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Topic: Driving 600 ohm headphones with an SPL Crimson (Read 11287 times) previous topic - next topic
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Driving 600 ohm headphones with an SPL Crimson

I have a pair of 600 ohm Beyerdynamic headphones.  I want to get a dedicated DAC/soundcard/whatever for the computer I will be using the headphones with.  However, it's not so easy driving these headphones.

O2 + ODAC
I have this very nice device that I love.  However, it can BARELY handle the headphones.  When it's all the way maxed out, it is just barely what I consider to be loud listening.  It's fine, but for a new purchase, I'd like a little bit of additional volume to spare for those moments when I want it to be a tad louder.

RME Babyface:
I also have this thing, which is very nice also.  However, same issue.  At the max volume (before clipping), it is again just barely loud enough.

Now I'm considering the SPL Crimson.  But I want to make sure it will be a little more powerful regarding the 600 ohm headphones specifically.  I'll also consider any kind of USB DAC.  I was considering the Schiit stuff, but there seems to be a fair amount of snake oil there, and I've been reading nwavguy's articles to really understand this stuff better.  So I'm not that comfy getting those kinds of DACs.  I like the Crimson for it's featureset, build quality, and routing/monitoring options.  And it seems like (correct me if I'm wrong) the sound for headphones from a Crimson should be just as good as the snake oil DACs.  However, I don't really know how to confirm these things.

Any advice is appreciated, thanks!

Driving 600 ohm headphones with an SPL Crimson

Reply #1 –
Quote from: superfoo on
Now I'm considering the SPL Crimson.  But I want to make sure it will be a little more powerful regarding the 600 ohm headphones specifically.


According to this page:

http://spl.info/de/produkte/interfaces/cri...sche-daten.html

Its output is 2.3 dB louder than the O2 running off of AC power.  Maybe a bit less depending on how they're defining "max" power. 

Driving 600 ohm headphones with an SPL Crimson

Reply #2 –
Quote from: saratoga on
Quote from: superfoo on
Now I'm considering the SPL Crimson.  But I want to make sure it will be a little more powerful regarding the 600 ohm headphones specifically.


According to this page:

http://spl.info/de/produkte/interfaces/cri...sche-daten.html

Its output is 2.3 dB louder than the O2 running off of AC power.  Maybe a bit less depending on how they're defining "max" power.

Thanks!  How did you get 2.3 dB, and is that a lot?  Sorry, i don't know how much louder that is!

For the O2, it says:
Max Output (600 Ohms)   88 mW

For the Crimson, it says:
Power max: 600 Ohm load: 150 mW

and for the Babyface, it says:
Maximum Output Level @ 0 dBFS Phones: +8 dBu

If only babyface had the same units, doh!  SO I can't tell.  Like I said, both the o2 and babyface can barely make the headphones what I'd consider loud.  The Crimson, if you go by mW, looks like it has almost twice the power of the O2.  Does that mean it is significantly louder?

Driving 600 ohm headphones with an SPL Crimson

Reply #3 –
150mW / 88mW ~ 1.7
log10(1.7) = 0.23, so it should be 2.3dB louder than O2.
If you want to check how much difference it makes you can play music in foobar and reduce volume with the slider, which shows you how many decibels it's limiting.

Which Beyers model is it?
For example DT880 has 96dB/mW sensitivity, and log10(88) is 1.94, so at full volume O2 can output 96 + 19 = 115dB which is about what you need for highly dynamic music.

Driving 600 ohm headphones with an SPL Crimson

Reply #4 –
Quote from: superfoo on
Sorry, i don't know how much louder that is!


Very slightly louder to not actually louder depending on how they're specing it.

Driving 600 ohm headphones with an SPL Crimson

Reply #5 –
Quote from: ieee754 on
150mW / 88mW ~ 1.7
log10(1.7) = 0.23, so it should be 2.3dB louder than O2.
If you want to check how much difference it makes you can play music in foobar and reduce volume with the slider, which shows you how many decibels it's limiting.

