[bmichels]

Pool:  BEST headphone for HUGO
*********************************************
 
Now that I finally received my HUGO, and was told by Rob NOT tu use any external Amp 

, I need to choose a "non leaking" headphone that has the best possible synergy with the HUGO  (I already have TH-900 & Roxane that pair very well with Hugo

 -)
 
--> Anybody tested  AlphaDOG,  SignaturePRO,  or other TOL "isolating" headphone with the HUGO ? 
 
 
 
Any, on a wider scope, any other headphone recommended that offer even more Grunt & Musicality with the HUGO...

 

[beemarman]

Pool:  [COLOR=B22222]BEST headphone for HUGO[/COLOR]
*********************************************

Now that I finally received my HUGO, and was told by Rob NOT tu use any external Amp  , I need to choose a "non leaking" headphone that has the best possible synergy with the HUGO  (I already have TH-900 & Roxane that pair very well with Hugo  -)

[COLOR=B22222]--> Anybody tested  AlphaDOG,  SignaturePRO,  or other TOL "isolating" headphone with the HUGO ? [/COLOR]



Any, on a wider scope, any other headphone recommended that offer even more Grunt & Musicality with the HUGO...

I use the Roxanne and the AKG 3003i and both sound very good.

 

[bmichels]

I use the Roxanne and the AKG 3003i and both sound very good.

I know, thanks, but here is is about  Full Size  headphone.

 

[Audiowood]

  I know, thanks, but here is is about  Full Size  headphone.

LCD X- if you dont mind its an open headphone. My fav headphone beside TH900. The LCD X is not the same dark signature as the LCD3 or LCD 2. Its treble is much more improved now. Try it with Hugo and I suspect you will like it.

 

[bmichels]

 
LCD X- if you dont mind its an open headphone. My fav headphone beside TH900. The LCD X is not the same dark signature as the LCD3 or LCD 2. Its treble is much more improved now. Try it with Hugo and I suspect you will like it.

thanks
 
PS: HUGO really has enough "juice" to drive the X to it's full potential ?

 

[Audiowood]

  thanks
 
PS: HUGO really has enough "juice" to drive the X to it's full potential ?

 
Oh yeah & with some juice left for supper!

 

[holeout]

  Pool:  BEST headphone for HUGO
*********************************************
 
Now that I finally received my HUGO, and was told by Rob NOT tu use any external Amp 

, I need to choose a "non leaking" headphone that has the best possible synergy with the HUGO  (I already have TH-900 & Roxane that pair very well with Hugo

 -)
 
--> Anybody tested  AlphaDOG,  SignaturePRO,  or other TOL "isolating" headphone with the HUGO ? 
 
 
 
Any, on a wider scope, any other headphone recommended that offer even more Grunt & Musicality with the HUGO...

Actually, the Th900 is nice pairing with the Hugo. However, isolation is not that good and I managed to broke one of the cable strain relief after a few road trips so TH900 is staying at home.
 
Just tried out some closed cans - Signature Pro, Shure 1540 and LCD XC last week. IMO:
 
Signature pro - Not very comfortable, feels plasticky, good isolation, SQ not quite my cup of tea
 
Shure 1540 - Light and comfortable, really like the carbon fibre/aluminium built, isolation better then TH900 but not as good as Sig pro and LCD XC, nice balanced sound
 
LCD XC - Heavy but comfortable, great build quality and feels sturdy, good isolation, pairs well with the Hugo - revealing with lots of detail and good extension both ways
 
Shure is quite good for light travelling and casual listening, but I pick the LCD XC for isolation and more engaging SQ/refinement.
 
I was using the T5P for the past few months as a portable setup and it also paired well with Hugo, really good isolation and portability. However, the bass is a touch lean especially if I'm travelling on a plane or ground transport. 

 

[nOtEcH]

1) True about sources, I can't change much about the original recording! That said, it is always a balancing act between refinement (sounding rich and smooth) and transparency (sounding detailed and revealing). The nice thing about Hugo, is that it is very revealing, but in a natural way without being in your face. You can never get the balance right that suits all circumstances for all people though.

2) Power - yes good point, I meant to add this in my post. I too wonder if a beefed up OP stage would improve things. The output voltage is limited to 5V RMS (very much bigger than usual for portable but a bit smaller than some desktops) so if users use 22 ohms or greater impedance then you are good until you just hit white on the volume control. If the load is 8 ohms then it will start to increase distortion at the ultra violet colour (the colour just before white). So please let me know if any user gets to these colours on the volume. I tested the HD800 at just white, and it was extremely (deafeningly) loud... But feedback on what people actually use their volume settings with a named headphone would be very much appreciated.

Hi Rob, and thank you for your contribution to the world of Hi-Fi and Head-Fi. It is no doubt that the Hugo is a remarkable device.

I have a question about amplification and power..

In my "Hi-Fi career" I have never had any problems playing loud, not even smaller 50W amps had any problems even with relatively hard to drive speakers.
What I have noticed though is that music tends to be some what compressed some times (smaller soundstage, instruments smaller etc) and especially if the music is complex and a lot is happening at the same time. With more power complex music is better reproduced (IMO), and it shows especially when playing loud. More controlled. More correct.

