OK, Who let the dogs(Sound) out? Yeah. First impressions listening to Diana Krall Live in Paris. Yeah this SRC does work well. It is like moving from an MP3 to a FLAC. It is not that subtle if yoor system resolves it. A level of veiling is removed. Soundstage depth is distinctly improved same for width. Essentially it regains more dimensionality. Is it just the highs. Heck No. Is it the midrange. No. So what about the Low end.....It does it everywhere. The sense of dimensionality, the applause is more real though applause is HARD to reproduce, the timing and little details come out just as when I changed over the AVCC from the LT1963 to the LT3042. Everywhere you say? Yes. Now maybe the output of the SRC has less jitter but whatever it is doing it is making it better at this time.
Now one warning though. If your DAC still has too much sheen and has edginess, I think this SRC could splash that in your face too much.
I will give more listening but it appears to do what it does well. It is able to retrieve more information on the recording than what we thought was there. Pretty amazing that it can be done.
At first I could not get it to run off the USB on my PC. My motherboard has a couple USB ports that is supposed to put out a cleaner 5V for USB based dacs. So I used it on a USB phone adapter.
Me thinks that I will build a dedicated 5V linear source using a 317 from my box and see how much more this thing can pump out. Maybe I will order another LT3042 to power this thing.
So Markw4, so far so good. It is not a cureall but possible one of the last steps.
Now one warning though. If your DAC still has too much sheen and has edginess, I think this SRC could splash that in your face too much.
I will give more listening but it appears to do what it does well. It is able to retrieve more information on the recording than what we thought was there. Pretty amazing that it can be done.
At first I could not get it to run off the USB on my PC. My motherboard has a couple USB ports that is supposed to put out a cleaner 5V for USB based dacs. So I used it on a USB phone adapter.
Me thinks that I will build a dedicated 5V linear source using a 317 from my box and see how much more this thing can pump out. Maybe I will order another LT3042 to power this thing.
So Markw4, so far so good. It is not a cureall but possible one of the last steps.
OK, been listening. Then checked the temps on the heatsinks for AVCC. Much warmer than they were before the up sampling. So one needs to pay attention to the increased current demand. My guesstimate is that the increased current might have doubled or tripled.
This DAC is getting so much better I've decided to go all in and put in a SuperReg for the IV stage PS. The final install will take longer.
I'm also now beginning to look for a superior clock.
This DAC is getting so much better I've decided to go all in and put in a SuperReg for the IV stage PS. The final install will take longer.
I'm also now beginning to look for a superior clock.
Looks like you are hearing a very slight remaining amount of distortion that comes out of SRC4392, although as you say, it helps a lot and once you hear it you would rather have it there than not.
However, the good thing about AK4137 is it doesn't have that little thing you are still hearing. That effect is replaced with a more detailed yet more easy and natural sound. The difference takes no effort to hear, if you tried it you would definitely keep the AK4137 and replace the SRC4392.
Isn't it interesting how it keeps getting better than expected because you never had any way of knowing all the information that is really on a CD, you just thought you did. It gets better as more of that information becomes audible and and turns out to be good sounding. No idea mastering ADCs were that good.
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Well, not only us but PS Audio has been touting that there is more information on a CD than we thought. They upsample PCM via an FPGA to DSD and then output it using transformers on their top end DAC. Their DAC jr. does the output with SS. Both are in totally different snack brackets. The AK4137 might be doing something similar in some fashion but it sure looks like when upsampling is done right, it works. Why? that is a mystery because it would seem that they are creating bits out of nowhere but not really. The algorithm is likely a form of SWAG. Sophisticated Wild As Guessing.
Upsampling seems to be doing more than one thing. One thing has to do with reconstruction filter transition band space, but there seems to be something else too. It may have to do with jitter, but I think it would probably take some very good test equipment to get a better understanding of it. I do know that DAC-3 only upsamples to 211kHz and it still sounds a little better than by modded DAC at 960kHz. But, they aren't using a 100MHz clock with it's higher jitter either. They do have a some nice test equipment at Benchmark and they have done a lot of measuring to help guide their design, we know that. And they say they have designed to get jitter (horizontal time axis errors) and digital processing errors (vertical amplitude axis errors) as low as they can.
