Correct, it is a grounding issue via the SPDIF connector which is very simple but you have to search..
The Pass amps employ a common ground between the power supply and the speaker feed. Ground is ground is ground.
As I write this I'm trying to mod the TORX optical converter module from the Mini2496 DAC to feed the V3. It won't answer the grounding issue but it will allow the V3 to be connected to the three power amps.
Absolutely the wrong approach, sorry. You know what the outcome of that will be. Using bandaids every day to stop wounds bleeding because you use to take the knife at he wrong side is not the real solution. I already gave some hints on the grounding issue but you did not reply. Please reread post #437. Toslink is not the real solution, it will also make the V3 less good. That is opposite our common audio set of rules AFAIK. At least it is against the design goals of V3 but we live in a free (edit by Edward Snowdon: well that's what you like to think) world so...
BTW "Ground is ground is ground" is not true in the real world. That direction is where you have to be looking. Start checking the power plugs as asked in post #437.
All this is totally off topic, not that I care much but still...
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Additionally - I do have the proper shield setup in the server PC as was mentioned earlier.
DIY PC/SPDIF Adapter
DIY PC/SPDIF Adapter
JP, there is no galvanic ground connection between the V3 BNC connector and it's bracket as described in that post. It's just on a wood base - no metal chassis yet. Are you talking about the other end, the PC?
I have no intention to use the TORX on a permanent basis. Just looking for a way to hear the V3 on other power amps.
The Pass ground comment came from a reliable source that helped clarify the differences between the LM3886 amps I had been building and the discrete approach. Not intended to be taken exactly verbatim. I'm more than happy to take this discussion off-line, but was concerned about what might happen with other builders with various amps.
Sorry if I've taken the thread in the wrong direction.
I have no intention to use the TORX on a permanent basis. Just looking for a way to hear the V3 on other power amps.
The Pass ground comment came from a reliable source that helped clarify the differences between the LM3886 amps I had been building and the discrete approach. Not intended to be taken exactly verbatim. I'm more than happy to take this discussion off-line, but was concerned about what might happen with other builders with various amps.
Sorry if I've taken the thread in the wrong direction.
Bob, I suggest to draw a diagram of all connected components, including the main and the safety earth. Then follow how the signal ground "flows". Notice that your Dac now connects the signal grounds of the source (PC?) to the "line out" preamp or amps. The dac is floating, but the other components can form a second loop outside the dac.
I tested the pads at L3, L4, L5, L6 before soldering them and all the voltages checked out. Now after soldering them in and testing, board did not work. Did some testing and the 3v3OSC leg does not check out. At L3 now I only get 1.0 v (instead 3.3v). At L1 voltage drops from 4.3v to 1.7v. Any ideas?
L4, L5, L6 all still check out at 3.6, 3.3 and 3.3.
L4, L5, L6 all still check out at 3.6, 3.3 and 3.3.
Thanks Fred, I'll do the diagram tomorrow. I'm as tired of writing about this as everyone is reading it, but I did do a final cycle for confirmation:
1. Isolated the PC end of the BNC from the chassis - no help.
2. Noticed motherboard SPDIF RCA ground was touching PC case.
3. Ran RCA SPDIF from OPPO DVD player to V3 DAC - no help.
4. Moved a completely different PC to a location right next to the DAC/AMP. RCA SPDIF feed - no help.
6. Reset music server > V3 > BrianGT amps system - perfect sound - no hum.
7. Hooked up a different MyRef FE build - perfect sound - no hum.
So there has been some "great" progress. I'll do the diagram for the Pass and FE beta amps after I catch my breath and put the server back together.
Still looking forward to reports of other Pass amp combinations - but I'll keep to V3 construction comments unless the subject is raised by others.
Thanks All
1. Isolated the PC end of the BNC from the chassis - no help.
2. Noticed motherboard SPDIF RCA ground was touching PC case.
3. Ran RCA SPDIF from OPPO DVD player to V3 DAC - no help.
4. Moved a completely different PC to a location right next to the DAC/AMP. RCA SPDIF feed - no help.
6. Reset music server > V3 > BrianGT amps system - perfect sound - no hum.
7. Hooked up a different MyRef FE build - perfect sound - no hum.
So there has been some "great" progress. I'll do the diagram for the Pass and FE beta amps after I catch my breath and put the server back together.
