Could this be arching across crap or dodgy solder connections? Maybe in the supply section. It may be worth re-flowing all pads associated with power supply. Then ultimately the whole board... pain in the ****!
Sounds like a connection rather than a component.
Not likely, I have tried 2 different set of setup, and they both are run behind power conditioner. I even changed the transformers. If I don't hear from Gigiwork, then I may try bypassing the 2nd opamp and go direct to the the RCA just to eliminate one stage of potential cause. For now, I want to leave it as stock so that I can claim the warranty if there is one .....
I've tried all different configurations, but no joy. What input are you using be.audiophil? What do you mean by using only one bridge (you need two right)?
I kind of visually inspected the solder joints. I thought about reflow the joints but didn't want to give them any excuse to void the warranty if there is any. My gut feeling tells me that this can be the path I will be going down
Do it, do it...
Just do the three that are part of the DAC regulation.
Which ones are they?
Now reading 28.4VAC across the 13V input terminal (2 white wires on my original pic).
Is this how it should be?
Thanks
This is equivalent to 14-0-14, well within the range. It is certainly not the cause of the symptom.
Just a shot in the dark, when I looked at your picture for your PS question, it seemed to me that your selector was set to coax input. Did you try coax input?
Thanks Fred
The good news is that tonight USB and coax are working fine. Not sure what I did to fix things, all I changed was swapping out the 5532 op amps and putting in some OPA627s which worked fine. Going back to the 5532s they worked fine too. This is a mysterious hobby....
The OPA627s are very nice by the way.
I think I'll let things settle before trying some output trafos
The good news is that tonight USB and coax are working fine. Not sure what I did to fix things, all I changed was swapping out the 5532 op amps and putting in some OPA627s which worked fine. Going back to the 5532s they worked fine too. This is a mysterious hobby....
The OPA627s are very nice by the way.
I think I'll let things settle before trying some output trafos
well ive connected everything right now i think. the dac is connected va usb to the computer but i dont hear a sound. the player plays music and the right device is selected.. hm..
edit:
its running. the input selection doesnt work like its shown in the shematics and on the pcb itself.. seems to be wrong.
thx to be.audiophil its working now - thank you again and also thank you @ the other guys that helped me
i will the test the dac now for some hours and if everything is fine i will connect it with the monacors !
edit:
its running. the input selection doesnt work like its shown in the shematics and on the pcb itself.. seems to be wrong.
thx to be.audiophil its working now
- thank you again and also thank you @ the other guys that helped me i will the test the dac now for some hours and if everything is fine i will connect it with the monacors !
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Hi Chris,
you´re welcome ...congrats for your working dac
@ LBJ and Chris
Yes ... as described before i found the two rows of pins for the input select are working different from the printing on the pcb ... i went for only one jumper in the first of this two rows of pins ... no jumper for SPDIF, one jumper over middle and left pin for usb and only one jumper over middle and right pin for optical/ Toslink ...
you´re welcome ...congrats for your working dac
@ LBJ and Chris
Yes ... as described before i found the two rows of pins for the input select are working different from the printing on the pcb ... i went for only one jumper in the first of this two rows of pins ... no jumper for SPDIF, one jumper over middle and left pin for usb and only one jumper over middle and right pin for optical/ Toslink ...
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In my LM-DAC3 V9, the printing of the input selection is correct. However, it isn't the most intuitive way to implement such function. When it came, both jumpers were set to 0 and 0 which is coax. To select optical or USB, you only move ONE jumper down. When you see the jumpers and the printing, you will know what I mean
My dac is now working. The seller, Ian Ma, graciously helped me with my power transformer wiring (an r-core I didn't purchase from him). Kudos to him.
There is intermittent static coming from the right channel however. I understand other people are having the same issue, anyone figure it out?
Btw, my board is like pchw's: the input selection is consistent with the documentation and silkscreening.
There is intermittent static coming from the right channel however. I understand other people are having the same issue, anyone figure it out?
Btw, my board is like pchw's: the input selection is consistent with the documentation and silkscreening.
lbj
As the static sound is coming from one channel then the problem would appear to be after the power section.
Are you using transformers or op-amps for output? Check your connection quality and eyeball solder pads and connections especially around the channel ouputs and RCA sockets (find a pin schematic for your op-amps if using them). Re-flow pads around op-amp section with solder iron if necessary
Is it a 'hiss' or 'crackle'. A hiss maybe a faulty component (old 'b' stock) whereas a crackle maybe arching across a dodgy connection.
Sometimes these things are a process of elimination. I have yet to receive my R core transformer so will be interested to see if I have the same problem. If I have then it would mean a consistent fault either in the PCB or one of the component batches.
A real pain mate, good luck
As the static sound is coming from one channel then the problem would appear to be after the power section.
Are you using transformers or op-amps for output? Check your connection quality and eyeball solder pads and connections especially around the channel ouputs and RCA sockets (find a pin schematic for your op-amps if using them). Re-flow pads around op-amp section with solder iron if necessary
Is it a 'hiss' or 'crackle'. A hiss maybe a faulty component (old 'b' stock) whereas a crackle maybe arching across a dodgy connection.
