Guess I'll take a chance and talk about something here that is fairly new to me and something I was not expecting at all.
It started like this: Jam, my high end audio designer friend came over one day and pulled out some XLR cables. He said to try them out and see if I notice if they sound different at all from the cables I normally was using. I didn't expect anything audible so I asked, what if I don't hear any difference? He said, then you need to get your ears checked. Haha, I thought, very funny - NOT.
Dac was down that day for some modding, but a few days later I had it working again and decided to try Jam's cables and get it over with. I connected them between the XLR outputs on AK4499 eval board and the Neurochrome HP-1 headphone amp input.
Wow! Everything sounded better, less distorted, and the difference was easy to hear! I was basically stunned, never expected it.
I saw that Jam used gold plated Neurtrik XLR connectors, so I ordered several and made up several XLR cables all 3' long. Each of the cables I made were from different types of mic cable, twisted shielded pair. Also ordered a 3' XLR of the latest Mogami Gold star quad. Had an older piece of pre-star quad Mogami Gold that I made into a cable. Every single cable sounded different.
I thought, I can't talk about this on the forum, it will drive them crazy, bring out all the crazys, have people telling me I am imagining things or lying. That still might happen even if writing in this thread, we will see.
Anyway, turns out Jam had his own wire manufactured based on a lot of trial and error research he did. He also designed and had manufactured some speaker wire. Since then I have had an opportunity to try those too and they sound better than what I was using before.
Only a few people have ever tried Jam's audio cables. Just some of his friends. Some of them were serious audiophiles who preferred Jam's cables over $2,000 and $4,000 cables they had been using before.
The whole thing about cables I used to think was phony. I still don't understand why it hasn't become common accepted engineering knowledge discovered a long time ago.
Next year one of Jam's audio businesses will start selling cables designed by him. Most here will probably never hear what the cables can do because they are going to be pretty expensive, although less so than many high end audio cables. That's something I feel is unfortunate, but probably not likely to change soon.
All I can do myself is offer people who come to visit to learn about dacs and audio stuff here in Auburn to also have an opportunity to swap around XLR, RCA, and speaker cables and see what they think about it. If they don't want to try listening to different cables they don't have to. It's just something I expect other people might find as surprising as I did at first.
EDIT: By the way, I did not write the above for any commercial purpose. My intent is only to describe the facts of what happened that I learned something from. Same as all the other posts in this thread when I was learning about how to make my modded dacs sound better. Now I have learned another way to make my system sound better, less distorted, more clean and true to the audio coming from the source device. No reason why it should be secret when I have talked about my other personal discoveries here.
Also, sorry for using the word, I, so much. Probably should have taken more time to edit and rewrite those out.
It started like this: Jam, my high end audio designer friend came over one day and pulled out some XLR cables. He said to try them out and see if I notice if they sound different at all from the cables I normally was using. I didn't expect anything audible so I asked, what if I don't hear any difference? He said, then you need to get your ears checked. Haha, I thought, very funny - NOT.
Dac was down that day for some modding, but a few days later I had it working again and decided to try Jam's cables and get it over with. I connected them between the XLR outputs on AK4499 eval board and the Neurochrome HP-1 headphone amp input.
Wow! Everything sounded better, less distorted, and the difference was easy to hear! I was basically stunned, never expected it.
I saw that Jam used gold plated Neurtrik XLR connectors, so I ordered several and made up several XLR cables all 3' long. Each of the cables I made were from different types of mic cable, twisted shielded pair. Also ordered a 3' XLR of the latest Mogami Gold star quad. Had an older piece of pre-star quad Mogami Gold that I made into a cable. Every single cable sounded different.
I thought, I can't talk about this on the forum, it will drive them crazy, bring out all the crazys, have people telling me I am imagining things or lying. That still might happen even if writing in this thread, we will see.
Anyway, turns out Jam had his own wire manufactured based on a lot of trial and error research he did. He also designed and had manufactured some speaker wire. Since then I have had an opportunity to try those too and they sound better than what I was using before.
Only a few people have ever tried Jam's audio cables. Just some of his friends. Some of them were serious audiophiles who preferred Jam's cables over $2,000 and $4,000 cables they had been using before.
