[austinfett]

So, I decided on buying the Audeze LCD-2's. Currently I'm running the ATH-ESW9A's with the Fiio E11 amp on my iPod.

Now,I'm thinking the max I want to spend is about $1100. I found the lcd 2's at Razordog audio for $795 as part of a one day deal and added it to my cart before they went back up.

My main question is do I need a DAC?

I was thinking of using the Objective2 amp. any other suggestions for a set up?

 

[billybob_jcv]

I've heard (briefly) the LCD-2s on several different amps, including inexpensive solid state (Magni), modest-priced tubes (Valhalla) and very high priced amps (Eddie Current & one I can't remember). To my poor old ears, they sounded great on all of them!

 

[Rhamnetin]

I definitely advise getting a DAC, and not using such high end headphones with low end systems.  Is an iPod still going to be your source?  

 

[austinfett]

For a little while, as my laptop broke and i have to buy a new one.

 

[diamondears]

For a little while, as my laptop broke and i have to buy a new one.

I highly recommend the iFi nano iDSD. Its an integrated DAC+amp. Its amp power is sufficient for the LCD-2, whether fazor or pre-fazor. You need an Apple Camera Connection Kit though to connect a USB cable from iDSD to your iPod.

 

[austinfett]

I have a 5th gen ipod, so could i just use a lighting to usb cable? It should work.

 

[diamondears]

I have a 5th gen ipod, so could i just use a lighting to usb cable? It should work.

Nope. Still needs a CCK (lightning to USB A-female).

 

[Head Injury]

The DAC in the iPod is very good, if you can bypass the amp (or don't, probably won't matter much.)
 
Going by manufacturer specs you'll want about 50 mW of power into 70 ohms, which comes out to 1.87 Vrms, to cover volume requirements for almost any listening situation. That's 110 dB peaks before clipping the amp, the volume I normally recommend as a goal. You can get away with less if you don't listen too loud or only listen to fairly dynamically compressed music (so no old obscure classical albums with huge volume peaks over the average).
 
The nano iDSD mentioned will do about 1.65 Vrms, which is 39 mW and nearly 109 dB. Not quite to my goal but close enough it likely won't matter.
 
The O2 is a good step up in objective performance from what you have, but you won't need the extra volume and improvements elsewhere may not be audible.
 
My recommendation is to stick with your E11. It performs quite well in distortion, noise, etc. and around 2.5 Vrms max output at 70 ohms which will be plenty loud.

 

[diamondears]

For me iFi nano iDSD is more than enough. Can't even go past 2 o'clock on the volume as its already ear deafening. Probably for those who mainly listen to classical music (peaks and lows) with no dynamic compression (loudness war), the nano iDSD might not be sufficient though.

 

[Head Injury]

For me iFi nano iDSD is more than enough. Can't even go past 2 o'clock on the volume as its already ear deafening. Probably for those who mainly listen to classical music (peaks and lows) with no dynamic compression (loudness war), the nano iDSD might not be sufficient though.

Going past 2 o'clock is actually going pretty high. Remember that 110 dB is a goal for peak volume, for average volume this will come out to 90-100 dB depending on compression. That difference of 10-20 dB comes out to a voltage difference of up to 10 times. There needs to be head room beyond normal listening volume so those peaks come through without clipping and distortion.
 
Also, depending on your source voltage and gain setting, the usable range of the volume knob can be reduced. For example, if you have a 1 Vrms source and 2.5x default gain, like the OP's set-up, but your amp can only go to 1.65 Vrms before clipping, the last section of the volume knob won't be usable because the amp won't be able to produce the last 0.85 Vrms.
 
Really, using the volume knob to determine available head room doesn't work that well unless you know exactly what voltages you need, what voltages you're getting, and what voltages you can get

 
But I do relate about not needing 110 dB, the iDSD is probably more than enough but I'm trying to cover all bases.

 

[diamondears]

Going past 2 o'clock is actually going pretty high. Remember that 110 dB is a goal for peak volume, for average volume this will come out to 90-100 dB depending on compression. That difference of 10-20 dB comes out to a voltage difference of up to 10 times. There needs to be head room beyond normal listening volume so those peaks come through without clipping and distortion.

