Focusrite 18i20 headphone output impedance? Should I buy a headphone amp??

stratmaster713

New member
been reading about how much of a difference a headphone amplifier makes. It makes sense how much a dedicated headphone amp can make compared to a computer soundcard but what about a Focusrite 18i20? Would buying a headphone amplifier really improve the sound quality of my headphones?? I currently use Sennheiser 280's (will probably soon upgrade to 600's or 650s later this year). I cannot find a spec on what the Focusrite 18i20 headphone output impedance is... I read if the output impedance of the source supplying the headphone is 1/10th the value of the headphone impedance, then you should be good to go. These sennhesier 280's are 64 ohms so I am curious if the Focusrite 18i20 headphone output impedance is <6.4 ohms??

Should I get a headphone amp?
 
been reading about how much of a difference a headphone amplifier makes. It makes sense how much a dedicated headphone amp can make compared to a computer soundcard but what about a Focusrite 18i20? Would buying a headphone amplifier really improve the sound quality of my headphones?? I currently use Sennheiser 280's (will probably soon upgrade to 600's or 650s later this year). I cannot find a spec on what the Focusrite 18i20 headphone output impedance is... I read if the output impedance of the source supplying the headphone is 1/10th the value of the headphone impedance, then you should be good to go. These sennhesier 280's are 64 ohms so I am curious if the Focusrite 18i20 headphone output impedance is <6.4 ohms??

Should I get a headphone amp?

A couple of years ago I had the Beyerdynamic T1 headphones and an RME Fireface UFX. I picked up the Beyerdynamic A1 headphone amp but it really didn't make much difference, if any at all.

I would definitely not recommend spending money on a dedicated headphone amp unless you need more headphone outputs or if you don't get enough volume.
 
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A couple of years ago I had the Beyerdynamic T1 headphones and an RME Fireface UFX. I picked up the Beyerdynamic A1 headphone amp but it really didn't make much difference, if any at all.

I would definitely not recommend spending money on a dedicated headphone amp unless you need more headphone outputs or if you don't get enough volume.

Thanks.

As far as headphone upgrade from Sennheiser 280, what would you suggest? I mostly do rock/blues music.
 
The output impedance of a headphone amplifier is usually around 100Ohms and purely resistive.
This is because the amplifiers are either dedicated "mini power amps" or op amps current boosted by a pair of 1W transistors. In both cases the amplifiers would be required to drive headphones from the hugely silly 8 Ohms Z to the eminently practical 600Ohms of professional grades. They do this by simply " slugging" the output with a resistor, usually 100R but can be as low as 33R.

"But what about damping" you cry? All bollox. Headphones all have a DC resistance very close to their nominal impedance . In fact my Sennheiser HD448s measure 33 Ohms but are nominally 32 Ohms!

There would obviously be no point in having an amp with a damping factor of 1000 if the cans inserted at least 33 Ohms!

External headphone amps can be a good idea since many otherwise exemplary interfaces have weak HP amps but this is due in part to the limited power that can be drawn from USB 2.0. Wither USB 3.0 inter faces? Let's USE that extra 2 watts!

Dave.
 
I just added a bulky old SONY home hi-fi amp because my 1641 headphone out was so low.
Some interfaces don't have a lot of juice, however the low output prevents from 12hrs of ear ringing later too... but its often the interface headphone out is just weak. a used headphone amp is usually around $60-$40 used, and they do have a nice gain, the behringer one I bought used is really decent. its n another room though.
 
Thanks.

As far as headphone upgrade from Sennheiser 280, what would you suggest? I mostly do rock/blues music.

If you're just using them for tracking, I see no point in upgrading. If you're mixing through them, I wouldn't bother upgrading either. I'd rather save up for monitors and room treatment. Mixes probably won't get much better even with better headphones. I tried mixing through the T1 but it still sounded like shit once I listened to the mixes through speakers.

If you're listening to music for pleasure on the other hand, you might want to look at the HD650 or the Beyerdynamic T70 or T1, depending on budget. I don't have the T1s any more but they were pretty awesome.

You should not need a dedicated headphone amp for sound quality.
 
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