Well over the last period, I've connected the 4392 SRC converter to a different power supply. I elected to use a very simple solution. I used a rechargeable phone power pack with a USB output for 5V.
The improvement was very easy to discern once again. The soundstage increased and imaging was much more stable. Some of the extra sibilance or distortion the little that the SRC imparts was reduced a bit but was not clear of the issue. Markw4, informs me that the AK4137 does not have or has much less of this distortion, so that will need to be sampled in the future. He is currently waiting to evaluate another AK4137 that is priced very attractively.
In the next while I will continue to use the DAC at the stage it is right now while I acquire a new crystek clock and await the SuperRegulator power supply PC board to arrive. When these two items have arrived, I will then case up the project.
I added some additional heatsinking for one of LT3042 because the high upsampling frequency is causing the Digital lines of the DAC to consume significantly more current. I will also have to drill some vent holes directly below and above the heatsinks to keep the components cool.
So far this DAC is now at a stage where every change is resolved very quiickly. It is a revealing DAC without harshness, in fact, if a component does introduce some distortion like the 4392 SRC converter, it will reveal it. The nice aspect to me is that all the components to bring it here are pretty much off the shelf. The only real construction will be the SuperRegulator Power Supply which is readily available at the DIYAUDIO store. Thus this can be a straighforward project for the intermediate builder.
The improvement was very easy to discern once again. The soundstage increased and imaging was much more stable. Some of the extra sibilance or distortion the little that the SRC imparts was reduced a bit but was not clear of the issue. Markw4, informs me that the AK4137 does not have or has much less of this distortion, so that will need to be sampled in the future. He is currently waiting to evaluate another AK4137 that is priced very attractively.
In the next while I will continue to use the DAC at the stage it is right now while I acquire a new crystek clock and await the SuperRegulator power supply PC board to arrive. When these two items have arrived, I will then case up the project.
I added some additional heatsinking for one of LT3042 because the high upsampling frequency is causing the Digital lines of the DAC to consume significantly more current. I will also have to drill some vent holes directly below and above the heatsinks to keep the components cool.
So far this DAC is now at a stage where every change is resolved very quiickly. It is a revealing DAC without harshness, in fact, if a component does introduce some distortion like the 4392 SRC converter, it will reveal it. The nice aspect to me is that all the components to bring it here are pretty much off the shelf. The only real construction will be the SuperRegulator Power Supply which is readily available at the DIYAUDIO store. Thus this can be a straighforward project for the intermediate builder.
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Since the last posting I am still listening with the SRC. Each time I listen I come back in awe of what I am now hearing.
Does it get better. Yes. I will be ordering a new Crystek oscillator. The nice thing is that underneath the current oscillator, there should be SMD pads that allow easy mounting of the Crystek 575 oscillator. YEAH. That WAS a nice discovery.
Next thing I would do instead and about to do....I will put the 317/337 regulators for the op amps back in and will use them as preregulators for the SuperRegulator power supply that I am now in the process of building. So If I had to start again, all I would need to do is replace one resistor on each channel that sets the regulator output voltage and then cut traces of both outputs of the regs and lead those to my SuperReg PS boards. Since the SuperReg PS boards feature remote sense, my wiring back to the PS will be accomodated in the feedback, but still good wiring to there is warranted.
Next thing I will do is this. I will remove the LT1963 for the AVCC, the left one. and use the rectified DC circuit built on the DAC board. The LT1963 built onto the board will be sufficient for the Vdd signals for the DAC. and will be retained. However, since I already have 2 LT3042s, I will then cut the trace that leads from the activated LT1963 and branches out to the oscillator/clock. This will now be fed directly from a dedicated LT3042. Retain the ferrite bead in the path as this helps with filtering very HF hash on the line. The pads from the removed LT1963 will then lead to my LT3042s which will both be fitted with their own LT317 preregulators.
