Random question guys really sorry!:
But will changing my batteries resolve the discharging issue I'm having? Over charged my 02 amp that came pre assembled from JDS Labs so I don't know anything about the electrical aspects of the unit besides what I've read about needing a control unit to cut off the charging of the batteries? Don't know why this didn't come pre installed or anything like that
But will changing my batteries resolve the discharging issue I'm having? Over charged my 02 amp that came pre assembled from JDS Labs so I don't know anything about the electrical aspects of the unit besides what I've read about needing a control unit to cut off the charging of the batteries? Don't know why this didn't come pre installed or anything like that
Hello! Please tell us more about your (battery) discharge problem. Is it discharging after sitting on the shelf unused for several weeks/months, or is it a case where it will discharge the batteries in a day or two sitting there turned off and unused, or is it a problem with just short battery life while on and being used? Each of those are different problems with different solutions it turns out.
In general you can't overcharge the batteries the way the O2 is designed. It uses "trickle charging" which is very slow (as in takes overnight to charge) but is safe for extended charging. I've even asked the question directly of the battery manufacturers and for the 9V NiMH up to 30mA or so, as I recall, was considered safe for unlimited (time) ongoing trickle charging (the O2 only charges at a maximum rate of 10mA). Where the control of the charging comes in is with "fast chargers" that use much higher currents. In those cases a battery management chip looks for various parameters and stops the charging cycle, but none of that applies to the O2 and its trickle charger.
I'm off to bed, but please post the answers to the above - it will help Mooly or other folks to help you out.
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So the issue was after about 3 days or 36 consecutive hours on the charger I bought from jds labs ( 15vac 500mA 7.5w <out>). After about 8 hours of use my o2 died and I hear some loud clicking, charged it for the night (12 hours) and the o2 died within 4 hours. Did I strain the batteries a little? Also I assume the unit needs to be turned on for it to start charging because of the lack I LED indication when turned off. Any help is appreciated! Also as a new o2 and separate odac owner what are some moss or benefits I can start learning for said o2 or maybe some input on what the balancing mod would do to my akg k712, is it worth the fuss? Thanks so much guys!
The 02 charges the batteries as long as AC power is present. The on/off switch has no effect on charging.
Lets do a bit maths... or at least a guesstimate.
If the battery is an 8.4 volt 170mAH then its going to need at least somewhere in the region 230 to say 280 mAH putting back to fully charge the batteries.
Now it gets tricky calculating because a discharged battery will pull the charge voltage down to say 7 volts and when the battery is fully charged its probably nearer 10 volts.
So charge current at 7 volts is the supply voltage (12 volts) less the battery voltage (7 volts) divided by 220 (the charging resistor). That gives 22 milliamps. To fully charge the battery at rate would need 12 hours give or take.
But hold on... the battery voltage on these small PP3 size rechargeables climb pretty quickly once on charge due to the high internal resistance of the cells. At a battery voltage of 8 volts we need nearly 16 hours. At 10 volts (which is around where it will climb to) we need 31 hours to fully charge the battery.
So 12 hours is nowhere near enough to fully charge the batteries. Probably nearer 20+ hours is closer to the mark. And that is for a battery capacity of 170mAH. Higher capacity and it will need longer still.
And how long should the batteries last ? Well the opamp current consumption adds up to around 23ma give or take. Add another couple of ma for good measure and we get say 25ma. So a 170mAH battery should last around 7 hours give or take.
Lets do a bit maths... or at least a guesstimate.
If the battery is an 8.4 volt 170mAH then its going to need at least somewhere in the region 230 to say 280 mAH putting back to fully charge the batteries.
Now it gets tricky calculating because a discharged battery will pull the charge voltage down to say 7 volts and when the battery is fully charged its probably nearer 10 volts.
So charge current at 7 volts is the supply voltage (12 volts) less the battery voltage (7 volts) divided by 220 (the charging resistor). That gives 22 milliamps. To fully charge the battery at rate would need 12 hours give or take.
But hold on... the battery voltage on these small PP3 size rechargeables climb pretty quickly once on charge due to the high internal resistance of the cells. At a battery voltage of 8 volts we need nearly 16 hours. At 10 volts (which is around where it will climb to) we need 31 hours to fully charge the battery.
So 12 hours is nowhere near enough to fully charge the batteries. Probably nearer 20+ hours is closer to the mark. And that is for a battery capacity of 170mAH. Higher capacity and it will need longer still.
