[onlychild]

Just to conclude yesterday’s conversation, this morning I pulled every cable out from my system and started again from scratch. Tbh I half expected this (metallic oscillating sound particularly noticeable with operatic voices on high sustained notes), would simply be ‘signal reflection’ on my 1m digital cable. I tried a 2m digital cable because a longer digital cable is known to improve that problem but unfortunately that did not sort it.


I then swapped cables throughout the system but this still failed to uncover the source of the problem.


I moved a power cable from touching a ferrite which was attached to my digital cable, this may have improved things very slightly.


Eventually I tried placing a big 12.5mm ferrite open on the plug attached to the Blu MkII, also the plug coming out of the Sigmas to the Blu MkII and the plug coming out of the Sigmas to the Dave (I already had them at the Dave end of that power cable). I also put one on the wall plug feeding the Sigmas and the plug going into the Sigmas. Hoorah! Problem solved.


Thank heavens for that. Fighting RFI is a war. Anyway an enjoyable afternoon has followed.


PS: thanks for your helpful suggestions yesterday guys.

Can you post a few pics of how you have the ferrites setup on your various cables? Much appreciated.

 

[DaveRedRef-III]

Can you post a few pics of how you have the ferrites setup on your various cables? Much appreciated.

Onlychild I don’t have time for all that. Sorry. If you look at an Isotek Optimal cable for instance. I just opened up a 12mm clip Ferrite and placed it open on the round connector where the cable goes into the connector.

I have since found that I only need to do ‘one’ end of each cable. Both ends was not necessary for my needs. I quite like this way of rejecting low level RFI because it’s not actually on the cable. It is just providing a low level ‘field’ of sorts which is less intrusive.

To recap essentially what I was trying to achieve was for my system to not accentuate that electronic or metallic oscillation on high Operatic notes.To a point i think it is still there in some recordings. I know certain mics and compressors can introduce it into the recording where it cannot be irradiated entirely unless in post-production. At least my system no longer accentuates that sound now and it is no longer a problem for the purposes of my listen.

 

[DaveRedRef-III]

I have continued experimenting with ferrites this morning and come across something unusual. I have been using two types of ferrite 12.5mm and 8mm over time. The 12.5mm accommodate the gauge of my Sarum Super Aray Digital cables. You may recall I had mentioned before that I didn’t find any benefit with putting them too close to the Blu MkII. I found it made my dynamics harder and less warm and musical. Anyway I thought I would experiment with the 8mm ferrites this morning, I don’t know why I thought it would be any different but they are just lighter and easier to place. Anyway I tried them on the digital BNC sleeves of my Sarum digital cables about 1" from the Blu MkII and the micro dynamics just fell into place. Delicacy and flow despite the fact that I still had 12.5mm along the remainder of the cable. It was unmistakable. So I took them off and replaced with the 12.5mm near the Blu MkII BNC connectors and as before the microdynamics hardened.

So what was happening?
I checked the specs and whilst the 12.5mm is 140ohm the 8mm is 100ohm. Apart from size, this is the only difference. My conclusion is that either my Sarum cables prefer 100ohm at the connector sleeves despite 140 ohm ferrites remaining on the rest of the cable or Blu MkII responds to 100ohm ferrites but fights 140ohm ferrites.

I don’t know if you guys can run the same experiment (for continuity I have also done the same with 8mm ferrites at the Dave end of the BNCs and I am posting a photo at the request of onlychild.

8mm
https://uk.farnell.com/wurth-elektronik/74271633s/ferrite-core-split-8mm-100-ohm/dp/1635622

12.5mm
https://uk.farnell.com/wurth-elektronik/74271622s/ferrite-core-split-12-5mm/dp/1635623

Edit: had the ohms the wrong way around. Corrected now
9/2/2019 - After yet further investigation I am quite convinced now that the Chord Sarum digital cable prefers 100ohm ferrites. This seems to produce superior timing in my system. I found that it was better to place ferrites no closer than 1.25" from the Blu MkII chassis for best results. You will know when you have gone too close to the Blu MkII because delicate instrument sounds like acoustic or classical guitar strings will begin to harden in their micro dynamics. Whilst the same 100ohm ferrites can go closer to the Dave end of the digital cables with no noticeable loss of delicacy.