Also, depending on your source voltage and gain setting, the usable range of the volume knob can be reduced. For example, if you have a 1 Vrms source and 2.5x default gain, like the OP's set-up, but your amp can only go to 1.65 Vrms before clipping, the last section of the volume knob won't be usable because the amp won't be able to produce the last 0.85 Vrms.

Really, using the volume knob to determine available head room doesn't work that well unless you know exactly what voltages you need, what voltages you're getting, and what voltages you can get

But I do relate about not needing 110 dB, the iDSD is probably more than enough but I'm trying to cover all bases.

So what's the ideal volume position for normal listening levels?

Can you elaborate on how to compute the ideal amp power? Sorry to press on this, just want to completely understand this aspect.

I have an iFi micro iDSD, which has 3 power options---Eco, Normal, and Turbo. When I use Eco, my normal listening volume position is around 1 o'clock; for Normal mode, around 9 o'clock.

Which in your opinion is better? The 9 o'clock?

 

[jodgey4]

Lower gain settings will usually mean less noise and/or distortion, so whichever makes you go up highest on the volume knob. Just go with whatever your ears like, IMHO. Listening is a subjective experience.
 
For ideal amp power, you need to know the impedance and sensitivity. For example, a can of 32 ohms and 90db/mW. You goal is either 110 db peaks or 120, depending on what you think makes sense. Most people would only need 110 db peaks, 120 covers darn near anything. Then, starting at that 90 db at 1 mW, you need twice the power for 3 more db. So to add 30db, you need 1024 mW of power for 120 db peaks. Power is a function of V^2/R, so look at your amps' specs, and just plug in different R values for whatever can you're using, keeping voltage constant. Some amps get weird at low impedances due to high output impedance (acts like a voltage divider and steals more and more power as your load drops) or due to limited current.

 

[Head Injury]

So what's the ideal volume position for normal listening levels?

Can you elaborate on how to compute the ideal amp power? Sorry to press on this, just want to completely understand this aspect.

I have an iFi micro iDSD, which has 3 power options---Eco, Normal, and Turbo. When I use Eco, my normal listening volume position is around 1 o'clock; for Normal mode, around 9 o'clock.

Which in your opinion is better? The 9 o'clock?

Amp power needed is determined by the headphone's sensitivity in dB/mW. The goal is 110 dB, so to figure out how much power you need in mW use this equation: 10 ^ ((110 - sensitivity) / 10). The LCD-2F has a sensitivity of 93 dB/mW, so we do 10 ^ ((110 - 93) / 10) = 10 ^ 1.7 = 50.12 mW. You can replace 110 with any other dB goal, like 80 dB for a safe average volume level or something. It's also helpful to know that every 10 dB increase in volume, you multiply the power by 10 (so 20 dB is 100x, 30 dB is 1000x).
 
To figure out how much power you're going to get from an amp's voltage, you use the impedance. Power = Voltage ^ 2 / Impedance. The result is in whole Watts, so to get to mW you multiply by 1000. In the iDSD's 1.65 Vrms case and the LCD-2F's 70 ohm impedance, you do 1.65 ^ 2 / 70 = 0.03889 W * 1000 = 38.89 mW. You can then do the opposite of the first power equation I posted to find what that does to the volume, which would be 10 * log(power), or 10 * log(38.89) = 15.9 dB increase. Add that to the sensitivity of 93 dB/mW and you get 108.9 dB of volume.
 
Some headphones, like Sennheiser's, will list sensitivity in volts instead of mW. It's sort of a combination of the mW value and impedance. You can skip the voltage to power equation and just take a log to find the change from a voltage, but you do 20 times the log instead of 10.
 
That's a lot of math and everyone hates math. This page has a calculator for both power and voltage changes to volume. Just enter the change in power/voltage or the change in dB and it'll calculate the other.
 
