[JaZZ]

 
Getting back to your main question - if I had used a bandwidth limited signal, then an ideal infinite sinc function filter would reproduce that bandwidth limited signal perfectly - with no added ringing at all. The interesting aspect about the theory is that it states that you must use an ideal sinc function filter to perfectly reproduce the original; that means that if you as a designer want a transparent filter that neither adds not subtracts then you must make your interpolation filter get as close to the ideal as possible - and that is simply what I have been trying to do over the past 20 years; and I will continue to do this until I can hear no change in SQ with a doubling of tap length. Every time I double the tap length, the difference between actual and ideal halves.
 
So theory is very simple - we have one and only one way to get perfection and that is unusual in audio, as often I am faced with many alternative ways of converging upon perfection. What is curious is that sampling theory has no message about the first bandwidth limiting filter before the signal is sampled - the ADC filter. Will pre-ringing be important? Will limiting to 22.05 kHz be audible? What is the best way to be able to do this? These important questions I hope to answer with the Davina project.

 
Thanks for your response, Rob!
 
So with «ideal» you're addressing the sonic difference between redbook and high-res, I guess? Do you expect Davina to definitely close the gap – since the requirement of a critical bandwidth limitation in close proximity to the audio band before digitization or during decimation from a high-res recording doesn't come with audible losses? The requirement of a bandwidth limitation for creating a CD-compatible recording is an underestimated issue which definitely compromizes the actual capability of a sophisticated DAC like DAVE with 44.1 kHz in my book. However, there's still a chance that ultrasonics do represent a vital component for an ultimately realistic music reproduction. How is your take on that? I'm thinking of interferences like this...
 

 
...between a 14.51 and a 26.1 kHz sine wave. The possibility that the resulting beat be audible can't be excluded – at first glance one would even think it will inevitably create an audible difference compared to a continuous 14.51 kHz tone. So the hypothesis would be that overtones could sound too sleek and polished without any ultrasonic content. Of course such a scenario is only imaginable with test tones like above which don't exist in nature, but after all the same applies to sine waves generally, which nevertheless serve as main signal for judging the fidelity of audio-reproduction devices.
 
 
On more question – to an entirely different topic. We both agree that adding a headphone amp to Mojo, Hugo and DAVE is a bad idea. My own experiments to the matter have revealed that the direct connection can't be beaten when it comes to accuracy and transparency, so I'm absolutely firm in my ampless approach myself. However, there's still a theoretical possibility that the addition of an amp would objectively improve a certain aspect of the sound, namely dynamics – by providing a «better» (faster, more powerful...) power supply. As mentioned, that's not in line with my own experiences, but I could imagine this scenario to be valid in some cases. Isn't the better (faster?) power supply in the form of supercapacitors and other measures responsible for the TT's sonic advantage over the Hugo? I'm mainly asking to have a better perspective, also in view of corresponding forum discussions with people swearing by excessive power reserves. On the other hand, according to my experience most low-impedance line outputs drive headphones very well and without compromising dynamics in any way. Moreover you have demonstrated yourself that the DAVE is better at driving high-efficiency speakers than via any amp (if you're ready to limit yourself to neighborhood-friendly loudness levels), and Romaz will confirm it.
 
That said, during my own audio journey I also experienced that a signal path as direct as it gets can absolutely sound disappointing (read brittle and hard) if something in the chain is not entirely right. Actually every component with a revealing characteristic contributes to a higher dependency of the over-all sound from perfection within the chain. So a smooth sounding headphone (be it due to forgivingness, e.g. created by internal reflections, or a really coherent and even characteristic) is a much better precondition for a signal path as direct as possible to sound pleasant and ear-friendly. Generally an uneven frequency response has to be equalized to make the headphone sound «better» than through a euphonically coloring headphone amplifier introducing the necessary forgivingness.

 

[Rob Watts]

 

 
Getting back to your main question - if I had used a bandwidth limited signal, then an ideal infinite sinc function filter would reproduce that bandwidth limited signal perfectly - with no added ringing at all. The interesting aspect about the theory is that it states that you must use an ideal sinc function filter to perfectly reproduce the original; that means that if you as a designer want a transparent filter that neither adds not subtracts then you must make your interpolation filter get as close to the ideal as possible - and that is simply what I have been trying to do over the past 20 years; and I will continue to do this until I can hear no change in SQ with a doubling of tap length. Every time I double the tap length, the difference between actual and ideal halves.
 