And I also decided to get a nice case for the power supply box.
When the SRC converter is used, the currents demanded on the Vdd lines (1.2V) increase dramatically.
It will I hope only get better.
In the meantime, I might be experimenting rolling op amps in the final stage. However my tube based Balanced to Single ended converter is beckoning.
This is turning out to be much better than I had anticipated.
Does it get better. Yes. I will be ordering a new Crystek oscillator. The nice thing is that underneath the current oscillator, there should be SMD pads that allow easy mounting of the Crystek 575 oscillator. YEAH. That WAS a nice discovery.
Next thing I would do instead and about to do....I will put the 317/337 regulators for the op amps back in and will use them as preregulators for the SuperRegulator power supply that I am now in the process of building. So If I had to start again, all I would need to do is replace one resistor on each channel that sets the regulator output voltage and then cut traces of both outputs of the regs and lead those to my SuperReg PS boards. Since the SuperReg PS boards feature remote sense, my wiring back to the PS will be accomodated in the feedback, but still good wiring to there is warranted.
Next thing I will do is this. I will remove the LT1963 for the AVCC, the left one. and use the rectified DC circuit built on the DAC board. The LT1963 built onto the board will be sufficient for the Vdd signals for the DAC. and will be retained. However, since I already have 2 LT3042s, I will then cut the trace that leads from the activated LT1963 and branches out to the oscillator/clock. This will now be fed directly from a dedicated LT3042. Retain the ferrite bead in the path as this helps with filtering very HF hash on the line. The pads from the removed LT1963 will then lead to my LT3042s which will both be fitted with their own LT317 preregulators.
And I also decided to get a nice case for the power supply box.
When the SRC converter is used, the currents demanded on the Vdd lines (1.2V) increase dramatically.
It will I hope only get better.
In the meantime, I might be experimenting rolling op amps in the final stage. However my tube based Balanced to Single ended converter is beckoning.
This is turning out to be much better than I had anticipated.
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Hello Mike
I am experimenting also different op amps on final stage and i have a question
The final stage is a simple op amp and i would like to test a double amp on the final stage .
What to do with the op amp no used ..... how to connect the inputs non used Thanks for your help
I have received two samples AD797 from analog devices and the results are very good ...better than the LME49710 ( Final stage )
Serge
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According to the data I remember the dual are supposed to be totally independent like the single so no cross talk should occur. I would short the inputs to mute it, thereby no signal entering.Hello Mike
I am experimenting also different op amps on final stage and i have a question
The final stage is a simple op amp and i would like to test a double amp on the final stage .
Thanks for your help
I have received two samples AD797 from analog devices and the results are very good ...better than the LME49710 ( Final stage )
Serge
I think the board suffers a bit from inadequate HF bypassing. So I'd recommend putting some 0.047-0.1uF HF bypass caps from the power pins to ground on the underside. That helped remove all tiny traces of harshness with the LME497x series. The 797 might really need it.
I will also be using the ladder strategy that Allo used a bit more. I've already done that with the 470uF immediately entering the AVCC line splitting to - 47uF tantalums - 0.1uF to DAC but I will be adding some 1uF films if I can find some tiny ones, then encasing it with glue to minimize vibrations. I know they exist because my crossover has a couple of them.
Yes, the 797 are also in the plans but I have some OPA1611 & OPA1612 coming as well.
I have tested the AD797,OPA1611,OPA1612 and the LME49710 on the final stage.
The AD797 and OPA1612 are new samples .
The OPA1611 and LME9710 are samples but older !!!
Without effort the AD797 and OPA1612 sound better than the OPA1611 and LME47910 .More level, space ,more energy in the bass...
to be continued
Serge
OPA1612 is a dual. All others mentioned are singles. How is the dual being compared with the singles?
In particular, why would the OPA1612 dual sound better than the OPA1611 single, because it is in a different socket and a different circuit? If that's why, then why would the difference be attributed to the opamps?
