[marcusd]

Finally got our hands on a TT2 paired it with the M Scaler with initial impressions, wow

https://headfonics.com/2020/04/chord-electronics-hugo-tt2-first-contact/

 

[hypnos1]

im using the Empy in combination with the Hugo TT2 atm. It sound so incredibly good. I tested Utopia and Stelia and the Hifiman stuff against it.
For me its the best combination.
The only headphone that is probably better that i have heard is the Final audio D8000. But that headphone is is just to uncomfortable for me

Certainly agree re. TT2 + Empyreans...they seem made for each other (especially if one can stretch to a nice OCC silver and copper replacement cable...or make it oneself!).

 

[hypnos1]

Just over a week now with my (used/immaculate) example, and without repeating the finer aspects of detail retrieval/clarity/ dynamics/'sparkle' etc. etc., the image/analogy that came into my mind today sums it all up (for me at least)...ie. lead crystal vs moulded/pressed glass!

And although obviously well burned in already, the same applies here as with new/different tubes...ie. the need for plenty of time to get a full and proper handle on any piece of audio equipment - both for the hardware and (as Mr Watts himself espouses), the brain! Each new day brings ever greater surprises with every single one of the test pieces I've heard literally hundreds of times these past few years...not to mention a grin that gets ever wider also .

 

[Rob Watts]

Hugo 2 is class A with a 300 ohm load; for loads below 300 ohm it is class AB. TT2 is biased an order of magnitude more as it is a much beefier output stage and I don't need to worry about power losses or thermal issues. I certainly don't need to further increase it, as you observe TT2 already has extremely low distortion with an 8 ohm load, and no crossover distortion at all. Crossover distortion is a major issue having huge subjective consequences. Another issue is how fast the OP stage is when going from Class A to Class B - the transistors are extremely fast (30nS) and so do not create phase intermodulation distortion - another issue that is very important subjectively. I have to have an extremely fast OP stage in order for the second order analogue noise shaper to work.

The fact that TT2 with 20Hz 12W into 8 ohms show no distortion at all above 3kHz - when I can resolve -180dB (that is less than 0.00000001%) indicates crossover distortion and phase intermodulation distortion is eliminated too as these are indicated by HF harmonics.

Happy listening and stay safe.

 

[RustyGates]

Hugo 2 is class A with a 300 ohm load; for loads below 300 ohm it is class AB. TT2 is biased an order of magnitude more as it is a much beefier output stage and I don't need to worry about power losses or thermal issues. I certainly don't need to further increase it, as you observe TT2 already has extremely low distortion with an 8 ohm load, and no crossover distortion at all. Crossover distortion is a major issue having huge subjective consequences. Another issue is how fast the OP stage is when going from Class A to Class B - the transistors are extremely fast (30nS) and so do not create phase intermodulation distortion - another issue that is very important subjectively. I have to have an extremely fast OP stage in order for the second order analogue noise shaper to work.

The fact that TT2 with 20Hz 12W into 8 ohms show no distortion at all above 3kHz - when I can resolve -180dB (that is less than 0.00000001%) indicates crossover distortion and phase intermodulation distortion is eliminated too as these are indicated by HF harmonics.

Happy listening and stay safe.

Thanks Rob, an order of magnitude more. Nice. So what does that correspond to in terms of the TT2's pure class A operating range threshold in terms of load impedance, before it switches to AB, then pure B? 30 Ohm?

Also, this begs the question, what is the benefit of biasing in pure class A, throughout a certain operating range, if the noise shaper architecture of the OP stage can cancel out Xover distortion, TIMD and IMD anyway? Why not design an OP stage which operates purely on Class AB to B, or even purely class B, throughout the whole range of power output?

 

[Rob Watts]

Yes it's in pure Class A for 30 ohms. By 8 ohms it is Class AB.

In one sense you are correct in that Class B biassing will give extremely low distortion with the analogue noise shaper approach - as distortion at 20kHz will be reduced by 1000 times or 60dB. That's a huge improvement. But - above 20MHz the analogue noise shaper will have no benefit, so we still have to bias the OP so that the OP transistors are never hard off and take too long to recover and turn on as this will increase phase intermodulation distortion and HF harmonics. For a given OP stage and load impedance there actually exists an optimum when increasing bias can either have no more reduction in distortion, or it can actually subtly increase the distortion levels. TT2 is bias tuned with 4 ohms or greater impedances.

 

[N Quarter]

For the last few days I have been running my Mscaler/TT2 driving my Dynaudio excite 12’s directly, with the TT2 set to low gain. I think it sounds much better than on high gain, and I have plenty of volume still. I am using the XLR outputs at the back, so how much power am I actually losing compared to high gain?
edit...wait a minute, I just switched back to high gain and it sounds just as good. Maybe my cables are burning in, or I had a setting wrong or something.

 

[RustyGates]

Yes it's in pure Class A for 30 ohms. By 8 ohms it is Class AB.

In one sense you are correct in that Class B biassing will give extremely low distortion with the analogue noise shaper approach - as distortion at 20kHz will be reduced by 1000 times or 60dB. That's a huge improvement. But - above 20MHz the analogue noise shaper will have no benefit, so we still have to bias the OP so that the OP transistors are never hard off and take too long to recover and turn on as this will increase phase intermodulation distortion and HF harmonics. For a given OP stage and load impedance there actually exists an optimum when increasing bias can either have no more reduction in distortion, or it can actually subtly increase the distortion levels. TT2 is bias tuned with 4 ohms or greater impedances.

