But is H2 and H5 connected to the DAC board? In my impression, only H1and H3 is in connection to the DAC board.View attachment 1211077
View attachment 1211078
There is ever so slight offset on H3 and H1, but big offset on H2 and H5. I can confirm next week, if nixie can bring his ad1862 board.
After staring at the pictures, I think i can get it to work. Fingers crossedSince the DAC board only uses H1 and H3 headers. It looks very close to still working. Would be interested to know when you get it a chance to check it against the DAC board.
As long as the four mounting holes are in the same position the electrical connections can be worked out. Albeit not as convenient but can work.
I'll let you know next week 🙂 In either case, i'd rather use copper jumping wires anyway than dubious brass pin headers, so all should be well with slight offset, if mounting holes match.
I took both pictures from jlsounds PDF documentation, laid one over the other and all headers with holes matched 😉
Based on new documentation: close jumpers J3 and J6
Not install R13 😊
Based on new documentation: close jumpers J3 and J6
Not install R13 😊
@miro : the cap is inside in the non A. I do not know the value and surmise the leads to be active too iirc Rogic or John maybe.
Something beween 470 to 820 pF I assume. I would go with 0.1 uF for the 14 DEM caps.
If the leads are internaly connected to the circuit ...then you know what 2 parrallel caps do. I bet for 470 pF.
Something beween 470 to 820 pF I assume. I would go with 0.1 uF for the 14 DEM caps.
If the leads are internaly connected to the circuit ...then you know what 2 parrallel caps do. I bet for 470 pF.
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@diyiggy@rehanabid Exactly as @diyiggy mentioned, you can use the non A TDA1541, but without the C15 capacitor (if the pins 16-17 are not internally connected in the chip, you can mount the capacitor, but I don't have this information) 🙂
Thank you both, come to think of it might give PIN 15-16 a try on LCR tester, may be will get some reading on capacitance.
On a separate note not related to this DAC, I decided not to trash the sacrificial SONY CDP-750 put in a 8 parallel TDA1387 chip as a replacement of TDA1541, replaced the old dual operational amp (5218 I think) with my favorite LME49720, Wallah, it sings but the problem is that even on first click of the power amp volume the output is like full, which to me seems like the output RMS of the CDP has increased significantly due to parallel OP-AMPs.
I remember long time ago I read a thread on this board when 4 or 6 TDA1543 were used in parallel the output current (i think) had to be limited via circuitry, any ideas how to limit output of CDP/TDA1387 parallel. I reduced the feedback resistor of OP AMP but it still doesn't seem to work. creating a new thread for the purpose seemed a bit inefficient to me many of the experts are already regular visitor to this one.
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Or just test both 14 DEM caps capacitance values without soldering the caps untill you are sure. When in the vias it usually works. So you can both test miro's bom and TDA1541 (non A) datasheet about the 14 DEM caps capacitance values and keep what you prefer according how it is blending with the non A.
Just a matter of curiosity, anyone tested direct soldering of DAC chips vs sockets on the board? Will there be any advantage?
Op amp may not be good to direct solder since checking out different op amps is our favorite thing to do.
Op amp may not be good to direct solder since checking out different op amps is our favorite thing to do.
I would advise against that. Yes there is a little bit contact resistance, yes soldering is the best way to connect, BUT, you could overheat the chip by soldering, and having it as a hot swap, outweights benefits and risks that soldering these rare chips bring 🙂 Use mill max sockets in your builds, and you won't notice the difference.
It depend of which OP, for slow socket can be used, but high speed OP should be soldered.Op amp may not be good to direct solder
Zoom, were you using the two external power supplies when you found a better performance of the new version?Hello Vunce, yes. Which i didnt expect.
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