In particular, why would the OPA1612 dual sound better than the OPA1611 single, because it is in a different socket and a different circuit? If that's why, then why would the difference be attributed to the opamps?
I didn't say stupid. How did you do it? On an adapter? I am trying to make sense of how there could be a difference. Obviously, I can't see what you are doing there. Maybe you have done something very clever, but right now it is not clear to me or probably anyone reading how to get different results with what seems like it should be the same. The only difference that you described so far is an age difference. Something else must be different too, at least a socket adapter? No?
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Yes, he is using one amp in the dual hence the initial question. This begs the question of why? Sample variance? The OPA1611 and 1612 seem to carry the same specs. But the 49720 and 49710 have different specs. So the results are more intriguing. Again without someone trying it or many, themselves, it could be a one off thing that gets the results.
We cannot really confirm until many more people get the same results.
Looking at the specs on the OPA1611, you can see its ability to put out more current is superior to the 49710. Actually, same ball park as the 797. Does this give better bass and open sound. I don't know but I do remember Walter Jung pointing out that it is best to not use the output stages from ICs to drive circuits that might need current. On the surface, current buffer stages should not be necessary in a preamps. However when we properly integrate them, the bass and sound typically opens up. Explanation...it is there but the elementary circuit analysis says no difference but it exists and I am sure there is some deep technical explanation.
Maybe we have found a good fit here. I will report back when I get my hands on the OPA1611 and 1612s...and 797s.
At the level of sound we are messing with now, personal preferences in synergy with your speakers, headphones etc. is the magic mix IMO. Something could be more accurate but how much does it matter? Is it so far off the sota that it sounds bad? I'm not sure.
We cannot really confirm until many more people get the same results.
Looking at the specs on the OPA1611, you can see its ability to put out more current is superior to the 49710. Actually, same ball park as the 797. Does this give better bass and open sound. I don't know but I do remember Walter Jung pointing out that it is best to not use the output stages from ICs to drive circuits that might need current. On the surface, current buffer stages should not be necessary in a preamps. However when we properly integrate them, the bass and sound typically opens up. Explanation...it is there but the elementary circuit analysis says no difference but it exists and I am sure there is some deep technical explanation.
Maybe we have found a good fit here. I will report back when I get my hands on the OPA1611 and 1612s...and 797s.
At the level of sound we are messing with now, personal preferences in synergy with your speakers, headphones etc. is the magic mix IMO. Something could be more accurate but how much does it matter? Is it so far off the sota that it sounds bad? I'm not sure.
Put in some 797s in place of the LME49710s. Can't say it is dramatic but the soundstage has shifted. With the LME49710s, you are there right in front with the performance. The 797s throws you back and you are now listening through a window. As for the bass, can't say yet. One thing is that the 797 has a different perspective, it kind of sounds like you are headed for the tube smoothness and relaxed sound BUT it loses space, whereas with tubes you gain spatiality.
Not sure it is my cup of tea, if I want a relaxed sound, I want more dimensionality.
I'll let it break in and see if there is a difference. Otherwise, it does show why this chip 797 is somewhat controversial. It is pleasant to the ears just not involving. Some may like this character.
Not sure it is my cup of tea, if I want a relaxed sound, I want more dimensionality.
I'll let it break in and see if there is a difference. Otherwise, it does show why this chip 797 is somewhat controversial. It is pleasant to the ears just not involving. Some may like this character.
The thing is if someone has a distorted, edgy dac and they put in an opamp that acts like a filter on that sound it may seem like the opamp is itself is better sounding. In reality, it can be that there is a problem and someone has stuck a bandaid on it and called it fixed. That can be problem where people have no good reference for comparison, or even a good headphone amp to let them hear what the sound is really like with good accuracy.
Correct without good reference for comparaison it's very difficult to have an objective idea about the op Amp .
i have a Woo audio wa6 headphone amp and a Sennheiser HD650 .
Even with a good amp ( tube
) , a day such aop is better than another and the other day it's the opposite.......A story without end
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