Which Beyers model is it?
For example DT880 has 96dB/mW sensitivity, and log10(88) is 1.94, so at full volume O2 can output 96 + 19 = 115dB which is about what you need for highly dynamic music.

Thanks.  I tested about 2-3 db difference with my current setup, and it's not that much.  It's sort of noticeable, but nothing to convince me to buy another piece of equipment.  Thanks for the calcs as well, that helps me compare products better.

So I think I found my answer!  I searched through these forums a bit, and it looks like the Headpod 4 from Aphex is going to be perfect for me!  They specifically claim volume is not a problem, they can handle headphones from 1-1000 ohms (beautiful!), it has 4 independent headphone jacks (awesome), and it even has 3 input options (sheesh!).  Seems like I'm not the only person to run into this issue, lol!

the specs:
max gain: 35 db
Input Z: Bal: 20kW / Unbal: 10kW
Output Z:   10W

I tell you, these specs are confusing, and I'm an electrical engineer!  But audio is a different animal it seems, I just need to understand these conversions and what they mean to my ear.  I never considered electrical engineering specs from an audio standpoint!

Driving 600 ohm headphones with an SPL Crimson

Reply #6 –
Quote from: superfoo on
So I think I found my answer!  I searched through these forums a bit, and it looks like the Headpod 4 from Aphex is going to be perfect for me!


According to the datasheet, thats much more quiet than the amps you already have.

Quote from: superfoo on
the specs:
max gain: 35 db
Input Z: Bal: 20kW / Unbal: 10kW
Output Z:   10W


None of those really matter here. 

Quote from: superfoo on
I tell you, these specs are confusing, and I'm an electrical engineer!


You're an electrical engineer?  Why are you asking the rest of us to apply ohms law for you...

Driving 600 ohm headphones with an SPL Crimson

Reply #7 –
Quote
I tell you, these specs are confusing, and I'm an electrical engineer! But audio is a different animal it seems....


max gain: 35 db - That's the voltage gain (~56).  At maximum gain, you put 1mV in and you get 56mV out. 


Input Z: Bal: 20kW / Unbal -  10kW -  Pro connections use balanced (3-wire) connections.  Home audio is 2-wire.    (Somehow the Omega symbol got turned into a "W"...  Normally W indicates Watts.)  10k or 20k Ohms is fine for any line-level connection or headphone output. 

Output Z: 10W  -  I assume 10 Ohms is the "source impedance".... The impedance "looking back into" the output.    This should be low relative to headphone impedance, and with 600 Ohm headphones it's not a spec to worry about.    (It's rare to have the source impedance published...  Usually they give you the "recommended minimum load impedance", if they give you anything at all.)


The important spec for you is the maximum output of +24dBu.  If I've done my math correctly, that's about 12VRMS.  (You might want to check my math.)

Driving 600 ohm headphones with an SPL Crimson

Reply #8 –
There is no info about output power of this amp also output impedance seems to be very high, it should be lower than 2 ohms if you want to use it with other headphones that might have lower impedance (like IEMs), for better damping factor.

Driving 600 ohm headphones with an SPL Crimson

Reply #9 –
Quote from: saratoga on
You're an electrical engineer?  Why are you asking the rest of us to apply ohms law for you...

Yea...I waited a few posts to say that, but it is kind of embarrasing.  And I've written books on the subject also  .

