you know that the 99% of distributors take between 35 and 45% margin? You're missing many things in that formula, my friend.
Because you like comparisions, do you think it's normal that you say that some Restaurant is bad or has a bad meal without even never tried it? So then, why have you posted that?
If you want to discuss with me any techincal thing, feel free to stop by my office when you want, I will be glad to receive you. Barcelona will always welcome you 🙂
Being said that, I close this discussion by my side.
Best regards,
Oriol.
You actually don't know the exact specifications of the board, I have not even yet shipped any unit because it is still on pre-sale.
This board was designed in early 2018 and is has not even yet introduced at all because as you said, Nutube brings some problems like microphonics. More than 7 revisions were needed to bring the final product, and the boards have traveled thousands of miles between Spain and Japan, because this is a collaboration between OSA and Korg. In fact, this board has been shown in Berlin IFA 2018, in the Korg stand:
I know that other dac could be used, I know the PCM5142 is not the best one probalby to be with the Nutube, and what I learned using it a lot in other designs is exactly why you said, this DAC does not work pretty well in slave mode and having the Pi as a clock source is not the best deal, and this is why this board uses master mode and low jitter clocks. But you are wrong regarding isolation, the i2s signals are isolated.
If we choose this dac it is because it's widely used and because I re-designed many times the design arround the PCM51XX to achieve the best result possible. Also the Pi market is very special, you cannot ask 500 Euros for Pi DAC boards, using a better DAC will increase the cost, and we were already happy with this combination result. The board is intended to act as a "headphone amplifier" not as a simple DAC, despite you see the RCA output. Here is why the use of the Nutube, or you want that I bring the 2Vrms output of the DAC directly to the 600 ohm headphones?
And now I am going to talk about why I feel this way bad with you, and why you should take care about what you write:
I quit my job and invested my savings from last 10 years to create OSA and design my own products. I have my own SMT line, with it's stencil printer, SPI, pick and place, reflow oven and AOI. Do you have an idea about how much this cost? Oh, and forgot to mention all the lab equipment, of course. Also as you can imagine I do not have all this stuff at home, so I need to pay an office rent, etc. And do you work for free? Because I do not. Do you? Have you ever tried to run a business?
Do you really think 150 Euros is a premium price being said that? All my boards are made in house, with EU or US components from authorized distributors like Arrow or Mouser. If you prefer to purchase a Chinese product because it's cheaper, go ahead, but do not understimate the work of the others.
It's funny to see how many European and US manufacturers have did their designs in China and tell that it has been made by themselfs.. I am tired to see many "Nuvoton" microcontrollers everywhere, on every audio board. But hey, they have a Sabre.. so people think they are good! When probably impelementation and components are crap.
My job is my passion, and I am pretty sure you don't like to see how people talks bad about your job, when they do not even know anything about it. Don't you?
Why people only see the components costs all the times? Do you know what engineering cost is? And many other things that are reflected in the final product price? Do you know that the 99% of distributors take between 35 and 45% margin? You're missing many things in that formula, my friend.
Because you like comparisions, do you think it's normal that you say that some Restaurant is bad or has a bad meal without even never tried it? So then, why have you posted that?
If you want to discuss with me any techincal thing, feel free to stop by my office when you want, I will be glad to receive you. Barcelona will always welcome you 🙂
Being said that, I close this discussion by my side.
Best regards,
Oriol.
Sorry, but I'm just tired of seeing the 100th iteration of a PCM5142 DAC that tries to compensate the flaws in this IC. If you would have used the PCM1793 for example (also a rather cheap IC, in 100 quantity its 4$ per IC), i would buy one. Of course this implementation will sound a bit more pleasing than many others, if you isolated the signal lines even more, but I know exactly how a well implemented PCM5142 sounds even with a very high end psu. Its still a garbage IC compared to others. Plz, reconsider making a "Pro" Version or something like this with for example the PCM1793 (This is the Chip, that has most potential in terms of price/value for me and still is very easy to implement, even on the little space available). I would buy such a device, this would be the way to go in my opinion.
Sorry for being impolite, if the headphone part is the reason for the nutube, than i didnt see it this way, sry. You are right, the nutube makes a very nice headphone amp.
I experimented a lot with the nutube as I/V and also buffer and i made some side by side comparisons with the different ICs. The PCM51xx is simply a problem IC, even though the nutube will make it sound a bit less agressive and digital, still no comparison to Sabres, PCM1793s or Wolfsons.
My Nutube went back into my preamp, but yes, it is a very nice headphone amp, just please give it a better input than the PCM51xx, than it will really rock 🙂
Sorry for being impolite, if the headphone part is the reason for the nutube, than i didnt see it this way, sry. You are right, the nutube makes a very nice headphone amp.
I experimented a lot with the nutube as I/V and also buffer and i made some side by side comparisons with the different ICs. The PCM51xx is simply a problem IC, even though the nutube will make it sound a bit less agressive and digital, still no comparison to Sabres, PCM1793s or Wolfsons.