Thanks Rob! Definitely looking forward to your Power Pulse Array mono-blocks!

 

[hypnos1]

Finally understanding the full impact of RW's intense focus on transient handling in his developmental use of FPGA architecture.

As per his explanations at the beginning of this thread (edit - mistake...the m-scaler thread!), its importance in final sound delivery struck me especially today in the vital area of leading and trailing edge note reproduction. The precise attack of the former, combined with either sudden, clean termination or delicious decay of the latter bring an overall clarity I'm sure is seldom equalled, let alone surpassed. And such precision is not in any way clinical, as some folks sometimes misinterpret in different pieces of equipment lol!

And perhaps most surprising of all (to me) is how this quality carries over into humble CD level resolution. I was astonished today by TT2's delivery of the 1964 recording (albeit remastered in 2014) of Tosca - Maria Callas/Tito Gobbi/Carlo Bergonzi/George Pretre. I never dreamt such an old recording could sound like this (on CD).

No doubt ably assisted by Naim's SSD source and Neotech UP-OCC silver and copper-wired cables throughout (including digital cable), but such CD performance has me wondering if the extra taps in TT2 are in effect outputting a higher resolution-like signal, over and above 16bit 44.1kHz...and proportional to the upscaling in m-scaler? No doubt others have a more accurate description of this effect .

Whatever, if m-scaler takes all this to appreciably greater heights, then my wallet is in for yet another hammering very soon lol!

 

[miketlse]

Finally understanding the full impact of RW's intense focus on transient handling in his developmental use of FPGA architecture.

As per his explanations at the beginning of this thread, its importance in final sound delivery struck me especially today in the vital area of leading and trailing edge note reproduction. The precise attack of the former, combined with either sudden, clean termination or delicious decay of the latter bring an overall clarity I'm sure is seldom equalled, let alone surpassed. And such precision is not in any way clinical, as some folks sometimes misinterpret in different pieces of equipment lol!

And perhaps most surprising of all (to me) is how this quality carries over into humble CD level resolution. I was astonished today by TT2's delivery of the 1964 recording (albeit remastered in 2014) of Tosca - Maria Callas/Tito Gobbi/Carlo Bergonzi/George Pretre. I never dreamt such an old recording could sound like this (on CD).

No doubt ably assisted by Naim's SSD source and Neotech UP-OCC silver and copper-wired cables throughout (including digital cable), but such CD performance has me wondering if the extra taps in TT2 are in effect outputting a higher resolution-like signal, over and above 16bit 44.1kHz...and proportional to the upscaling in m-scaler? No doubt others have a more accurate description of this effect .

Whatever, if m-scaler takes all this to appreciably greater heights, then my wallet is in for yet another hammering very soon lol!

I can only speak for myself when I listen to some 1950/1960 jazz cds from my mediatheque, and think that 'those guys were having fun'.
The future with TT2 and DAVE promises better.

 

[nwavesailor]

I currently have a Qutest paired with GSX Mini and Cavalli LP. I am using the latest 7th gen iPod Touch but do have the latest iPad. HP are Empy and ZMF Verite open. I like the Qutest but was thinking of moving up to the TT2. If I am using an iPod for a source as well as Pandora or Spotify using the iPad will this be a waste of money for this amp/DAC upgrade from the Qutest?

 

[hypnos1]

OK...wallet battered, and m-scaler ordered...guess I'll have to plead the current situation as culprit if (when!) the better half finds out. On second thoughts, ignorance can indeed be bliss(?!).

So, someone please reassure me there'll be a soft landing when I finally hit the bottom of this rabbit hole lol ...(methinks I'm going to need an extra dose of TT2 tonight to prepare me for blissful sleep!).

 

[jcn3]

I currently have a Qutest paired with GSX Mini and Cavalli LP. I am using the latest 7th gen iPod Touch but do have the latest iPad. HP are Empy and ZMF Verite open. I like the Qutest but was thinking of moving up to the TT2. If I am using an iPod for a source as well as Pandora or Spotify using the iPad will this be a waste of money for this amp/DAC upgrade from the Qutest?

given the quality of the rest of your amps and headphones, i think you should improve your source first and think about using qobuz or tidal for their high quality streaming (16/44 or better).

 

[JM1979]

I currently have a Qutest paired with GSX Mini and Cavalli LP. I am using the latest 7th gen iPod Touch but do have the latest iPad. HP are Empy and ZMF Verite open. I like the Qutest but was thinking of moving up to the TT2. If I am using an iPod for a source as well as Pandora or Spotify using the iPad will this be a waste of money for this amp/DAC upgrade from the Qutest?

You have all that great gear; feed it with a better source whether you stay with the Qutest or upgrade to a TT2.

All the chord dacs I’ve had (mojo, Hugo 2, Qutest, TT2) all perform so much better with better sources.

 

[nwavesailor]

Thanks @JM1979 and @jcn3.
I will look into qobuz or tidal using my iPad.
@JM1979 does the TT2 pair well with your VC and are you using the amp section of the TT2?