I don't think it will do any difference in lower frequency response. But it surely will hurt frequencies above 1khz. I might be wrong.
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I tested with 33uh. But only change is tgat i used 1m instead of 10m on pin 2 to 1 of tl074. Will that hurt efficiency that much?. And did you do resistor load testing? What efficiency did you get?
use all parts exact as at the schematic i told you, that is the 10m should remain 10mega . the inductance that is the one i saw has a significance change when increased. by the way what type of inductor are you using?
Indeed very simple, but notice that there’s no feedback loop. One has to consider its hifi-ness.
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To all that has build it and since this thread has grew a lot, which schematic is considered the most "final" version? Or at least the most mature? For some definition of 'final' or 'mature'.
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To all that has build it and since this thread has grew a lot, which schematic is considered the most "final" version? Or at least the most mature? For some definition of 'final' or 'mature'.
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hi all , i have made many pcb versions of this amp ,
i still stick to the original schematic in the above link.
the thing i found interesting in this amp is that it requires original tl074/084 and bc327 and bc337 . if you compromise in this area it will consume alot of current at idle an produce hf noise.
my question is can i use two lm339 instead of tl074/084 and which other transistor can i use to substitute bc337 and bc327 😕
vvv vvv my current project vvv vvv
Attachments
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IMG_20210322_195354_314.jpg -
IMG_20210322_195027_990.jpg -
IMG_20210322_195039_540.jpg -
IMG_20210322_102949_683.jpg -
IMG_20210322_103048_038.jpg -
200wt strd ver1.2 dc prtc long bom.pdf
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GerberFiles 200wt strd ver1.2 dc prtc long gerber.zip
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200wt strd ver1.2 dc prtc long pcb bottom.pdf
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200wt strd ver1.2 dc prtc long pcb top .pdf.pdf
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200wt strd ver1.2 dc prtc long schematic .pdf.pdf
LM339 are comparators with open collector output. While they'd be faster, because of the nature of their output the circuit would need rework.
hello all , i have made my latest version of this amp , i opted for a through hole ic due to challenges in getting a geniune tl074/84 smd . imagine the smd also have issue 🙁,
A not original ic works fine in preamp,eq, crossovers etc , but can't work well in this class d amp ,
with this amplifier it works but the amp produces a lot of hf . but when i use a good geniune ic the hf noise reduces and the amp does not draw a lot of current
but a geniune tl074/84 works with no issues at all .
here is my project and pcb files . have fun fam 😀😀
A not original ic works fine in preamp,eq, crossovers etc , but can't work well in this class d amp ,
with this amplifier it works but the amp produces a lot of hf . but when i use a good geniune ic the hf noise reduces and the amp does not draw a lot of current
but a geniune tl074/84 works with no issues at all .
here is my project and pcb files . have fun fam 😀😀
Attachments
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200wt strd smd large ver1.25 dc prtc long pcb bottom.pdf
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200wt strd smd large ver1.25 dc prtc long pcb top.pdf
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200wt strd smd large ver1.25 dc prtc long schematic.png -
IMG_20210401_181716_986 cccc.jpg -
IMG_20210401_220756_877.jpg -
IMG_20210401_220745_900 ccc.jpg -
IMG_20210401_181533_308 cccc.jpg -
IMG_20210401_181758_239 ccc.jpg -
200wt strd smd large eagle pcb files.zip
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It is quite slow, but it doesn't suffer from phase reversal. Of all old opamps it is closest to a comparator.
I didn't have opportunity to sit and rework the schematic yet, sorry.