Mini Dac TDA1543 X 4 NOS
Sep 29, 2011 at 10:48 PM Post #676 of 1,063
removed caps between tda's altogether, muuuch better. the result made me feel justified for having bought it. result was a much faster sound, more coherent soundstage with better seperation. (only reason why i even thought to remove them was because of the vishays --  meanwhile in the chameleon thread some are using 47uf and .1 vishays each inbetween the tda)


Do you mean all 4 of the caps (as seen in this pic) or just the 3 that sit between the TDAs? I still have to try removing/shorting the output caps but if you think removing these other ones helps the sound as well I might give that a try too.
 
Oct 2, 2011 at 9:54 AM Post #680 of 1,063


Quote:
 Thanks. I agree that I am probably hearing something else in the chain. It is only slightly noticeable and I'll find the culprit eventually. This is a mod that gets a thumbs up, it is on par with replacing the output caps (wish I could get rid of them altogether but that's too risky).
 



 
Why do you think it's risk to do both mod altogether?
 
Oct 2, 2011 at 10:22 PM Post #681 of 1,063


Quote:
What are the caps there for originally? Will removing them have any knock-on effect electrically?



Those caps are 'decouplers'. What that means is they keep the power supply to each chip stable at high frequencies. Removing them might improve the sound because they force HF currents through the groundplane which then appear as voltages in the output signal. A better (but more difficult) mod which I've done is to isolate the grounds of each chip (pin4) from the groundplane and wire each one individually back to a common 'star' grounding point at the regulator.
 
Oct 3, 2011 at 1:10 AM Post #682 of 1,063


Quote:
Those caps are 'decouplers'. What that means is they keep the power supply to each chip stable at high frequencies. Removing them might improve the sound because they force HF currents through the groundplane which then appear as voltages in the output signal. A better (but more difficult) mod which I've done is to isolate the grounds of each chip (pin4) from the groundplane and wire each one individually back to a common 'star' grounding point at the regulator.



Is there any risk if i do both shorted output cap and remove those cap?
 
Oct 3, 2011 at 10:10 AM Post #683 of 1,063
No risk to anything from removing those 4 caps. The risk in removing (shorting) the output coupling caps (not the output filtering ones which are the smaller valued ones) is to the equipment you have downstream of this DAC. If it can tolerate a few volts of DC offset (i.e. has an input coupling capacitor) you'll be fine to go. If not, beware!
 
Oct 3, 2011 at 12:14 PM Post #684 of 1,063


Quote:
No risk to anything from removing those 4 caps. The risk in removing (shorting) the output coupling caps (not the output filtering ones which are the smaller valued ones) is to the equipment you have downstream of this DAC. If it can tolerate a few volts of DC offset (i.e. has an input coupling capacitor) you'll be fine to go. If not, beware!



And how about remove the 0.0022uf caps, can i do all 3 mod without any problem?
I have just tried to do remove 4 cap mod but in instead of remove them, i shorted them and the unlock led is on all the time?
 
Oct 3, 2011 at 2:05 PM Post #685 of 1,063
Looks like you've shorted the supply to the DACs. The 317 regulator will be getting a tad toasty and you won't be getting any sound then. After you've removed those 4 shorts you can also remove the 2n2 caps yeah.
 
Oct 3, 2011 at 8:51 PM Post #686 of 1,063
Sapientam, a picture would be nice...

plz :biggrin:
 
Oct 4, 2011 at 8:26 AM Post #689 of 1,063

 
OK - your wish is my command. There's quite a bit of cutting of the groundplane which isn't visible here - if you'd like to
copy my mods then feel free to ask questions to clarify them. I'll be happy to respond to enthusiastic modders 
cool.gif

 
You'll note I've totally removed the Toslink input, that's because I think it got damaged when the 1117 was at 5V, and I don't use Toslink anyway. The switch got extracted too as its redundant when no Toslink-in is available. Yellow wires are replacement grounds. Since I took these pics I've done even more groundplane cutting - around the SPDIF and PSU inputs.
 
Oct 4, 2011 at 10:51 AM Post #690 of 1,063


Quote:

 
OK - your wish is my command. There's quite a bit of cutting of the groundplane which isn't visible here - if you'd like to
copy my mods then feel free to ask questions to clarify them. I'll be happy to respond to enthusiastic modders 
cool.gif

 
You'll note I've totally removed the Toslink input, that's because I think it got damaged when the 1117 was at 5V, and I don't use Toslink anyway. The switch got extracted too as its redundant when no Toslink-in is available. Yellow wires are replacement grounds. Since I took these pics I've done even more groundplane cutting - around the SPDIF and PSU inputs.


 
Thanks for the great pic, here is my DAC, i shorted cap all the way because i have some problem with my solder iron that i can't remove those cap easily and i got no sound, un-lock led on all time, i don't know what's wrong?

 

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