They should be very close to the same in terms of sound, if not exactly the same. The difference is that pin 1 on CCHD is the enable/disable pin (which is used for some dual audio clock systems). For CVHD, pin 1 is a control voltage input to allow very a very tiny amount of clock frequency tuning (typically of no use for audio).
Kay, and others interested in clock division and synchronization for best AK4137 sound: The last few days I have been looking into the possibility of using a simpler clock divider that does not have a variable delay capability. Unfortunately, I find there are some very difficult issues I am probably not equipped to examine more closely.
From trial and error, I found that adjusting AK4137 DSD timing by 150ps can have an audible effect on sound quality, and that a difference of 150ps from the best setting can be enough to make the sound quality significantly worse. It means that under the test conditions I have here that the timing resolution needed corresponds to about +-1% of the MCLK clock period (the difference period expressed in reciprocal form as frequency would correspond with about 10GHz). At the moment the best I have been able to muster is a 600MHz scope with passive probes, which is simply not good enough to measure what I want to know. Another issue is that LVCMOS typically operates at fairly high impedance levels, far too high for effective transmission line behavior. Thus, clock pulses look like sine waves and rise times look very slow relative to clock periods. Hard to say from looking at waveforms exactly when timing is right. There are also issues trying to use passive scope probes at very high frequencies. Differential probes would help a lot, but I don' have them and they cost almost $3,000 each. So, not going to happen.
The bottom line is that right now the only way I have to make the dac operate where it sounds best is to coarsely adjust timing with lengths of coax cables where I am using LVDS clock signals rather than LVCMOS. Fine time is adjusted with LMK01000 delay line(s). It works and it is stable over time, but I don't know how to design a simpler way, or even if a simpler way can be designed since I can't really measure at what exact time it sounds best (AK4137 DSD clock vs dac chip MCLK).
Considering the foregoing, I think will work on trying some experiments running the dac at lower clock speeds, perhaps as low as 25MHz or so. In that case, the dac could be run synchronously with AK4137 (although I don't know how that will sound).
Also, I should have an opportunity to try the same things with AK4499 since it comes with an AK4137 included on the evaluation board. At some point I should be able to opine about what sounds best and then see where to go from there.
In theory, it should be possible to design a little LMK01000 board that would cost a lot less that the evaluation board I am presently using. The chips themselves cost about $15 each in low quantities. Then there are some LVDS converter chips also in use.
In the meantime there are various experiments that could be done, or people could try synchronous clocking of AK4137 and hope for the best. There is a fairly large timing window where DAC clock vs MCLK timing provides reasonably good sound quality and DPLL bandwidth can be set to 1 with excellent stability. Also, the dac can be put into master mode and some effort could be made to try to align a synchronously clocked AK4137 chip generated DSD clock with the DSD clock generated by the dac in master mode (a scope would be needed to see that). That should produce pretty good sound quality, but most likely not the very best SQ possible with more or less perfect timing.
From trial and error, I found that adjusting AK4137 DSD timing by 150ps can have an audible effect on sound quality, and that a difference of 150ps from the best setting can be enough to make the sound quality significantly worse. It means that under the test conditions I have here that the timing resolution needed corresponds to about +-1% of the MCLK clock period (the difference period expressed in reciprocal form as frequency would correspond with about 10GHz). At the moment the best I have been able to muster is a 600MHz scope with passive probes, which is simply not good enough to measure what I want to know. Another issue is that LVCMOS typically operates at fairly high impedance levels, far too high for effective transmission line behavior. Thus, clock pulses look like sine waves and rise times look very slow relative to clock periods. Hard to say from looking at waveforms exactly when timing is right. There are also issues trying to use passive scope probes at very high frequencies. Differential probes would help a lot, but I don' have them and they cost almost $3,000 each. So, not going to happen.
The bottom line is that right now the only way I have to make the dac operate where it sounds best is to coarsely adjust timing with lengths of coax cables where I am using LVDS clock signals rather than LVCMOS. Fine time is adjusted with LMK01000 delay line(s). It works and it is stable over time, but I don't know how to design a simpler way, or even if a simpler way can be designed since I can't really measure at what exact time it sounds best (AK4137 DSD clock vs dac chip MCLK).
Considering the foregoing, I think will work on trying some experiments running the dac at lower clock speeds, perhaps as low as 25MHz or so. In that case, the dac could be run synchronously with AK4137 (although I don't know how that will sound).
Also, I should have an opportunity to try the same things with AK4499 since it comes with an AK4137 included on the evaluation board. At some point I should be able to opine about what sounds best and then see where to go from there.
In theory, it should be possible to design a little LMK01000 board that would cost a lot less that the evaluation board I am presently using. The chips themselves cost about $15 each in low quantities. Then there are some LVDS converter chips also in use.