I'm just not getting the whole decibel, gain, volume, mixed with how to choose the right headphone.  I'm still reading all sorts of stuff on the web and you guys have been very helpful.  I'll post useful information as I come across it.

haha, this makes me feel better, I was just reading this on wikipedia:
Quote
According to several articles published in Electrical Engineering[27] and the Journal of the Acoustical Society of America,[28][29][30] the decibel suffers from the following disadvantages:

The decibel creates confusion.
The logarithmic form obscures reasoning.
Decibels are more related to the era of slide rules than that of modern digital processing.
Decibels are cumbersome and difficult to interpret.
Representing the equivalent of zero watts is not possible, causing problems in conversions.
Hickling concludes "Decibels are a useless affectation, which is impeding the development of noise control as an engineering discipline".[29]

Driving 600 ohm headphones with an SPL Crimson

Reply #10 –
Regarding the headpod, here are some screenshots from their marketing video that I felt were helpful regarding this kind of information:


Driving 600 ohm headphones with an SPL Crimson

Reply #11 –
The question here is why the O2 is not loud enough for you.

DT770-600 produces about 96 dB/mW. That is about 98 dB/V.
The ODAC outputs 2V. The standard O2 gain is 2.5x, so we get an output of max 5V.

So you should be able to reach 98+14 = 112 dB for a full-scale sine wave.


If you really want to go louder then you should aim at 10 dB more. That means a theoretical output of ~16V or over 0.4W into 600 ohm. Most headphone amps will not even get close to this.
So you might even want to try some power amp.

But: depending on the genre of music you're listening to, your hearing will be permanently damaged within minutes.

"I hear it when I see it."

Driving 600 ohm headphones with an SPL Crimson

Reply #12 –
Quote from: xnor on
The question here is why the O2 is not loud enough for you.

DT770-600 produces about 96 dB/mW. That is about 98 dB/V.
The ODAC outputs 2V. The standard O2 gain is 2.5x, so we get an output of max 5V.

So you should be able to reach 98+14 = 112 dB for a full-scale sine wave.


If you really want to go louder then you should aim at 10 dB more. That means a theoretical output of ~16V or over 0.4W into 600 ohm. Most headphone amps will not even get close to this.
So you might even want to try some power amp.

But: depending on the genre of music you're listening to, your hearing will be permanently damaged within minutes.

It is a good question, and one I have for myself.
Well, first thing I noticed was that for both the Babyface and the O2, I had to crank the knob to max to listen at my preferred volume.  Now, I had a similar discussion last year with someone, along the lines of "anything louder and it's bad for you".  I went to my doctor and got a hearing check, and everything was perfect, no loss of hearing from 10 years ago, and I've been listening to music at that volume and louder often.  So I feel my "comfort" level, whatever it is, is not too loud.

The other thing I noticed is substantial hissing when all these things were cranked to the max, even though the overall volume of the music wasn't that bad.  I don't mind the hissing, but I was wondering if I got a more powerful headphone amp, would I be able to avoid the hissing? 

The other thing is that I'd like to have some extra room on the volume/gain knob to go higher than usual.  Right now, I'm all maxed out.  I'm max on the headphone amp, I'm max on the windows volume driver setting, I'm almost max in whatever software I'm playing back with.  I just would feel more comfortable if I had some top room left.  I don't want everything maxed out and I feel like I'd still want a little more volume.  I want to be at that 50-75% range.

But I'll change my mind if there's a reason to.  I'm having a hard time figuring it all out, though.

Regarding the O2 and 600 ohm headphones...I forgot where I put the calculations, but when I was following some recommended formulas, it appeared to me that the O2 was just slightly underpowered for 600 ohm headphones.  However, on the internet, most people say that the O2 will drive the 600 ohm headphones perfectly fine.  But my experience matches my formula...that is, sure, it's loud enough to work with, but it's right on the edge and I swear I can use a tad more volume.

And cranking the knobs that final 10% increases the hissing a lot.  Let's say the knob goes from 1-10.  There's no hissing at 5, then by 7 it increases dramatically and does so continuously until 10.

