NAD 7140 and 600ohm headphones

[Deafdog68]

Hi, can anyone state that the NAD 7140 receiver will drive 600ohm headphones? I do not want to buy a pair and find they don't work or suffer very low volume. Any advice appreciated.

 

[nopiano]

Eventually I found a manual for it. The spec includes this:-

Phones: >10V into 600 ohms.

It might not quite blow your head off but it surely will be fine?!

https://nad.manymanuals.com/receivers-and-amplifiers/7140/user-manual-24460/3

 

[Gray]

It might not quite blow your head off

...you'll be pleased to know 😆

 

[Jasonovich]

...you'll be pleased to know 😆

 

[Deafdog68]

Eventually I found a manual for it. The spec includes this:-

Phones: >10V into 600 ohms.

It might not quite blow your head off but it surely will be fine?!

https://nad.manymanuals.com/receivers-and-amplifiers/7140/user-manual-24460/3

thanks nopiano... i am totally oblivious to all the technical stuff re hifi but as long as they will produce enough volume to listen to that will be great... 🙂

 

[Vincent Kars]

Manual says output impedance of the phones is 220 Ohm. A damping ratio of 8 is recommended as a bare minimum. So you need a 1760 Ohm headphone impedance?

Phones: >10V into 600 ohms.

Manual also says >500 mV into 8 Ohm. If the impedance drops, the voltage drops too????
Wonder if this manual is correct and if it is, you better buy a decent headphone amp (impedance well below 1 Ohm)

 

[nopiano]

Manual says output impedance of the phones is 220 Ohm. A damping ratio of 8 is recommended as a bare minimum. So you need a 1760 Ohm headphone impedance?

Manual also says >500 mV into 8 Ohm. If the impedance drops, the voltage drops too????
Wonder if this manual is correct and if it is, you better buy a decent headphone amp (impedance well below 1 Ohm)

Well, I did check the 600 ohm requirement, and found 8volts was a suggested minimum. Hence I concluded 10volts should be fine.

I didn’t look at the rest tbh, as I always find it confusing how volts and watts are used almost at random in headphone specs.

 

[Deafdog68]

Thanks all..maybe I will go with 250ohm phones... 🙂

 

[Gray]

Thanks all..maybe I will go with 250ohm phones... 🙂

My Sennheiser HD-560S are a good compromise of 120 ohms - working well direct from a phone, laptop or from headphone amplifiers.
(At full (£169) price they're a bargain - but currently available for £99).

When reading through the specifications, for what it's worth, note the quoted sensitivity figure.
Sennheiser quote 110dB at 1v for mine for example.
Nobody should ever want to exceed 80dB for long-term headphone listening - ideally MUCH lower to preserve hearing.

 

[Deafdog68]

thanks all...this HiFi lark is very complicated..i wish i had not destroyed my hearing doing terrible Hendrix impressions when I was younger then i could buy any amp and any headphones and enjoy music

 

[nopiano]

thanks all...this HiFi lark is very complicated..i wish i had not destroyed my hearing doing terrible Hendrix impressions when I was younger then i could buy any amp and any headphones and enjoy music

As @Gray implied, it is not simply about the impedance, because more sensitive phones will be louder than less sensitive ones. Many retailers will let you try in store, or return unsuitable items. Check their T&Cs.

I’m not a massive headphone user, but in my limited experience the issues arise mostly with trying to plug serious hifi stuff into mobilephones or weedy portables. The NAD probably uses the speaker output padded down for the headphone socket and will be more than enough. And you could always add a dedicated headphone amp if your perfect cans weren’t loud enough.