[ExpatinJapan]

I'm looking for the output from the original version not V2.

First hit on Google

V1

 

[Sefelt103]

Is it possible to calculate the output in mW at medium gain (single ended) for a 300ohm headphone from this ?

 

[HeadphoneAddict]

I'm looking for the output from the original version not V2.

Okay. I know from experience that the M8 V1 has plenty of power for my HE600/6XX/800. Going from memory years ago I recall someone saying it's around 75 mW max power into 300 ohms. I found a couple of good reviews below of the M8 V1, but Tyll Herstens at InnerFidelity didn't test past 150 ohms. His testing showed 600 mW into 32 ohm and 160 Mw into 150 ohm, with a output voltage of 5v (10 peak to peak). We know the M8 V1 is pretty strong when driving 300 ohm headphones. I don't know much about 600 ohm ones (Beyer Dynamic only?). See

https://www.innerfidelity.com/conte...n-centrance-hifi-m8-portable-headphone-ampdac
"THD+Noise vs. Output Vrms shows an amp with reasonably low distortion, but having very high output power and voltage capabilities."

https://www.cnet.com/news/raising-t...hifi-m8-digital-converterheadphone-amplifier/
"The HiFi-M8 is the best sounding all-in-one portable digital converter/headphone amp the Audiophiliac has ever tested... ...My high-impedance (250 ohms) Beyerdynamic T70 is another headphone that isn't at its best with phones or iPods, but the HiFi-M8 allowed them to really strut their stuff. The T70 can sound thin at home with some AC-powered headphone amps, but with the HiFi-M8 they sounded sweet! With the amp's bass boost switch in the mid position the T70 delivered remarkably solid, very deep bass. These headphones never sounded better."

Also, According to Tyll's measurements at http://www.innerfidelity.com/images/SennheiserHD600.pdf you need 0.230Vrms for 90dB = 102.7dB/1V. Likewise, you need 0.17mW for 90dB = 97.7dB/mW. So, the M8 V1 into a 300 ohm HD600 could hit over 121dB in volume. Note - the M8 V2 has double the voltage swing of the M8 V1.

EDIT - Lastly, the claimed 1.4W total in the V1 specs posted above was both channels driven, and Tyll measured 1.2W max total driven at 32 ohm.

 

[Sefelt103]

Thanks for the info. HeadphoneAddict

 

[goldgears55]

For V1, when we plug optical cable to input 3.5mm plug ,then what’ switch signal selection I should use , go left , right or center. I try to select all positions but it’s not work, any advice?

 

[Sefelt103]

Left is usb type B female (for PC) and right is optical (female). Centre is power off. The battery state should be indicated in left/right position (the same battery state). The optical cabe (male to male) should connect direct to a device with optical output or a dock with optical output. 3.5mm is for analogue and therefore won't work. The rear panels of Centrance only take digital/optical input and not analogue.

 

[goldgears55]

Left is usb type B female (for PC) and right is optical (female). Centre is power off. The battery state should be indicated in left/right position (the same battery state). The optical cabe (male to male) should connect direct to a device with optical output or a dock with optical output. 3.5mm is for analogue and therefore won't work. The rear panels of Centrance only take digital/optical input and not analogue.

Thanks a lot for your advice. But it’s still not work. Please see pictures below for the set up.

 

[goldgears55]

Thanks a lot for your advice. But it’s still not work. Please see pictures below for the set up.

I play song from PC. So the optical cable come out from PC to the M8.

 

[elira]

Thanks a lot for your advice. But it’s still not work. Please see pictures below for the set up.

I believe the version you have doesn't include optical input.

 

[goldgears55]

I think it’s came with optical input feature. I bought from Jaben in Singapore in 2014. But I never try that feature until now.

 

[ExpatinJapan]

hifi- m8 versions



Usb-A version



optical version

note: on the front is a 3.5mm/ optical OUT port. Sendingsignal to headphones or into an amp, home system etc



on the back is the optical IN



computer to - usb cable - to one of the ports at the back - headphones out the front
....should work.

 

[goldgears55]

hifi- m8 versions



Usb-A version



optical version

note: on the front is a 3.5mm/ optical OUT port. Sendingsignal to headphones or into an amp, home system etc



on the back is the optical IN



computer to - usb cable - to one of the ports at the back - headphones out the front
....should work.

Thanks a lot. That mean my version is not optical input(only optical output) as of 4XL version that is no optical port at the back.

 

[doctorjazz]

That usb in is difficult, what cable would work from a PC?

 

[MikeyFresh]

.

 

[doctorjazz]

Is that, ahem, audiophile enough...?