Do all DACs need a headphone amplifier?

[tomli747]

It seems advantages of using a headphone amplifier are more power and lower output impedance.

If a DAC has low output impedance and sufficient volume for high impedance headphones,
does it need a headphone amplifier?

Will I get any benefit or just more distortion?

 

[solderdude]

There is another aspect at play here.
Not just output voltage under a light load and low output impedance.
That DAC would also need to be able to provide enough current.

It is very easy to build a DAC output stage with close to 0 Ohm output resistance yet may only be able to provide 40mA or so.
Enough for high efficiency headphones but may be under powered for some other low impedance headphones.

When your DAC sounds fine and loud enough on your headphone(s) you don't need an amp.

 

[amirm]

The general rule is that it won't work well unless shown otherwise.

 

[twsecrest]

It seems advantages of using a headphone amplifier are more power and lower output impedance.
If a DAC has low output impedance and sufficient volume for high impedance headphones,
does it need a headphone amplifier?
Will I get any benefit or just more distortion?

If a DAC has a built in headphone jack and can drive high impedance headphones, it means it already has a built in headphone amplifier.

 

[tomli747]

I have the chord mojo and want to upgrade my setup.
According to the review, it has low output impedance and can drive the HD650 well.
Is adding a headphone amplifier useless in this case?

 

[amirm]

Likely so.

 

[Roen]

I have the chord mojo and want to upgrade my setup.
According to the review, it has low output impedance and can drive the HD650 well.
Is adding a headphone amplifier useless in this case?

What do you want out of your setup?

 

[Headphonaholic]

I have the chord mojo and want to upgrade my setup.

The Chord Mojo has a headphone amplifier built in... do you need more power than it provides?

 

[tomli747]

I posted this because I bought the THX AAA 789 amp and found no difference when I conpared Mojo+HD650 and Mojo+THX+HD650.
Should I get a better DAC such as Topping D50?
Or the Mojo is good enough?

 

[Jorj]

I posted this because I bought the THX AAA 789 amp and found no difference when I conpared Mojo+HD650 and Mojo+THX+HD650.
Should I get a better DAC such as Topping D50?
Or the Mojo is good enough?

I have tested the same setup, and concluded that the Mojo all alone is sufficient and subjectively indistinguishable from the DAC+789 combo.

That said, I don't use the Mojo on my desk since it is battery powered and I reserve it for portable outings with more power-hungry cans like HD800 and HD6xx. My desktop rig is set up for convenience with PC sourced music and has balanced interconnects because of all the EMI sources on my desk, which I can clearly hear intermittently buzzing and hissing through the Mojo (but only with super efficient IEMs). Personally, I like having the remote for the DX7 which makes the occasional fiddling with settings easier.

 

[Roen]

I posted this because I bought the THX AAA 789 amp and found no difference when I conpared Mojo+HD650 and Mojo+THX+HD650.
Should I get a better DAC such as Topping D50?
Or the Mojo is good enough?

A Mojo isn’t a DAC.

It’s a DAC / Amp.

You basically added an Amp after an existing Amp. As the THX is transparent, it’s not surprising you hear no difference.

My Topping D50 is an example of a solo DAC.

 

[tomli747]

A Mojo isn’t a DAC.

It’s a DAC / Amp.

You basically added an Amp after an existing Amp. As the THX is transparent, it’s not surprising you hear no difference.

My Topping D50 is an example of a solo DAC.

I noticed that after reading the review of Mojo.
But I had bought the THX at that time.

Is a DAC like D50 + THX amp noticeably better than Mojo?

 

[garbulky]

I used to think that any DAC amp combo was not worth the salt for high impedance headphones. But my experience with the Mytek Liberty changed that. It did very well with the HD650.

 

[Jorj]

Is a DAC like D50 + THX amp noticeably better than Mojo?

Audibly better? Not unless:

1. Your ears are as good as Michael Fremer claims his to be, or
2. You listen at ear-health detrimental levels (which Mojo might struggle with driving some cans), or
3. You've come to terms with the reality that what you think you are going to hear is what you actually perceive.

If you're looking to save money, the Mojo you already have is just fine. It does not have as much power and suffers a tiny little bit from measurement envy compared to the THX 789. Adding the D50 would not be crazy, but you'd have a very hard time hearing the difference between the D50+THX 789 and the Mojo. This is not my opinion, it is the objective analysis of the measurements we've been able to lay hands on, many of them kindly provided by @amirm.

 

[tomli747]

TBH, I want a DAC because I don't want the THX amp being "wasted".
Of course it should be better than the Mojo at least.

I used to think that any DAC amp combo was not worth the salt for high impedance headphones. But my experience with the Mytek Liberty changed that. It did very well with the HD650.

That's a bit too expensive, I'm considering Topping D50 or SMSL SU-8 now, both are below USD200 in my country.
Any recommendation below USD300 would be appreciated.

Adding the D50 would not be crazy, but you'd have a very hard time hearing the difference between the D50+THX 789 and the Mojo.

How about the SMSL SU-8? It has balanced output and have better measurements than D50.
Or I need a much more expensive DAC to hear any difference?

 

[garbulky]

TBH, I want a DAC because I don't want the THX amp being "wasted".
Of course it should be better than the Mojo at least.


That's a bit too expensive, I'm considering Topping D50 or SMSL SU-8 now, both are below USD200 in my country.
Any recommendation below USD300 would be appreciated.


How about the SMSL SU-8? It has balanced output and have better measurements than D50.
Or I need a much more expensive DAC to hear any difference?

I have not used the systems you mentioned.

I use the Emotiva Basx A-100. It sounds amazing with my HD600 and HD6xx in direct drive mode (jumpers engaged, resistors bypassed). It costs about $200. It has a huge amount of power in direct drive mode.
Chord pushes out about 70 mwatts @ 300 ohms for your hd650.
The A-100 pushes a silly 1300 mwatts @ 300 ohms.
You probably don't need all that much power but that is its claim to fame.

Disadvantages: . Compared to the Mojo, it's a lot bigger and heavier. It's a small speaker amp. So it's not really portable. It sits on your desk. In direct drive mode, the noise floor is increased so there is a slight hiss on silence, not noticeable during music. Without the jumpers put in, there is no hiss but the sound isn't quite as nice to me. The A-100 doesn't come with a DAC so you have to factor that in if you don't have one.

 

[Jorj]

How about the SMSL SU-8? It has balanced output and have better measurements than D50.
Or I need a much more expensive DAC to hear any difference?

The SU-8 would be fine (make sure it is v2) if you want balanced outputs. Not gonna get into the real or imagined benefits of balanced, but it really costs so little to have it, so if you want it, it's just fine.

The Topping D10 is $75 on Massdrop and works just fine for a single-ended DAC.