So theory is very simple - we have one and only one way to get perfection and that is unusual in audio, as often I am faced with many alternative ways of converging upon perfection. What is curious is that sampling theory has no message about the first bandwidth limiting filter before the signal is sampled - the ADC filter. Will pre-ringing be important? Will limiting to 22.05 kHz be audible? What is the best way to be able to do this? These important questions I hope to answer with the Davina project.

 
Thanks for your response, Rob!
 
So with «ideal» you're addressing the sonic difference between redbook and high-res, I guess? Do you expect Davina to definitely close the gap – since the requirement of a critical bandwidth limitation in close proximity to the audio band before digitization or during decimation from a high-res recording doesn't come with audible losses? The requirement of a bandwidth limitation for creating a CD-compatible recording is an underestimated issue which definitely compromizes the actual capability of a sophisticated DAC like DAVE with 44.1 kHz in my book. However, there's still a chance that ultrasonics do represent a vital component for an ultimately realistic music reproduction. How is your take on that? I'm thinking of interferences like this...
 

 
...between a 14.51 and a 26.1 kHz sine wave. The possibility that the resulting beat be audible can't be excluded – at first glance one would even think it will inevitably create an audible difference compared to a continuous 14.51 kHz tone. So the hypothesis would be that overtones could sound too sleek and polished without any ultrasonic content. Of course such a scenario is only imaginable with test tones like above which don't exist in nature, but after all the same applies to sine waves generally, which nevertheless serve as main signal for judging the fidelity of audio-reproduction devices.
 
 
On more question – to an entirely different topic. We both agree that adding a headphone amp to Mojo, Hugo and DAVE is a bad idea. My own experiments to the matter have revealed that the direct connection can't be beaten when it comes to accuracy and transparency, so I'm absolutely firm in my ampless approach myself. However, there's still a theoretical possibility that the addition of an amp would objectively improve a certain aspect of the sound, namely dynamics – by providing a «better» (faster, more powerful...) power supply. As mentioned, that's not in line with my own experiences, but I could imagine this scenario to be valid in some cases. Isn't the better (faster?) power supply in the form of supercapacitors and other measures responsible for the TT's sonic advantage over the Hugo? I'm mainly asking to have a better perspective, also in view of corresponding forum discussions with people swearing by excessive power reserves. On the other hand, according to my experience most low-impedance line outputs drive headphones very well and without compromising dynamics in any way. Moreover you have demonstrated yourself that the DAVE is better at driving high-efficiency speakers than via any amp (if you're ready to limit yourself to neighborhood-friendly loudness levels), and Romaz will confirm it.
 
That said, during my own audio journey I also experienced that a signal path as direct as it gets can absolutely sound disappointing (read brittle and hard) if something in the chain is not entirely right. Actually every component with a revealing characteristic contributes to a higher dependency of the over-all sound from perfection within the chain. So a smooth sounding headphone (be it due to forgivingness, e.g. created by internal reflections, or a really coherent and even characteristic) is a much better precondition for a signal path as direct as possible to sound pleasant and ear-friendly. Generally an uneven frequency response has to be equalized to make the headphone sound «better» than through a euphonically coloring headphone amplifier introducing the necessary forgivingness.

On the issue of HF out of bound signals - I am very much more worried when these occur because of sampling - such as aliasing during decimation, and insufficient rejection on interpolation - and these problems are clearly unnatural and audible due to the changes that happen with the timing of transients. On a real recording, it is not a major concern - the levels at 20 kHz are typically 60 dB below the main output, and on real high res recordings the HF content is swamped by the ADC distortion and noise from the ADC noise shaper. This of course won't happen with Davina, as ADC noise shaper noise will not be present, even with 768 kHz recordings.
 
As too things sounding too bright when driving direct - there are very few HP that need more power. Particularly as the HP that causes most grief is actually easy to drive and only 300 ohms - if you are driving below white you are getting the perfect drive for it. But Hugo can't hide a poor HP - if a HP creates LF distortion then driving it directly will make the problems of the HP much more obvious. But I am certainly aware of the need sometimes for a softer sound - that's why I added the filter adjustments with Hugo 2, so you would have the possibility of a more forgiving sound.
 
EQ is certainly a good fix when there are FR issues, and a good way of hiding the effects of LF distortion. But I worry about digital EQ having designed parametric digital EQ before - then I worked at better than 200 dB THD and noise (under all circumstances) which was ground breaking then; now I know we need 350 dB to maintain depth perception, I worry that current digital EQ won't meet that performance level in order to be perfectly transparent.
 
