oe pins seen to be pulled low via 1k r to gnd/-vref
stcp pins are fed from those f-fs you mentioned
dunno about shcp
SSASSEN,
Maybe your comments have not been fully expressed because I would not hesitate to agree with you that the use of expensive resistors will not turn the sow's ear into the silk purse.
But the case here is that the majority of us think SOEKRIS has come up with an excellent circuit that sounds very good in its basic form. That is the impulse for many of us: to improve upon what is there. Let's face it for the modest sum SOEKRIS charges one cannot expect the very finest of components to have been specified and sure enough they are not. Instead there is canny selection of components that works very well and offers excellent value.
Modifications are a tribute to the circuit not a condemnation.
I can assure you if you went to the trouble of trying the A123 26650 battery powering of the SOEKRIS (I feel sure you are quite capable of doing it without harming it) you might be in for a surprise.
I had used battery power in the past and had found it OK but not really better, the proverbial "different" with dynamics lacking. Of course, speaking of comparing a better than average regulator and using SLA batteries.
Scoff all you want and you are welcome to continue to scoff but the difference in sound quality is significant and not simply different with this. There seems to be an affinity between digital circuits and these batteries.
It is not an easy modification if done properly. I have no desire to ever do it again. It would be very interesting to hear what someone like yourself might find after hearing it for yourself.
There is a tremendous reduction in the insidious noises associated with digital processing. If these noises do not bother you, I am jealous. Maybe you are not perceiving them and this might be because you have lost contact with the sound of analogue. Certainly analogue is extremely noisy but almost all of the noise is easily distinguished from the music signal where the digital noise is interwoven with the music signal and can be considered "just how it is" until you hear something with reduced levels of it.
Remember the story of those who upon first hearing Edison's early phonograph (I cannot remember what he called it) thought it sounded like the person was in the room which is pretty hilarious to us now. But there is a lesson in how we have to learn how we perceive. We have to work at improving our abilities to hear fine details. I am speaking on a personal level.
For some of us greater enjoyment is found from these exercises when we are able to improve the sound of our systems. Of course, it is an obsession and could easily be classified as a mild form of mental illness but then all of us possess mild forms of mental illness. This is a benign one.
If one is not hearing these artifacts then they are lucky in a way. But I would wonder do they know what is missing, or in the case of digital noise what is added?
I know from a mutual friend that you are not averse to using a better component, speaking of clocks here. So I know YOU know components can make a difference. No question that component comes with documentation and a reasonable explanation of why it will improve the sound. But sometimes those of us you might consider uneducated in the field can come up with valuable insights. I am not putting myself in that category since I choose carefully whose ideas I think are worth pursuing. I have added nothing to the battery power scheme, I just used it and found that it works very well.
Someone, such as yourself, giving it a try would give an impetus to finding out what is at work here.
Maybe your comments have not been fully expressed because I would not hesitate to agree with you that the use of expensive resistors will not turn the sow's ear into the silk purse.
But the case here is that the majority of us think SOEKRIS has come up with an excellent circuit that sounds very good in its basic form. That is the impulse for many of us: to improve upon what is there. Let's face it for the modest sum SOEKRIS charges one cannot expect the very finest of components to have been specified and sure enough they are not. Instead there is canny selection of components that works very well and offers excellent value.
Modifications are a tribute to the circuit not a condemnation.
I can assure you if you went to the trouble of trying the A123 26650 battery powering of the SOEKRIS (I feel sure you are quite capable of doing it without harming it) you might be in for a surprise.
I had used battery power in the past and had found it OK but not really better, the proverbial "different" with dynamics lacking. Of course, speaking of comparing a better than average regulator and using SLA batteries.
Scoff all you want and you are welcome to continue to scoff but the difference in sound quality is significant and not simply different with this. There seems to be an affinity between digital circuits and these batteries.
It is not an easy modification if done properly. I have no desire to ever do it again. It would be very interesting to hear what someone like yourself might find after hearing it for yourself.