The whole thing about cables I used to think was phony. I still don't understand why it hasn't become common accepted engineering knowledge discovered a long time ago.
Next year one of Jam's audio businesses will start selling cables designed by him. Most here will probably never hear what the cables can do because they are going to be pretty expensive, although less so than many high end audio cables. That's something I feel is unfortunate, but probably not likely to change soon.
All I can do myself is offer people who come to visit to learn about dacs and audio stuff here in Auburn to also have an opportunity to swap around XLR, RCA, and speaker cables and see what they think about it. If they don't want to try listening to different cables they don't have to. It's just something I expect other people might find as surprising as I did at first.
EDIT: By the way, I did not write the above for any commercial purpose. My intent is only to describe the facts of what happened that I learned something from. Same as all the other posts in this thread when I was learning about how to make my modded dacs sound better. Now I have learned another way to make my system sound better, less distorted, more clean and true to the audio coming from the source device. No reason why it should be secret when I have talked about my other personal discoveries here.
Also, sorry for using the word, I, so much. Probably should have taken more time to edit and rewrite those out.
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The whole thing about cables I used to think was phony until it isn't.
It takes a lot of listening to develop the skills to pick them out. Some people never develop the skills or the differences don't matter to their senses. Some are more sensitive to it. So tread carefully when testing.
You've now graduated to the audiofool club or demoted to?
It takes a lot of listening to develop the skills to pick them out. Some people never develop the skills or the differences don't matter to their senses. Some are more sensitive to it. So tread carefully when testing.
You've now graduated to the audiofool club or demoted to?
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Mike,
Small differences become much easier to hear on a system that is carefully designed to be as low distortion as possible in the first place. Usually, there is a whole lot of masking going on that hides small details. When unmasked, I think they probably become observable to most people. Can't say for sure until enough people come by to listen. Then I will have at least a tiny bit of data.
Small differences become much easier to hear on a system that is carefully designed to be as low distortion as possible in the first place. Usually, there is a whole lot of masking going on that hides small details. When unmasked, I think they probably become observable to most people. Can't say for sure until enough people come by to listen. Then I will have at least a tiny bit of data.
How about that, at the peak of shopping season, you post praising testimonies about someone's audio business products, then go in denial mode. There is a legitimate way to advertise on this forum. What you did is called "freeload".
More like hired as official business associate.
still not clear whether I can use AK4118 digital Interface output to Fifo Pi Input
without receiver pi
same question about JLsounds I2S over usb
without receiver pi
same question about JLsounds I2S over usb
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Yes, have made a few.
It depends on the DAC output impedance. If you have a DAC that is true CCS
output (very high impedance), the circuit can work very well.
If the DAC has low OP impedance / high current swing, you will end up with too much distortion.
I have spent considerable time on LTspice playing with various open loop, I-V
converters for Sabre DAC. I came to the conclusion that unless you run
absolutely huge quiescent currents, they all just make too much distortion.
TCD
Both AK4118 and I2soverUSB have I2S outputs. RPi GPIO bus has I2S outputs that go into FIFO_Pi if you plug the two together. If you don't plug FIFO_Pi into RPI, then you can plug any I2S outputs you want into the I2S inputs on FIFO_Pi.
So the answer to your questions is yes to both.
Don't forget to hookup the grounds too.
thank you Mark
what Is your opinion regarding different output stage to ES9038 like [Resolved] PCM1794A: Mono differential output - Audio forum - Audio - TI E2E support forums or IVY III The IVY Balanced Line Stage Instead of last recommended ES9038Q2M Board
that way there Is no bother with Inserting Vref
what Is your opinion regarding different output stage to ES9038 like [Resolved] PCM1794A: Mono differential output - Audio forum - Audio - TI E2E support forums or IVY III The IVY Balanced Line Stage Instead of last recommended ES9038Q2M Board
that way there Is no bother with Inserting Vref
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Hi i wanted to use it for.this q2m and the pro version too.
Bascally i dsnt have to be open loop.