 

[DaveRedRef-III]

Sorry guys I listed the ohms the wrong way around. Corrected now. 12.5mm is 140ohm and 8mm ferrite is 100ohm

 

[Triode User]

I have continued experimenting with ferrites this morning and come across something unusual. I have been using two types of ferrite 12.5mm and 8mm over time. The 12.5mm accommodate the gauge of my Sarum Super Aray Digital cables. You may recall I had mentioned before that I didn’t find any benefit with putting them too close to the Blu MkII. I found it made my dynamics harder and less warm and musical. Anyway I thought I would experiment with the 8mm ferrites this morning, I don’t know why I thought it would be any different but they are just lighter and easier to place. Anyway I tried them on the digital BNC sleeves of my Sarum digital cables about 1" from the Blu MkII and the micro dynamics just fell into place. Delicacy and flow despite the fact that I still had 12.5mm along the remainder of the cable. It was unmistakable. So I took them off and replaced with the 12.5mm near the Blu MkII BNC connectors and as before the microdynamics hardened.

So what was happening?
I checked the specs and whilst the 12.5mm is 140ohm the 8mm is 100ohm. Apart from size, this is the only difference. My conclusion is that either my Sarum cables prefer 100ohm at the connector sleeves despite 140 ohm ferrites remaining on the rest of the cable or Blu MkII responds to 100ohm ferrites but fights 140ohm ferrites.

I don’t know if you guys can run the same experiment (for continuity I have also done the same with 8mm ferrites at the Dave end of the BNCs and I am posting a photo at the request of onlychild.

8mm
https://uk.farnell.com/wurth-elektronik/74271633s/ferrite-core-split-8mm-100-ohm/dp/1635622

12.5mm
https://uk.farnell.com/wurth-elektronik/74271622s/ferrite-core-split-12-5mm/dp/1635623

Edit: had the ohms the wrong way around. Corrected now

My 2p is I think you are not using enough ferrites on the BNC cables. I would suggest using whichever size allows you to clamp them shut on your BNC cables and then start with say 20 per BNC cable. I use ferrites that are stronger than the ones you are trying and even then I find it takes 20 per cable. You might need more than 20.

 

[DaveRedRef-III]

Thanks for the reply Nick.

I stopped adding when I found the sound became too dark and slightly unbalanced. The Sarum has quite a bit of dielectric protection already. I plan to be making further changes in other areas soon which should provide more separation so I’ll try some more ferrites again just to re-test it then. I really like the balance of my sound right now though.

 

[Triode User]

Thanks for the reply Nick.

I stopped adding when I found the sound became too dark and slightly unbalanced. The Sarum has quite a bit of dielectric protection already. I plan to be making further changes in other areas soon which should provide more separation so I’ll try some more ferrites again just to re-test it then. I really like the balance of my sound right now though.

I'm with Rob in the sense that when seeking the least amount of RF in the system there is no such thing as 'too dark'. The ferrites after all are not altering the musical signal and are only removing RF noise from the cable carrying the digital signal. Therefore the darkest possible sound is the closest to the original musical signal. Beware of retaining an amount of 'life' or whatever in this process or stopping short of achieving the darkest sound. In my experience it might at first seem as if the music is too dull or lifeless but as ones ears adjust to the new normal so the detail comes back and indeed even more detail is revealed once teh masking effect of teh RF noise is removed.

I too have caught myself thinking that the music had become flat or uninteresting and started taking off ferrites to get this back and in a way to 'tune' the sound but then I realised all I was doing was the reintroducing the very courseness that I had been trying to eliminate, so back on went all the ferrites.