Rob    

 

[JaZZ]

So you don't think ultrasonics contribute anything to realism on a recording? Maybe my wording was unclear; the interference scenario should have served as an example as to how they could be indirectly audible, hence their absence be perceived as a sonic deficit.
 
Since the Hugo TT's better power supply is the main cause of the sonic improvement compared to the Hugo, it is legitimate to deduce that the better power supply of an external headphone amp for the Hugo would provide a similar benefit, although with the downside of reduced transparency due to the unnecessary amplification. What exactly is the TT's power supply's effect on the sound?
 
About equalizers: Can they effectively add distortion (?) or noise? If so, would it be possible to design one without this issue? In any event, apart from the hypothetical THD/noise issue there's also the fact that all sound transducers distrort the frequency response, and this to a significant degree – a musically highly relevant flaw. To my ears the benefit from a more even amplitude response far outweighs any possible reduction of S/N ratio. Moreover the perception of depth is very much dependent on resolution, which in turn is dependent on a flat frequency response (to avoid masking effects).
 
Thinking about it: Virtually all recordings we listen to have been equalized, and fortunately so. In any event, the available recordings don't meet your high standards anyway and certainly don't care for THD/moulation-noise figures around –350 dB – it's your WTA filter which makes the best out of it. So I'm somewhat optimistic that my own equalizing habit doesn't do much harm (if any), and this although I use quite simple equalizers.

 

[tjw321]

This is quite an illuminating look into what digital filters do to the signal: http://t-filter.engineerjs.com/

 

[PANURUS]

Thank you. Arpiben

 

[JaZZ]

Rob?   (@Rob Watts)

 

[Arpiben]

PANURUS

Vectorial analyzers are mainly use in Microwave domain (basically for frequencies above 1GHz).Scattering parameters S (matrix) are then used for describing the multipole (multiport).
At such frequencies a signal is not anymore described by voltage/current but by waves at port level.
A scalar analyzer gives you their module part. A vectorial analyzer will add the phase information.
Dealing with audio spectrum I sincerely doubt about such instruments' usefulness even if we are still dealing with Real/Imaginary parts or Amplitude & Phase.
Hope it helps.

 

[Rob Watts]

  Rob?   (@Rob Watts)

Been crazy busy recently... Code being fine tuned ready for production....

  So you don't think ultrasonics contribute anything to realism on a recording? Maybe my wording was unclear; the interference scenario should have served as an example as to how they could be indirectly audible, hence their absence be perceived as a sonic deficit.
 
Since the Hugo TT's better power supply is the main cause of the sonic improvement compared to the Hugo, it is legitimate to deduce that the better power supply of an external headphone amp for the Hugo would provide a similar benefit, although with the downside of reduced transparency due to the unnecessary amplification. What exactly is the TT's power supply's effect on the sound?
 
About equalizers: Can they effectively add distortion (?) or noise? If so, would it be possible to design one without this issue? In any event, apart from the hypothetical THD/noise issue there's also the fact that all sound transducers distrort the frequency response, and this to a significant degree – a musically highly relevant flaw. To my ears the benefit from a more even amplitude response far outweighs any possible reduction of S/N ratio. Moreover the perception of depth is very much dependent on resolution, which in turn is dependent on a flat frequency response (to avoid masking effects).
 
Thinking about it: Virtually all recordings we listen to have been equalized, and fortunately so. In any event, the available recordings don't meet your high standards anyway and certainly don't care for THD/moulation-noise figures around –350 dB – it's your WTA filter which makes the best out of it. So I'm somewhat optimistic that my own equalizing habit doesn't do much harm (if any), and this although I use quite simple equalizers.

 
Hmm - ultrasonics and realism - firstly my answer is conjecture, and I know nothing for sure. That's one reason why I have selected microphones that will work flat to 50 kHz, so I can actually answer this question based on hard listening tests with the Davina project.
 
For sure ultrasonics can intermodulate so that difference tones then become audible. All we need is a non-linear medium, and the air supplies that. So a simple bandwidth limited 20k microphone recorded at 44.1 will accurately record the intermodulation from ultrasonic tones as it passes through air. But what of the ears themselves? They are badly non-linear, and we may get intermodulation products from ultrasonics that are audible only if the ear hears the ultrasonics. Hence my interest in recording flat to 50 kHz.
 
