Question regarding amp/dac power ratings

[Stipes90]

Hi guys, beginner audiophile here.

I've just ordered a hd58x and I bought a Meizu HiFi Pro DAC/AMP to go with it.

The specs on the meizu say this:
Output power - 30mW 2 channel @ 32ohms and 6.7mW 2 channel @ 600ohms

What does this mean exactly? Given the impedance on the hd58x is 150ohms and the efficiency is 96dB/mW. Will this dongle drive the 58x's to their full potential, over a desktop dac/amp like the E10K?

 

[0bs3rv3r]

If you get 96dB from 1mW from your phones then you don't need many milliwatts for a very loud sound. You are going to get somewhere between 6.7 and 30mW from that amp, so you have plenty.

 

[Stipes90]

So the meizu pro will definitely do the job for the hd58x? And I don't need a desktop dac/amp like the Fiio E10K or soundblasterx g6?

I'm going to use it mainly for PC gaming on windows 10

 

[Veri]

So the meizu pro will definitely do the job for the hd58x? And I don't need a desktop dac/amp like the Fiio E10K or soundblasterx g6?

The meizu should do fine for the easy-to-drive hd58x. However a desktop PC is not the most favourable host for a mobile-size dongle in terms of power and noise. Perhaps consider the hidisz S8 which has better noise rejection:
https://www.audiosciencereview.com/...dizs-s8-usb-c-headphone-adapter-review.10823/

Or you could start with the $8 apple usb-c adapter and see how it does it's only 8 dollars.

 

[Stipes90]

The meizu should do fine for the easy-to-drive hd58x. However a desktop PC is not the most favourable host for a mobile-size dongle in terms of power and noise. Perhaps consider the hidisz S8 which has better noise rejection:
https://www.audiosciencereview.com/...dizs-s8-usb-c-headphone-adapter-review.10823/

Or you could start with the $8 apple usb-c adapter and see how it does it's only 8 dollars.

Hmm maybe I didnt make the best purchase. Guess I'll have to test it out when it arrives.

 

[Veri]

Hmm maybe I didnt make the best purchase. Guess I'll have to test it out when it arrives.

I didn't want to worry you, I use a meizu dongle at work all the time! The cheaper $22 one it could be absolutely fine

 

[Stipes90]

I didn't want to worry you, I use a meizu dongle at work all the time! The cheaper $22 one it could be absolutely fine

I hope its fine!

 

[solderdude]

27mW in 150 Ohm. You can reach 110dB peaks without clipping so good for about 90-95 Phon.
This is pretty loud.

 

[Stipes90]

27mW in 150 Ohm. You can reach 110dB peaks without clipping so good for about 90-95 Phon.
This is pretty loud.

Where did you get this information from? And whats Phon?

 

[solderdude]

Calculated the data. Easy to do when one knows the output powers in 2 impedances and knows what it means.
Phon is sort of dBA but corrected for human hearing.
dB doesn't quite telll the same story as Phon.
We hear in Phon, not in dB when it comes to lower frequencies (bass and lower mids)

 

[Stipes90]

Calculated the data. Easy to do when one knows the output powers in 2 impedances and knows what it means.
Phon is sort of dBA but corrected for human hearing.
dB doesn't quite telll the same story as Phon.
We hear in Phon, not in dB when it comes to lower frequencies (bass and lower mids)

Care to explain how you worked it out?

 

[Jimbob54]

Hmm maybe I didnt make the best purchase. Guess I'll have to test it out when it arrives.

Ive replied to you on the Meizu thread. Given what others more knowledgeable say here, ignore my latter suggestions- the Meizu should be fine. For the cost, just get one and see. But like I said, dont expect "night and day" from any new kit over a functioning existing set up. Didnt realise you werent in posession of the 58x yet, why dont you just see how perform from PC directly?

 

[solderdude]

Care to explain how you worked it out?

You calculate the output voltage at 600 Ohm (a given) = 2V
One reasons 150 Ohm ensures current limits aren't reached so 2V in 150Ohm = 27mW

Efficiency: 96 dB/1mW (104dB/1V) so 2V is 6dB above 104dB = 110dB peak levels.
when considering DR of well recorded music is around 15dB this means 95dB average dBSPL so roughly somewhere between 90 and 95Phon with average music.
In other words fairly loud.

 

[Stipes90]

You calculate the output voltage at 600 Ohm (a given) = 2V
One reasons 150 Ohm ensures current limits aren't reached so 2V in 150Ohm = 27mW

Efficiency: 96 dB/1mW (104dB/1V) so 2V is 6dB above 104dB = 110dB peak levels.
when considering DR of well recorded music is around 15dB this means 95dB average dBSPL so roughly somewhere between 90 and 95Phon with average music.
In other words fairly loud.

The Meizu Pro's Vrms is 1.75 though, does that make a difference?

 

[ZolaIII]

You calculate the output voltage at 600 Ohm (a given) = 2V
One reasons 150 Ohm ensures current limits aren't reached so 2V in 150Ohm = 27mW

Efficiency: 96 dB/1mW (104dB/1V) so 2V is 6dB above 104dB = 110dB peak levels.
when considering DR of well recorded music is around 15dB this means 95dB average dBSPL so roughly somewhere between 90 and 95Phon with average music.
In other words fairly loud.

When you get in consideration; DSD, EQ, possibly replay - gain and dialing it down 3 dB it comes short.

 

[solderdude]

The Meizu Pro's Vrms is 1.75 though, does that make a difference?

6.7mW into 600 Ohm = 2,00 V
30mW into 32 Ohm = 1V = 30mA

So either their power ratings are too optimistic (not unheard of ) or the 1.75V is incorrect.

let's suppose it is 1.75V = 1.16dB less output.