In the meantime there are various experiments that could be done, or people could try synchronous clocking of AK4137 and hope for the best. There is a fairly large timing window where DAC clock vs MCLK timing provides reasonably good sound quality and DPLL bandwidth can be set to 1 with excellent stability. Also, the dac can be put into master mode and some effort could be made to try to align a synchronously clocked AK4137 chip generated DSD clock with the DSD clock generated by the dac in master mode (a scope would be needed to see that). That should produce pretty good sound quality, but most likely not the very best SQ possible with more or less perfect timing.
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What would you say? Can you help me? I want to change the registry on the dac. Sorry for my english. I don't have translate now.
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What would you say? Can you help me? I want to change the registry on the dac. Sorry for my english. I don't have translate now.
Hey.
I'm also waiting for the clock divider for ak4137. If there is something simpler, I'm all for it!) On Ali, ak 4137 board appeared with a remote control and a display. All the same, I would like to keep the control of the DAC using the remote. here it is 4 711.99 rub. 11% DISCOUNT | AK4137 flagship high-end DAC SRC audio 384 K 32Bit DSD256 DSD PCM conversion
AK4137 Flagship High end DAC SRC Audio 384K 32Bit DSD256 DSD PCM Conversion-in Switch Caps from Home Improvement on Aliexpress.com | Alibaba Group. yes, not cheap. but the functions remain) I would like to hear your opinion about it - does it make sense? I'm not talking about the price.
if I do not decide on the purchase of an expensive board, I ask you in advance to advise which one to buy the board version ak4137. there are three 1,767.75 rubles. 52% DISCOUNT | New AK4137 I2S / DSD Sample Rate Conversion Board Supports PCM / DSD Exchange Supports Auxiliary Input for Hi-Fi AmplificatoreG8-003
New AK4137 I2S/DSD Sample Rate Conversion Board Supports PCM/DSD Interchange Supports DOP Input for Hifi AmplificatoreG8 003-in Replacement Parts & Accessories from Consumer Electronics on Aliexpress.com | Alibaba Group. Standard, low and 768k.
I'm also waiting for the clock divider for ak4137. If there is something simpler, I'm all for it!) On Ali, ak 4137 board appeared with a remote control and a display. All the same, I would like to keep the control of the DAC using the remote. here it is 4 711.99 rub. 11% DISCOUNT | AK4137 flagship high-end DAC SRC audio 384 K 32Bit DSD256 DSD PCM conversion
AK4137 Flagship High end DAC SRC Audio 384K 32Bit DSD256 DSD PCM Conversion-in Switch Caps from Home Improvement on Aliexpress.com | Alibaba Group. yes, not cheap. but the functions remain) I would like to hear your opinion about it - does it make sense? I'm not talking about the price.
if I do not decide on the purchase of an expensive board, I ask you in advance to advise which one to buy the board version ak4137. there are three 1,767.75 rubles. 52% DISCOUNT | New AK4137 I2S / DSD Sample Rate Conversion Board Supports PCM / DSD Exchange Supports Auxiliary Input for Hi-Fi AmplificatoreG8-003
New AK4137 I2S/DSD Sample Rate Conversion Board Supports PCM/DSD Interchange Supports DOP Input for Hifi AmplificatoreG8 003-in Replacement Parts & Accessories from Consumer Electronics on Aliexpress.com | Alibaba Group. Standard, low and 768k.
Regarding the isolator board, it looks the same as the Sparkfun version, so that is probably okay.
The Arduino Nano is a rather old Arduino design. Some low cost boards may not come with the Arduino bootloader installed, and it needs to have a rather old version. Then again, it might work fine and come with the boot loader, they look maybe cheap enough to try.
The pin header extender cables would probably work, but some cables like that are made out of some kind of steel wire or something that can't be soldered. If you want to use them as they come and not cut off any excess length then they might be okay. Its like kind of hit or miss to find ribbon cables with pre-attached pin connectors that are made out of copper wire, or tinned copper wire that could be soldered if there was some wish to shorten them or to attach one end to a different connector. For that reason, I also purchase un-terminated ribbon cable and attach my own connectors that I both crimp and solder.
The higher cost AK4137 board you linked to is the one that supports SPDIF, TOSLINK and AES inputs. If you only need USB then you don't need that one. However, the particular one you linked to doesn't have the same display I am used to seeing. Most seem to have a larger display that is not attached to the board. Also, it looks like that one has the output pin header already soldered to the board. The boards like that one I am used to seeing come with a separate pin header you can solder on if you want, or leave off. I would prefer not to have the pin header soldered on because that is the one that needs gold pins for minimum jitter.