But - most people claim that higher sample rates are better because of ultrasonics - and I completely disagree with that. I have spent lots of time developing WTA filters and can say with certainty that timing recovery with interpolation in all DAC's is a major issue, of enormous realism consequences. That's why I have the 1M tap length filters, that's why I WTA filter to 88 nS - because these things make huge differences to the sound and musicality - and I am constantly surprised at how sensitive the brain/ear is to extremely small non-linear timing errors.
 
So I don't subscribe to the idea that ultrasonics is important to realism at all - but like I said, I could be wrong about that. But in all my career, reducing out of band noise always sounded smoother and better - and that is simply down to improvements in noise floor modulation (in this case we are trying to remove unnatural intermodulation). So the jury is still out, but if I were a betting man I would predict that the jury will say unanimously that ultrasonics are not guilty of degrading realism. 
 
As to EQ - yes I accept EQ has it's place, but I am worried about depth reproduction. I have listened to -350 dB noise shapers many many times now, under lots of different conditions. The thing about listening tests is that it is very easy to get things wrong. And I was extremely worried about making frankly ridiculous claims about depth perception - and the idea that the ear brain can detect performance levels as low as -350 dB is quite simply insane. But I have repeated it many many times with truncation noise shapers as well as DAC noise shapers, and with different gear and many different times - and always the same - improving noise shaper performance gave better perceived depth. But perhaps my worries are not founded; EQ apps are capable of 350 dB performance under all circumstances - but somehow I doubt it. I know how difficult it was achieving 200 dB performance with parametric EQ before... And yes it is possible to design a 350 dB performance EQ. But it would need to run at 768 kHz, so that the output may be with 24 bits and still maintain 350 dB THD and noise within the audio bandwidth.
 
Rob

 

[JaZZ]

 

  Rob?   (@Rob Watts)

Been crazy busy recently... Code being fine tuned ready for production....

  So you don't think ultrasonics contribute anything to realism on a recording? Maybe my wording was unclear; the interference scenario should have served as an example as to how they could be indirectly audible, hence their absence be perceived as a sonic deficit.
 
Since the Hugo TT's better power supply is the main cause of the sonic improvement compared to the Hugo, it is legitimate to deduce that the better power supply of an external headphone amp for the Hugo would provide a similar benefit, although with the downside of reduced transparency due to the unnecessary amplification. What exactly is the TT's power supply's effect on the sound?
 
About equalizers: Can they effectively add distortion (?) or noise? If so, would it be possible to design one without this issue? In any event, apart from the hypothetical THD/noise issue there's also the fact that all sound transducers distrort the frequency response, and this to a significant degree – a musically highly relevant flaw. To my ears the benefit from a more even amplitude response far outweighs any possible reduction of S/N ratio. Moreover the perception of depth is very much dependent on resolution, which in turn is dependent on a flat frequency response (to avoid masking effects).
 
Thinking about it: Virtually all recordings we listen to have been equalized, and fortunately so. In any event, the available recordings don't meet your high standards anyway and certainly don't care for THD/moulation-noise figures around –350 dB – it's your WTA filter which makes the best out of it. So I'm somewhat optimistic that my own equalizing habit doesn't do much harm (if any), and this although I use quite simple equalizers.

 
Hmm - ultrasonics and realism - firstly my answer is conjecture, and I know nothing for sure. That's one reason why I have selected microphones that will work flat to 50 kHz, so I can actually answer this question based on hard listening tests with the Davina project.
 
For sure ultrasonics can intermodulate so that difference tones then become audible. All we need is a non-linear medium, and the air supplies that. So a simple bandwidth limited 20k microphone recorded at 44.1 will accurately record the intermodulation from ultrasonic tones as it passes through air. But what of the ears themselves? They are badly non-linear, and we may get intermodulation products from ultrasonics that are audible only if the ear hears the ultrasonics. Hence my interest in recording flat to 50 kHz.
 
But - most people claim that higher sample rates are better because of ultrasonics - and I completely disagree with that. I have spent lots of time developing WTA filters and can say with certainty that timing recovery with interpolation in all DAC's is a major issue, of enormous realism consequences. That's why I have the 1M tap length filters, that's why I WTA filter to 88 nS - because these things make huge differences to the sound and musicality - and I am constantly surprised at how sensitive the brain/ear is to extremely small non-linear timing errors.
 
So I don't subscribe to the idea that ultrasonics is important to realism at all - but like I said, I could be wrong about that. But in all my career, reducing out of band noise always sounded smoother and better - and that is simply down to improvements in noise floor modulation (in this case we are trying to remove unnatural intermodulation). So the jury is still out, but if I were a betting man I would predict that the jury will say unanimously that ultrasonics are not guilty of degrading realism. 
 
