Connecting headphone amp to device with no fixed line out

Tony212

Active Member
Some amps and preamps have no on-board headphone amp, e.g. NAD M10 and M12. These two examples also don't provide a fixed level line out, so the only option is to use the analogue pre-out to feed an external headphone amp, possibly with a Y connector if you're feeding active speakers as well.

In this case (or when you simply want to improve headphone listening with an external amp that's better than the one built in) is the usual method to turn the external headphone amp volume to maximum and use the source amp's volume control?

I've seen comments that doing this can increase the noise floor, affecting the quality of the headphone audio, but I can't think of another way to do it.
 

gibbsy

Moderator
If the amp has a record loop then that is the connection to go for which is a fixed gain and the volume is controlled by the headphone amp. Some amps, my Rega Elicit-R as an example, do have a dedicated fixed gain line out for headphone amps. The NADs are different and just have a pre-out which makes connecting a headphone amp somewhat difficult.
 

wine man

Active Member
When I tried connecting my Teac headphone amp to a spare pre out on my Chord preamp it caused distortion in the headphones, I assumed it was over driving the Teac. Running the Teac from the tape out connection is fine however.
 

Tony212

Active Member
Thanks both. I'll look for devices with a fixed gain analogue output (eg Anthem STR) or digital out. At least the NAD M12 preamp has a digital out, so I could connect it to an external DAC/headphone amp. I'm looking for a preamp for active speakers, but a headphone facility is also important.
 

gibbsy

Moderator
external DAC/headphone amp
Would certainly solve a lot of problems for you. Plenty of good DAC/amp combinations available. How deep are your pockets?
 

Tony212

Active Member
Would certainly solve a lot of problems for you. Plenty of good DAC/amp combinations available. How deep are your pockets?
Well I wish they were deeper, but I can factor in another £300 for an external DAC/amp, which would cover the likes of Ifi Zen, Pro-ject etc, which is fine for now.
 

gibbsy

Moderator
What headphones do you have?
 

Tony212

Active Member
What headphones do you have?
Sony WH-1000XM4 Bluetooth. I intend to keep them just for the phone as the LDAC streaming and ANC works well, and when I can afford it, buy some decent open back HiFi cans for hard wired listening at home.

Since starting this thread I've had a look around and and I think for the preamp it could be a toss up between the NAD M12 which has a digital out, requiring a DAC amp for headphone use, and the Anthem STR which has no digital out but does have a fixed level analogue out, therefore just requiring an analogue headphone amp. The Anthem will probably win due to its room correction.

The NAD C658 preamp also has a lot to offer but I'm told that the built-in headphone amp is pretty average. It doesn't have digital or fixed level outputs to be able to use an external amp, so its back to square one.
 

gibbsy

Moderator
I had no choice as there is no headphone amp with my Rega Elicit. I decided to invest in a good headphone amp as I listen to most of my music on headphones. A quality headphone amp will almost always beat that fitted to amps.
 

Tony212

Active Member
Especially as a lot of amps just take their headphone feed from the speaker output, with a resistor or two to adjust the impedance.
True. It surprises me that so few amps or preamps anticipate the use of an external headphone amp by installing a 'tape out'/fixed line level, especially when there isn't a headphone feed on board.
 

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