[dakanao]

Small-signal errors don't mean compressed dynamic range. Your reasoning reminds me of a fellow Head-Fier (it was years ago) who attributed the increased bit depth of DVD-As with «redbook on steroids», meaning that he believed to hear the increased dynamic range as increased dynamics.

The better explanation for your impression is the psychoacoustic effect of dominating frequency bands perceived as higher dynamics.

During my long-term occupation with equalizing I never encountered an audible loss of dynamics. Not to speak of a measurable one – an easy task.

What I mean by compressed dynamics; is everytime when I apply digital real-time EQ to headphones, all the sounds (louder and softer sounds), even sounds in fr-ranges I've not EQ'ed, sound slightly more at the same volume vs no EQ.

It's that reason why I dislike digital EQ (haven't tried analog EQ).

 

[Rob Watts]

So one way to evaluate whether the EQ engine on your PC (it's 64 bit floating point) itself is changing the sound quality is to set all the sliders on parametric eq to -1dB. Then on your Chord DAC increase volume by 1dB. A perfect EQ should sound identical with it on or off; but when I have tried it, it clearly does not sound the same.

With EQ on and volume increased by +1dB on my M scaled Dave, things sound significantly brighter with added treble glare. Instrument separation and focus is degraded, and depth sounds significantly flatter.

Try it yourself and post your findings...

 

[HeeBroG]

So one way to evaluate whether the EQ engine on your PC (it's 64 bit floating point) itself is changing the sound quality is to set all the sliders on parametric eq to -1dB. Then on your Chord DAC increase volume by 1dB. A perfect EQ should sound identical with it on or off; but when I have tried it, it clearly does not sound the same.

With EQ on and volume increased by +1dB on my M scaled Dave, things sound significantly brighter with added treble glare. Instrument separation and focus is degraded, and depth sounds significantly flatter.

Try it yourself and post your findings...

Hi Rob.

Would EQ be the same as modern day convolution filters used in DSP correction?

G

 

[Rob Watts]

It all depends upon the actual implementation. My worries are with infinite impulse response filters (IIR). But FIR filters also can screw up depth, detail resolution and instrument separation too! As to convolving in the frequency domain using FFTs that's something I have had no experience with - but this will have similar issues, it all depends upon accuracy and how truncation issues are resolved.

 

[manueljenkin]

This could be the birth of a new Head-fi myth.

Seriously, though: I would not use it (on a daily basis) if that was the case.

Let's just rather keep it in terms of "modulation". A complex modulation. Depending upon signal, the perceived character can be anything, including dynamic range. Most people are unable to describe the precise effect they feel, so they throw in terms known to them, and they relate closely to

 

[bhobba]

It's been a while since I posted about my experience with the TT2 and M-Scaler. This has been because I broke my Distal Femur and then Covid. Finally the guy that installs my stuff has had a chance to check it out and has done some preliminary listening. He used it only with the M-Scaler and some very good (but not the best I have heard) quality SPDIF cables connecting the M-Scaler to the TT2. The SPDIF cables were made by my dealer, who also makes cables, specifically for connecting to the DAC. The speakers are about 90db with an 8inch HDS bass driver and Seas Exotic tweeter. The crossover uses 10 gauge air-coil inductors, pass resistors and Duelund VSF capacitors throughout. The source was a heavily modified Squeezebox via SPDIF. The speaker and RCA were the top of the line cables from a specialist cable maker we both know, KLE Innovations. The person doing the test sells them as part of the installations he does. My association is he is a member of the same audio club I am.

At first he used a low power SET amp heavily modified with Duelund capacitors etc and was very impressed. He then tried direct connecting to the speakers, but this time using some home made zip chord cables. To my surprise he preferred the SET, to him direct connecting was slightly metallic. Possibly some euphonics from the SET, but he wants KLE to build some better cables for the direct connection and for the SPDIF cables. Anyway he will do some further listening and Covid permitting, when finished I can go and have a listen.

