Hugo TT 2 by Chord Electronics - The Official Thread

[JaZZ]

The supercaps are in the TT2. I wouldn't bother with another PSU as disconnecting the supplied PSU (for 10 seconds) produces no audible change. Linear PSUs generally do not have the RF filters built into SMPS and so normally sound brighter with the illusion of more transparency - but they are actually worse, and measure a lot worse due to lots more LF noise and magnetic noise, with higher leakage currents. The PSU I use has been selected, and measures identically to a battery supply using high bandwidth measurements.

Oh dear.

PSU noise at 55kHz is a completely meaningless specification for the M scaler. You could put HUGE levels of noise at this frequency and it will have NO effect whatsoever at the DAC side, due to the multistage regulation and filtering plus the OP galvanic isolation within the M scaler.

You have missed the most important point - capacitive coupling, and it's capacitive coupling that makes all the difference.

The M scaler has galvanic isolation on its OP but it has capacitive coupling of 2pF across the isolated domains. At 2GHz that is an impedance of 40 ohms; which means the isolation is not very effective, and there exists a path for current to potentially flow. And it's the current flowing into the DACs ground plane that is so important, as a current flow into the DAC ground-plane will create more noise floor modulation (brighter sound fooling people into thinking it is more transparent) and more correlated small signal errors (poorer perception of depth - giving the illusion of a wider and "better" soundstage).

I have spent many man months over several years researching this issue, and I fully understand the situation and how to take steps to ameliorate it; given the fixed and inescapable domain coupling capacitance, the problem is reduced via RF filters, which have course been embedded within the M scaler - to lengths that you wouldn't believe (even logic to logic coupling is treated). I spent a lot of time running SPICE simulations to improve the isolation - and this can be done via RF filters which constrains the current path within the local domain, thus breaking the current flowing into the DAC. But this approach is dependent upon parasitic capacitances which then dominate the effectiveness of this approach.

Given that I have done everything that is possible within the M scaler, how can the PSU help? Remember that the issue is current flow, and this only depends upon the loop impedance: mains>PSU>M scaler>Galvanic isolation on M scaler>BNC cables>DAC ground plane>DAC PSU>mains. You only need one of those steps to have high impedance at 2GHz and you are done; no current will flow and you will get no loss in SQ at all. And for readers that have not followed my previous posts it is the 2GHz range where we have the problem.

So how can we improve it with the PSU? You must use RF filters on the input side and the output side; RF filters reduces the coupling currents and helps; you should use a non grounded PSU - then the coupling is via neutral on the mains not earth - and to reduce coupling via the neutral you need a low inter-winding capacitance without using a grounded screen as this will increase the coupling capacitance. You get all these things with the supplied PSU - it has RF filter on the input and output, being a SMPS it uses a small transformer with low coupling capacitance and it is not grounded.

When you connect an "audiophile" linear PSU you will destroy all of these benefits - no RF filters at all, big screened toroidal transformers with huge capacitive inter-winding capacitance; so you will degrade the isolation at 2GHz, and increase the coupling currents into the DAC. You then get rewarded with a brighter SQ (conning you into thinking it's more transparent), a wider soundstage, an artificial etched quality and of course more listening fatigue - all due to more noise floor modulation and increased small signal amplitude errors.

Sorry if I am being a bit hard on you, but I do get very frustrated when I see audiophiles spend cash on "upgrades" that I know are damaging sound quality and more importantly the ability to enjoy music.

Keep safe and happy listening in these troubled times.

Certainly it's legitimate to doubt Rob's findings if you have good counter arguments (and I happen to disagree with him on one thing myself), but it's hard to believe others' interpretations of «better sound» if you have experienced numerous cases where objectively worse sound is interpreted as better. And in the case of Chord's SMPS Rob's explanation is hard to counter.

 

[lawshredpower]

Certainly it's legitimate to doubt Rob's findings if you have good counter arguments (and I happen to disagree with him on one thing myself), but it's hard to believe others' interpretations of «better sound» if you have experienced numerous cases where objectively worse sound is interpreted as better. And in the case of Chord's SMPS Rob's explanation is hard to counter.

