[Jawed]

DAVE is sensitive to RF noise, wherever it comes from.

Blu 2 generates some RF noise itself and streaming sources that you connect to Blu 2 will also generate some RF noise, which Blu 2 passes on to DAVE. The RF "adds up" when it gets to DAVE, so both the noise from the streaming source and Blu 2's own noise affect DAVE.

You can use strong filtering on the cables that connect Blu 2 to DAVE to prevent any audible problem in DAVE caused by the RF noise. If the filtering is strong enough, then you won't hear a difference between CD replay (RF noise solely from Blu 2) and streaming source (both RF noise sources "adding up").

Opinions vary on the best way to filter the connection between Blu 2 and DAVE. Inevitably it requires lots (tens) of ferrites on each cable. There's no point in using just one or two ferrites.

A useful technique to minimise the noise that Blu 2, alone, can inject into DAVE (i.e. without a streaming source connected to Blu 2) is to use a single electrical plug for the mains cables that go into Blu 2 and DAVE. This minimises the voltage differential that can exist between Blu 2 and DAVE. A voltage differential is what helps the RF noise travel into DAVE.

In general when building a hi-fi, all the components should have their power cables going into a single plug. And all the cables should be the same length and manufacture, so that their electrical measurements are effectively identical. But it's quite difficult to fit more than 2 cables into a single plug!

Additionally, since DAVE will detect RF noise on all of its inputs simultaneously, there should only be a single device connected to DAVE. If you have a USB or an AES connected device plugged into DAVE as well as Blu 2, then you will suffer RF noise from that other device while you are listening to Blu 2. Disconnect it from DAVE to find out if you can hear a problem. A device connected with optical cable can't cause an RF problem so it's safe to leave it connected.

Now playing: Wolf Alice - Giant Peach

 

[Triode User]

DAVE is sensitive to RF noise, wherever it comes from.

Blu 2 generates some RF noise itself and streaming sources that you connect to Blu 2 will also generate some RF noise, which Blu 2 passes on to DAVE. The RF "adds up" when it gets to DAVE, so both the noise from the streaming source and Blu 2's own noise affect DAVE.

You can use strong filtering on the cables that connect Blu 2 to DAVE to prevent any audible problem in DAVE caused by the RF noise. If the filtering is strong enough, then you won't hear a difference between CD replay (RF noise solely from Blu 2) and streaming source (both RF noise sources "adding up").

Opinions vary on the best way to filter the connection between Blu 2 and DAVE. Inevitably it requires lots (tens) of ferrites on each cable. There's no point in using just one or two ferrites.

A useful technique to minimise the noise that Blu 2, alone, can inject into DAVE (i.e. without a streaming source connected to Blu 2) is to use a single electrical plug for the mains cables that go into Blu 2 and DAVE. This minimises the voltage differential that can exist between Blu 2 and DAVE. A voltage differential is what helps the RF noise travel into DAVE.

In general when building a hi-fi, all the components should have their power cables going into a single plug. And all the cables should be the same length and manufacture, so that their electrical measurements are effectively identical. But it's quite difficult to fit more than 2 cables into a single plug!

Additionally, since DAVE will detect RF noise on all of its inputs simultaneously, there should only be a single device connected to DAVE. If you have a USB or an AES connected device plugged into DAVE as well as Blu 2, then you will suffer RF noise from that other device while you are listening to Blu 2. Disconnect it from DAVE to find out if you can hear a problem. A device connected with optical cable can't cause an RF problem so it's safe to leave it connected.

Now playing: Wolf Alice - Giant Peach

Your post states these things as fact. Can I play devils advocate for a little while?

I thought I had seen a post from Rob stating that unused inputs on the Dave are disconnected internally and that there was no need to disconnect cables in order to isolate Dave from other sources.

You state that ideally all devices should be connected with same length power cables and into the same socket outlet to minimise voltage drops between devices. I have never heard of this before and wonder where that nugget of wisdom comes from. And what tolerances are you talking about for cable lengths? Plus or minus say one inch? Less? More? What about the length of power cabling within the device? Should that be taken into account? I have my skeptics hat on here.

