Been there, done that...
-but did not do much experimenting...just added 220nF & R.
BTW, tried different resistors?
Arne K
-but did not do much experimenting...just added 220nF & R.
BTW, tried different resistors?
Arne K
Re: Been there, done that...
🙂
No, just 1 ohm.
I think it's better to deal with one component at each time.
Maby there's more to test, and more to improve, any beta testers out there?😎
Cobra2 said:
🙂
No, just 1 ohm.
I think it's better to deal with one component at each time.
Maby there's more to test, and more to improve, any beta testers out there?😎
Re: 1 ohm or another
That is a really good question.
Carbon (or film) resistors is the way to go, no bobinated resistors here.
I'm testing with a 1 ohm 3w resistor, although I think that two 2.2ohms 3w in parallel would be fine too.
It's recommended something from 5 to 10w.
3w carbon resistors I can find easily.
More than that is not so easy around here, only bobinated.
I could order (more expensive) film resistors, but for test purposes it's carbon.
And it works fine.
Cobra2 said:
That is a really good question.
Carbon (or film) resistors is the way to go, no bobinated resistors here.
I'm testing with a 1 ohm 3w resistor, although I think that two 2.2ohms 3w in parallel would be fine too.
It's recommended something from 5 to 10w.
3w carbon resistors I can find easily.
More than that is not so easy around here, only bobinated.
I could order (more expensive) film resistors, but for test purposes it's carbon.
And it works fine.
Very interesting.
Does the small value RC bypass include the small cap directly across +/- pins on the chip?
Does the small value RC bypass include the small cap directly across +/- pins on the chip?
since i've built my ucd180 based class d amp i've got a few gc's laying around doing nothing. i think i'll give it a try.
How much influence do the small caps have that are soldered to the chip? In all of my current clones these are ~1000uF panasonics or black gates. Do i need to replace them with smaller value ones?
How much influence do the small caps have that are soldered to the chip? In all of my current clones these are ~1000uF panasonics or black gates. Do i need to replace them with smaller value ones?
ChuckT said:
I'm not using it on this LM4780 board, due to lack of space (and the crazy pinout this chip has), but with LM3886 and others I normaly use 270nf poly between + and - pins on the chip.
matjans said:
Do it.😉
matjans said:
Yes, after the snubber there should not be big caps.
It would defeat the snubber's job.
100uf is what I use on the chip.
Alas, what works fine with regulated PSU also works fine here.
Upupa Epops said:
I was about to test this for some time.
I know your schematic and I didn't see a snubber on the caps.
Also, your pdf schematic file has many question marks (?), it doesn't show the values of many components.
Upupa Epops said:
Upupa Epops said:
Now I'm confused.
What do you mean?
Can you elaborate?
Upupa Epops said:
You only have a PA03 amp in the Projects seccion.😕
Would be nice if someone would use black gate for the snubber? Bad or good?
Carlos, do you have any?
Carlos, do you have any?
Well, Black Gate NX Hi-Q 0.1uF/50V would be the one to use in this case. I doubt it would do much good if at all, but still would be interesting to try.carlosfm said:
To Carlos : Do you mean this RC element on your schematic? Do shorter traces on PS and you don't need it. By the way, wattage of this resistor is enough 0.25 W, not 3 W.
Matjans,
I know this is off topic but I am thinking of buying a 2 x UCD180 class D modules. How does it compare sonically to the gainclone? I have asked this question on class D forum but no direct comparisons given. I have built gainclone and know the sound and wondered how much better UCD180 modules were?
John
I know this is off topic but I am thinking of buying a 2 x UCD180 class D modules. How does it compare sonically to the gainclone? I have asked this question on class D forum but no direct comparisons given. I have built gainclone and know the sound and wondered how much better UCD180 modules were?
John
Upupa Epops said:
Nah, I tested bigger caps on the chip's pins and with higher than 1,500uf per rail/chip it starts sounding worse and worse.
Upupa, read my posts and those articles, as I think it should be quite clear that it's not a question of cabling or PCB traces.
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