As to EQ - yes I accept EQ has it's place, but I am worried about depth reproduction. I have listened to -350 dB noise shapers many many times now, under lots of different conditions. The thing about listening tests is that it is very easy to get things wrong. And I was extremely worried about making frankly ridiculous claims about depth perception - and the idea that the ear brain can detect performance levels as low as -350 dB is quite simply insane. But I have repeated it many many times with truncation noise shapers as well as DAC noise shapers, and with different gear and many different times - and always the same - improving noise shaper performance gave better perceived depth. But perhaps my worries are not founded; EQ apps are capable of 350 dB performance under all circumstances - but somehow I doubt it. I know how difficult it was achieving 200 dB performance with parametric EQ before... And yes it is possible to design a 350 dB performance EQ. But it would need to run at 768 kHz, so that the output may be with 24 bits and still maintain 350 dB THD and noise within the audio bandwidth.
 
Rob

 
Thanks a lot for your time, Rob, and sorry for bothering you with my questions, keeping you from doing more important things. There's still one thing I must know:
 
We both agree that adding a headphone amp to Mojo, Hugo and DAVE is a bad idea. My own experiments to the matter have revealed that the direct connection can't be beaten when it comes to accuracy and transparency, so I'm absolutely firm in my ampless approach myself. However, there's still a theoretical possibility that the addition of an amp would objectively improve a certain aspect of the sound, namely dynamics – by providing a «better» (faster, more powerful...) power supply. As mentioned, that's not in line with my own experiences, but I could imagine this scenario to be valid in some cases. Isn't the better (faster?) power supply in the form of supercapacitors and other measures responsible for the TT's sonic advantage over the Hugo? I'm mainly asking to have a better perspective, also in view of corresponding forum discussions with people swearing by excessive power reserves.

 

[Rob Watts]

Hugo TT is better than Hugo partly because of the lower impedance offered by the power supply - but mostly because of the much better discrete references, the galvanic isolation on USB, and the enhanced Class A bias on the output stage. I would guess that the PSU is only about 20% of the SQ going from Hugo to TT.
 
But let's be clear - it is not the power delivery, nor a function of the speed of current delivery, but the actual impedance presented, coupled with signal related errors on the PSU coming through the amps power supply rejection ratio (PSRR). So the issue of PSU and SQ is actually a very complex interaction of differing parts and sensitivities.
 
But the whole question of Hugo not being able to drive certain headphones is I believe generally a fallacy - if you are not in white, then there is plenty of power available to drive all headphones. The issue of adding extra amps is about adding distortion and coloration to soften up a fundamentally hard set of HP. Its curious that the HP that creates most postings about needing external amps has very large levels of low frequency distortion; and I have noticed that HP that sound closer to loudspeakers all share the similarity of low levels of LF distortion (or even better when distortion does not rise with lower frequency).
 
Rob 

 

[x RELIC x]

A very good question JaZZ, and I would also very much like to know Rob's thoughts on the 'reserve power' perspective for headphones. I've always felt that if the device has enough power to reproduce the most demanding part of the music to a certain acceptable dB level then the rest of the voltage/current available from the amp, that's not being used, just won't be seen by the headphone and is simply a waste.

I've always been curious why the TT uses supercapacitors and the other Chord DACs do not, especially since the Mojo, Hugo, HugoTT are very close in power output. Also, from reading your post, I would not confuse power supply quality with power reserves (amount). I take power reserves as being able to deliver the necessary voltage/current on demand, where quality power is just that, quality power (better, cleaner, faster). I'm sure there are many powerful amps with plenty of power reserves that are of poor quality.

I read far too often that the Mojo can't drive, say, an ETHER Flow. I run the Mojo at double red volume, sometimes barely double yellow, with the ETHER Flow and there are plenty of reserves left. However, many swear up and down that a powerful desktop amp is required to get the best out of them, along with many other headphones. In this scenario would there be any real benefit to using an external amp? In my experience, from a transparency/distortion perspective I would say no, but could there be other benefits besides tonal preference? I can completely understand the argument for very inefficient headphones, like the HE-6, but for the majority of headphones that don't require too much power is there any extra benefit if driving the music to adequate levels for the most demanding parts of the dynamics in the music?

