DirectStream DAC MKII Beta Tester Reviews

Known issues so far, please let me know what I missed:

USB doesn’t do quadrate.

Turning the power off on unused Ethernet/remote debugging, USB or I2S inputs isn’t in the UI

The green/red light on I2S inputs can be a bit confusing. I don’t think the Mk II uses quite the same algo as the DS yet, but we’ll check into it.

Bitperfect testing is disabled pending testing the dual AES features.

Dual AES is disabled pending more testing.

Optional setting of polarities of the I2S bits is disabled pending more testing.

Probably fixed in next FPGA software:

Auto input select can cause “blurbles” for a short while after a track change, this sound can also be a hiss that fades away.

Switching to coax or having the auto input select switch to coax might mute the box or cause the input selection status on the top of the screen “chatter”. Similarly for TOSLink when the source is 176.4 or 192k.

Apparently at least one of you got a version of the FPGA software that inverts the bits in I2S inputs. This will change the polarity of I2S and the display will say 44.1/24 instead of 44.1/16 for Redbook, but is otherwise benign. This was fixed in the next FPGA software release.

Display related issues:

Size of fonts

Default displays that depend on whether a fixed output level is set.

Documenting things like the connection status green/red

Mysteries:

Unknown issue wherein the unit “mutes” in the middle of a track and stays muted with other inputs selected, but keeps displaying input, sample rate and sample width correctly if input selection is changed.

Potential problem where the unit gets warmer/hot. May or may not be related to spontaneous muting.

Experiments that would help us:

I might have missed it, but so far I don’t know of a box that isn’t hot but with a single input connected (of AES3, I2S or TOSLink) that has gone silent in the middle of playing a track.

Also there’s a potential difference between units going silent in the middle of a track, vs those who have an input that doesn’t seem to work when other inputs are working.

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