There is a tremendous reduction in the insidious noises associated with digital processing. If these noises do not bother you, I am jealous. Maybe you are not perceiving them and this might be because you have lost contact with the sound of analogue. Certainly analogue is extremely noisy but almost all of the noise is easily distinguished from the music signal where the digital noise is interwoven with the music signal and can be considered "just how it is" until you hear something with reduced levels of it.
Remember the story of those who upon first hearing Edison's early phonograph (I cannot remember what he called it) thought it sounded like the person was in the room which is pretty hilarious to us now. But there is a lesson in how we have to learn how we perceive. We have to work at improving our abilities to hear fine details. I am speaking on a personal level.
For some of us greater enjoyment is found from these exercises when we are able to improve the sound of our systems. Of course, it is an obsession and could easily be classified as a mild form of mental illness but then all of us possess mild forms of mental illness. This is a benign one.
If one is not hearing these artifacts then they are lucky in a way. But I would wonder do they know what is missing, or in the case of digital noise what is added?
I know from a mutual friend that you are not averse to using a better component, speaking of clocks here. So I know YOU know components can make a difference. No question that component comes with documentation and a reasonable explanation of why it will improve the sound. But sometimes those of us you might consider uneducated in the field can come up with valuable insights. I am not putting myself in that category since I choose carefully whose ideas I think are worth pursuing. I have added nothing to the battery power scheme, I just used it and found that it works very well.
Someone, such as yourself, giving it a try would give an impetus to finding out what is at work here.
Allow me to share my setup. Please refer to the attachment. For other power rails, you can do the same. Only the r2r part is most complicate. You can use two or four batteries per dam r2r because they are separated already after the opamp. And please remove the 5V ldo. (you should also remove the original regulator for individual power rail that you want to replace)
Attachments
As four batteries provide power independently and are not regulated (I assume) they should be providing (slightly) different voltages to different sets of shift registers. Do you hear any type of distortion when this happens?
Yes, you are right. Even for 2 batteries, due to their physical condition, the discharge rate may be different. As a result the voltage drop may be different.
For 4 batteries mode, the discharge rate is even diverse. However, as a human, I can't hear the difference in left/right balance.
I think this is one of the big issues when using battery in this area. However, my experience is that applying battery in this area affect the overall sound quality most. Whether this kind of "affect" is positive or negative, to me, it is positive, but to people who care about the correctness of signal, it must be negative.
If you use regulated ps to continously maintain the voltage levels voltages will be more consistant over time
Essentially its using the lifepo4 cells as capacitors
I dont know if regulated ps still can apply to there, as I know, the battery is 3.2V but the ps is 4V, I afraid prolong charging the battery will damage the battery. May be 3.7V battery is more suitable in this configuration.
Use external 3.3v regulated supply a linear one
Switch between ps and cells and between cells and vref and your good to go
regardless the stock reg would not last long if the batteries got depleted for any reason
i burnt out the stock 4v regs charging supercaps
ive got several float charged cells in various devices that are in constant operation for around three years and all works like clockwork no failures
besides the floating phenomenon is not exactly new
its used in alarm back up systems and almost every motor vehicle
I think this is more exact for the illustration.
https://drive.google.com/open?id=0B15LqQoMxKDfSks4OHFMcU1wSG8
nige2000 and jkeny who post more often at TIR NA are the ones who developed the scheme. nige2000 led the way with how to do it with the DAM.
Tír Na HiFi • View topic - Soekris Dam Dac
It is simplicity actually. I had used the scheme to power a computer motherboard so I was familiar with what it could do.
When all of the Vref controversy arose I tried to do those mods and quickly realized it would be easier in many way to do this.
As nige says earlier if you think of the battery as a capacitor (which it is for all intents and purposes in this scheme) it all becomes easy to understand.
We are using 3.3 volts for the Vref since that is all one shoudl ask of these batteries. I have no idea why SORKRIS chose four volts but none of us who have done this hear any ill effects from 3.3. The output is just as robust as it was before.
