[uzi2]

Interesting, I am sure that is counterintuitive to most of us, who would think that a shorter cable has less exposure to RF noise.

 

[Rob Watts]

Yes it was definitely odd using longer cables! Once you use solid core ferrites, length doesn't matter. And the reason is the common mode impedance - or rather the RF impedance of the ground connections from the M scaler to the DAC. Adding 2GHz ferrites increases this impedance. Adding longer cables also increases this impedance - doubling the length doubles the inductance, which halves the circulating ground currents - and its these ground currents going into the DAC ground plane that is the problem.

 

[Triode User]

Like Rob, I also did the comparison with longer cables and can confirm that I heard an improvement with longer cables but to my ears that improvement was subtle compared to adding ferrites.

 

[The Jester]

Would using a 2Ghz ferrite on the DC power cables have a similar effect ?
If so, the relatively thin power cable could be looped through several times ... or am I missing something ...
also I’d be interested in your opinion on the optimum length of Spdif cables ... some say short, some a 1.3 metre minimum ..
while I’m at it I must add thanks for the hard work, had my Qutest DAC plus MScaler for a month now and I’m listening to more music than ever ...
soundstage and detail is impressive enough but the sound of acoustic instruments is something else ...

 

[AndrewOld]

Yes it was definitely odd using longer cables! Once you use solid core ferrites, length doesn't matter. And the reason is the common mode impedance - or rather the RF impedance of the ground connections from the M scaler to the DAC. Adding 2GHz ferrites increases this impedance. Adding longer cables also increases this impedance - doubling the length doubles the inductance, which halves the circulating ground currents - and its these ground currents going into the DAC ground plane that is the problem.

I have to say I find incredible, and very disappointing, that as the designer of the M Scaler, the TT2 and the DAVE you have to use a £1410 third-party cable to connect them to get the best performance. Are you happy about that? Do you think that £1410 is a fair price for these cables?

 

[The Jester]

Not alone there, my power amp came with a standard $5 IEC “jug cord” to make it work out of the box,
later read a comment attributed to the company owner and designer that “it really shines with a good quality heavy duty power cord” ..
they start around $300 and go up from there ...
edit:
went with the 10% rule listening to a few cables in that price range ... $350 for my final choice was A fair bit less ..
If I recall, the wave cable design was originally for a more significant issue with the Dave and Blu Mkll which are around £15,000 for the pair ... well within the 10% rule ...
Different story when it comes to say MScaler + Qutest ..

 

[Usak]

Very interesting.
I also think so.WAVE's BNC cable is expensive.
But,There seem to be several types, but is the cheapest ”STONE Performance” not enough? (Is this also expensive? Maybe you're right.)

 

[Mediahound]

In terms of digital BNC cable length and digital reflections, that is something inherent to any digital coax connection from any two digital devices.

Here's an article on that: http://www.positive-feedback.com/Issue14/spdif.htm

 

[Ards]

I have to say I find incredible, and very disappointing, that as the designer of the M Scaler, the TT2 and the DAVE you have to use a £1410 third-party cable to connect them to get the best performance. Are you happy about that? Do you think that £1410 is a fair price for these cables?

If you are referring to the Wave cables, then this price, for the performance they deliver, is an absolute bargain in the hi-fi world.

 

[Rob Watts]

Like Rob, I also did the comparison with longer cables and can confirm that I heard an improvement with longer cables but to my ears that improvement was subtle compared to adding ferrites.

It's always difficult to put numbers on the scale of changes, as often one hears a tiny improvement in the scheme of things, but it gets transformed into a huge change. Often when I am doing depth AB listening tests, the organ objectively sounds a little further away on A say; but when actually listening a little further away becomes B is as flat as a pancake, and A is cavernous depth perception. But I would say that a 2m cable over 1m is about 25-33% the improvement from using GHz solid core ferrites.

Would using a 2Ghz ferrite on the DC power cables have a similar effect ?
If so, the relatively thin power cable could be looped through several times ... or am I missing something ...
also I’d be interested in your opinion on the optimum length of Spdif cables ... some say short, some a 1.3 metre minimum ..
while I’m at it I must add thanks for the hard work, had my Qutest DAC plus MScaler for a month now and I’m listening to more music than ever ...
soundstage and detail is impressive enough but the sound of acoustic instruments is something else ...

In principle yes. So we are trying to increase the loop impedance to reduce the ground currents entering the DAC - and the loop is mains>M scaler PSU>M scaler ground plane>BNC galvanic isolation>BNC cables>DAC ground plane>mains. So long as one of those links have high impedance at around 2GHz you are done, as current flows in loops only. No current flows if one of the links has a very high impedance. So ferrites add impedance on the cables; a battery supply has very high impedance to the mains if its isolated (actually its not infinite, as there is a parasitic capacitance of about 0.05 pF to ground - but this is enough for effective isolation).

