FredA
Headphoneus Supremus
- Joined
- Dec 15, 2013
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in here he says
Accuracy of the ladder resistors (tolerance):but if you scroll down to these sections ..
...
The solution is to correct the ladder and not only depend on the tolerance of resistors. It’s a combination of both: Ultra-low tolerance resistors controlled by a correction technology using very high speed FPGA are applicable in in our design.
Importunacy of the FPGA in the R2R 7:... you'll see no mention of correcting resistors
FPGA tasks in the R2R 7
does anyone know ...
1) what the physical resistor precision is
2) if correction is being applied
Two fpgas are used on each of the da-7 dac boards. Compensation is done, that's been mentioned. I think 0.01% resistors are used. Good enough given compensation.
Two fpgas are used on the digital board to handle the inputs and fifo reclocking. So the r2r 7 is a six-fpga dac, and the da-7 modules are even two-sided (there are approximately 800 precison resitors used counting both boards). So you are talking high-end implementation. You know your money is not going to marketing, distributor and resellers when popping up the hood. Check the nad m51 on the other end.