The HD800 (300 ohm) can handle 500mW continously from an amp. The Hugo can give 70mW and that is under 1/5 of what it is capable of.
So I would guess that more power could be beneficial if you are playing complex music and loud?

I guess that music will sound quite ok with my HD800 anyhow though, as people seems to like the pairing.


Side note:
In two days I will recieve my own Hugo, and I am very much looking forward to it!
I will be buying Noble's Kaiser 10 to pair with the Hugo and I am not worried about lack of power for those.

Again thanks for your contribution. I know I will be enjoying the Hugo!

 

[Crashem]

Thanks for putting the amp argument to rest.

 
I appreciate the Hugo's designer's input on his amp design.  But this issue is far from settled.  Rob doesn't really go into detail on how his amp section is setup.  Reading the technical presentation from the website, it looks like he is using a class a arranged op-amp to amplify the signal and really taking advantage of his clean output of the dac.  op-amp have their advantages and disadvantages.  If I am reading it right as well as Rob's comments right and guessing right, it almost looks the Hugo is using digital amplification to raise the sound level much higher than normally done and therefore only requiring the analog amp portion to do less work.  Hard for me to comment unless I know more about what the circuit/parts actually used.  However, his comments on distortion at different dbs being low being the "proof" that the amp is "great" is only one of the measurable factors you look at in technically comparing amps.
 
To my ears, the Hugo isn't matching up to a variety of amps I have tested against.  Like Rob, I favor a clean neutral presentation.  Maybe it is the fact I have been testing via harder to drive ortho's and using pretty high end equipment..  I'm not sure, but it is pretty noticeable to me even on lesser equipment such as Peachtree Nova.

 

[Crashem]

I want to thank the Hugo Designer Rob Watts for his comments.  While I don't necessarily agree with all his points, I am a believer in the product and own one.  I do have some questions/comments that I would love to hear his input.  I will say the recent innovative approaches from him and others is really exciting.  Personally I look forward to testing the Hugo against some of the other more innovative approaches I can afford to test against (PS Audio DirectStream, Lampizator) and hopefully some I can't afford (MSB).
 
1) In its most simplistic form: Is the Hugo DAC still a multi Delta Sigma based design (looks like you are using the PCM2706 chip for this) while applying a bunch of custom designed digital filters (WTA, noise shaping, etc.) to clean up the digital signal?  I have heard reference to the Hugo to being a delta sigma dac and it not being one.
 
2) Master Clock: Is the master clock running at 12mhz and is it the one in the PCM2706?  There are many high end dac makers who would consider the resulting nanosecond accuracy not to be accurate enough.  MSB upgrades clocks are down to sub pico second accuracy.  However, given a big part of MSB's secret sauce is reclocking the data stream for their R2R implementation, I guess it would be more sensitive to clock jitter.  Assuming I am accurate in understand the specs of the master clock, I am curious why an even higher end clock wasn't used.  Is it one of or some combination of the following reasons:
 a) Basic design of Hugo DAC implementation is inherently more resistant to clock based jitter given your use of digital PLL as an example?
 b) Belief that sub nanosecond accuracy doesn't make a difference in SQ
 
3) USB Implementation: Any details on USB implementation and how resistant it is to USB related issues?  Personally, I find the coaxial digital input to sound cleaner than the USB.  If we look at something like the Berkeley Alpha USB, we see extensive efforts to separate possible USB related issues from the DAC.  A lot of those "solutions" would be difficult to take advantage in the box the size of the Hugo.  I'm curious what measures were taken however.
 
4) With your basic design implementation, you have stated that an infinite number of FIR taps to mimic a true audio wave which makes perfect sense.  With your previous designs, you have also stated that the WTA filter reduces the need to have a huge amount of FIR taps and that you reach essentially significant diminishing returns in the 1-2k.  Given that the new FPGA allowed you to almost exponentially increase the number of FIR taps to 26kish using limited power, where are your thoughts on the number of FIR taps before significant diminishing returns lie?  If tomorrow a new low power FPGA came out that allowed you to increase the number of FIR taps to 256k and nothing else changed, do you think it would be audibly noticeable?
 
Thanks in advance!

 

[Stormfriend]

Personally, I find the coaxial digital input to sound cleaner than the USB.

Have you had a chance to compare the Toslink input to coax and USB? It would be useful to know how it fares when looking for a new source.

If anyone can compare a Fiio X5 to an MBP that would be really useful too. Does a simpler device give better sound quality?

 

[Rob Watts]

  I want to thank the Hugo Designer Rob Watts for his comments.  While I don't necessarily agree with all his points, I am a believer in the product and own one.  I do have some questions/comments that I would love to hear his input.  I will say the recent innovative approaches from him and others is really exciting.  Personally I look forward to testing the Hugo against some of the other more innovative approaches I can afford to test against (PS Audio DirectStream, Lampizator) and hopefully some I can't afford (MSB).
 