They all say “it just sounds better”. It would be more honest if it was “I just prefer the sound when it has added noise, brighter, more artificial and more small signal amplitude errors”.

I think it’s hard for some to come to terms they prefer the “scientifically worse” sound. There’s nothing wrong with that!

 

[jarnopp]

They all say “it just sounds better”. It would be more honest if it was “I just prefer the sound when it has added noise, brighter, more artificial and more small signal amplitude errors”.

I think it’s hard for some to come to terms they prefer the “scientifically worse” sound. There’s nothing wrong with that!

I think it’s worth keeping in mind this post and the subsequent romaz posts and the idea that experienced listeners can have different opinions:
https://www.head-fi.org/threads/cho...official-thread.831343/page-196#post-14103671

 

[lawshredpower]

I think it’s worth keeping in mind this post and the subsequent romaz posts and the idea that experienced listeners can have different opinions:
https://www.head-fi.org/threads/cho...official-thread.831343/page-196#post-14103671

Absolutely!

 

[InstantSilence]

Components matter!

 

[Hoegaardener70]

Hi Chord friends, I have a comparison question to which I will not find an answer due to lack of access to the gear. In your opinion, how would the ifi Pro idsd in combination with a ifi Pro iCan fare against the Hugo TT2? I'd be really interested if anybody had a chance for a side by side comparison.

 

[dawktah2]

Well, when Rob Watts will be here in my room listening to my headphones and observing no difference I will believe him. Unfortunately I am the one sitting here, owning during the years 3 DACs designed by him and observing on 2 of them improvements using linear power supplies. He told on all threads the same thing that there is no difference using LPS or the supplied one or even worse. Well, I beg to differ

Double blind test is the way tun put this to bed.

That is just a power brick, the real power supply is inside TT2. As far as I'm aware, the power brick get's regulated to a smoother and less noisy frequency inside TT2, that along with it's 6 super caps helps avoid big power fluctuations/draw which in turn creates noise.

Correct me if I'm wrong, which I may very well be as I'm winging it here, or maybe I read it on chords website, or seen it in startrek voyager when it's warpcore started fluctuation.

You sir are correct! It's just power to the internals

They all say “it just sounds better”. It would be more honest if it was “I just prefer the sound when it has added noise, brighter, more artificial and more small signal amplitude errors”.

I think it’s hard for some to come to terms they prefer the “scientifically worse” sound. There’s nothing wrong with that!

Well, I *upgraded * from the cheap USB cable included with the tt2 to a anticable usb a to b and easily observed a change in sound
I don't have any experience with any power supplies of any sort.
But I do know... Components matter!

Double blind...

 

[InstantSilence]

Double blind test is the way tun put this to bed.



You sir are correct! It's just power to the internals




Double blind...

I had my friend switch back and forth behind me, the usb cable, under about 8 tracks within 3 genres, I was able to tell the difference each time within 15 seconds of each track. Not a massive massive difference at all but a difference for sure.
Why wouldn't materials matter? Why wouldn't components matter and a make a difference?

 

[NeoDiNardo]

Personally, I would rather my PSUs to be built into the main unit and be well designed from the get go. I see Rob Watts posting not to replace the Chord TT2 PSU. OK, but what if you ran that Chord TT2 PSU off of a nice squeegee clean battery? Would that not solve all the PSU problems on the table?

 

[Hooster]

Personally, I would rather any PSU to be a high quality one to begin with and be built inside of the main unit. I see Rob Watts posts saying not to replace the Chord TT2 PSU. OK, but what if you ran that Chord TT2 PSU off of a nice squeegee clean battery? Would that not be a better upgrade?

No, because the TT2 has "super capacitors". Spend the money on better headphones.

 

[dawktah2]

I had my friend switch back and forth behind me, the usb cable, under about 8 tracks within 3 genres, I was able to tell the difference each time within 15 seconds of each track. Not a massive massive difference at all but a difference for sure.
Why wouldn't materials matter? Why wouldn't components matter and a make a difference?