My Nutube went back into my preamp, but yes, it is a very nice headphone amp, just please give it a better input than the PCM51xx, than it will really rock 🙂
Ok, I feel somewhat involved here as well.... because I responded to the question: ..."I wonder if it is microphonic?"
Even though I did not use this particular tube (because it is microphonic...), from what I can say from the Pass Korg NuTube thread, is that it is very microphonic. The poor souls that built it have regretted it... and the project is all but abandoned due to this microphony. So, this would be the only reason why I would not buy a DAC based on this tube.
Now, the good stuff:
- the DAC board is an incredible value for money (especially for those who pre-order)
- it can be a great learning platform - introduction to tube sound(??)
- I do like the power supply regulation, decoupling and the capacitors used (attached photo)
- there's little doubt that the engineering that went into designing this board... can never be compensated by such a low price, so kudos there to designer
I will not comment on the choice of the DAC chip; the implementation seems okay, so that should not be a main deciding factor not to buy the DAC board (however, judging by what others say, it IS a deciding factor indeed for some, and I respect that as well)
Even though I did not use this particular tube (because it is microphonic...), from what I can say from the Pass Korg NuTube thread, is that it is very microphonic. The poor souls that built it have regretted it... and the project is all but abandoned due to this microphony. So, this would be the only reason why I would not buy a DAC based on this tube.
Now, the good stuff:
- the DAC board is an incredible value for money (especially for those who pre-order)
- it can be a great learning platform - introduction to tube sound(??)
- I do like the power supply regulation, decoupling and the capacitors used (attached photo)
- there's little doubt that the engineering that went into designing this board... can never be compensated by such a low price, so kudos there to designer
I will not comment on the choice of the DAC chip; the implementation seems okay, so that should not be a main deciding factor not to buy the DAC board (however, judging by what others say, it IS a deciding factor indeed for some, and I respect that as well)
Attachments
Wow, really? Perhaps LinuxGeek was a bit short with his reply on the matter, but he's not wrong. The fact you have put yourself into debt and heavily invested in the development of something, doesn't make the decision to do so any more sound. You call it a 'High end professional audio sound card' in your marketing blurb. it is none of those things and we do not have to listen to it to see that.
This is very funny. Yes the tube is microphonic. The regretful, poor souls who have abandoned it are up to 6200+ posts and figured out how to tame the tube long ago. Building and enjoyment continues.
As to the Pass Korg NuTube build, there are many who have had highly positive experiences and love their preamps. I am one, which is why this DAC interested me. And there are some proven techniques to eliminate, reduce or minimize the microphonics.
It also seems that some particular NuTubes are very microphonic and others are not. Kind of a hit or miss for the buyer.
I would agree it is unfortunate the Korg device is often so microphonic. Hopefully Korg can address that issue. If they do not or cannot, it does raise questions about the viability of the NuTube and its applications, and turns off a number of consumers, as in your case.
It also seems that some particular NuTubes are very microphonic and others are not. Kind of a hit or miss for the buyer.
I would agree it is unfortunate the Korg device is often so microphonic. Hopefully Korg can address that issue. If they do not or cannot, it does raise questions about the viability of the NuTube and its applications, and turns off a number of consumers, as in your case.
The funny thing is the sound of the 2 coupling capacitors in the signal path and the ringing tube.
Either i was a lucky guy or it is as simple as dampening it a bit. Mine was also a bit problematic if it was under vibrations. But it was enough to let it sit on a very light foam and connect the pins with very soft high frequency copper stranded wire. I dont know if its always this way, but now i can hardly measure any problems. In the beginning it was a bit recognizeable, but after the foam and soft wire treatment it was ok. Thought that its always like this with the Nutubes and that I was already an unlucky guy, hope this is so easy to tame for all users.
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Don't get me wrong.... I have spent many decades in search of audio nirvana, and just when I was about to give up on digital audio reproduction (and go back to analog - turntable and reel-to-reel), I discovered the May DAC. So, for me, it's this DAC (no sound coupling caps in the signal path), and then straight to Aleph J (no caps as well - I removed the C1), and then to my Dynaudio speakers. With HQ Player, I get exceptional sound. So, my standards are quite high.
However, when the Korg NuTube pre-amp was released to wider masses, I discarded it straight away - because of those 2 sound coupling caps in the signal path. Later on... I learned that NuTube likes to ring and needs special attention., HOWEVER, as I posted before, I firmly believe that, for the money, it definitely should be explored... and it seems that many have done just that with great success.
However, when the Korg NuTube pre-amp was released to wider masses, I discarded it straight away - because of those 2 sound coupling caps in the signal path. Later on... I learned that NuTube likes to ring and needs special attention., HOWEVER, as I posted before, I firmly believe that, for the money, it definitely should be explored... and it seems that many have done just that with great success.
You 'think' your standards are high. What you personally think is best does not necessarily correlate to a 'high standard'
You must hate the fact that the music you listen to might have gone through hundreds of coupling caps.
You know better. I meant it in general BTW. If quality would be the deciding factor there would be less buyers.
In this specific case the DAC chip itself is not to write home about. I never got it to be good enough and even discarded the PCBs with it.
The leader-follower principle works OK 🙂
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