1) In its most simplistic form: Is the Hugo DAC still a multi Delta Sigma based design (looks like you are using the PCM2706 chip for this) while applying a bunch of custom designed digital filters (WTA, noise shaping, etc.) to clean up the digital signal?  I have heard reference to the Hugo to being a delta sigma dac and it not being one.
 
2) Master Clock: Is the master clock running at 12mhz and is it the one in the PCM2706?  There are many high end dac makers who would consider the resulting nanosecond accuracy not to be accurate enough.  MSB upgrades clocks are down to sub pico second accuracy.  However, given a big part of MSB's secret sauce is reclocking the data stream for their R2R implementation, I guess it would be more sensitive to clock jitter.  Assuming I am accurate in understand the specs of the master clock, I am curious why an even higher end clock wasn't used.  Is it one of or some combination of the following reasons:
 a) Basic design of Hugo DAC implementation is inherently more resistant to clock based jitter given your use of digital PLL as an example?
 b) Belief that sub nanosecond accuracy doesn't make a difference in SQ
 
3) USB Implementation: Any details on USB implementation and how resistant it is to USB related issues?  Personally, I find the coaxial digital input to sound cleaner than the USB.  If we look at something like the Berkeley Alpha USB, we see extensive efforts to separate possible USB related issues from the DAC.  A lot of those "solutions" would be difficult to take advantage in the box the size of the Hugo.  I'm curious what measures were taken however.
 
4) With your basic design implementation, you have stated that an infinite number of FIR taps to mimic a true audio wave which makes perfect sense.  With your previous designs, you have also stated that the WTA filter reduces the need to have a huge amount of FIR taps and that you reach essentially significant diminishing returns in the 1-2k.  Given that the new FPGA allowed you to almost exponentially increase the number of FIR taps to 26kish using limited power, where are your thoughts on the number of FIR taps before significant diminishing returns lie?  If tomorrow a new low power FPGA came out that allowed you to increase the number of FIR taps to 256k and nothing else changed, do you think it would be audibly noticeable?
 
Thanks in advance!

OK, The PCM2706 is just used for the SD USB, it most categorically is not the DAC. The DAC is a pulse array DAC, which uses discrete flip-flops for the analogue OP. The noise shaper for the pulse array runs at 104 MHz, which is fed from a very low jitter crystal oscillator. The noise shaper is in the FPGA. So you are mistaken in thinking the DAC runs at 12 MHz. As to the master clock jitter requirements, this is a complex issue and not easily explained in a simple post. Certainly, the DAC implementation does have a large bearing on the sensitivity to clock jitter, so does the noise shaper characteristics, so does the signal RF noise levels. To further complicate the matter, fixed noise from jitter sources is not audible as such (in terms of SQ), as it just contributes to the dynamic range noise. What is much more damaging is noise floor modulation, and clock jitter can affect this. But I have spent a lot of effort to minimize this aspect of performance. The HD USB is isochronous, but frankly this does not matter much as the DPLL effectively eliminates source jitter anyway. On the WTA filter, yes the WTA algorithm does give roughly the same sound as a conventional half band filter that has ten times the tap length. But I have always said that increasing tap size improves performance,even with using the WTA, and I am certain that 26k is not the limit. You can hear big changes from 16k to 18k; and there was a big change from 18k to 26k. Now there has to be a limit to when the tap size will no longer improve the sound, and if I were to put a number on it (and this is entirely a guess) I would say 1M taps for an 8 times OS filter. That would guarantee accuracy to better than 16 bits, as the sinx/x coefficients are now well below the 16 bit level.  But this is a guess. It could be 100K, it might be 10M. Nobody knows. I will find out - that's what makes this so interesting at the moment.      

 

[Sunya]

Mr. Watts, how does the current QBD76 compares to the Hugo? Besides offering balanced outputs is there something else in it that makes it superior to the Hugo?
 
When the QBD76 was launched there were mentioned 4096 taps for the WTA filter, but now I saw 17000 taps quoted; was this a recent software update within the Spartan3 FPGA that the QBD76 uses? Are there planned any hardware updates on the QBD76 for it to also include the Spartan6?

 

[jamato8]

The Hugo did not wow me on first listen, that is good. A wow factor, often means there is something too prominent, sometimes not. Now it is wowing me, after listening for some time and that means I am appreciating the delivery, the musical truth the Hugo conveys. Great stuff. 

 

[ted_b]

Rob,
Thanks for these great responses.  I have a question about non-headphone use.  I am going to use my Hugo (don't have it yet; Bluebird sending me soon) like I currently use my Chord Qute EX...that is, as my main rig DAC, connected to a Concert Fidelity CF-080 tube hybrid preamplifier.  However, the CF-080 has a maximum input voltage (RCA single ended) of 2V RMS.  Am I reading that the Hugo output at "bypass" is 3V RMS or more?  If so, is my short-term (before I replace my vaunted preamp ) solution to turn down the gain in the Hugo to some color?  If so, any sonic tradeoffs?  Thanks
Ted

Edit: nevermind, I see your Chord website now has the manual.  In the tradition of RTFM, I did.    Volume bypass is set at 2V RMS.  YEah!  Thanks!