Sometimes these things are a process of elimination. I have yet to receive my R core transformer so will be interested to see if I have the same problem. If I have then it would mean a consistent fault either in the PCB or one of the component batches.
A real pain mate, good luck
Thanks RichLund. It's more like a crackling sound, like an old pot (I believe pchw described a similar sound on his board). Sometimes loud enough to distract while music is playing, sometimes not. Always audible when between tracks. It seems to quiet down a bit after the dac's been on for a while, I'll know more later when I've run it longer.
Visually, I don't see any problems with the solder joints, although I'm sure a problem could be hiding in there somewhere. I'm using the stock opamps, but my plan was to go with some nickel core transformers at some point. "Hopefully" the problem lies with one of the opamps. I'm considering a) getting some cheap $4 opamps and ruling out the opamps, b) getting some cheap Edcor trannies and seeing if the problem lies in the analog section after the dac output, or c) just biting the bullet and getting the nickel cores.
Visually, I don't see any problems with the solder joints, although I'm sure a problem could be hiding in there somewhere. I'm using the stock opamps, but my plan was to go with some nickel core transformers at some point. "Hopefully" the problem lies with one of the opamps. I'm considering a) getting some cheap $4 opamps and ruling out the opamps, b) getting some cheap Edcor trannies and seeing if the problem lies in the analog section after the dac output, or c) just biting the bullet and getting the nickel cores.
lbj
Interesting. The crackling reduces after a while playing. Sounds like a duff connection expanding under heat thus closing the gap?
Try swapping op-amps around. I remember reading that only the centre op-amp is required the one on the outside is a buffer or muting circuit? So try using one, swapping between both. Check the thread for info.
Also this thread on Stereo Net:
My new dac
To be fair it is very unlikely that the op-amps are faulty (not impossible just unlikely). The manufacturing processes these days are generally spot on.
If your thinking of getting new op-amps I take it you've done the homework and shortlisted better alternatives like LM4562 and OPA1611, all in the $4 -$6 range. I think I will get Cinemag CMOQ-2H nickel core transformers too. They are $55.74 each and you wont have to pay the $38 postage like I do in the UK! By-passing the whole opamp stage will almost certainly solve the problem. If it doesn't then its the Dac chip area.
To be fair, if i was making and selling these DAC's I would test each before despatch. It really wouldn't be too much trouble would it? mine wasn't packed too securely, just in a anti static bag and padded envelope, so maybe transit damage?
Or just send the bloody thing back and demand a tested new one!!
Rich
Interesting. The crackling reduces after a while playing. Sounds like a duff connection expanding under heat thus closing the gap?
Try swapping op-amps around. I remember reading that only the centre op-amp is required the one on the outside is a buffer or muting circuit? So try using one, swapping between both. Check the thread for info.
Also this thread on Stereo Net:
My new dac
To be fair it is very unlikely that the op-amps are faulty (not impossible just unlikely). The manufacturing processes these days are generally spot on.
If your thinking of getting new op-amps I take it you've done the homework and shortlisted better alternatives like LM4562 and OPA1611, all in the $4 -$6 range. I think I will get Cinemag CMOQ-2H nickel core transformers too. They are $55.74 each and you wont have to pay the $38 postage like I do in the UK! By-passing the whole opamp stage will almost certainly solve the problem. If it doesn't then its the Dac chip area.
To be fair, if i was making and selling these DAC's I would test each before despatch. It really wouldn't be too much trouble would it? mine wasn't packed too securely, just in a anti static bag and padded envelope, so maybe transit damage?
Or just send the bloody thing back and demand a tested new one!!
Rich
Hi Lbj,
I think we have the same issue except it both channels to me. It is like you are trying to overload a cheap $2 speaker. I can hear very noticeable (well, my significant half said she did hear it, so YMMV applies) crackling. Can it be jittering?
Ian also responded to me and asked me to post him a picture to him. He also asked me whether I had other opamps to try. Sounds like a possibility. I do have a pair of opa2134 and a pair of lm4562. So, I am going to try them and report back. You may also want to report this problem to Ian so that he is aware of the instance.
I have a pair of this Edcor trannies. They are now used behind the counterpoint of the Buffalo 24 for the SE output. They will be tested in the big dac after it gets a clean bill. There is really no point to try anything with the known issue for the moment.
I think we have the same issue except it both channels to me. It is like you are trying to overload a cheap $2 speaker. I can hear very noticeable (well, my significant half said she did hear it, so YMMV applies) crackling. Can it be jittering?
Ian also responded to me and asked me to post him a picture to him. He also asked me whether I had other opamps to try. Sounds like a possibility. I do have a pair of opa2134 and a pair of lm4562. So, I am going to try them and report back. You may also want to report this problem to Ian so that he is aware of the instance.
I have a pair of this Edcor trannies. They are now used behind the counterpoint of the Buffalo 24 for the SE output. They will be tested in the big dac after it gets a clean bill. There is really no point to try anything with the known issue for the moment.