Soekris Dam Dac

[tony]

The PC issue has happened to me many times. Removing the battery and sometimes just disconnecting all power also does the trick.
Not sure what board you are using Rick but my MSI is a bit like that when you go at it and start messing with power. I had it when the batteries ran a bit low. Now leave then on trickle charge from the traffo/regs despite all the scary warnings on that asylum site!

[rickmcinnis]

I guess I somehow convinced myself that one could do on/off switching with the ground. My elegant solution is elegant but it does not work. I think I will be able to install switches at the power end and not increase the paths by much.

Wish I had paid more attention to your set-up Randy!

At least I can see that it will likely work after that is done. Sure did not want to buy a DAC.

Thanks for all of the help and encouragement.

[nige2000]

I guess I somehow convinced myself that one could do on/off switching with the ground. My elegant solution is elegant but it does not work. I think I will be able to install switches at the power end and not increase the paths by much.

you can its just when youve got more than two voltages say like 0v and 3.3v break on ground is no problem
but if you have -3.3, 0, and 3.3v you still have a circuit if you break dac gnd because there is a mid point between -3.3 and 3.3v because the batteries are joined stuff will be on!

Wish I had paid more attention to your set-up Randy!

At least I can see that it will likely work after that is done. Sure did not want to buy a DAC.

Thanks for all of the help and encouragement.

[randytsuch]

I have to disagree Nigel, I think you can switch ground with batteries, but as I have said, I don't like to do it that way, so I switch voltages.
But, I don't see any reason why switching grounds would not work, if done correctly.

For the +/-3.3V to the shift registers, you just need to tie the "ground" of each battery to your switch, where ground of the -3.3V is the positive of the battery.

Rick
So we've all been there, and I know it REALLY sucks when you do a project like this, and it doesn't work the first time. Some of my most depressing moments where when I turned a switch on, and nothing happened :(

But we're here to help. Sometimes it's good to take a break for a little bit, clear your head, and then come back to it. I've actually "fixed" many problems when I'm not sitting in front of the problem, but eating or doing something else.

If it was me, I would get the PC working first. It would be great if you had another USB dac that you could try, one that you know works. It makes it easier if you're only fixing one problem at a time. I have a spare little one that I could loan you for the cost of postage. Easily fit in a small usps priority mail box.

The other thing that I like to do is to make incremental changes, testing along the way. So I'll make a small change, and then fire it up, and make sure everything still works as expected. That makes it easier to troubleshoot if it doesn't. Of course, you're way past that now.

At this point, I wouldn't worry about looks and how long wires are, just make it work, and then you can clean it up if you want.

So good luck. And if you have any specific question or problem, give us details and pics if possible, and we'll do what we can to help.

For my status, I am now using a exD USB to I2S converter instead of the Amanero. I've already set it up to use 3.3 Lifepo4 power, that was really easy. It makes +5 and something around 1.2V, I need to decide how much I want to mess with the power on this guy. And I think it sounds a little better than the Amanero, but I'll have to switch back at some point to be sure.

Randy

[nige2000]

I have to disagree Nigel, I think you can switch ground with batteries, but as I have said, I don't like to do it that way, so I switch voltages.
But, I don't see any reason why switching grounds would not work, if done correctly.

For the +/-3.3V to the shift registers, you just need to tie the "ground" of each battery to your switch, where ground of the -3.3V is the positive of the battery.

f-sake :)
i never said you cant switch with gnd read again!
rick states hes got the green light on whether gnd is open or closed
so there is a circuit !!
its more complicated to switch on gnd with multiple cells and voltages as each voltage battery pack needs to be isolated for off position

see here pic might help



some pics of the dac will help us help you rick

Rick
So we've all been there, and I know it REALLY sucks when you do a project like this, and it doesn't work the first time. Some of my most depressing moments where when I turned a switch on, and nothing happened :(

But we're here to help. Sometimes it's good to take a break for a little bit, clear your head, and then come back to it. I've actually "fixed" many problems when I'm not sitting in front of the problem, but eating or doing something else.

If it was me, I would get the PC working first. It would be great if you had another USB dac that you could try, one that you know works. It makes it easier if you're only fixing one problem at a time. I have a spare little one that I could loan you for the cost of postage. Easily fit in a small usps priority mail box.

The other thing that I like to do is to make incremental changes, testing along the way. So I'll make a small change, and then fire it up, and make sure everything still works as expected. That makes it easier to troubleshoot if it doesn't. Of course, you're way past that now.

At this point, I wouldn't worry about looks and how long wires are, just make it work, and then you can clean it up if you want.

So good luck. And if you have any specific question or problem, give us details and pics if possible, and we'll do what we can to help.