Driving 600 ohm headphones with an SPL Crimson

Reply #13 –
And that is with the ODAC? That's weird, there shouldn't be much hissing if at all.. Maybe it's a hardware problem, but maybe even switching USB port helps.
If you have hissing problems with an O2 then I'm afraid that many other amps won't be much better in that respect, provided that there's nothing wrong with your hardware.

edit: Yeah, if you really want to stay in that volume control range (compared to your O2 maxed which I assume has 2.5x gain) you will need quite a bit higher voltage. As I've written above, those extra 10 dB would result in 16V, that is a 64W (into 4 ohm) power amp.
Wanting to stay at 50% volume you could even get a 100W amp...


I'm still surprised by this. Something seems way off.
"I hear it when I see it."

Driving 600 ohm headphones with an SPL Crimson

Reply #14 –
You are doing something wrong or something is broken.

Driving 600 ohm headphones with an SPL Crimson

Reply #16 –
Yeah... Btw, if you have hiss problems with a working O2 then be prepared for roughly 30-40 dB more noise from a power amp. 
"I hear it when I see it."

Driving 600 ohm headphones with an SPL Crimson

Reply #17 –
Quote from: superfoo on
Quote from: xnor on
The question here is why the O2 is not loud enough for you.

DT770-600 produces about 96 dB/mW. That is about 98 dB/V.
The ODAC outputs 2V. The standard O2 gain is 2.5x, so we get an output of max 5V.

So you should be able to reach 98+14 = 112 dB for a full-scale sine wave.


If you really want to go louder then you should aim at 10 dB more. That means a theoretical output of ~16V or over 0.4W into 600 ohm. Most headphone amps will not even get close to this.
So you might even want to try some power amp.

But: depending on the genre of music you're listening to, your hearing will be permanently damaged within minutes.

It is a good question, and one I have for myself.
Well, first thing I noticed was that for both the Babyface and the O2, I had to crank the knob to max to listen at my preferred volume.  Now, I had a similar discussion last year with someone, along the lines of "anything louder and it's bad for you".  I went to my doctor and got a hearing check, and everything was perfect, no loss of hearing from 10 years ago, and I've been listening to music at that volume and louder often.  So I feel my "comfort" level, whatever it is, is not too loud.

The other thing I noticed is substantial hissing when all these things were cranked to the max, even though the overall volume of the music wasn't that bad.  I don't mind the hissing, but I was wondering if I got a more powerful headphone amp, would I be able to avoid the hissing? 

The other thing is that I'd like to have some extra room on the volume/gain knob to go higher than usual.  Right now, I'm all maxed out.  I'm max on the headphone amp, I'm max on the windows volume driver setting, I'm almost max in whatever software I'm playing back with.  I just would feel more comfortable if I had some top room left.  I don't want everything maxed out and I feel like I'd still want a little more volume.  I want to be at that 50-75% range.

But I'll change my mind if there's a reason to.  I'm having a hard time figuring it all out, though.

Regarding the O2 and 600 ohm headphones...I forgot where I put the calculations, but when I was following some recommended formulas, it appeared to me that the O2 was just slightly underpowered for 600 ohm headphones.  However, on the internet, most people say that the O2 will drive the 600 ohm headphones perfectly fine.  But my experience matches my formula...that is, sure, it's loud enough to work with, but it's right on the edge and I swear I can use a tad more volume.

And cranking the knobs that final 10% increases the hissing a lot.  Let's say the knob goes from 1-10.  There's no hissing at 5, then by 7 it increases dramatically and does so continuously until 10.


It appears that your comments are conflating two independent issues being maximum output and SNR.

Given a high quality headphone amp like the O2, the most likely source of noise is the source, not the headphone amp.



The only active circutry in the O2 that is ahead of the gain control (VR1) is the NJM 2068D preamp which has low noise and low gain.

What effect does the gain switch on the O2 have on the hated noise?

What effect does disconnecting the input cable from the O2 have on the hated noise?

Driving 600 ohm headphones with an SPL Crimson

Reply #18 –
I tested the hissing at home again.  Both on the babyface and the O2.  I don't think it's really a problem.  It's the normal slight hiss you'd hear on any headphones/amp when you have maxed out the knobs.  It goes away quickly when it's lowered slightly.