You can't always go by the amp's rated max output. If it has high output impedance or can only produce so much current, voltage output will decrease as the impedance decreases. An example of this is the O2, where the relatively low max current reduces the max voltage into low impedance loads (by design to reduce volume). The iFi should be OK for its max 1.65 Vrms at 70 ohms, the 1 ohm output impedance is negligible and it appears to have plenty of current (130 mW at 16 ohms requires 90 mA, 1.65 Vrms at 70 ohms only needs 23.5)
 
It's hard to say what gain setting you should use. The Eco mode will have plenty provided you can reach its 2 Vrms maximum, but I don't know how the gain is set up. If Eco is unity gain (1x) like I suspect it might be, you may be maxed out at 1 Vrms with a 1 volt source like your iPhone. But then 1 Vrms might be all you need with your listening habits. iFi seems to be suggesting volumes between 12 and 2 o'clock on their product page, so I think you're safe on Eco.
 

  you need twice the power for 3 more db. So to add 30db, you need 1024 mW of power for 120 db peaks

 
To be completely accurate, it's exactly 10 times the power per 10 dB, so 30 dB increase is 1000 mW. The extra 24 you got is because of a rounding error when doubling power every 3 dB; it's actually 1.995 times the power per 3 dB (10 ^ 3/10 = 1.995) but 2 is accurate enough when making small changes.
 
I'm being super nit-picky.

 

[diamondears]

Lower gain settings will usually mean less noise and/or distortion, so whichever makes you go up highest on the volume knob. Just go with whatever your ears like, IMHO. Listening is a subjective experience.

For ideal amp power, you need to know the impedance and sensitivity. For example, a can of 32 ohms and 90db/mW. You goal is either 110 db peaks or 120, depending on what you think makes sense. Most people would only need 110 db peaks, 120 covers darn near anything. Then, starting at that 90 db at 1 mW, you need twice the power for 3 more db. So to add 30db, you need 1024 mW of power for 120 db peaks. Power is a function of V^2/R, so look at your amps' specs, and just plug in different R values for whatever can you're using, keeping voltage constant. Some amps get weird at low impedances due to high output impedance (acts like a voltage divider and steals more and more power as your load drops) or due to limited current.

Amp power needed is determined by the headphone's sensitivity in dB/mW. The goal is 110 dB, so to figure out how much power you need in mW use this equation: 10 ^ ((110 - sensitivity) / 10). The LCD-2F has a sensitivity of 93 dB/mW, so we do 10 ^ ((110 - 93) / 10) = 10 ^ 1.7 = 50.12 mW. You can replace 110 with any other dB goal, like 80 dB for a safe average volume level or something. It's also helpful to know that every 10 dB increase in volume, you multiply the power by 10 (so 20 dB is 100x, 30 dB is 1000x).

To figure out how much power you're going to get from an amp's voltage, you use the impedance. Power = Voltage ^ 2 / Impedance. The result is in whole Watts, so to get to mW you multiply by 1000. In the iDSD's 1.65 Vrms case and the LCD-2F's 70 ohm impedance, you do 1.65 ^ 2 / 70 = 0.03889 W * 1000 = 38.89 mW. You can then do the opposite of the first power equation I posted to find what that does to the volume, which would be 10 * log(power), or 10 * log(38.89) = 15.9 dB increase. Add that to the sensitivity of 93 dB/mW and you get 108.9 dB of volume.

Some headphones, like Sennheiser's, will list sensitivity in volts instead of mW. It's sort of a combination of the mW value and impedance. You can skip the voltage to power equation and just take a log to find the change from a voltage, but you do 20 times the log instead of 10.

That's a lot of math and everyone hates math. This page has a calculator for both power and voltage changes to volume. Just enter the change in power/voltage or the change in dB and it'll calculate the other.

