Saturday, 15 August 2015

Commenting enabled and Balanced DAM1021 firmware!

Another tiny update: I just found out why most people couldn't leave comments so now it should be enabled!

I saw over on head-fi here that the Soekris board was updated to be enabled in left-right balanced mode so I bought another DAM1021-2 to let myself play with this feature:
Soekris released a new set of features with the latest firmware. Looks like balanced dual mono is now possible
  • Revision 0.99 firmware have the following bug fixes / improvements / new functions:
  • PLL Clock Sync at sample rate change cut down to less than 0.2 second
  • Isolated Serial port now works, note that port is at 3.3V cmos level
  • Serial Port now interrupt driven, no character loss at high speed
  • Volume Control now is -80db to +10 db, and phase bug fixed
  • Volume Control also now have zero crossing detect
  • Power Off plop can be reduced to 1/3 by adding a single 27K4 resistors, see picture attachment
  • FIR1 filters doubled in size, so max 2032 coeff @ 44K/48K, 1016 @ 88/96K, 508 @ 176/192K, 127 @ 352/384K
  • You can now select four sets of filters, named Linear, Mixed, Minimum and Soft.
  • FIR1 coefficients are now 1.31 format, filters should be good down to around -150 db
  • Stock filter now have improved deemphasis filter
  • Input Source Select bug fixed
  • New mode setting: Normal, Inverted, Balanced Left, Balanced Right
  • The tiny bug on signal saturation on -full scale fixed
  • Should now be possible to do balanced and crossovers by parallel the inputs and connecting the isolated serial ports together, more details to follow.
  • DSD is next major feature on the list. This would be the first R2R DAC with built in DSD conversion.



  1. which actual R2R chip does the Soekris utilize. I see the Yggy uses the AD5971BRUZ and the new Multibit upgrade for the Gungnir will use the AD5781BRUZ chip. Just wondering how the chipset in the Soekris board compares quality wise.

    1. As far as I know, the Soekris DAC does not use a dedicated DAC chip and instead utilizes a Spartan 6 FPGA rather like the Chord Hugo backed up by an R-2R resistor network. I'm not quite sure how to explain further about how it's implemented however; the below links should provide you with enough information to satisfy your curiosity.