I'm beginning to think it's just a question of power.  There's no straight or simple formulaic conversion from electronic circuitry to loudness.  I just need a little more juice.  I also am beginning to think I'm over complicating it.

Ohms law:
V=RI
P=(V^2)/R

I have high impedance headphones.  If I plug in lower impedance ones, it's great as far as voltage.  But I need more voltage to get the power needed for these headphones.  The headamp claims to be able to drive headphones from 1-1000 ohms.  Which means at 600 ohms, that knob should still have plenty of top room left.  it also sounds like for low impedance phones, the knob will have a much smaller range.  And that's confirmed by their warning of "turn down the knobs before plugging in the headphones."

it's a question of power, simply.

Driving 600 ohm headphones with an SPL Crimson

Reply #19 –
Quote from: superfoo on
I'm beginning to think it's just a question of power.  There's no straight or simple formulaic conversion from electronic circuitry to loudness.  I just need a little more juice.  I also am beginning to think I'm over complicating it.


http://en.wikipedia.org/wiki/Headphones#El...characteristics

Quote from: superfoo on
The headamp claims to be able to drive headphones from 1-1000 ohms.  Which means at 600 ohms, that knob should still have plenty of top room left.


Take a look at that wikipedia page.  The impedance here matters for calculating power transfer, but only if you're using obnoxious units.  If you just take the sensitivity in dB/volt, you can compute the voltage you need and not even needing to care about impedance.

Probably the impedance range given for the amp isn't meaningful anyway.

Quote from: superfoo on
it also sounds like for low impedance phones, the knob will have a much smaller range.  And that's confirmed by their warning of "turn down the knobs before plugging in the headphones."


No it has the same range but much higher zero point, which is why you have to turn down the volume to avoid blowing our your ears. 

Driving 600 ohm headphones with an SPL Crimson

Reply #20 –
I don't hear any hiss with my O2 even at full volume (completely black background when nothing plays, and I reduced volume in foobar by 20dB and played some music also no audible hiss or distortion), there must be something wrong with your amp. And don't believe anything they say about this headamp, it's just marketing BS, I wouldn't be surprised if it has much less power than O2.

Driving 600 ohm headphones with an SPL Crimson

Reply #21 –
Quote from: ieee754 on
I don't hear any hiss with my O2 even at full volume (completely black background when nothing plays, and I reduced volume in foobar by 20dB and played some music also no audible hiss or distortion), there must be something wrong with your amp. And don't believe anything they say about this headamp, it's just marketing BS, I wouldn't be surprised if it has much less power than O2.

Damn.  I would be VERY surprised if that were the case.  I'm going to take my headphones this weekend and try it out in the store.

Re: Driving 600 ohm headphones with an SPL Crimson

Reply #22 –
Please, can you help me?

I have a Steinberg UR44 Audio Interface. I have to work a lot with headphones, but sometimes I think the headphones outputs of this interface haven't enough power... I'm using the UR44 with AKG K240 MKII headphones but I'm thinking to buy soon the AKG K712 PRO to improve my equipment. And I have read that this new headphones require some more power to work properly (although theorically they are only 62 Ohm).

Then... I'm thinking if I also need to buy a good headphone amplifier for using them, or directly change my UR44 interface for another one with more power in the headphones outputs. But if I do this, I need to find something that really improve the headphone outputs of my UR44.

So I've thinking about some options:

1. If I replace my audio interface, the SPL Crimson is an option because it's similar to my UR44. But... does it have really more power in the headphone outputs?

2. Other thing is complement the UR44 with the SPL 2Control. I would like to go for the Phonitor 2, but it's too much expensive for me now. The SPL 2Control is cheaper, also has Crossfeed (something that I think can be very usefull for me) but it's not really a headphone amplifier... So again: does it have really more power in the headphone outputs than my UR44 or the Crimson? I also know the Phonitor mini, but I would like to have 2 or more headphone outputs.

