Yes I see it now, buried in the hard to read english, it is a 2nd input for 3.5mm line in, and logic to switch between the two inputs 😀
The 1 chip could be for the head phone. And the other chip handles the memory for the volume, and it will limit to a fixed value if the volume is too
high when start up. My guess.
high when start up. My guess.
black picture is clearer, it is an input, not a headphone-output
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Doesn't a rotary encoder and mcu based volume control imply an ADC-DAC in the input chain? This is adding unnecessary stuff to what was a fairly pure analog chain. Probably sounds fine, but I think I like the analog only input.
The volume may be something like an mcp4241, which is a digital pot which works in the analog domain. I have used these with AVR MCU and found them to be noisy if used purely for audio pot. I have had better results using them to control lightspeed attenuators(optocoupler like NSL-32).
I think volume control is in the like 20 pin chip on left side, but could be anything, even the same as minidsp LOL
Bootstrap Snubber Mod
Has anyone done bootstrap snubber mod on the red Y/J 2.0 board? Post pics please. Draw me if you can. Please.
Has anyone done bootstrap snubber mod on the red Y/J 2.0 board? Post pics please. Draw me if you can. Please.
Yes, I was just going to request the very same thing, as I was looking at my red YJ with the Panasonic Oscan mod and thinking it would be a great addition. But the surface mount parts will make it tricky. I know some have done it on other SMD boards, but not the red YJ to my knowledge.
It was my first board TPA3116, and for the current $9.99 price at YJ, it's the steal of the century. Anyone who is in the market for one of those crappy docking stations needs to be educated about this board: even when mated with a pair of cheap speakers like the Pioneer BS-22 or Daytons, this thing will deliver gobs more sound.
looking from tpa3116 chip YJred all topsides from 220nF bootstraps or signaltrace towards inductors above 220nF must be used to attach a 330pf that will be connected to 10 ohm resistor that will be connected to gnd. For 220nF most left side, GND is topside 10nF and 104, you can easily go there. For two most right 220nF the fill between both signaltraces towards inductors is GND, easy too. 2nd from left 220nF has least room but fill up and coming down between middle 2 inductors is GND. looks easiest when using smallest smd available cog and 1/2watt.
There may be neater ways, just my thoughts looking at YJred
There may be neater ways, just my thoughts looking at YJred
No. Almost all digital volume controls are analog. In fact, I can't find a single one that is digital. What it does is just to switch between a number of internal fixed resistors just like a stepped attenuator. It is the control that is digital. The signal is just as analog as it would be with a volume potmeter.
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is there a pcb file for chinesse boards?
just whant to build one more amp but differen layout
just whant to build one more amp but differen layout
An externally hosted image should be here but it was not working when we last tested it.
LOL paint is mmm 2 options for far left and far right, so 6 snubbers in this draw🙂 you need 4🙂 orange = remove red soldermask to clear copper and then solder. grey=soldered smd's together but not to pcb! do not remove soldermask🙂 It is very small area to work with YJred. Maybe both snubbers for middle bootstraps best in middle of board? And side bootstraps far left and far right, you do not want to connect inductor to ground, removing red mask just below inductor soldercontact might be tricky? And bigger in pic than in real?
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Thank You Irribeo but I can't solder, good, normal parts. SMD no no no. Only oscon it is.
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well seems more complicated but you may have little ... like these:
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That is some precision surgery there. I like it! A good pair magnifying binocular goggles with light, good Swiss made stainless tweezers, 0.015 tip iron, flux, good lead based solder, and slow breathing. 🙂
Hi
I have posted a picture of this mod in the YJ red board.
see post 5374 in this thread.
Sound fantastic driving Markaudio 12p BTW.
cheers
kp93300