Still looking forward to reports of other Pass amp combinations - but I'll keep to V3 construction comments unless the subject is raised by others.
Thanks All
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Sorry - just not my weekend. Try this.
I have been using the Chip Quick alloy and flux for a couple years but you probably don't want to wait for the delivery. There is another part of the post that suggests using two soldering irons, but I have never tried that.
I have been using the Chip Quick alloy and flux for a couple years but you probably don't want to wait for the delivery. There is another part of the post that suggests using two soldering irons, but I have never tried that.
lots of solder wick and flux. Keep working one corner as clean as possible then try and lift the corner by a thou and slide the tip of a craft blade under, let it cool then work the other corners. If the XO is faulty then only worry about saving the pads
Get C17 out of the way obviously.
A piece of kapton tape or such can be slid under the corners to form a barrier while cooling.
Good luck.
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Well, that was my fastest build.
Waiting for the transformer.
Finished the motherboard...
Functional check... Check!
Drill it!
DAC sitting in the first floor
Done...
Thank you for this great GB project.
The sound is also great, not too bright or any special coloration I would notice. Definitely better soundstage and resolution of fine detail than the Sony DTC2000ES of a friend is capable of.
So long... guten Rutsch!
Waiting for the transformer.
Finished the motherboard...
Functional check... Check!
Drill it!
DAC sitting in the first floor
Done...
Thank you for this great GB project.
The sound is also great, not too bright or any special coloration I would notice. Definitely better soundstage and resolution of fine detail than the Sony DTC2000ES of a friend is capable of.
So long... guten Rutsch!
getting there
Received front back plates for both enclosures so after polishing I ll do final assemblies.
Question on how to combine dac+pre+filter grounds remains open.
Or should I leave them floating and only do the earth connected to enclosure floor ?
Received front back plates for both enclosures so after polishing I ll do final assemblies.
Question on how to combine dac+pre+filter grounds remains open.
Or should I leave them floating and only do the earth connected to enclosure floor ?
Attachments
@Joschl:
fast and clean build, well done!! Your soldering is impeccable!
Quick question: I see that you are using a print transformer from Block... those are available at Conrad --> is it this one?
http://www.conrad.de/ce/de/product/...2x9-V-2-x-155-mA-28-VA-VB-2829-Block?ref=list
Guten Rutsch!
(cannot be literally translated into 'Happy Slide')
Happy New Year to everyone!
fast and clean build, well done!! Your soldering is impeccable!
Quick question: I see that you are using a print transformer from Block... those are available at Conrad --> is it this one?
http://www.conrad.de/ce/de/product/...2x9-V-2-x-155-mA-28-VA-VB-2829-Block?ref=list
Guten Rutsch!
(cannot be literally translated into 'Happy Slide'
)Happy New Year to everyone!
Thanxalot @Stixx
The WM8804 has very little solder on the pads after wiping them with solder wick. But I decided to leave it that way and not heat everything up again. And Q2 is a bitch I wasn't able to mount it flush on the board.
The transformer is this one:
http://www.conrad.de/ce/de/product/...ndaer-9-V-311-mA-28-VA-VB-2819-Block?ref=list
The WM8804 has very little solder on the pads after wiping them with solder wick. But I decided to leave it that way and not heat everything up again. And Q2 is a bitch
I wasn't able to mount it flush on the board.The transformer is this one:
http://www.conrad.de/ce/de/product/...ndaer-9-V-311-mA-28-VA-VB-2819-Block?ref=list
Thanxalot @Stixx
The WM8804 has very little solder on the pads after wiping them with solder wick. But I decided to leave it that way and not heat everything up again. And Q2 is a bitch
The transformer is this one:
http://www.conrad.de/ce/de/product/...ndaer-9-V-311-mA-28-VA-VB-2819-Block?ref=list
Joschl, great work! Is the extra circuitry all related to the optical input? Kind regards.