I used the mravica reg which is also in the VENDOR'S BAZAAR for Vref. It is two positive regs combined for the two polarities. I think this arrangement offers the advantage of the voltages being equal. They are in my case. I have monitored them during playback and they stay the same.
I used four batteries for the Vref - two for each channel since this is the only way to keep the leads as short as possible. I use a switch between the circuit and the respective battery. There are clones but I prefer using A123 26650s. Some suppliers offer them with tabs - I would get those!
For the front end a battery powers the pads where the 3.3 volts reg was. I am using the reg I got from DDDAC, a 3.3 volts shunt reg. It was what I had I am not saying a shunt reg is important here. In fact, nige has found that the reg should be of good quality but does not need to be crazy. I tend to use as good a regulator as will fit in the space.
The DC converter that powers the FPGA is replaced in my case with a low voltage BELLESON. The same battery powers this. This battery has its own power switch. SOEKRIS advised that one should have the "front end" turn on before the resistor stack. Other than order there is nothing critical here. You can take your time turning on the Vref batteries after switching on the "front end" battery. I have found one can do firmware updates with just the front end "on" which is no surprise.
In my case there are no components left on the board that are not needed. There remains none of the original regulators, the output op amps. the only ceramic caps remaining are between the FPGA and the resistor stack. nige has replaced these with PANASONIC plastic caps. I have not.
randytsuch has pictures of his installation at his blog and nige and I have posted pictures at TIR NA. http://randytsuch-audio.blogspot.com/2015/11/soekris-r2r-dam-dac-modding.htm
I used silver wire between batteries and the DAM. The lengths are short and would be very difficult to manage with typical tight insulation and I worry about oxidation of bare copper. The silver wire has cotton sleeving which is loose, has no effect on oxidation but does keep things from shorting.
It has been awhile since I did this so I feel sure I am missing some details.
You will see we all did this slightly different from each other. Look over all of it and see which way you think is best to go. I bet you come up with refinements we did not consider!
I am using three separate power transformers, one for each supply since I am obsessive.
This is an elegant approach. It is fundamentally simple. It is completely stable. I have never had a single glitch since doing it.
The basic DAM is good. I listened to it AS IS for many months before doing this. Mine is a first generation board with the Vref problems so my comparison might be flawed. I have not heard the latest generation of the DAM.
I cannot imagine this not having a positive effect on any generation of DAM but would suspect the difference would not be as great with the Vref improvements in the newer boards.
This is not an easy modification. If you do not have extensive experience with soldering and even more importantly soldering in such tiny spaces DO NOT ATTEMPT THIS. You do not have to solder in SMD components but you will be using the pads from the removed components. One has to be very careful when removing the components - if you lose a pad you might be DONE.
I did not have much experience with SMD stuff so I took it very slowly and deliberately. I had made plenty of audio projects over the years but through hole component sized boards are pretty simple to deal with. You will need to get solder bits for this purpose.
Take your time and plan how you will do this. Be methodical and you will be fine.
Luckily I had my phonograph setup to keep me from music withdrawal during the process. Do not get in a hurry!
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Hi Rick
Thank you very much for the detailed description.
If I understood you correctly, that you are using the batteries as capacitors it means your batteries are permanently connected to a power supply and being charged and discharged at the same time?
I have once tested a similar approach with an Altmann Attraction DAC and an Optima RedTop Battery with not so good results. The sound of the DAC was clearly better when only the Optima alone was powering the DAC without a power supply connected that maintains the Optima being fully charged all the time.
Kind Regards
Phil
PS: The Link to RandyRutschs Blog does not work for me.
Thank you very much for the detailed description.
If I understood you correctly, that you are using the batteries as capacitors it means your batteries are permanently connected to a power supply and being charged and discharged at the same time?
I have once tested a similar approach with an Altmann Attraction DAC and an Optima RedTop Battery with not so good results. The sound of the DAC was clearly better when only the Optima alone was powering the DAC without a power supply connected that maintains the Optima being fully charged all the time.