More observations to follow - this was just preliminary. There will be a GTG soon, Covid permitting, for the release of a new speaker my dealer is building. It uses a 6-7 inch new Seas Graphine woofer and Seas Exotic tweeter. He usually uses Duelund or Jupiter capacitors, but recently has switched to Jantzen Alumen bypassed with a Duelund silver bypass which he now has a slight preference for. Personally I like Jupiter Copper with a Duelund bypass - but there is not a lot in it, and a big price difference. Duelund's and Jantzen are dead neutral, the Jupiter is slightly euphonic. Anyway there will be a number of different DAC's there including the Gradinote I want to do a direct comparison against.

Thanks
Bill

 

[Usak]

Hi, Rob.
I am currently using a HUGO 2 for headphones and considering buying a DAVE for speakers.

But I also think that. "What if DAVE 2 is released!".
I'd like to ask you to come straight to the point. Do you have any plans for DAVE 2?

Yes, of course I know it's difficult to talk about details. But could you give me a hint?


Thank you.

 

[Rob Watts]

I have a number of projects that will keep me busy for at least 18 months - and Dave 2 is not one of them. And given that things take much longer than one expects, if you want performance to be as best as you can - which I always do - it's gonna be a long time. Of course, particularly in these uncertain times, we don't know what is going to happen tomorrow, but it's not on my horizon at the moment.

 

[DaveRedRef-III]

Rob
Do you see something like a 3 band fully parametric digital EQ in the Chord Electronics digital stream at some point?

I am thinking of something that would offer adjustment for room nodes and speaker frequency deficiencies.

 

[Usak]

I have a number of projects that will keep me busy for at least 18 months - and Dave 2 is not one of them. And given that things take much longer than one expects, if you want performance to be as best as you can - which I always do - it's gonna be a long time. Of course, particularly in these uncertain times, we don't know what is going to happen tomorrow, but it's not on my horizon at the moment.

Hi,Rob.

Thank you for answering. I decided to buy DAVE.

I love the "Best" product you make. I'm looking forward to it.
Please take care of yourself.

 

[Rob Watts]

Rob
Do you see something like a 3 band fully parametric digital EQ in the Chord Electronics digital stream at some point?

I am thinking of something that would offer adjustment for room nodes and speaker frequency deficiencies.

Missing a one or a two?

Yes I think so long term - so long as the bi-quad DSP engine can be made perfectly transparent. It's something in my long term plans as digital loudspeakers needs such an engine for the crossovers.

Hi,Rob.

Thank you for answering. I decided to buy DAVE.

I love the "Best" product you make. I'm looking forward to it.
Please take care of yourself.

Thank-you. It's pretty amazing how Dave has stood the test of time - and by this I am certainly not thinking about Chord's competitors - but the competition from newer designs from myself.

Keep safe and happy listening!

 

[bhobba]

Just a few further impressions. The M-Scaler was disconnected. In some ways it was preferred without the M-Scaler - the M-Scaler had better separation, detail etc, but sounded slightly more 'metallic. He still preferred the SET, but the direct connection seemed to show the strengths of the M-Scaler more.

Thanks
Bill

 

[jagwap]

Yes I think so long term - so long as the bi-quad DSP engine can be made perfectly transparent. It's something in my long term plans as digital loudspeakers needs such an engine for the crossovers.

With your expertise in FIR filters, I sure you can do it. How about some high order FIR brickwall filters? Perhaps subtractive so they add perfectly? Linkwitz-Riley is a compromise made necessary by analogue crossovers.

 

[feddar]

Rob,

I bought an HSM and TT2 a month ago, and I thoroughly enjoy the sound with my Utopia headphones. I have also truly enjoyed reading this thread, and am impressed with your commitment to and love for your work and audience. Thanks!

My source is an Android phone using USB Audio Player in bit perfect mode. As I am now close to my endgame setup, I am thinking of how to maximize the setup. From my understanding of your posts:

1. The stock USB cable does not need to be changed.

2. The stock PSU for the TT2 should not be changed.

3. Power bars and conditioners are not necessary for the TT2, and could cause distortion because “nobody understands how crucial RF noise is, and do not properly filter from 100kHz to 10GHz.”