You can't always go by the amp's rated max output. If it has high output impedance or can only produce so much current, voltage output will decrease as the impedance decreases. An example of this is the O2, where the relatively low max current reduces the max voltage into low impedance loads (by design to reduce volume). The iFi should be OK for its max 1.65 Vrms at 70 ohms, the 1 ohm output impedance is negligible and it appears to have plenty of current (130 mW at 16 ohms requires 90 mA, 1.65 Vrms at 70 ohms only needs 23.5)

It's hard to say what gain setting you should use. The Eco mode will have plenty provided you can reach its 2 Vrms maximum, but I don't know how the gain is set up. If Eco is unity gain (1x) like I suspect it might be, you may be maxed out at 1 Vrms with a 1 volt source like your iPhone. But then 1 Vrms might be all you need with your listening habits. iFi seems to be suggesting volumes between 12 and 2 o'clock on their product page, so I think you're safe on Eco.


To be completely accurate, it's exactly 10 times the power per 10 dB, so 30 dB increase is 1000 mW. The extra 24 you got is because of a rounding error when doubling power every 3 dB; it's actually 1.995 times the power per 3 dB (10 ^ 3/10 = 1.995) but 2 is accurate enough when making small changes.

I'm being super nit-picky.

Thank you very much for going at this length to explain everything. Very informative.

Cheers!

 

[diamondears]

Amp power needed is determined by the headphone's sensitivity in dB/mW. The goal is 110 dB, so to figure out how much power you need in mW use this equation: 10 ^ ((110 - sensitivity) / 10). The LCD-2F has a sensitivity of 93 dB/mW, so we do 10 ^ ((110 - 93) / 10) = 10 ^ 1.7 = 50.12 mW. You can replace 110 with any other dB goal, like 80 dB for a safe average volume level or something. It's also helpful to know that every 10 dB increase in volume, you multiply the power by 10 (so 20 dB is 100x, 30 dB is 1000x).

To figure out how much power you're going to get from an amp's voltage, you use the impedance. Power = Voltage ^ 2 / Impedance. The result is in whole Watts, so to get to mW you multiply by 1000. In the iDSD's 1.65 Vrms case and the LCD-2F's 70 ohm impedance, you do 1.65 ^ 2 / 70 = 0.03889 W * 1000 = 38.89 mW. You can then do the opposite of the first power equation I posted to find what that does to the volume, which would be 10 * log(power), or 10 * log(38.89) = 15.9 dB increase. Add that to the sensitivity of 93 dB/mW and you get 108.9 dB of volume.

Some headphones, like Sennheiser's, will list sensitivity in volts instead of mW. It's sort of a combination of the mW value and impedance. You can skip the voltage to power equation and just take a log to find the change from a voltage, but you do 20 times the log instead of 10.

That's a lot of math and everyone hates math. This page has a calculator for both power and voltage changes to volume. Just enter the change in power/voltage or the change in dB and it'll calculate the other.

You can't always go by the amp's rated max output. If it has high output impedance or can only produce so much current, voltage output will decrease as the impedance decreases. An example of this is the O2, where the relatively low max current reduces the max voltage into low impedance loads (by design to reduce volume). The iFi should be OK for its max 1.65 Vrms at 70 ohms, the 1 ohm output impedance is negligible and it appears to have plenty of current (130 mW at 16 ohms requires 90 mA, 1.65 Vrms at 70 ohms only needs 23.5)

It's hard to say what gain setting you should use. The Eco mode will have plenty provided you can reach its 2 Vrms maximum, but I don't know how the gain is set up. If Eco is unity gain (1x) like I suspect it might be, you may be maxed out at 1 Vrms with a 1 volt source like your iPhone. But then 1 Vrms might be all you need with your listening habits. iFi seems to be suggesting volumes between 12 and 2 o'clock on their product page, so I think you're safe on Eco.


To be completely accurate, it's exactly 10 times the power per 10 dB, so 30 dB increase is 1000 mW. The extra 24 you got is because of a rounding error when doubling power every 3 dB; it's actually 1.995 times the power per 3 dB (10 ^ 3/10 = 1.995) but 2 is accurate enough when making small changes.

I'm being super nit-picky.

How do I determine the max Vrms of an amp? Amp's specs always states this relative to the HP impedance; so how do I convert that to, say, 70 ohm impedance of LCD-2F?