And how long should the batteries last ? Well the opamp current consumption adds up to around 23ma give or take. Add another couple of ma for good measure and we get say 25ma. So a 170mAH battery should last around 7 hours give or take.
Okay, having some problems with a build and stumped on troubleshooting. I think I might have a bad component, but I'd like to confirm what it might be before I order a replacement.
I'm getting zero output on the right channel. In addition to the checks in the Initial testing and Troubleshooting sections (which passed), I've also tried swapping U3/U4, with no change in output. I've got an insulator under S2.
My instinct is that U1 is defective/damaged, VR1 is half dead, or either input or output jack is somehow nonfunctional.
However, I'm having trouble devising tests I trust to check these components. Thanks in advance for any help you folks can lend!
I'm getting zero output on the right channel. In addition to the checks in the Initial testing and Troubleshooting sections (which passed), I've also tried swapping U3/U4, with no change in output. I've got an insulator under S2.
My instinct is that U1 is defective/damaged, VR1 is half dead, or either input or output jack is somehow nonfunctional.
However, I'm having trouble devising tests I trust to check these components. Thanks in advance for any help you folks can lend!
It means further toward the inputs
So you have good mono sound with the wipers linked. That proves U3 and U4 and the headphone socket are good. Remove the link so that its back to one channel again.
There are a couple of things to check now. First you need to just confirm that the DC voltage on pins 1 and 7 of U1 are zero. Put the black meter lead onto ground and measure to each pin. If its not zero on both then we need to find why.
If it is zero then just try linking pins 1 and 3 on the 'off board input' connector. You should get mono sound again through both channels. If you do then the problem is probably around the input socket or the connections to it or the connection from the socket to U1.
So you have good mono sound with the wipers linked. That proves U3 and U4 and the headphone socket are good. Remove the link so that its back to one channel again.
There are a couple of things to check now. First you need to just confirm that the DC voltage on pins 1 and 7 of U1 are zero. Put the black meter lead onto ground and measure to each pin. If its not zero on both then we need to find why.
If it is zero then just try linking pins 1 and 3 on the 'off board input' connector. You should get mono sound again through both channels. If you do then the problem is probably around the input socket or the connections to it or the connection from the socket to U1.
Huh, in lighting control systems (day job stuff) forward would be towards outputs. Glad I asked.
More test results: With U1 socketed, I see 10.5 mV on pin 1 (lower left, closest to dot) and -0.2mV on pin 7 (count counter-clockwise). With the chip out of socket, it is 0V on both pins, though that's what I would expect anyways, right?
I flowed a smidge more solder into the socket pins under U1 (chip removed), and tried the above test again, with no change in results.
10.5 mV doesn't seem like zero but also doesn't seem like lots, so I tried the off-board input link as well - putting a short jumper in the most outboard and most inboard pads. I only got left-channel output.
I took a look at all the pads for caps and resistors between J2 and U1, everything looks fine.
I'm pretty sure this points towards U1. Right?
More test results: With U1 socketed, I see 10.5 mV on pin 1 (lower left, closest to dot) and -0.2mV on pin 7 (count counter-clockwise). With the chip out of socket, it is 0V on both pins, though that's what I would expect anyways, right?
I flowed a smidge more solder into the socket pins under U1 (chip removed), and tried the above test again, with no change in results.
10.5 mV doesn't seem like zero but also doesn't seem like lots, so I tried the off-board input link as well - putting a short jumper in the most outboard and most inboard pads. I only got left-channel output.
I took a look at all the pads for caps and resistors between J2 and U1, everything looks fine.
I'm pretty sure this points towards U1. Right?
It just a phrase I use without having given it much thought tbh
Your voltage readings are fine and the small DC value is just the normal 'DC offset' of the opamp.
I doubt the opamp is faulty. It would be the last thing to suspect really.
Did you link the pins of the connector as I suggested ? That would feed the same signal to both halves of the opamp. Or link pins 3 and 5 on the opamp itself.
(if you want to prove the opamp is good then you can swap it for either of the 4556 devices. It will still all work as normal)
Your voltage readings are fine and the small DC value is just the normal 'DC offset' of the opamp.
I doubt the opamp is faulty. It would be the last thing to suspect really.
Did you link the pins of the connector as I suggested ? That would feed the same signal to both halves of the opamp. Or link pins 3 and 5 on the opamp itself.
(if you want to prove the opamp is good then you can swap it for either of the 4556 devices. It will still all work as normal)
02 + 0dac conflicting information
Hey guys, first post here =D.