I am using a PowerQuest3, mostly for the connected components warrantee. They claim “Differential-Mode Noise Dissipation: In excess of 22dB reduction from 30kHz-1GHz; Common-Mode Noise Dissipation: In excess of 22dB reduction from 30kHz-100MHz. Both filters linearized for dynamic (rising) line impedance with frequency from 0.05 Ohms (source) and 10 to 50 Ohm load, (system current dependent).” Does this sound like it should help, or at least not hurt?


4. Do not loop up BNC cables, and do not let them touch other cables.

I am confused about what to do with the BNC joining the HMS and TT2. In a prior post, you mentioned that the BNC cables joining a Blu and Dave could be improved if using a 1m length of cable and ferrites on the Dave end. Does this apply to the HSM/TT2 combination as well, or do the improvements in these two make changing the cables unnecessary?

Recently, you seem to be saying that the stock BNC cables do not need to be changed if an external battery is used for the HMS. Would that be only if connecting a 12V battery directly to the HMS, or would using a 110V plug on the battery work as well?

I am considering getting Wave ferrite covered BNC cables for joining the HMS and the TT2. Does the actual cable matter much, or is it more the ferrites?


Thanks for you help,

Fed

 

[Rob Watts]

Rob,

I bought an HSM and TT2 a month ago, and I thoroughly enjoy the sound with my Utopia headphones. I have also truly enjoyed reading this thread, and am impressed with your commitment to and love for your work and audience. Thanks!

My source is an Android phone using USB Audio Player in bit perfect mode. As I am now close to my endgame setup, I am thinking of how to maximize the setup. From my understanding of your posts:

1. The stock USB cable does not need to be changed.

2. The stock PSU for the TT2 should not be changed.

3. Power bars and conditioners are not necessary for the TT2, and could cause distortion because “nobody understands how crucial RF noise is, and do not properly filter from 100kHz to 10GHz.”

I am using a PowerQuest3, mostly for the connected components warrantee. They claim “Differential-Mode Noise Dissipation: In excess of 22dB reduction from 30kHz-1GHz; Common-Mode Noise Dissipation: In excess of 22dB reduction from 30kHz-100MHz. Both filters linearized for dynamic (rising) line impedance with frequency from 0.05 Ohms (source) and 10 to 50 Ohm load, (system current dependent).” Does this sound like it should help, or at least not hurt?


4. Do not loop up BNC cables, and do not let them touch other cables.

I am confused about what to do with the BNC joining the HMS and TT2. In a prior post, you mentioned that the BNC cables joining a Blu and Dave could be improved if using a 1m length of cable and ferrites on the Dave end. Does this apply to the HSM/TT2 combination as well, or do the improvements in these two make changing the cables unnecessary?

Recently, you seem to be saying that the stock BNC cables do not need to be changed if an external battery is used for the HMS. Would that be only if connecting a 12V battery directly to the HMS, or would using a 110V plug on the battery work as well?

I am considering getting Wave ferrite covered BNC cables for joining the HMS and the TT2. Does the actual cable matter much, or is it more the ferrites?


Thanks for you help,

Fed

Agreed on points 1 and 2.

As to RF filters, this is a complex area; also 22dB reduction would not be enough to eliminate the issue; also it's rated using a 50 ohm load which is not what one would get in practice. That said, best thing to do is to give it a listen; if it sounds warmer then run with it. I had no benefit with using batteries on TT2 though, but each system is different.

As to BNC cables, clip on ferrites helped with Blu 2; but they sounded worse with the Hugo M Scaler, due to the improved isolation on the BNC outputs. A simple way to improve the SQ is using 2m of BNC cables rather than 1m. The cable length is important (longer length is greater inductance to 2GHz impedance for ground loop currents is greater), so to a much lesser amount cable construction. Solid core 2GHz ferrites do work and will give the largest improvement and I use Wave cables myself.

Running the M scaler on batteries does indeed improve the situation and solves the BNC cable issues as batteries (you need to run it isolated completely from the mains) severs the ground loop from M scaler to TT2; thus RF currents can't flow into the DAC ground plane, and the problem is solved.

I should stress that this is very much surface finish of the icing on the cake - it's a significant difference on an AB test, but the scale of the change is forgotten about after a few days.

Happy listening!