I wouldn't loop the wire around the ferrites though. Firstly, they have to be GHz ferrites, and looping will create significant parasitic capacitance between the wire - this will tend to short out the ferrite.

I have to say I find incredible, and very disappointing, that as the designer of the M Scaler, the TT2 and the DAVE you have to use a £1410 third-party cable to connect them to get the best performance. Are you happy about that? Do you think that £1410 is a fair price for these cables?

No I am not happy about that too - in the sense that the considerable isolation that has gone into the M scaler is still not 100% effective. But then you didn't hear the initial versions, nor see the huge amount of work that went into creating and improving the isolation. The remarkable thing is not that BNC cables make a difference, but that having spent a huge amount of time and effort into isolating the BNC drivers, it is still audible. We are talking about very tiny effects here; and improving an almost perfect telescope mirror into a perfect mirror takes infinite amounts of time and effort! We are talking about miniscule levels of RF noise being important, and that's the crazy thing about this situation.

As to whether it's a fair price depends upon the buyer. To some, £1400 is just the price of a good bottle of wine; to others it's enough to feed a family for a year, so represents enormous wealth. Only you can decide if the improvements is worth the price. Remember also that the Wave Stone cables are more reasonable at under £500.

And I certainly do not say you have to use Wave cables or indeed have to use ferrites - this is the surface finish on the icing of the cake after all. I post what is technically accurate, and my subjective observations are based upon honest, serious and careful listening tests. This approach has upset people within the industry; but I will only post what I see as being accurate at that moment in time (as my knowledge is (hopefully!) expanding). So I recommend Wave cables, as they work subjectively, and there is solid technical reasons why they work. I have in the past said that audiophile USB cables either sound the same as certified type 2 cables, or they degrade sound quality by adding more RF noise - they are designed unwittingly as RF noise generators. So too with audiophile BNC cables - the exception being Wave. I have taken some considerable flak from audiophiles who always assume that some exotic expensive brand will outperform the standard certified generic cables - and they get very upset when I humbly point out that they are "enjoying" a degradation. Look at the trouble I get into about SMPS against linears as another example.

To conclude: Wave cables work technically and subjectively. Only you can decide from trying them whether it's worth the cost, and represents value to you.

Happy listening, Rob

 

[Triode User]

It's always difficult to put numbers on the scale of changes, as often one hears a tiny improvement in the scheme of things, but it gets transformed into a huge change. Often when I am doing depth AB listening tests, the organ objectively sounds a little further away on A say; but when actually listening a little further away becomes B is as flat as a pancake, and A is cavernous depth perception. But I would say that a 2m cable over 1m is about 25-33% the improvement from using GHz solid core ferrites.

Rob, we are in the same ball park here. I got to about 4 ferrites on a 1m cable before they became better than simply increasing the unferrited cable length from 1m to 2m. A total of 16 ferrites were needed before I struggled to hear any improvement by adding more but I settled on using 20 to allow some scope for different RF sensitivities in different systems (the cables are not just used in Chord systems). So 4 ferrites out of 16 is about 25% which is where you were in your estimate.

 

[musickid]

True integrity is a rare quality in this day and age.

 

[feddar]

Rob,

Thank you your explanation about BNC cables with regards to fine tuning my system. I now have a question about headphone cables. I currently use the stock Focal Utopia cable, and it sounds great. Do you think another cable could improve things even more?

I have read a lot about balanced cables, and am wondering why you did not include a balanced headphone output in the TT2.

Also, is there a difference between using any of the headphone outputs? Can you use more than one output at the same time, safely?

Thanks again, for I am truly loving my music more than ever!

 

[Rob Watts]

I haven't come across the stock Focal cables, so I can't comment as to whether it's good o not.

Analogue cables can make very big differences to SQ for a host of different reasons. I have yet to see a cable that covers all the issues though, which is why I make my own analogue cables.

Active balanced headphone output would degrade transparency, as you have double the active electronics in the signal path. So why are people in favour of it? There can be benefits - cancellation of even order harmonics is one. But if you have zero, or almost zero distortion, like TT2, then this is not a benefit. The other benefit is voltage drive - balanced doubles the available voltage, quadrupling the power (assuming current drive keeps up). But TT2 has huge voltage and current drive whilst single ended at 9.3v RMS and 5A current; this is more than enough for any headphone. Hence going balanced would only give you degraded transparency and no benefits.

Sure you can run multiple headphones without loss of SQ, as the drive capability and ultra low output impedance allows this.

 

[alxw0w]

Rob can you tell us how the name Dave was chosen for the Dave ?
How you guys came up with that ? First there was DAVE name and then you figured out Digital to Analogue Veritas in Extremis ?
I always liked very unusual naming in chord as well as the design. Much different than anything on the market.