@Rob Watts any pearls of wisdom on this?

 

[JaZZ]

As I see it, the ground of unused (but connected) inputs isn't disconnected, and since RF noise is transported via ground connections, it's recommended to unplug the corresponding cables.

I leave the rest to Jawed and Rob.

 

[Jawed]

Your post states these things as fact.

They're things you can try.

Admittedly you'll need to buy a plug that you can wire yourself to find out if wiring two components into one plug sounds better. If you have lots of ferrites between Blu 2 and DAVE you might have effectively solved the problem (filtering common mode noise) so then try a different pair of components, e.g. DAVE and power amp.

When I had a big system I ran the CD player, pre-amp and six power amps from a single plug. This required soldering and so most people with lots of components are going to struggle to do the same. But in a small system it should be possible without soldering.

This is a modern approach:

http://www.ebay.com.sg/itm/AUDIO-FRIENDLY-SILVER-Hydra-mains-power-cable-Naim-3m-/310106268737

Disconnecting other inputs from DAVE is pretty easy, if you have any...

Now playing: Black Honey - Dig

 

[musickid]

if optical is best on dave how can this be if dave's clock is slave to the sources clock even though rf is not an issue here? if you connected optical from a mains powered computer to dave even though we have electrical isolation is there any chance for negative artefacts to enter dave as say if connected to a non mains powered optical source if such a thing exists? finally how is dave technically handling sensitive headphones like oppo pm1 which are easily driven by most sources. i have listened to dave/pm1 and with excellent results. how can chord dacs adapt effortlessly to the whole spectrum of headphone impedences 8-800?

listening to gregory porter take me to the alley via roon mojo/pm1. sounds like gregory is singing in my room!

 

[jonstatt]

Just a side note for those thinking of using optical and considering expensive glass cables.....one of the most expensive, the WireWorld Supernova 7 is not compatible with DAVE. Due to the recessed connections on DAVE, the cable doesn't lock in all the way and it will not hold a 24/192 connection.

 

[Triode User]

Just a side note for those thinking of using optical and considering expensive glass cables.....one of the most expensive, the WireWorld Supernova 7 is not compatible with DAVE. Due to the recessed connections on DAVE, the cable doesn't lock in all the way and it will not hold a 24/192 connection.

This is not just with expensive optical cables. I have taken a knife to my optical cable plugs to get them to fit within the recess. Fine if they are cheap but it will spoil any resale value for expensive cables.

 

[penguin69]

if optical is best on dave how can this be if dave's clock is slave to the sources clock even though rf is not an issue here? if you connected optical from a mains powered computer to dave even though we have electrical isolation is there any chance for negative artefacts to enter dave as say if connected to a non mains powered optical source if such a thing exists? finally how is dave technically handling sensitive headphones like oppo pm1 which are easily driven by most sources. i have listened to dave/pm1 and with excellent results. how can chord dacs adapt effortlessly to the whole spectrum of headphone impedences 8-800?

listening to gregory porter take me to the alley via roon mojo/pm1. sounds like gregory is singing in my room!

The Chord Dave will not be using the S/PDIF clock information. I'm not a world expert here, but most modern DAC designs (and chips) will buffer and re-clock source data, supported by a digital phased locked loop.

Regarding the optical connection, there should be no negative (electrical) artefacts entering by this means. All you really have is timed pulses of light entering the DAC. My recent experience with optical is that you get 'all or nothing' failures, namely drop-outs if things aren't quite right. I wouldn't expect anything else, since the job of the optical connection is simply to transfer all the bits and interpolated clock data. As I've mentioned before, Toslink receivers are supposed to be a source of jitter, but I believe this is corrected by internal reclocking architectures. I think the supplied source clock data could also be a source of jitter, but as stated this is remediated by re-clocking.

Hope this helps. I'm sure someone more expert can chime in if I have made any mistakes.

 

[jonstatt]

the super nova 7 plug has a different diameter to the super nova 6.The super nova 7 fit's Dave perfect,and is also 1 of the best optical cables I've ever heard.