Kind Regards
Phil
PS: The Link to RandyRutschs Blog does not work for me.
Batteries are not all the same. An optima redtop is a lead acid battery. You need to try it with a lifepo4 battery. BTW, I have switches so I can turn on or off the power supply independently of the battery, and I can't hear a difference.
randytsuch link for dac mods
Randy
I have used the OPTIMA battery with the ALTMANN phono stage (my back up which I have not had to use in quite awhile).
I used a real float charger to charge it since this was before I became aware of the jkeny scheme with regulators and A123 26650s and I must admit when I would forget to remove the charger I would not hear much of any difference at all and this thing HAD to be much noisier than a simple voltage regulator.
I would not use four A123s in series, too much complication and the OPTIMA's ESR is much better.
The DAC would be a different case and I have never heard the ALTMANN DAC though I was very curious to hear one. He is quite an interesting character. I would have never realized that Germans were interested in Harley Davidson motorcycles turned into virtually unrideable machines if not for getting my preamp in a box stuffed with catalogue pages for making one's motorcycle into one of those things. Everyone has their foibles, I guess. Or it could be my assumption is nothing more than that and he had the catalogue so he could order those gold plated battery connectors he supplied with the preamp. Nonetheless, I think Herr Altmann one of the most interesting fellows in audio and his ideas are worth consideration and implementation.
The OPTIMA is certainly not another lead acid battery. It's ESR specification is in a class of its own. Brian Lowe compared one to his regulator (at my request) and had to admit it was out of the ordinary. Superpower Super Regulator by Belleson
But as Randy says this battery is different and all I can say is there seems to be an affinity between these batteries and digital circuits.
The last thing I would want to do is to encourage someone to do this with their SOEKRIS DAC. Please proceed only after assuring yourself you think this is THE WAY.
I used a real float charger to charge it since this was before I became aware of the jkeny scheme with regulators and A123 26650s and I must admit when I would forget to remove the charger I would not hear much of any difference at all and this thing HAD to be much noisier than a simple voltage regulator.
I would not use four A123s in series, too much complication and the OPTIMA's ESR is much better.
The DAC would be a different case and I have never heard the ALTMANN DAC though I was very curious to hear one. He is quite an interesting character. I would have never realized that Germans were interested in Harley Davidson motorcycles turned into virtually unrideable machines if not for getting my preamp in a box stuffed with catalogue pages for making one's motorcycle into one of those things. Everyone has their foibles, I guess. Or it could be my assumption is nothing more than that and he had the catalogue so he could order those gold plated battery connectors he supplied with the preamp. Nonetheless, I think Herr Altmann one of the most interesting fellows in audio and his ideas are worth consideration and implementation.
The OPTIMA is certainly not another lead acid battery. It's ESR specification is in a class of its own. Brian Lowe compared one to his regulator (at my request) and had to admit it was out of the ordinary. Superpower Super Regulator by Belleson
But as Randy says this battery is different and all I can say is there seems to be an affinity between these batteries and digital circuits.
The last thing I would want to do is to encourage someone to do this with their SOEKRIS DAC. Please proceed only after assuring yourself you think this is THE WAY.
@all battery champions
I am in the camp of those who know this is the way. I have implemented battery based solutions in other projects with very positive results.
The question I have is whether anybody has compared the reportedly very well performing A123 26650 (or clones of it) rechargeable batteries with other types of batteries. Also, as internal battery resistance decreases with increase of battery capacity, what in turn decreases the noise floor, did you have a chance to compare batteries of the same type but with different capacities?
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When I was using a computer as a player I used battery power on the motherboard.
I initially went with the A123s for all P24 rails - 3.3, 5 and 12 volts.
The four in series for the 12 volts rail failed since I did nothing to balance the charge between them. Therefore I would never recommend using them this way. The 12 volts P24 rail is not critical so I used a modest sized PANASONIC SLA for that rail and never had trouble again. I certainly did not hear any sonic degradation.
Just so no one misunderstands - all are float charged with voltage regulators of the voltage required.