I built an class a amp and now i like very much is sound so if it can work in class a mode would be the best. I will keep seeking.
and considerigThanks Szabolcs
The PCM1794 circuit will give more distortion since the I/V output will always be below ground, which gives a common mode offset for the differential summing stage. Ideally, Vref should be adjusted as I described to produce zero common mode offset at the I/V outputs.
The Ivy circuit isn't the best sounding. There are good reasons TP went on to design yet another try at an output stage after Ivy. Not ideal that time either, they don't listen carefully enough, IMHO only, of course.
My recommendations for output stages haven't changed yet.
The Ivy circuit isn't the best sounding. There are good reasons TP went on to design yet another try at an output stage after Ivy. Not ideal that time either, they don't listen carefully enough, IMHO only, of course.
My recommendations for output stages haven't changed yet.
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The purpose of class A is to get good sound quality, is it not?
You won't get good sound quality with this dac chip using a class A output stage. The dac chip is not designed to work that way.
Also, I keep trying to tell people there is some low level RF that comes out of the dac chip. It is likely to come out of the output stage differential mode, common mode, or both modes at once. The RF can easily affect sound quality of any amplifier that follows the dac output stage circuit. It can also affect the output stage itself. Still recommended to use the standard 3-opamp output stage and to attend to all the little issues we already know about that can adversely affect sound quality. Then you will have the best results.
With q2m i built the 3 opa ív stage (by freezebox 1294). It sounds ok. Just simple fall in love with the class a voice and this is why concidered if possible to apply it here too.
Thanks i will re thinm
If the 3-opamp output stage with OPA1612 only sounds okay, then it means there are other things wrong with the dac: AVCC power supply, clock jitter, separate VCCA/Clock/DVCC voltage regulators, ground plane, output stage mounting, DPLL not set to minimum stable value, etc. Look to one or more of those things that still hasn't been done. The problem will not be fixed by a Class A output stage since the output stage is not what is causing the problem.
Hi Terry,
Have you tested Pass I/V too?
D1 IV Mosfet
Also an intersting article from Nelson:
http://www.firstwatt.com/pdf/art_zen_iv.pdf
What have you tested?
Thanks,
Sz.
some thoughts about differential I/V one can find inhttps://www.diyaudio.com/forums/digital-line-level/340331-questions-es90xx-output-stages.html
for PRO chips OPA1632 with an output buffer works pretty well.
Hi i wanted to use it for.this q2m and the pro version too.
Bascally i dsnt have to be open loop.
I built an class a amp and now i like very much is sound so if it can work in class a mode would be the best. I will keep seeking.
Thanks Szabolcs
OK, so if it has mirrors and has feedback then we are talking about a CFB,
discrete opamp, I think...
We also tried this approach years ago. It did sound good but there are two issues:
a/ The DAC we used it with had fairly moderate OP impedance and not so high current swing
b/ Assuming it's a current FB opamp, you cant wrap a pole of the LPF around it without extra compensation methods. Usually (and the way I solved it) was
adding a resistor from feedback 'node' in series with -IP to lower BW and allow stable operation. This also increases distortion. The CFB topology
already has limited open loop gain by nature of it's design so it will end up being pretty high distortion when used for Sabre, especially the Pro version.
There are some discrete voltage opamps that I believe would be as good or better than the usual OPA1611/2 but they are quite complex and very
expensive. They both use two pole compensation, a 'jensen enhanced' input stage and as usual, high current OP stage. All things that normal monolythic
opamps don't (can't) have.
To brew one yourself would be a massive job and you would need access to a
really good distortion analyzer to track performance.
We sound like we are trying to discourage you... that's not in the spirit of DIY!
TCD
on the other hand the same OPA1612 will sound different depending on their power supply z(f) dependance. here those big film caps Mark recommends matter, or a good shunt reg then. btw I tried some discrete in I/V, but found 50mA quiscent not very practical and the THD still worse than OPA1612.
if the output stage is too weak for an opamp choosen then some buffering like bellow may do the trick
if the output stage is too weak for an opamp choosen then some buffering like bellow may do the trick
Attachments
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Or you can use something like BUF634 in wide BW mode. It is complementary,
runs quite a bit of quiescent and can do 250mA.
T