Hugo TT 2 by Chord Electronics - The Official Thread

[GoldenSound]

Chord’s DAC’s do not have an amplification stage

Chord DACs do have an output stage.

Rob Watts has also talked about the output stage design a few times:

When you add an amp to it, you are just adding colouration and distortion without much gain

Not necessarily. Running off the outputs directly is not necessarily the cleanest way to do things.

For example using the DAVE into a high quality external amp and running the headphones off that provides lower distortion for many headphones than running off the headphone amp in the DAVE.
I actually measured this a while back in a similar discussion, will see if I can dig those tests up

 

[kkrazik2008]

This is simply not true, as Chord’s DAC’s do not have an amplification stage and the volume adjustment is done on the DAC directly and you are listening direct from the DAC’s output. This is Rob Watt’s custom FPGA design and they do not use any off-the-shelf chips.

For the vast majority of headphones, except maybe a handful of very hard to drive ones, the TT2’s output will give enough power to drive them to ear bleeding levels. When you add an amp to it, you are just adding colouration and distortion without much gain. Of course some people prefer a particular kind of colouration and that’s okay, but most people will find the reduced transparency not worth the money and efforts.

I’m quite familiar with the TT2’s headphone output, I own one and use it in conjunction with multiple amplifiers for speakers and headphones. Both methods work well, there is no right or wrong approach only preference.

You should look into the design more closely, the FPGA is not producing the amplifier output but rather the output stage as described here on the TT2 webpage:

“A brand new high-power discreet output stage coupled with second-order noise-shaping integrated between the DAC output and filter is also employed to massively reduce distortion. Further improvements have also been made to the power delivery. Hugo TT 2 eschews the Li-Po battery power supply of the original and ushers in six super capacitors capable of delivering huge, linear dynamic currents when the music demands it with peak output of 5A, 9.3V RMS.”

To be clear I’m not speaking on the DAC chip or module, but rather a DAC as a component. Also the person I was responding to used the double amplifier description, though I appreciate your counter argument.

 

[kkrazik2008]

Chord DACs do have an output stage.



Rob Watts has also talked about the output stage design a few times:




Not necessarily. Running off the outputs directly is not necessarily the cleanest way to do things.

For example using the DAVE into a high quality external amp and running the headphones off that provides lower distortion for many headphones than running off the headphone amp in the DAVE.
I actually measured this a while back in a similar discussion, will see if I can dig those tests up

Thank you @GoldenOne for cutting through the cheese, my attempt was rookie level.

 

[Reactcore]

Chord DACs do have an output stage.

Yeap.
Any transistor can be seen as an amp. As they translate a small signal to a bigger one. Either in voltage or current.
Dave, as most DAC's, have them in their analog section.

Its the last transistor in series with the load (in this case headphones) that does the heavy lifting for that load. (Dave's class AB has 2 transistors in series)

But this last transistor is most dependent on its power supply as any weakness in stabillity of its voltage will directly translate to output distortion.

By using an external amp the headphone load is not on Dave's last transistors anymore but shifted to that amp.

Some dedicated amps have an advantage as they deploy more stable voltages vs Dave's PSU, but indeed will bring a small loss in transparency as the signal needs to run through quite some more components and interlink cables. But the better drive capabillity can outweigh the transparency loss.

This is why i focussed to improve Dave's power feed to its amp section, to keep both benefits.

 

[rkt31]

tried fiio ft3 with tt2 +hms few days back vs mojo 2. tt2+hms obviously ahead in terms of imaging and depth but then you lose the advantage of eq with tt2. to me fiio ft3 needs one or two click down at 20khz to deal with most commercial recordings. with very clean recordings fiio ft3 with tt2+hms is like the complete end game set up. i could barely go beyond -18L or -17L with most recordings. so tt2 in low gain out of headphone se out is enough and the cleanest way to drive headphones imo.

 

[rkt31]

there used to be debate over tt2's low vs high gain. to me low gain sounded slightly better while many others found high gain to be punchier and more dynamic etc etc. there is a graph in asr measurements of power in low gain v high gain where for the same power low gain has slight advantage in s/n. so if someone doesn't need too much power, imo stick to low gain.

 

[Amberlamps]

W.T.F, the TT2 thread is on page 2, surely something must be wrong ?

Well, it’s now back on page 1

 

[AnalogEuphoria]

Low activity in the chord threads lately, everyone enjoying listening?

 

[Nisachar]

Low activity in the chord threads lately, everyone enjoying listening?

All the time. TT2 is

 

[rkt31]

Some facts about tt2 which people get wrong. (1) high gain is cleaner, in actuality low gain has slight advantage. (2) xlr is less refind than se. In actuality xlr is better because of noise cancelling advantage and also due to the fact that negative out is same as positive out in xlr as both negative and positive are exactly identical. (3) any high impedance headphone requires only higher voltage not higher current. In fact as the impedance increases there is less current required for same output power. So you are ok with higher impedance even in low gain as long as you are not maxing out on volume. You need enough current supply which tt2 has in plenty.

 

[Nisachar]

Some facts about tt2 which people get wrong. (1) high gain is cleaner, in actuality low gain has slight advantage. (2) xlr is less refind than se. In actuality xlr is better because of noise cancelling advantage and also due to the fact that negative out is same as positive out in xlr as both negative and positive are exactly identical. (3) any high impedance headphone requires only higher voltage not higher current. In fact as the impedance increases there is less current required for same output power. So you are ok with higher impedance even in low gain as long as you are not maxing out on volume. You need enough current supply which tt2 has in plenty.

Point 2: does it make sense to use the XLR out then for headphones ?

 

[rkt31]

Point 2: does it make sense to use the XLR out then for headphones ?

Only when you need to drive very low sensitivity headphones. For most headphones se output is sufficient. If you try to use xlr out for headphones, be careful with adapters. Leave the sleeve unconnected if using balance cable. When you don't need higher output but still using xlr out, you will operate tt2 at 6db lower volume setting as xlr has double the se voltage ie 4x the power for the same volume setting, which will cause unnecessary attenuation. So with my experience use tt2 in low gain with se headphone out, even with power hungry or inefficient headphones, as long as you don't clip or maxing out in volume setting. Tt2 is capable of very clean power and current delivery right upto just before clipping, irrespective of load impedance.

 

[TheMiddleSky]

Low activity in the chord threads lately, everyone enjoying listening?

So far so good, I plug to my tube amp more frequent than direct TT though.

(2) xlr is less refind than se. In actuality xlr is better because of noise cancelling advantage and also due to the fact that negative out is same as positive out in xlr as both negative and positive are exactly identical.

Well, the final result may depend on the topology for amp input as well.

In my case with Ultrasonic Oblivion, a SE input amp, but also has XLR input for convenient, TT2 with RCA is definitely better sounding.

In other case, with Cen.Grand Silver Fox, that convert any SE input turn into Balance Signal (internal process in Silver Fox), I can see why some people prefer XLR output of TT2.

It's good to have both option indeed.

 

[STR-1]

Received email from Chord today saying that because of improvements in the supply chain, with many components returning to pre-Covid prices, they are able to reduce prices on the following products:

Mojo 2……….Reduced by £100
Poly…………Reduced by £100
Qutest………Reduced by £200
Hugo TT2………Reduced by £1000
Hugo M Scaler……Reduced by £700

 

[CaptainFantastic]

Walking back those ridiculous price increases. I gather the TT2 wasn't exactly flying off the shelves.