Looking for help understanding clock usage in my system


I should say up front that I don't completely understand how external clocks work (I understand the basics).  I'm currently using a LYH ock-2.  It's connected to a Gustard U-18 ddc, Gustard X-30 dac, and a Gustard N18 pro ethernet switch.  The LHY has three 10 mhz outputs in sine wave and three in square wave.  I've tried both and prefer square wave.

The ddc is connected to my Innous Zen Mkiii streamer by USB and connected to my dac via i2S.

I have recently purchased a Gustard U-26 ddc which should be a notable upgrade to the U-18 ddc.  Because the U-26 has a better clock, I'm wondering if I'll even need the LYH ock-2.  I'm going to try it both ways.

Here's my question....If I don't use the LHY ock-2 with the ddc and/or dac, would there be any point in using it at all?  It could be connected to the N18pro ethernet switch.  

Suggestions/advice would be appreciated.

sls883

I‘d frankly do away with the DDC, use USB via LHY audio UIP-1 ( an excellent USB decrapifier) and have the switch, DAC and UIP use the OCK-2 clock. That way your INNUoS streamer would be slaved to your DAC. USB in my mind is wrongly maligned. It is an excellent interface provided you have clean 5V power and galvanic isolation of the signal, hence the UIP recommendation

The U-26 just delivered a little bit ago.  I have it hooked up without the LHY ock-2 connected to anything except the N18 Pro ethernet switch.  I don't know if it's worth keeping the LHY solely for that purpose.  I guess I can compare listening with and without the clock to see if it's having any impact.

So far, it's sounds excellent.  I'll have more time to listen after work tonight.

 

Hi, I'm a U26 owner here. I have a LUMIN U1 Mini + Kit + LPS, which is fantastic. It's connected via USB to the U26, and the U26 connects via I2S to two DACs: a Holo Cyan 2 and an SMSL SU-X. I only use digital volume from LEEDH Processing, and my go-to is the SU-X, which I disable the PLL for. That's when it really sounds incredible. The impact of a DDC is very significant (even with a LUMIN as the source, using a server with fiber optic cable and an Ethernet switch with TXCO). A well-known and reliable YouTuber tested the U26 with an external 10 MHz clock and found no difference, thanks to the excellent implementation of the U26's OCXO. The U26 is very sensitive to the quality of the power cable... Enjoy your listening.

Dump the DDC.

Use the external clock into the DAC., test sine & square, use USB from your streamer.

With USB the DAC's clock (with the help of the external clock) is in charge and you do not have the inherent problems of IIS - with IIS the clock signal is transmitted from the source through the cable - and attaching the external clock to the DAC will not save you from the jitter occurring over IIS connection, the DAC's clock is not used.

Using IIS as a digital interconnect seems to me to be fundamentally flawed - the clock signal is being transmitted over (at least) .5 meters - the connection was designed to transfer data between on board chips!

USB buffers the data and clocking is completely handled by the DAC.

@tutonunez I've listened to a dozen of my reference songs and I'm very impressed with the U-26.  The U-18 and LHY ock-2 are in boxes.

The soundstage is bigger, punchier bass, better separation of instruments, more clarity/detail.  No harshness.  I'm very happy with the X-30 and U-26 combination.