The lower cost AK4137 board you linked to looks like the kind I normally see. It does not support SPDIF inputs, only USB is supported. If that's all you need, then it should be fine. Unfortunately, those boards come with the output pin connector already installed and it can be a little bit hard to remove and replace with gold pins to reduce jitter.
Regarding clock division, I have not given up on trying to find a lower cost way than the way I used, but it may take some time (months) to see how that will work out. In the meantime, AK4137 can still be used with the existing clocks, and some reduction in DPLL bandwidth is still possible. If there is interest, I could explain how to remove one of the clocks and replace it with a ufl connector. Also, I installed a ufl connector at one of the GPIO pins on the dac board. The dac chip has two GPIO pins. The dac board we use comes with both GPIO pins already in use: one for SPDIF and one for TOSLINK (optical). We could talk about how to possibly retain both of those functions, while freeing up one GPIO pin to export the MCLK signal from the dac. For low cost frequency division I would suggest using the IDT ICS542 divider chip. It could be mounted somewhere to divide MCLK by 4 to produce 25MHz for AK4137 clocking. Even though the divided clock signal would be at 25MHz, we would remove the 22.5MHz clock on the AK4137 board since that is the one used for DSD. Depending on how it sounds we might try inverting the phase of the divided clock signal using a small single channel logic chip such as SN74LVC1G04 or something similar. If still sound quality issues we might look at reclocking with some D-Flip Flop chip that might be clocked by the dac chip running in master mode. None of the above things can guarantee very best DSD sound quality if running the dac using a 100MHz clock and using AK4137 for DSD conversion. But they are probably worth trying to find out how well they do work, and we just might get lucky too.
In other words, there are a number of things that could be tried without spending a lot of money on an LMK01000 evaluation board and LVDS interface chips. (Or without designing and making boards for LMK0100 with LVDS interface boards located where they will work, and where RF leakage won't make the dac sound worse.)
Also, I should mention I have some commitments for spending time on AK4499 when it comes out. Its possible the same sort of questions about clocking may arise with it. Don't know yet.
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OK. more or less clear) that when using the low-cost version of ak4137, it is possible to save spdif entries, which is good. but you did not tell me which version to order. there are three of them under the link.
I'm not doing fashion so quickly. In the near future I plan to replace the clock. and I want to fix the register in the zap. after a while I'll take care of ak4137. in the meantime, carefully read what is happening on the forum. Perhaps there will be new ideas on mods.
I want to try to load the tps7a4700 power output with a resistor. as originally es9038 is a small load. could you recommend the resistance value. I also found out that when adding film capacitors of less than 1 µF at the output of ldo, I feel better than electrolytes! I tried from 47 microfarads to 3000 microfarads at 6 v. the sound becomes as if thin and the more microfarads the more bass
I'm not doing fashion so quickly. In the near future I plan to replace the clock. and I want to fix the register in the zap. after a while I'll take care of ak4137. in the meantime, carefully read what is happening on the forum. Perhaps there will be new ideas on mods.
I want to try to load the tps7a4700 power output with a resistor. as originally es9038 is a small load. could you recommend the resistance value. I also found out that when adding film capacitors of less than 1 µF at the output of ldo, I feel better than electrolytes! I tried from 47 microfarads to 3000 microfarads at 6 v. the sound becomes as if thin and the more microfarads the more bass
I only found 2 links to AK4137 boards, and I could not get them to work by clicking on them directly. I had to copy the links to notepad as text, then copy from there and paste into Chrome. Maybe my antivirus had a problem with them, I don't know.
Anyway, you can use the cheapest AK4137 board that will do what you want. If if you don't want SPDIF, or if you don't care if SPDIF is converted to DSD then you can buy the cheapest one. If you want SPDIF and you want it upsampled and converted to DSD, then you would need the more expensive AK4137 board that includes optical and SPDIF inputs.
tps7a4700 is rated for up to 1A of current. But, how much power dissipates depends on the voltage drop across it. P = I x E, right? So long as the voltage across it is low so it doesn't get too hot (might need a heat sink), you might try selecting a resistor that would draw 100ma or maybe a few hundred ma. Hard to say what might sound best. If it is a 3.3v regulator, then a 33ohm resistor would draw 100ma. The resistor would dissipate P = I x E = 100ma x 3.3v = 0.33 watts. If you use half watt resistors you could try putting one from the regulator output to ground, and then try adding one or two more in parallel with the first one to see if it sounds any better.
You never heard me recommend to put film caps at the output of an LDO. Better read the data sheet and see what it says about output caps. You might be making it oscillate. At the least you will probably reduce the regulation bandwidth, although load transient response might improve (so long as no oscillation problems).
