Here is another little different LM1875 TDA2030 board,
Any thoughts on this one?
Different LM1875 TDA2030 PCB with inductor
Any thoughts on this one?
Different LM1875 TDA2030 PCB with inductor
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Hi Dave
For me the pcb looks well done like the our pcb. its similar to sadface pcb to use a big film cap as input cap. i personal find that the decoupling caps 110nF or 220nF + electrolytic should be placed as near as possible at the chip. so ideally they should be soldered at the bottom side of the pcb directly at the pins.
the ebay board is well done..
chris
big space to use a fat film cap as input cap....fine.
0,7µH as output filter coil like the LM3886 boards is new for me.
Hi Dave
i noted this board. its from "Zero Zone" and looks not bad. the components are unknown. 1 pcb for a complete amplifier with enough space between the chips to have sufficient heat sink usage. i find this important if i want to use both amps at 1 pcb.
SUQIYA 20W Gaincard version of the two channel LM1875 power amplifier kit finished board tube flavor|Amplifier| - AliExpress
bare board - supply is AC-0-AC
DIY PCB for GC Gaincard Version Dual Channel LM1875 Power Amplifier PCB Empty Board Guts Power Amplifier Board|Amplifier| - AliExpress
chris
i noted this board. its from "Zero Zone" and looks not bad. the components are unknown. 1 pcb for a complete amplifier with enough space between the chips to have sufficient heat sink usage. i find this important if i want to use both amps at 1 pcb.
SUQIYA 20W Gaincard version of the two channel LM1875 power amplifier kit finished board tube flavor|Amplifier| - AliExpress
bare board - supply is AC-0-AC
DIY PCB for GC Gaincard Version Dual Channel LM1875 Power Amplifier PCB Empty Board Guts Power Amplifier Board|Amplifier| - AliExpress
chris
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I'm no amp designer but I can see a few issues on this LM1875 PCB.
There's no 100nF by-pass caps near the chip and the Thiele network is incomplete. It has the 0.7uH inductor but no parallel resistor so it would not work as required. Better to link it out than have a non functioning filter. Maybe those items are under the PCB. I don't get the 47pF and 10K resistor.
IMO, the LM1875 PCB that started this thread if hard to beat on price, layout and component values.
That's not the original Chipamp.com LM1875 PCB as they were mono boards and the power supply was very different. Looks like someone is using their name as Chipamp.com no longer exists AFAIK.
And how do you think this compares to the Ebay LM1875?
Fortunately I ordered 6 of the $2.00 Ebay LM1875 kits, because I had the same solder pad "disappear" on two of the boards when soldering and had to toss them.
I would like to order some quality LM1875 boards from PCBway or JLCPCB based on a known good design.
What was your BOM for this board?
Thank you,
David.
Hi David
i ordered from Sadface some boards but the delivery is not really fast
.
in a technical view I would say that this board give you the advantage to use a big space of the input cap - film cap as feedback cap 22µF is huge! and fuses on board...and for sure a better quality for soldering.
chris
i ordered from Sadface some boards but the delivery is not really fast
.in a technical view I would say that this board give you the advantage to use a big space of the input cap - film cap as feedback cap 22µF is huge! and fuses on board...and for sure a better quality for soldering.
chris
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Hi
if you use a original chip LM1875 then its not needed. the short circuit protection is working fine. the dc protection board should have an additionally circuit for pop on/off - so if you feel better and you have enough space in your housing then you can use it.
i personally dont try a DC protection board. be aware of the Chinese "interpretation" --> test it before you use it.
chris
if you use a original chip LM1875 then its not needed. the short circuit protection is working fine. the dc protection board should have an additionally circuit for pop on/off - so if you feel better and you have enough space in your housing then you can use it.
i personally dont try a DC protection board. be aware of the Chinese "interpretation" --> test it before you use it.
chris
Hi Dave
i didn´t test such a board but as i remember there is a chip/or a circuit on the pcb which is "detection" of the DC voltage Level. i cant remember the chips name.
DC speaker protection for audio amplifier - YouTube
connect the board with a lab supply and test it with 12V-to power up the DC board. then build a 1-5V input signal at the speakers terminal.
here a video about 1 minute....or at 4min with a battery AAA
What Does DC Voltage Do To Your Speaker ? Speaker Protection Circuit - YouTube
chris
i didn´t test such a board but as i remember there is a chip/or a circuit on the pcb which is "detection" of the DC voltage Level. i cant remember the chips name.
DC speaker protection for audio amplifier - YouTube
connect the board with a lab supply and test it with 12V-to power up the DC board. then build a 1-5V input signal at the speakers terminal.
here a video about 1 minute....or at 4min with a battery AAA
What Does DC Voltage Do To Your Speaker ? Speaker Protection Circuit - YouTube
chris
Hi, in my experience with the lm1875 ebay boards, they do make for a pretty loud on/off thump or pop. And this was using all legit parts from digikey or such. Then again the 1875 lacks a mute pin so that shouldn't be a surprise I guess.
Dc protection aside, I think the time delay those little protection boards provide is a must have.
You will probably need a separate power supply and/or transformer too, so plan for that lost space.
Dc protection aside, I think the time delay those little protection boards provide is a must have.
You will probably need a separate power supply and/or transformer too, so plan for that lost space.