For my status, I am now using a exD USB to I2S converter instead of the Amanero. I've already set it up to use 3.3 Lifepo4 power, that was really easy. It makes +5 and something around 1.2V, I need to decide how much I want to mess with the power on this guy. And I think it sounds a little better than the Amanero, but I'll have to switch back at some point to be sure.

Randy

[randytsuch]

f-sake :)
i never said you cant switch with gnd read again!
rick states hes got the green light on whether gnd is open or closed
so there is a circuit !!
its more complicated to switch on gnd with multiple cells and voltages as each voltage battery pack needs to be isolated for off position

My bad, sorry for the misunderstanding.

And I missed your point about the battery ground, the pic cleared that up, I see what you mean, and that could be Rick's problem if wired that way.

[rickmcinnis]

I think Nigel sees the problem with my original setup and that is the only thing I can conceive that would explain it and I was not able to conceive it before he put it into words!

Got almost all of the re-wiring done. Would have finished if not for waiting for glue to dry. Built a tower to hold the switch over the 3.3 volts reg pads - the battery is mounted so it sits atop the board next to this. As always trying to minimize wire lengths (good wire is expensive).

The wiring for the output has added 4 inches of wire to and from the batteries -from the wires attached to the capacitor pads - two inches each way. Just kills me ...

So there are three switches - one for the 3.3 v front end and two for the resistor stacks - one per channel. So I figure I initially turn on the "front end" supply and then move my hand to the other side of the board and flip those two switches on. I wonder if it makes any difference if they are turned on at a slightly different time - like one slightly before the other? I have been practicing moving both toggles simultaneously!

My computer is working - just not with the battery supplies! Can't even use the big OPTIMA to power P4 - I connect it and nothing happens. Voltage reads fine. Maybe the battery has failed - voltage but no current. Very strange. The battery is about ten years old but has always been inside. I guess it is possible.

Needless to say will not miss that lummox. Now I will get LiFePo for this. AS I said the P24 12 volt batteries have failed (they do not share the same charger) but quite a coincidence. Will replace these with full size 26650s.

Hope the 5 and 3.3 P24 rails are OK. Voltage shown is correct but then so is the OPTIMA. Could leaving the batteries idling with the chargers on shorten their lives?

Hoping to be able to say tomorrow that this thing does work so I can cancel the order for that SCHIIT DAC!

[jkeny]

Glad you seem to have it sorted - yes, Nige's explanation would seem to be correct.
I hate when multiple devices fail at the same time - makes for a depressing scenario & makes finding the problems difficult

I don't believe that trickle charging any battery shortens its life - it's a fallacy - cars trickle charge their SLA batteries & the electric cars do the same with LiFePO4s

Shame about cancelling the Yggi - I was hoping to hear your impressions of how that multibit DAC fares Vs the tweaked Soekris R2R

[rickmcinnis]

I said I hope to be able to cancel it. Depending on the outcome of the SOEKRIS experiment.

I will only have one DAC at a time. Can't afford a collection of the things!

Been so long since I have heard digital music I could only compare it to my phono system so my comments would be of limited value. I feel confident my phono system sounds better than any digital system I could ever afford.

Wrote them to ask if I could get the thing without an enclosure. They sell a B stock version but had run out of them. I do not want an enclosure and the thought of not paying for one appealed to my vague Scots heritage. There is a metal plate all of the boards are mounted upon which is then attached to the enclosure so it is not as if they would be shipping me an assortment of of PCBs. Within my letter I made it clear I realized that such a unit would not have a warranty.

So I get this curt response. "We do not sell parts and the unit would not have a warranty". Really made me mad.
Parts, I did not ask to buy parts and the other aspect made me wonder if the dumbass even read my note.

I really want the SOEKRIS to work since I get the feeling these are not the kind of people I want to do business with. Makes me wonder how much involvement Moffat has with the running of the company. I wrote back and told them they remind me of the new owners of THETA. For all I know they are the same people.

I would not think trickle charging would harm a battery either. Probably just got old.

Changing my mind on its replacement - The OPTIMA REDTOP would have less than a third of the ESR of a set of series connected LiFePos and be much easier to deal with so I think I will stick with a big battery for the P4. The OPTIMA is not the typical SLA battery. I can see Nigel shaking his head ...

[jkeny]

Yes the RedTop is different technology to most SLA & is the one I saw favoured by the audiophile community. I reckoned it's low esr (16mOHm?) was the main reason for it's superior sound in audio use but this was in amplifiers, AFAIR where current delivery is important.

It may be that this is the main battery characteristic that is important in audio (chemical reaction & low noise; esr Vs Frequency being some others I can think of) but man, they are expensive $200 or so - maybe not so bad stateside but don't know any suppliers over here