Eventually I replaced the A123s for the 3.3 and 5 volts rails with much larger batteries LiFePO4 Prismatic Module: 3.2V 40 Ah, 10C Rate (128 wh) --- UN38.3 Passed (DGR).
I felt I was asking too much of the A123s but nige2000 continues to use them and has had no problems. I did feel I got a more muscular sound from the bigger batteries. Who knows? It is much too complicated and time consuming to go back and forth. All I know is I never had another glitch after making the change.
I used the OPTIMA battery for P4 and to power a video card which is something those who persist in using a computer for a player should consider. It relieves the CPU of video duties and does allow better sound.
I have probably mentioned that the computer that was a player has been reconfigured as a CD ripper and SD card writer since I am using the excellent SDTrans as my player. I cannot praise this thing enough.
The SDTrans is using A123 battery power, too, of course.
I would have never thought such sound was possible with digital. I have had my moment of apostasy (though things can always change with audio kooks) but for the moment I prefer the digital setup to the phonograph. The tonal balance is superior, detail retrieval is equal - only thing missing is the initial transients are a little softer but who knows which one is correct? That perception of greater attack could easily be the sound of a rock sliding across a rough plastic surface.
I am an LP guy so this is frustrating since my collection of CDs is nothing compared to the LP collection.
All comparisons made with REDBOOK. I am not a "believer" in high rez which has even more digital noise but for those insensitive to the noise it must be spectacular to hear the proponent's accolades.
I initially went with the A123s for all P24 rails - 3.3, 5 and 12 volts.
The four in series for the 12 volts rail failed since I did nothing to balance the charge between them. Therefore I would never recommend using them this way. The 12 volts P24 rail is not critical so I used a modest sized PANASONIC SLA for that rail and never had trouble again. I certainly did not hear any sonic degradation.
Just so no one misunderstands - all are float charged with voltage regulators of the voltage required.
Eventually I replaced the A123s for the 3.3 and 5 volts rails with much larger batteries LiFePO4 Prismatic Module: 3.2V 40 Ah, 10C Rate (128 wh) --- UN38.3 Passed (DGR).
I felt I was asking too much of the A123s but nige2000 continues to use them and has had no problems. I did feel I got a more muscular sound from the bigger batteries. Who knows? It is much too complicated and time consuming to go back and forth. All I know is I never had another glitch after making the change.
I used the OPTIMA battery for P4 and to power a video card which is something those who persist in using a computer for a player should consider. It relieves the CPU of video duties and does allow better sound.
I have probably mentioned that the computer that was a player has been reconfigured as a CD ripper and SD card writer since I am using the excellent SDTrans as my player. I cannot praise this thing enough.
The SDTrans is using A123 battery power, too, of course.
I would have never thought such sound was possible with digital. I have had my moment of apostasy (though things can always change with audio kooks) but for the moment I prefer the digital setup to the phonograph. The tonal balance is superior, detail retrieval is equal - only thing missing is the initial transients are a little softer but who knows which one is correct? That perception of greater attack could easily be the sound of a rock sliding across a rough plastic surface.
I am an LP guy so this is frustrating since my collection of CDs is nothing compared to the LP collection.
All comparisons made with REDBOOK. I am not a "believer" in high rez which has even more digital noise but for those insensitive to the noise it must be spectacular to hear the proponent's accolades.
Re high res files, generally I have good experience with it but not with all of them. I can definately hear significant to ignore differences (to the better) in SQ in my system.
I think listenability of high res files, as well as redbook ones BTW, depends on a number of factors, e.g. whether you are listening to a native file or a conversion.
However, to support your observations wrt the cd quality sound, I just recently made some modes to my cd front end and now rediscover all my cd's again.
NB: my main system is analogue as well.
I think listenability of high res files, as well as redbook ones BTW, depends on a number of factors, e.g. whether you are listening to a native file or a conversion.
However, to support your observations wrt the cd quality sound, I just recently made some modes to my cd front end and now rediscover all my cd's again.
NB: my main system is analogue as well.