Are people mistaking amp 'distortion', coloration, preference, synergy, for the power required? Does a headphone that only requires 0.155Vrms to reach 90dB SPL (ETHER Flow) need 1-4W of headphone amp power to reach - I hate this term - 'it's full potential'. Rob's listening tests and experience would be valuable to me knowing his perspective on the matter, specific to headphones.

Edit: Cross post with Rob's reply. Thanks Rob.

 

[JaZZ]

A very good question @JaZZ, and I would also very much like to know Rob's thoughts on the 'reserve power' perspective for headphones. I've always felt that if the device has enough power to reproduce the most demanding part of the music to a certain acceptable dB level then the rest of the voltage/current available from the amp, that's not being used, just won't be seen by the headphone and is simply a waste.

I've always been curious why the TT uses supercapacitors and the other Chord DACs do not, especially since the Mojo, Hugo, HugoTT are very close in power output. Also, from reading your post, I would not confuse power supply quality with power reserves (amount). I take power reserves as being able to deliver the necessary voltage/current on demand, where quality power is just that, quality power (better, cleaner, faster). I'm sure there are many powerful amps with plenty of power reserves that are of poor quality.

I read far too often that the Mojo can't drive, say, an ETHER Flow. I run the Mojo at double red volume, sometimes barely double yellow, with the ETHER Flow and there are plenty of reserves left. However, many swear up and down that a powerful desktop amp is required to get the best out of them, along with many other headphones. In this scenario would there be any real benefit to using an external amp? In my experience, from a transparency/distortion perspective I would say no, but could there be other benefits besides tonal preference? I can completely understand the argument for very inefficient headphones, like the HE-6, but for the majority of headphones that don't require too much power is there any extra benefit if driving the music to adequate levels for the most demanding parts of the dynamics in the music?

Are people mistaking amp 'distortion', coloration, preference, synergy, for the power required? Does a headphone that only requires 0.155Vrms to reach 90dB SPL (ETHER Flow) need 1-4W of headphone amp power to reach - I hate this term - 'it's full potential'. Rob's listening tests and experience would be valuable to me knowing his perspective on the matter, specific to headphones.

Edit: Cross post with Rob's reply. Thanks Rob.

 
Craig, the reason why I sometimes equate power reserves and power supply is that the most likely scenario for a benefit from oversized power reserves would be an oversized power supply. I exclude that the power reserves themselves do anything.
 
That said, from my own experience I don't have the least reason to suppose that adding amps to Mojo, Hugo and DAVE improves the sound of my headphones. Quite the opposite. On the other hand I do hear the forgivingness they provide. So I'm quite certain that what people perceive as improvement is just that – since those who use amps usually don't consider the method that would make forgivingness obsolete.

 

[JaZZ]

  Hugo TT is better than Hugo partly because of the lower impedance offered by the power supply...

 
So it's still possible that external amps would reproduce this advantage and provide some improvements with partial aspects of the sound? How likely is it?
 
What's the exact mechanism of the lower PS impedance and its effect on the signal, and how is it reflected in the sound quality?

 

[x RELIC x]

Craig, the reason why I sometimes equate power reserves and power supply is that the most likely scenario for a benefit from oversized power reserves would be an oversized power supply. I exclude that the power reserves themselves do anything.

That said, from my own experience I don't have the least reason to suppose that adding amps to Mojo, Hugo and DAVE improves the sound of my headphones. Quite the opposite. On the other hand I do hear the forgivingness they provide. So I'm quite certain that what people perceive as improvement is just that – since those who use amps usually don't consider the method that would make forgivingness obsolete.

I know where you were going with your statements. I suppose I was rather talking to a general audience as opposed to specifically saying you were confusing the two. No worries Marcel, I think you've raised a great topic and you know we share very similar thoughts on the matter. Agree 100% on the forgiveness aspect, and as Rob mentioned, I too feel that many qualities of different headphones are brought to light without the use of an external amp added to Rob's DACs. One of the first things I noticed when I first used the Mojo, and even more so with the DAVE.

 

[thePhones]

Hi Rob, first thank you very much for the awesome Hugo and stuff
 
I personally noticed a very big change in dynamics by adding super capacitors to the original Hugo. I somehow managed to get them in the casing
Guitar strings became way more vibrant and the lower base became more noticeable, also more tight i would say. Maybe it depends on the headphones but I also noticed it by connecting it to my Heko Victa speakers. Regularly I´m hearing with my Ultrasone Edition 5
I hope to hear the Hugo TT sometime to maybe hear the difference to my Hugo(+)
 
Greeting´s from Hamburg, Germany