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building a TPA3255 260-2-29A, and need some guidance

Slight turn off pop, and some noise through the tweeter >_<. Maybe I need a better SMPS?
The pop is only because you don't have a control circuit to disable the amps before the power supply turns off (or before the PSU turns on, same issue). These minimal builds will always have this issue, don't worry about it.

If you have noise through the tweeter then it's got nothing to do with the power supply, it's the residual noise from the amp modules plus the input noise.
 
The pop is only because you don't have a control circuit to disable the amps before the power supply turns off (or before the PSU turns on, same issue). These minimal builds will always have this issue, don't worry about it.

If you have noise through the tweeter then it's got nothing to do with the power supply, it's the residual noise from the amp modules plus the input noise.
Good to know about the "pop" sound isn't an issue. Now to try and solve the slight crackle noise/ whatever is deciding to leak through. Any idea on how to tackle that? How about the slight hum noise from the psu?

Thanks
 
Good to know about the "pop" sound isn't an issue. Now to try and solve the slight crackle noise/ whatever is deciding to leak through. Any idea on how to tackle that? How about the slight hum noise from the psu?

Thanks
Do you mean the PSU is physically vibrating and making a noise that way? That's not expected from an SMPS.
 
narrowed it down to my USB cable into my minidsp HT..... Do I just get a different cable? Under the assumption digital shouldn't be having these issues..
 
narrowed it down to my USB cable into my minidsp HT..... Do I just get a different cable? Under the assumption digital shouldn't be having these issues..
It’s a ground loop then, nothing to do with digital. It will almost certainly go away if you can go balanced between the MiniDSP and amp, or optical between the PC and MiniDSP
 
It’s a ground loop then, nothing to do with digital. It will almost certainly go away if you can go balanced between the MiniDSP and amp, or optical between the PC and MiniDSP
it doesn't allow balanced connection :/ I have noticed when I connect my RCA to the minidsp Flex HT without any power or usb/ signal, I end up getting some noise through the speaker. Is this caused by a ground issue between the two or? Should I use Balanced out from my amplifier to unbalanced converter, or am I simply moving the noise chain around?
 
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now it seems it's an issue when I hook up two modules into it. One module, both channels no issues. Once I do both, then noise. Is there a setting I'm missing? What about removing the earth ground?

Once everything is powered and on, the USB is causing most of the noise, and I can hear my mouse move as well when using the PC.
 
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now it seems it's an issue when I hook up two modules into it. One module, both channels no issues. Once I do both, then noise. Is there a setting I'm missing? What about removing the earth ground?

Once everything is powered and on, the USB is causing most of the noise, and I can hear my mouse move as well when using the PC.
use a USB ground Isolator, or use TOSLINK instead of USB.

Either will solve the problem. I'd suggest TOSLINK as easier to implement. You can get cheap USB to Toslink devices.
 
Perhaps one of the boards should be in slave mode (if there is such an option on the board).
there is a slave mode, but once I try it, then there's no audio...
 
use a USB ground Isolator, or use TOSLINK instead of USB.

Either will solve the problem. I'd suggest TOSLINK as easier to implement. You can get cheap USB to Toslink devices.
Bought a USB isolator (topping hs02). Toslink won't work for me sadly. Doesn't output 4.1 Uncompressed/ not enough bandwidth. Will keep you posted.
 
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use a USB ground Isolator, or use TOSLINK instead of USB.

Either will solve the problem. I'd suggest TOSLINK as easier to implement. You can get cheap USB to Toslink devices.
I love you (no homo) it worked :)

If I use an AC cleaner/ noise suppressor for the unit, will that help the slight hum from the mains on the power side?

Seems my issue comes down to when I connect another module, I get some noise introduced.
 
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there is a slave mode, but once I try it, then there's no audio...
To enable slave mode you need to (only on the slave module!!) solder a 2 pin header to J6, place a jumper across this, in addition to wiring the modules together on IOM/IOP.
 
The pop is only because you don't have a control circuit to disable the amps before the power supply turns off (or before the PSU turns on, same issue). These minimal builds will always have this issue, don't worry about it.

If you have noise through the tweeter then it's got nothing to do with the power supply, it's the residual noise from the amp modules plus the input noise.
I have these 3E modules and have found that for me the ONLY way to prevent the loud POP at power off is to (first) pull RESET=pin4 low and THEN pull PS_CTRL=pin2 low. The reverse sequence STILL pops, also if you only ground PS_CTRL (without first grounding RESET) that will pop. And since I am building a 9 channel amp with 6 modules, I am now building a PIC16 control system to manage all of this power up / power down and fault/clip detection.
 
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To enable slave mode you need to (only on the slave module!!) solder a 2 pin header to J6, place a jumper across this, in addition to wiring the modules together on IOM/IOP.
wiring the modules together on IOM/IOP. I don't get this part. I soldered J6 together and used a jumper across the IOM thingy with no luck.

Thanks
 
Once everything is powered and on, the USB is causing most of the noise, and I can hear my mouse move as well when using the PC.
You said you have noise when the MiniDSP is powered off though? Can you be super careful and work through this process?
  • Speakers connected to amp, amp powered on, no cables connected to amp
  • Speakers connected to amp, amp powered on, RCA cables connected to amp only, not the Flex
  • Speakers connected to amp, amp powered on, RCA cables connected to amp and Flex, Flex power cable not connected
  • Speakers connected to amp, amp powered on, RCA cables connected to amp and Flex, Flex power cable connected and powered on
  • Speakers connected to amp, amp powered on, RCA cables connected to amp and Flex, Flex power cable connected and powered on, USB cable connected to PC, PC powered on
 
wiring the modules together on IOM/IOP. I don't get this part. I soldered J6 together and used a jumper across the IOM thingy with no luck.

Thanks
I'm not aware of this being any more than a theoretical issue when using amp modules. It may matter when building multiple TPA3255 chips into a single module in close proximity, but that's not your use case. People stuff multiple TPA3255 modules into cases all the time with no issues. Certainly not issues that would give noise when you move a mouse.
 
wiring the modules together on IOM/IOP. I don't get this part. I soldered J6 together and used a jumper across the IOM thingy with no luck.

Thanks
Look at these 2 pics, now see what I mean? This is working for me
pic1.jpg

pic2.jpg



EDIT - to clarify when I said "this is working for me" all that means is this wiring configuration produces audio sound as expected. The BIG question (not yet answered) is "does going to these extra efforts make any audible difference / under what specific conditions? Having listened both ways (2 masters vs master+slave) I cannot hear any differences. I am purchasing some more instruments so that I can make the kind of measurements that ASR expects for these kinds of evaluations. Will let you know how that goes (over in "my" amp build thread).
 

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Look at these 2 pics, now see what I mean? This is working for me
View attachment 377659
View attachment 377658


EDIT - to clarify when I said "this is working for me" all that means is this wiring configuration produces audio sound as expected. The BIG question (not yet answered) is "does going to these extra efforts make any audible difference / under what specific conditions? Having listened both ways (2 masters vs master+slave) I cannot hear any differences. I am purchasing some more instruments so that I can make the kind of measurements that ASR expects for these kinds of evaluations. Will let you know how that goes (over in "my" amp build thread).
What in the world! I never got that from reading the manual. That's much more than what I was doing. I just need to find those individual pins to make this work. I'm just wanting to remove this damn cross talk or w.e is causing this noise between the two modules. Luckily I fixed the USB noise, which was driving me bonkers. I'm literally a foot away from my amp and speakers, so everything needs to be dead silent, or it will really bug me. I will do this, and report back if this fixes my issue!
 
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