So I'm currently building a o2 amp + dac V1.1 from head,n,fi. Run into some conflicting information regarding connections of the 0dac. I have a reddit post below that details it already with no response, figure ill link as it has links to the info already.
ODac connection to 02, conflicting information : diyaudio
Also is there a complete V1.1 amp + 0dac instructions?
Hey guys, first post here =D.
So I'm currently building a o2 amp + dac V1.1 from head,n,fi. Run into some conflicting information regarding connections of the 0dac. I have a reddit post below that details it already with no response, figure ill link as it has links to the info already.
ODac connection to 02, conflicting information : diyaudio
Also is there a complete V1.1 amp + 0dac instructions?
The details are here on NwAvGuy's blog.
Basically, if you connect the odac's output to the O2's J2 you will not be able switch between the odac and the O2's input, and the O2's input jack will also double as output for the odac. Kind of weird, but actually pretty usable.
Otherwise, you can connect the odac to the input jack's center pins, and by cutting the traces as show on NwAvGuy's blogg, you will be able to automatically switch from the odac to the input by connecting a source to the input jack. You can still have a separate odac output by using the optional jack on the odac. That is the way I did it, I think it is the neatest option.
Basically, if you connect the odac's output to the O2's J2 you will not be able switch between the odac and the O2's input, and the O2's input jack will also double as output for the odac. Kind of weird, but actually pretty usable.
Otherwise, you can connect the odac to the input jack's center pins, and by cutting the traces as show on NwAvGuy's blogg, you will be able to automatically switch from the odac to the input by connecting a source to the input jack. You can still have a separate odac output by using the optional jack on the odac. That is the way I did it, I think it is the neatest option.
I Decided to connect the Odac to P1, With a help from a redditor, i went from Odac L, R, GND, GND, to the P1(L, Gnd/Gnd, R) Yes Left channel is soldered to left channel. Now I can't hear left channel through odac(it works perfectly fine both channels with just the O2(amp)) tried resoldering the connections to the board from both odac and o2 and different usb cables/ports. I Also checked volatages from the line out on the Odac and im getting 0v from Left to either grounds, and 0.03V from Right to gnds. Maybe I have a dud odac? Jds labs told me not to short the jumpers below the Odac if I'm connecting RCA jacks instead of the 3.5mm jack, Is that right?
It just a phrase I use without having given it much thought tbh
Your voltage readings are fine and the small DC value is just the normal 'DC offset' of the opamp.
I doubt the opamp is faulty. It would be the last thing to suspect really.
Did you link the pins of the connector as I suggested ? That would feed the same signal to both halves of the opamp. Or link pins 3 and 5 on the opamp itself.
(if you want to prove the opamp is good then you can swap it for either of the 4556 devices. It will still all work as normal)
Hey so I wasn't able to get back to this for a couple days. I did link the output pins on P1 (the outer and the innermost, leaving the center pin open) I did not get mono output at that time.
I tried the pin 3-5 link tonight, and strangely go no output. I took the link out and went back to test for the previous condition (sound in one channel only) but still have no sound output.
So I started over on the checks. I am now finding volts on P2 - ~314 mV on from pin 1 to pin 3 and ~309 mV from pin 1 to pin 4. Did I miss or bork this test the first time? Did something change? Who knows, but this seems to be the avenue to check at this point. All other DC voltage checks in "Basic Troubleshooting" passed.
Start at the beginning so we can make sense of it all again.
P2 should have pins 1 and 2 connected to ground. Measuring from ground to pin 3 or to pin 4 should show essentially zero volts DC. A few millivolts is OK but nothing more. That is measured with no signal applied.
(I don't know if you mean you measured AC volts there because ~ is a recognised AC symbol) All you need check is the DC voltage. Should be zero.
If you have audio from one channel only then do the check of linking the wipers again. You should have audio from both channels. That proves the output side of things is OK.
We'll take it from there depending on the outcome.
P2 should have pins 1 and 2 connected to ground. Measuring from ground to pin 3 or to pin 4 should show essentially zero volts DC. A few millivolts is OK but nothing more. That is measured with no signal applied.
(I don't know if you mean you measured AC volts there because ~ is a recognised AC symbol) All you need check is the DC voltage. Should be zero.
If you have audio from one channel only then do the check of linking the wipers again. You should have audio from both channels. That proves the output side of things is OK.
We'll take it from there depending on the outcome.
I measured DC volts from the grounded pin 1 (square pad) to pin 3 and 4 and read approximately 314 mV to pin 3 and 309 mV to pin 4. (Sorry about the stray maths symbol!) The guide says that should be <0.008 mV, which is why I stopped troubleshooting at that point.