That's single blind

No, because the TT2 has "super capacitors". Spend the money on better headphones.

Yep

 

[GreenBow]

A little comparison before weekend start. Duel between duo DAC+Amp that I'm familiar with, love them both, but actually never AB them at one time. The price difference is significant though (5.5k vs 2k): Chord Hugo TT2 vs Questyle CMA 12 Master

Sound Character:
Surprise me more than anything, they actually sound much more similar than different, The treble, mid and bass quantity (and presentation) really sounds alike.

Overall, TT2 retain slight (read: only slight) warmer sounding in midrange and bass, not significant, but I can feel the constant "warm aura" there.

Treble quantity, impact, and bite also behave similarly whith CMA 12 Master slight offering more energy (not quantity).

Midrange is where they perform a bit different (not much, but easy noticeable). TT2 is more forward, more mid centric nature, slight more relax impact. Both sounds silky smooth with lifelike vocal presentation.

Bass, again, rather similar in quantity and impact. Questyle offer slight more mid bass, and TT2 has slight more linear bass to the sub bass area.

Soundstage has almost similar "shape". TT2 slight wider, CMA slight offer mode depth, with height presentation that I couldn't differentiate.

Technical Quality:
Micro detail, from the last note of a string, or from singer, or the texture from cello, violin, and double bass definitely has more presence in TT2. Not type of detail that everyone looking for because most of them don't even realise these sounds exist in the recording. But, it's there with TT2.

I can't say that TT2 has better bass extension, but the slight less mid bass does bring the very lowest sub bass notes easier to hear with Chord (not significant though). Questyle present slight fuller mid bass, that perhaps hide the latest sub bass notes a little bit. No, both of them don't offer bass like V281, which has more body from both Chord and Questyle.

Soundstage:
Actually 12 Master manage to put the "depth" positioning better than Chord (I know, what a surprise). Chord produce overall sharper imaging though. More accuracy in pin point of each instrument. A little differences here and there in each instrument positioning, may feels slight if we only pay attention to one instrument, but could change the whole listening experience when everything just simply has more accurate location.

Overall experience:
Fluid and smoothness of Chord still unbeatable here. This company really knows well how to create fatigue free product. I always think my 12 Master is an extremely smooth product, full body sound, and excellent black background presentation. The Questyle amp section also has smoother and more relax presentation with fuller midrange than Wells Milo Vishay, or Violectric V281. However, TT2 present the same full body sound, with fluidity and smoothness effect to the next level ahead.

Thanks for read my random comparison!

The Questyle CMA 12 Master is a thing of beauty.

 

[OctavianH]

Since it’s ultimately a matter of taste, I don’t think there’s anything wrong in preferring the TT2 sound when you degrade its isolation and increase its coupling currents. Or maybe you think that’s not what’s happening when you use a LPSU with the TT2? What are you thoughts on the differences and what causes them?

The effects are somehow similar with what you observe when you filter the usb input. More clarity, detail, bass is tighter and goes deeper and the background is blacker. I do not try to discuss graphs or mathematical formulas, after all I listen to rock music where the electric guitar might be considered by others a "distorted" sound. So it is a matter of preference. But I ask one thing, everyone is claiming that the super capacitors in TT2 are solving the problems and one should not try to use anything else. What is the case of M Scaler + TT2 combo? M Scaler does not use such super capacitors and still, has that identical power supply. I know it is just an upscaler, with input and output as digital signal, but anyway.

PS. The same effect I obtained on my tube amp when adding a Furman power conditioner to power it and some other gear. So, what to say...

 

[lawshredpower]

The effects are somehow similar with what you observe when you filter the usb input. More clarity, detail, bass is tighter and goes deeper and the background is blacker. I do not try to discuss graphs or mathematical formulas, after all I listen to rock music where the electric guitar might be considered by others a "distorted" sound. So it is a matter of preference. But I ask one thing, everyone is claiming that the super capacitors in TT2 are solving the problems and one should not try to use anything else. What is the case of M Scaler + TT2 combo? M Scaler does not use such super capacitors and still, has that identical power supply. I know it is just an upscaler, with input and output as digital signal, but anyway.

