I Saw this board on Aliexpress.
As per marketing info it should support a 48vdc but i would use a 36v max psu.
This board is prettty similar to the tpa 3251 from the same brand. It uses some Ne5532 aop
As per marketing info it should support a 48vdc but i would use a 36v max psu.
This board is prettty similar to the tpa 3251 from the same brand. It uses some Ne5532 aop
An externally hosted image should be here but it was not working when we last tested it.
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Well spotted, Dani.
If the same component values are used in lithoc's amplifier, it is a "101" Buck choke, thus 100uH. This should give 1/10 of the current ripple on the Zero Zone board. The SMPS chip may be an LM2596 (150KHz) and not an LM2575 (52KHz). If so, the ripple current is reduced further to 1/3.
If the same component values are used in lithoc's amplifier, it is a "101" Buck choke, thus 100uH. This should give 1/10 of the current ripple on the Zero Zone board. The SMPS chip may be an LM2596 (150KHz) and not an LM2575 (52KHz). If so, the ripple current is reduced further to 1/3.
In the same tenor, I suggest people having a TPA3255 amplifier to check the type of the DC-DC converter IC and the value of the Buck choke inductance.
The IC type is important for maximum operating voltage and switching frequency. The choke inductance together with the IC switching frequency allows estimation of the Buck current ripple. It seems that in particular these auxiliary power Buck converters are often poorly designed.
The TPA3255 chip uses 12V as an auxiliary supply voltage so it is convenient in the board design to use the same 12V for supply of the input buffer OP-AMPs. 12V is not much for OP-AMPs like TL072, NE5532 or even LM4562. I suggest you replace these OP-AMPs with OPA1622 or OPA1688 if possible. A particular feature of OPA1622 and OPA1688 is their high performance at low supply voltages.
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Hi Dani,
Unfortunately you did not get any response on your last posting. One advise I will pass on is to use a supply voltage in the low end of the valid supply range in a first attempt. I used 24Vdc. I believe you have a 28Vdc supply. The lower the voltage, the larger the margin to trouble is the principle. If the low supply voltage works you can increase it afterward.
Unfortunately you did not get any response on your last posting. One advise I will pass on is to use a supply voltage in the low end of the valid supply range in a first attempt. I used 24Vdc. I believe you have a 28Vdc supply. The lower the voltage, the larger the margin to trouble is the principle. If the low supply voltage works you can increase it afterward.
Hi amigos,
I have tested with the 24VAC PSU... does not work.. the LM2575HV (60V) started to smoke... I think the board is deffective or something else that goes beyond my capacities...
I sent it back to the seller.
Hi amigos again;
I am doing crazy... I started a new project and I do not understand why I am not getting any sound going out from my speakers.... I checked everything but I probably made a mistake... here some pictures so you can help me please :
Spec :
3E Audio : eaumt-0140-2-a
93DB / 100W 4/8 ohms floor speakers
Toroidal 24VAC PSU (primary 220V / single secondary 24V)
Unregulated AC DC Power Supply (measured exactly @ 34V DC)
I am doing crazy... I started a new project and I do not understand why I am not getting any sound going out from my speakers.... I checked everything but I probably made a mistake... here some pictures so you can help me please :
Spec :
3E Audio : eaumt-0140-2-a
93DB / 100W 4/8 ohms floor speakers
Toroidal 24VAC PSU (primary 220V / single secondary 24V)
Unregulated AC DC Power Supply (measured exactly @ 34V DC)
OK, look at this picture :
Normally, only the red Led should light... The white one indicates a default, can someone confirm ?
I will test later with my SMPS 300RS 28V PSU (not Toroidal).
For me : the polarities are OK...I tested with my SMPS300RS 28V and seems to work (I did not test with the speakers yet). The white led turned off now...
Do you think the problem comes from the Unregulated Power Supply AC/DC itself (maybe some issue with the Nover Capacitors ??)
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Careful powering up with no load attached. Not wise for class d.
I have one of those psu pcbs with Nover caps. All good.
You have proven the amp powers up without fault.
Now piece back together systematically checking it powers up along the way.... it please connect some speakers or a load resistor to the outputs.
I have one of those psu pcbs with Nover caps. All good.
You have proven the amp powers up without fault.
Now piece back together systematically checking it powers up along the way.... it please connect some speakers or a load resistor to the outputs.
Back guys ! found out what was going wrong =)
It was a defective RCA connector ! I changed it and now everything is working great yeahhhhhhhhh
another question : do you think I can use a 28VAC Toroidal instead of a 24VAC, I measured the VDC @ 40V with that PSU. Any risk ?