I currently have audio from zero channels.
I re-checked all resistances and voltages in the basic troubleshooting section. When I get back to it I'll re-do the step-by-step DC voltages, and double check the measurements above from the negative-terminal. I can also tie the wipers back together, and see if anything happens.
I currently have audio from zero channels.
I re-checked all resistances and voltages in the basic troubleshooting section. When I get back to it I'll re-do the step-by-step DC voltages, and double check the measurements above from the negative-terminal. I can also tie the wipers back together, and see if anything happens.
I have some questions to the circuitry of the O2.
1)How is the Active Current Limitting deisgned? I cant find explanation or calculating with schematic.
2)Batterie charging. Have someone a link with explanation how to build a circuit to load two 9V batteries? With automatic shut down when the battery is full loaded?
It should have shutdown automatic when the batteries reach a critic voltage of 7V I would say!?
1)How is the Active Current Limitting deisgned? I cant find explanation or calculating with schematic.
2)Batterie charging. Have someone a link with explanation how to build a circuit to load two 9V batteries? With automatic shut down when the battery is full loaded?
It should have shutdown automatic when the batteries reach a critic voltage of 7V I would say!?
The only active current limiting is,
1/ The opamp outputs themselves are limited by the protection offered within the chip. I think the 4556 is rated as 'continuous' meaning it can withstand a short indefinitely. Check on the data sheet though before taking my word for it.
The 78 and 7912 regulators have inbuilt protection.
The 02 lacks any other form of protection. When using rechargeable batteries a fuse or circuit protector is always recommended for safety.
2/ The O2 does turn off when the batteries discharge however the cut-off point depends totally on the forward volt drop of the LED used in the comparator circuit.
1/ The opamp outputs themselves are limited by the protection offered within the chip. I think the 4556 is rated as 'continuous' meaning it can withstand a short indefinitely. Check on the data sheet though before taking my word for it.
The 78 and 7912 regulators have inbuilt protection.
The 02 lacks any other form of protection. When using rechargeable batteries a fuse or circuit protector is always recommended for safety.
2/ The O2 does turn off when the batteries discharge however the cut-off point depends totally on the forward volt drop of the LED used in the comparator circuit.
No sound
Hi everyone,
Just built a desktop version of ODAC+O2 with no 3.5mm aux input and rca out. I didn't have the correct back plate so I first built it without the RCA output.
I had routed the line-out from ODAC to directly P1. This was working just fine.
I then followed the instructions at http://www.jdslabs.com/pdf/Custom O2-ODAC - Complete Soldering Guide.pdf, Dedicated RCA DAC line-output. Basically, you route line-out to RCA and AUDIO_OUT to J2.
No since I have the desktop version my front plate doesn't have the 3.5mm input jack so I have nothing on J2. With this configuration I get no sound. The RCA work but that's it. I did cut the traces next to the L and R of J2 as the instructions say. I also noticed that the headphone jack there seems to be 2 pins for left and 2 for right and there is continuity between each of them. Since I dont have the jack installed, I tried to jumper them on the board, solder a small lead between L and the solder point next to it and the same for R.
I've redone all this 4 times now and clearly I am doing something wrong. If someone has advice on what I can try I would greatly appreciate it. It's worth noting that I rewired everything as it was for the first build and everything is fine so the rest of the circuit seems fine.
Thanks
Hi everyone,
Just built a desktop version of ODAC+O2 with no 3.5mm aux input and rca out. I didn't have the correct back plate so I first built it without the RCA output.
I had routed the line-out from ODAC to directly P1. This was working just fine.
I then followed the instructions at http://www.jdslabs.com/pdf/Custom O2-ODAC - Complete Soldering Guide.pdf, Dedicated RCA DAC line-output. Basically, you route line-out to RCA and AUDIO_OUT to J2.
No since I have the desktop version my front plate doesn't have the 3.5mm input jack so I have nothing on J2. With this configuration I get no sound. The RCA work but that's it. I did cut the traces next to the L and R of J2 as the instructions say. I also noticed that the headphone jack there seems to be 2 pins for left and 2 for right and there is continuity between each of them. Since I dont have the jack installed, I tried to jumper them on the board, solder a small lead between L and the solder point next to it and the same for R.
I've redone all this 4 times now and clearly I am doing something wrong. If someone has advice on what I can try I would greatly appreciate it. It's worth noting that I rewired everything as it was for the first build and everything is fine so the rest of the circuit seems fine.
Thanks