The 'dielectric protection' you mention will do nothing for the RF noise which is already in the conductors by the time the signal leaves the Blu2.

 

[DaveRedRef-III]

Nick I agree to a point but these changes do not happen in a vacuum. When you increase the bass balance, which the ferrites achieve by creating a less inhibited environment for signal flow and therefore bass (which I agree is most desirable), that changes the loading of the room and the affect that bass loading has on the speakers also. Now we may be able to move the speakers further from the wall to adjust for this change but that depends on how much room we have available. I have fairly powerful speakers and they are on the limits for my room size so I have less leeway than some.

With regard to dielectric protection, I believe there is a little more to it than your explanation above. Imo a close fitting dielectric jacket impedes RFI even when it is already in the signal. I suspect this is because the signal travels on the surface of the metal.

 

[Triode User]

and that is why it is good to have a dialogue (even if you maybe wrong)

 

[jacc]

and that is why it is good to have a dialogue (even if you maybe wrong)

Speaking about RF noise, I recently tried the ifi ipurifier 3 in front of the USB cable just before entering Blu. It made the sound smoother and less edgy.

 

[Triode User]

Speaking about RF noise, I recently tried the ifi ipurifier 3 in front of the USB cable just before entering Blu. It made the sound smoother and less edgy.

I have found that if you fully ferrite the dual BNC cables then this solves the issue of RF getting into the Dac and so the usb source maybe less of an issue because the RF is taken out anyway before it gets to where it can do harm in the dac analogue stage.

Just a thought.

 

[jacc]

Thank Nick. I have already used 10 12.5mm on each bnc cable (7 2.5ghz + 3 1ghz) but still find the sounds get smoother with the USB tweak. The USB signal is already come from a very decent music server too. I will try more ferrite but I thought there is no limit to lowering of RF as you said.

 

[Triode User]

Thank Nick. I have already used 10 12.5mm on each bnc cable (7 2.5ghz + 3 1ghz) but still find the sounds get smoother with the USB tweak. The USB signal is already come from a very decent music server too. I will try more ferrite but I thought there is no limit to lowering of RF as you said.

With only 10 ferrites I doubt that you are filtering sufficient RF noise through the dual BNC. The ferrites I use are very tight fitting on the cables but even so I noticed improvements up to 20 ferrites (loose fit ones were less effective in my experiments). For me 10 ferrites still left an appreciable amount of RF artifact in the music that I could hear. Interestingly this applied to the Mscaler as well as to Blu2 despite the MScaler built in ferrites and RF isolation.

With the clip on ferrites you might even notice improvements up to about 30 ferrites per BNC cable. I seem to remember a Head-Fier reporting using that sort of number.

 

[jacc]

My bnc cables are quite thick so 12.5mm is actually a reasonably tight fit. Will order some more ferrite and report back

 

[DaveRedRef-III]

Have updated my post above with a conclusion to my findings.

Just thought I would add a comment for new owners of the Blu MkII because this took me a while to work this out for myself. If you don’t know already, you have bought a product with staggering resolution capability even via the humble CD and whilst everyone has a finite budget for ancillary products I would urge you to focus on the weak link in the chain which will almost certainly be your analogue interconnect. Don’t assume a company which produces a brilliant high resolution digital cable will design an equally brilliant high resolution analogue cable either. We talk a lot here about reducing RFI and that is critically important too but when you have eradicated RFI it will be the cable geometry and quality of materials used that will count regarding SQ. Imo you should find the absolute highest resolution analogue interconnect you can afford to get the best out of Blu MkII because it is possible to hear greater resolution from red book than I believe many out there are hearing from 96/24 without a stellar resolving analogue interconnect cable. What you will get will be better separation, detail, Timbre and harmonics as well as vastly more resolved and smoother orchestral strings. This product (Blu MkII) is truly amazing imo and identifying any bottleneck in your chain will serve to improve your enjoyment I am sure. Happy listening.