What I have said is that that film caps should be put near the opamps, not near the regulator. Maybe best to have some length of wire (a little resistance) between the regulator output and the film caps in case the regulator doesn't like it. Also, if using a high gain regulator, better check the output with a scope for any signs of oscillation. Film caps work great with low gain regulators like LM317, and or if close to the opamps, and or not too close to regulators.
If using high gain regulators such as active shunts, Nazar, Jung-Didden, etc., then be careful with film caps so you don't cause new problems.
If not sure about LDOs then better carefully read the data sheet first to see what it says about output caps (usually in the applications section). If an LDO is close to the load, it may be safer to try film caps at the input of the regulator, but that could potentially cause problems too. Always best to check with a scope if wanting to try film caps when using high gain, high bandwidth regulators.
Now, trying load resistors with LDOs should be pretty safe, just so long as you don't let regulators or load resistors overheat.
Also, it may help to remember that series regulators (regulators with a pass transistor) can only turn on the pass element to allow more current to flow to the load in order to regulate up the voltage. If there is no ready supply of current at the regulator input pin, the turning on the pass transistor may not be optimally effective. Usually, data sheets have some advice (and maybe some warnings) about input caps, too (again, usually in the applications section).
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thanks for the detailed answer!) film caps removed the sharpness of high frequencies. the sound became softer. my wife noticed that too. now I'm thinking about it... electrolytes did nothing good. it was the low esr of the motherboards. perhaps the film has added resistance at the LDO output. the film is inexpensive, without high performance. I will not be in a hurry to remove the tps7a4700 from the AVCC power supply. especially according to the Datasheet of this ldo for dac. I'll add resistors to the ldo output. about results I will unsubscribe. perhaps low impedance es9038q2m plays a role.
perhaps later I will collect Nazar controller for avcc lines. then and compare.
perhaps later I will collect Nazar controller for avcc lines. then and compare.
I want to add. that the film is 0.033 µf. in my opinion. I'm away. the dac is far from me. the addition of the film at the entrance did not play a role, in my opinion, became worse. but the electrolytic super capacitor of less than 1 UF looks good.
ldo with pins comes into place capacitors for avcc. here the distance is minimal. on your recommendation.
ldo with pins comes into place capacitors for avcc. here the distance is minimal. on your recommendation.
Here is what version of cheap ak4137 on exiled:
Standard crystal: oscillator Configuration 22,5792 M 24,576 m.
Low frequency crystal: oscillator Configuration 11,2896 M 12,288 m.
768 K crystal: oscillator Configuration 22,5972 M 49,152 m.
therefore, I asked - what is more suitable for fashion DAC
Standard crystal: oscillator Configuration 22,5792 M 24,576 m.
Low frequency crystal: oscillator Configuration 11,2896 M 12,288 m.
768 K crystal: oscillator Configuration 22,5972 M 49,152 m.
therefore, I asked - what is more suitable for fashion DAC
after lm317 can't exactly say what. it's a Chinese regulator. looks like low esr. then go twisted wires +- to ldo. here I put the electrolytic supercapacitor less than 1mkf at 5.5 V. but after tps7a4700 I tried to put the motherboard capacitors low esr nominal value of 47 UF to 3000 UF. I didn't like the sound. but the tape sounded. but her nominal less than 1uf. I'm inclined to believe Mark. so I'll put the tape away when I get home from work.
Its not quite that simple. High quality film after LM317 works pretty reliably. Cheap film may not work so well, depends how the cap is manufactured. tps7a4700 may or may not work well for AVCC, resistors might help (could be small caps can help too, don't know). Opamp supplies as recommended by ESS work quite well for ES9038Q2M dacs (PRO series dacs need more AVCC current, which may change how regulators tend to work).
Regarding AK4137 boards, either get the standard crystals, or get the 768k support version. Do not get the low frequency crystal version, that's for AKM dacs, not sure which ones.
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I use tps7a4700 for preregulator at this dac ...and on digital supply lines at dac projects. I have tried lt304x...and they are not so good for my taste , but i like them on analog supply lines at my dac projects. I also use tps7a4700 as main 3,3v regulator at Amanero boards (instead of ADPxxx or LPxxx). Main supply for es9038q2m is 8V lipo, because i use transformer ouput stage. Supercaps are fine but just on right positions.
I use Kubota as preregulator on soekris dac. I also tried both TPS +- regulator combinations but not for my ears.
Right now i collect things to modify es9038pro dac. Future plan is the same as Marks ...ak4499. But no AK4137 SRC.
Last test with Hugo tt2 and upscaler convinced me even more what i hear (feel).
I use Kubota as preregulator on soekris dac. I also tried both TPS +- regulator combinations but not for my ears.
Right now i collect things to modify es9038pro dac. Future plan is the same as Marks ...ak4499. But no AK4137 SRC.
Last test with Hugo tt2 and upscaler convinced me even more what i hear (feel).