PS. The same effect I obtained on my tube amp when adding a Furman power conditioner to power it and some other gear. So, what to say...

I do not own the M-scaler, nor am a fan of it. But I think it was already explained here:

Oh dear.

PSU noise at 55kHz is a completely meaningless specification for the M scaler. You could put HUGE levels of noise at this frequency and it will have NO effect whatsoever at the DAC side, due to the multistage regulation and filtering plus the OP galvanic isolation within the M scaler.

You have missed the most important point - capacitive coupling, and it's capacitive coupling that makes all the difference.

The M scaler has galvanic isolation on its OP but it has capacitive coupling of 2pF across the isolated domains. At 2GHz that is an impedance of 40 ohms; which means the isolation is not very effective, and there exists a path for current to potentially flow. And it's the current flowing into the DACs ground plane that is so important, as a current flow into the DAC ground-plane will create more noise floor modulation (brighter sound fooling people into thinking it is more transparent) and more correlated small signal errors (poorer perception of depth - giving the illusion of a wider and "better" soundstage).

I have spent many man months over several years researching this issue, and I fully understand the situation and how to take steps to ameliorate it; given the fixed and inescapable domain coupling capacitance, the problem is reduced via RF filters, which have course been embedded within the M scaler - to lengths that you wouldn't believe (even logic to logic coupling is treated). I spent a lot of time running SPICE simulations to improve the isolation - and this can be done via RF filters which constrains the current path within the local domain, thus breaking the current flowing into the DAC. But this approach is dependent upon parasitic capacitances which then dominate the effectiveness of this approach.

Given that I have done everything that is possible within the M scaler, how can the PSU help? Remember that the issue is current flow, and this only depends upon the loop impedance: mains>PSU>M scaler>Galvanic isolation on M scaler>BNC cables>DAC ground plane>DAC PSU>mains. You only need one of those steps to have high impedance at 2GHz and you are done; no current will flow and you will get no loss in SQ at all. And for readers that have not followed my previous posts it is the 2GHz range where we have the problem.

So how can we improve it with the PSU? You must use RF filters on the input side and the output side; RF filters reduces the coupling currents and helps; you should use a non grounded PSU - then the coupling is via neutral on the mains not earth - and to reduce coupling via the neutral you need a low inter-winding capacitance without using a grounded screen as this will increase the coupling capacitance. You get all these things with the supplied PSU - it has RF filter on the input and output, being a SMPS it uses a small transformer with low coupling capacitance and it is not grounded.

When you connect an "audiophile" linear PSU you will destroy all of these benefits - no RF filters at all, big screened toroidal transformers with huge capacitive inter-winding capacitance; so you will degrade the isolation at 2GHz, and increase the coupling currents into the DAC. You then get rewarded with a brighter SQ (conning you into thinking it's more transparent), a wider soundstage, an artificial etched quality and of course more listening fatigue - all due to more noise floor modulation and increased small signal amplitude errors.

Sorry if I am being a bit hard on you, but I do get very frustrated when I see audiophiles spend cash on "upgrades" that I know are damaging sound quality and more importantly the ability to enjoy music.

Keep safe and happy listening in these troubled times.

Either way, what matters is being happy with the sound. But it’s strange how some people deny the reasons why the sound changes, that’s all.

 

[OctavianH]

Either way, what matters is being happy with the sound. But it’s strange how some people deny the reasons why the sound changes, that’s all.

Many thanks, it was indeed explained but I somehow missed to read this carefully. However, what I have described were my findings related to 2Qute and Qutest. We will see what I will discover using TT2 and M-Scaler powered by LPS when they will arrive. According to all these explanations I will just need to return them, save money and drink a lot of beer. Well, it is a dream scenario but unfortunately I was not lucky on my previous 2 DAC and the whole audio line (because the Furman power conditioner was also a very good adition) and I have a feeling history will repeat itself. Well, over and out, I do not want to start here a debate on power, I just answered to what I was asked.