It certainly does not fit in my Dave. It does connect enough to work at lower sample rates but not 24/192. You mentioned you actually use yours with Blu 2 so I wonder if its TOSLINK input is slightly different (not as recessed). I know the cable is fine as it works perfectly from the same source to a Hugo2.

 

[Triode User]

It certainly does not fit in my Dave. It does connect enough to work at lower sample rates but not 24/192. You mentioned you actually use yours with Blu 2 so I wonder if its TOSLINK input is slightly different (not as recessed). I know the cable is fine as it works perfectly from the same source to a Hugo2.

Blu2 doesn't have an optical input.

 

[jonstatt]

Blu2 doesn't have an optical input.

Oops of course it doesn't! I am trying to ignore the existence of Blu2 for now as I only got my order in a week and a half ago for a unit and I am expecting a long wait!

 

[jscmd2000]

Could this be true? At first, I was impressed with the optical input to my Dave, so I ordered a better quality toslink cable and did some testing.

I hear absolutely no audible difference in a/b testing between the following setup using my Mac powerbook (2014 model). None!

1. USB(AudioQuest Carbon) -> UpTone Audio USB Regen -> USB(AudioQuest Carbon) ->Dave
2. AK380cu -> Toslink ($7 from amazon) -> Dave
3. AK380cu -> Wireworld Supernova 7 Toslink -> Dave

The $7 Toslink is this one: https://www.amazon.com/gp/product/B00T8HWUVS/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
The Supernova 7 does work with my Dave but not for higher sample rate tracks, same as the cheaper Toslink cable.
Maybe there is a difference that I am just not hearing? Maybe I am a cheap date for this stuff?? lol

 

[penguin69]

Could this be true? At first I was impressed with optical input to my Dave, so I ordered a better quality toslink cable and did some testing.

I hear absolutely no audible difference in a/b testing between the following setup using my Mac powerbook (2014 model). None!

1. USB(AudioQuest Carbon) -> UpTone Audio USB Regen -> USB(AudioQuest Carbon) ->Dave
2. AK380cu -> Toslink ($7 from amazon) -> Dave
3. AK380cu -> Wireworld Supernova 7 Toslink -> Dave

The $7 Toslink is this one: https://www.amazon.com/gp/product/B00T8HWUVS/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
The Supernova 7 does work with my Dave but not for higher sample rate tracks.
Maybe there is a difference that I am just not hearing? Maybe I am a cheap date for this stuff?? lol

Likewise, I have various source systems and different quality optical cables - but I hear no difference between my optical set-ups, other than that one configuration drops out occasionally whilst the others do not. (Almost certainly a local wifi issue.)

This is what I would expect.

Of course, YMMV, etc.

 

[lovethatsound]

It certainly does not fit in my Dave. It does connect enough to work at lower sample rates but not 24/192. You mentioned you actually use yours with Blu 2 so I wonder if its TOSLINK input is slightly different (not as recessed). I know the cable is fine as it works perfectly from the same source to a Hugo2.

I used the super nova 7 with the original blu to the Dave.The super nova 7 i have fit's my Dave perfectly.ive had no problems with the super nova 7 and the Dave at all.It could be that chord have changed the design of the Dave abit.If so,Chord should know better, and indeed should have learned from the original hugo,not to recess cable ports on there equipment,especially on a full size dac,theirs no excuse for it.Maybe you could get in touch with chord and they might correct there mistake.

 

[rayl]

I used the super nova 7 with the original blu to the Dave.The super nova 7 i have fit's my Dave perfectly.ive had no problems with the super nova 7 and the Dave at all.It could be that chord have changed the design of the Dave abit.If so,Chord should know better, and indeed should have learned from the original hugo,not to recess cable ports on there equipment,especially on a full size dac,theirs no excuse for it.Maybe you could get in touch with chord and they might correct there mistake.

I actually had this problem with some XLR connectors too.... the recess was preventing engagement of the locking tab... but I just swapped connectors (and cables attached to them).