Which USB Re Clocker

The Innous is basically a small format computer board with a standard computer motherboard USB output.  That being said, it does have a very excellent linear power supply (which definitely helps!!).

The stock Wyred 4 Sound Recovery "usb reclocker" might help.  I could not guess on how much it would help.  The Wyred 4 Sound device would definitely be better if you get an linear power supply upgrade.  The stock version just has a  wal-wart switching power supply adapter.  There are definitely better USB reclockers.

The Innous Pheonix is likely the absolute best USB reclocker with a high end linear power supply with extensive filtering/regulation and a OCXO (oven controlled) clock.  Whether it's worth $3k to you is another question.  I haven't directly tested these types of devices, but the general consensus is the better USB signal feed results in better sound quality. 

I have always used S/PDIF coax as the better result.  In my system, S/PDIF coax from either an Asus Xonar Essence card or my (discontinued) Digital Musiland S/PDIF card has resulted in better sound quality than the USB output from my computer motherboard.  I even have a reference high quality USB cable.  That being said, the JCAT USB card is on my list of things to try.

The USB reclockers can definitely help things, but in my opinion, they are like a bandaid for a flawed source.  In my opinion, it's always best to have the signal clocked properly from the source instead of "fixing it along the way".  That pretty much means a different music server. 

I have found that the Innous music servers actually are not fully transparent to the audio data.  Even the music servers will alter the waveforms with their DSP logic.  If you like this altered/smoothed sound, then that's great.  It's all about personal preference. 

The USB receiver in your DAC may or may not be high end.  Can you tell us what your DAC is?  Depending on what you say, it could be that a really good USB-to-SPDIF converter might end up being a better choice.  Something such as the Singxer SU-6 with a linear power supply.  If you do DSD, you can still support DSD output through i2s if you have an i2s compatible DAC.

Your Metrum Octave does not support DSD files.  The Metrum has a decent USB receiver, but probably not quite as good as those DACS with the latest version of Amanero USB receiver.

If you wanted to improve things, I would go with the Singxer SU-6 with an external linear power supply upgrade.  Both the Singxer and the Metrum Octave DAC have a true BNC connector (which is highly superior to normal RCA digital connectors). You can then get an amazing S/PDIF cable to drive the Metrum.  I use a 2-meter Nordost Heimdall II digital coax.  I have not found anything better.  Though, some of the Black Cat digital cables may also be excellent.

The Singxer SU-6 and linear power supply upgrade won't be a wasted investment.  You can always upgrade your DAC in the future.  The Singxer is really there to make the Innous a lot better. 

Audio-gd DI-20 is not a Reclocker but a DDC and it will improve the sound of your DAC a LOT.

I'm re-reading this thread and came across this post, which led me to researching the Audio-GD DI-20.  I didn't know Audio-GD made a product like this.  Based on initial review, I would say that this DI-20 could be much better than the stock Singxer SU-6.  It already has a built in linear power supply, uses the Amanero USB board, and has options for Accusilicon 90/98M clocks (which isn't that much more in cost).  I have direct experience using the Accusilicon clocks and they are abosutely excellent.  The double speed 90/98 clocks will likely be more accurate that standard 45/49 clocks.

The HE version looks to be much better with a much beefier power supply.  This one could be sleeper!