3. I've seen a lot of other headphones amps, some very cheaper like the HeadAMP 4 or the BEHRINGER HA400, perhaps designed for record not for mix or mastering that are my purposes, and others a lot more expensive as the mentioned Phonitor 2 or the Grace Design m920 and other audiophile headphones, but I don't know how I can see which of them will really improve or increase the power of the headphones outputs of my UR44. I'm trying to see the specifications but... I don't have enough knowledgement to understand all the numbers about Ohm, pressure, dB... to imagine what will be the real difference in practice.

What would be the best solution for me? Thank you very much.

Re: Driving 600 ohm headphones with an SPL Crimson

Reply #23 –
I believe the 600 Ohm standard is an old-outdated standard from the tube & transformer days.   Some audiophiles may think it's "better" because there were some old professional 600 ohm headphones known to have good sound.

I don't have all of the specs on all of that equipment, but I can give you a little technical information that might help.

Headphone sensitivity is usually given as some dB SPL at some voltage or sometimes at some power level (mW).

You can make a conversion between Volts and Watts if you know the resistance (or impedance):   Power = V2/R.

From that equation you should notice two things:
  Power is proportional to the square of the voltage.  If you double the voltage you get 4 times the power.
  Power is inversely proportional to the resistance (impedance).   If you double the resistance you get 1/2 the power.

At 600 Ohms you're getting 1/10th the power of a 60 Ohm headphone, and that's why it's usually quieter, depending on the efficiency/sensitivity of the headphone.

Power is related to loudness, but not all headphones (or speakers) are equally efficient at converting electrical energy to sound energy.

We need the headphone specs to calculate dB SPL (loudness), but relative  dB can be calculated from a voltage-change or a power-change:
dB = 20log(VNew/VRef)    For example, if you double the voltage that's +6dB.
dB = 10log(PNew/PRef)    For example, if you double the power that's +3dB.

If the specs for a headphone amplifier are published, they usually give you a (maximum) voltage (instead of watts or milliwatts) into a minimum load.

Most amplifiers (including headphone amps) are "constant voltage" devices.   That doesn't really  mean the voltage is constant, but it's independent of the load (as long as you are within the normal operating parameters).    So, if the headphone amp is putting  100mV into your 600-Ohm headphones and you switch to 60-Ohm headphones without changing the volume, it should still put out 100mV.   Or, if the amp is rated for 1V (without clipping) into 16-Ohms, it should put-out 1V (or maybe slightly more) into high impedance headphones.        (But if you plug-in a 4-Ohm speaker, the voltage will probably drop and bad things might happen.)


P.S.
While I'm throwing formulas at you, Ohm's Law says Current = Voltage/Resistance.    And the basic power formula is Power = Voltage x Current.    (From those two equations you can derive the voltage-squared power formula I gave you above.)  

 
 

  

Re: Driving 600 ohm headphones with an SPL Crimson

Reply #24 –
WOW! Thank you very much for your explanation! I’m trying to understand… but still a bit complex.

I’ve trying to get all the specs of the hardware mentioned… Some things I still don’t know, like what is CMR, Crosstalk or THD&N data… But the main problem is that the published specs of my actual Steinberg UR44 audio interface are very few data and (for me) contradictory… So I’m not sure if I can compare with the other audio interfaces or headphone amplifiers that I’m thinking to buy.

