Buffalo DAC (ESS Sabre 9008)

[Feebleminded]

Originally Posted by BrianDonegan

Try checking the line level outputs on the USB module directly and see if the hiccups are occurring there as well.

Brian, the analog outputs on the USB module are not experiencing the hickups, any ideas?

[glt]

Originally Posted by Feebleminded

Brian, the analog outputs on the USB module are not experiencing the hickups, any ideas?

The I2S is not good enough for the picky DPLL! :-)

Switch to spdif.

I experienced the exact type of dropouts on I2S (but not on the spdif line) but for a different device (Musiland MINI). For me, I had to increase the bandwidth of the dpll (but you need to program the chip to do that).

[Feebleminded]

Originally Posted by glt

The I2S is not good enough for the picky DPLL! :-)

Switch to spdif.

I experienced the exact type of dropouts on I2S (but not on the spdif line) but for a different device (Musiland MINI). For me, I had to increase the bandwidth of the dpll (but you need to program the chip to do that).

I would have never known, thanks for the heads up! I switched it over to SPDIF and all is good

[glt]

Hmmm. Good to know. That makes two devices for which Apparently the SPDIF is better than the I2S going into the Buffalo and your device is the well known PCM 2707. I wonder if there is something else at play...

[fred_com]

Guys, count me in on the hiccups issue with Buff II and I2S. I'm using Teradak USB-SPDIF-I2S converter with Tenor 7022 chip. The hiccups are exactly the same.

Glt, thanks for the tip about switching to the SPDIF. Or maybe it is possible for you to upload firmware with increased DPLL? If it is allowed by NDA.

Thanks,
Fedor

[glt]

Originally Posted by fred_com

Guys, count me in on the hiccups issue with Buff II and I2S. I'm using Teradak USB-SPDIF-I2S converter with Tenor 7022 chip. The hiccups are exactly the same.

Glt, thanks for the tip about switching to the SPDIF. Or maybe it is possible for you to upload firmware with increased DPLL? If it is allowed by NDA.

Thanks,
Fedor

[glt]

I am using an Arduino to control the DAC. I had programmed the controller to vary the bandwidth. So I just dialed one at a time until the hiccups disappeared.

However, 3 devices where the I2S is "worse" than the spdif cannot be a coincidence. There has to be something else...

[fred_com]

Hi glt, thanks for the answer.

Seems, that only other option is to wait for Russ to finish his XMOS USB transport device.

[Russ White]

This SPDIF is fundamentally easier to lock just because of the way the chip decodes it.

Unfortunately the PC2707 has quite a lot of phase noise on the bit clock, especially for 44.1khz playback. It is because of the PCM2707 pretty crude analog PLL. The clock is actually derived, and not really well. That is why for Opus we generally recommend people use it SPDIF out(so that it would be reclocked be a receiver) or with Metronome for best results. For Buffalo I would definitely suggest SPDIF out.

[Russ White]

On thing I am thinking of doing for next firmware revision is making the DPLL BW adaptive. So that it will auto adjust to your source.