Let’s see…

The specs of the HEADPHONES that I have (AKG K240 MK II) and those I want to buy to improve the sound quality (AKG K712 PRO), are clear, because they are from the same brand and share the same data. As I can see, the AKG K712 have a bit more impedance so if I'm correct they should sound a bit less than mines at same volume… So yes, sure I will need something better to move them:



AKG K240 MK II (I have)

Sensitivity: 104 dB SPL/V
Frequency range: 15 Hz - 25,000 Hz
Rated Impedance: 55 Ohms
Max. Input Power: 200 mW


AKG K712 PRO (I’m going for)

Sensitivity: 105 dB/V
Frequency range: 10 Hz – 39,800 Hz
Rated Impedance: 62 ohms
Max. input power: 200 mW



Now starts the confusion… I’m considering and deciding between to buy a new interface (SPL Crimson or Audient ID 22, I prefer Crimson) or maintain my actual audio interface (Steinberg UR44) and go for an extra headphone amp like the SPL 2Control. I’m trying to compare the headphone outputs of the SPL Crimson with another option like the Audient ID 22 or the SPL 2Control, but I’m not sure which of them will give me more power, better sound and less noise. I can also compare with Phonitor Mini that (theoricaly) should be the most powerful option because it’s a dedicated only headphone amp, isn’t it?

Let’s see again…



SPL CRIMSON

Output Impedance Headphones: 33 ohms
Frequency Response Headphones: 10Hz - > 200 kHz

Power at 0 dBu:
47 ohms load: 13 mW
300 ohms load: 1.7 mW
600 ohms load: 1.0 mW

Max. Power:
47 ohms load: 670 mW
300 ohms load: 265 mW
600 ohms load: 150 mW

THD+N Ratio (at 1 kHz, Power at 0 dBu):
47 ohms : 0.0026%
300 & 600 ohms : 0.002%


SPL 2CONTROL

Output Impedance Headphones: 22 Ohm
Frequency range Headphones: 10 Hz to 200 kHz, -3 dB
Volume control range Headphones: -65 dB to +14,9 dB

THD & N: 0,002 % (@1 kHz, 0 dBu input level, unity gain)
CMRR: › 60 dB (@1 kHz, 0 dBu input level, unity gain)
Signal to noise ratio: : -85 dB


AUDIENT ID 22

Output Impedance Headphones: <50Ω Balanced
Frequency Response Headphones: +/-0.5dB 5Hz to Fs/2

Maximum Output Level: +18dBu
Digital Reference Level: 0dBFS = +18dBu
CROSSTALK: -110dBu @ 1kHz & 10kHz
THD+N @ -1dBFS (1kHz): <0.0008% (-101dB)
DYNAMIC RANGE: 110dB un-weighted / 114dB A-weighted

Max. Level:
30ohms: +8dBu, 0.0032% THD+N, 2.75VpkPower: 250mW or Pavg 125mW
60ohms: +11dBu, 0.0022%THD+N, 4.3VpkPower: 300mW or Pavg 150mW
600ohms: +17.2dBu, 0.0013%THD+N, 7.94VpkPower: 105mW or Pavg 52.5mW


SPL Phonitor Mini

Impedance: 0,18 Ω
Attenuation Factor: 180 at 40 Ohm
Frequency Range: ‹10 Hz to ›300 kHz (-3 dB)

CMR: -88 dB at 1 kHz
Crosstalk: -80 dB at 1 kHz
THD&N: 0,00052 % at 1 kHz
At +24 dBu input level and unity gain, 1kHz, 100 kOhm load

Noise: Unweighted -100 dB
A-weighted: -103 dB
CCIR: -94 dB
Dynamic Range: Unweighted 133,62 dB

Power Amplifier:
2x 1W (+30dBu) at 1 kHz, 600Ω
2x 2W (+30dBu) at 1 kHz, 300Ω



As I have said, now the problem is that the specs published about my actual Steinberg UR44 I think doesn’t help me too much to compare with all these options to know if I will really gain a lot or not:



STEINBERG UR44

0,6 mW 40 ohms  (in the diagram of the manual)
mW @ 40 Ohm: 35mW (in the specs on the web)



Why two different data? Which is correct? And how to compare with all the other hardware? Which is exactly the impedance of the Steinberg UR44 headphones output? And how can I know all the other data just without these few numbers?

Thank you very much again, I will try to look for more info about all of this and trying to understand all you explained me.