[kaufex]

Hi guys!  I would like to have some advice to find out what's the best way to setup for my AKG Q701 and Senn HD650 to one computer.  I currently have a Centrance Dacport LX and a Meier Stepdance 2 amp. 
 
When listening to music with my partner, is it better to get a headphone splitter with separate volume control for my portable amp OR
get another amp with a Y-splitter and connect both amps to a USB DAC?  I currently use a headphone splitter but it stopped working properly.  Was thinking of getting a cheap amp like FiiO if the 2nd option is a better setup. 
 
In addition when watching movies with my partner, is the setup will be a little different?  I forgo my DAC and plug the amp directly into my computer audio out if I want to have the Dolby Home Theater V4 sound effect for my headphones.  Is that correct?
 
Thanks guys!  

 

[StanD]

  Hi guys!  I would like to have some advice to find out what's the best way to setup for my AKG Q701 and Senn HD650 to one computer.  I currently have a Centrance Dacport LX and a Meier Stepdance 2 amp. 
 
When listening to music with my partner, is it better to get a headphone splitter with separate volume control for my portable amp OR
get another amp with a Y-splitter and connect both amps to a USB DAC?  I currently use a headphone splitter but it stopped working properly.  Was thinking of getting a cheap amp like FiiO if the 2nd option is a better setup. 
 
In addition when watching movies with my partner, is the setup will be a little different?  I forgo my DAC and plug the amp directly into my computer audio out if I want to have the Dolby Home Theater V4 sound effect for my headphones.  Is that correct?
 
Thanks guys!  

You are better off with two amps and a Y cable as they two cans have different impedances and sensitivities, Take a look at the Schiit Magni 2 amp,possibly the Uber option if you find the preamp out useful.
You can get an audio switch to select between the DAC output and the computer output and connect the Y cable to the switch.

 

[goodvibes]

Beyond that it wouldn't be a bad idea to put a resistor in series with one of the amps to isolate loads a bit. Something like at least 100 ohms up to 1k ohms depending on input impedance. Try to stay at leat 20-1 relative to input impedance and even lower values will help. Subtle difference but generally audible and the resistor won't hurt anything except a slight change in gain on whichever amp it's fronting. Ask Shiit about it and see what they think. I'd suspect Mike Moffat would agree though not a huge deal. 
 
I heard a Gungnir the other day. Kinda better than real in a good way, LOL. Mike can still voice things.

 

[cel4145]

You are better off with two amps and a Y cable as they two cans have different impedances and sensitivities, Take a look at the Schiit Magni 2 amp,possibly the Uber option if you find the preamp out useful.
You can get an audio switch to select between the DAC output and the computer output and connect the Y cable to the switch.

Agreed. Two different cans, you definitely want another amp.

 

[StanD]

  Beyond that it wouldn't be a bad idea to put a resistor in series with one of the amps to isolate loads a bit. Something like at least 100 ohms up to 1k ohms depending on input impedance. Try to stay at leat 20-1 relative to input impedance and even lower values will help. Subtle difference but generally audible and the resistor won't hurt anything except a slight change in gain on whichever amp it's fronting. Ask Shiit about it and see what they think. I'd suspect Mike Moffat would agree though not a huge deal.

Resistors are not needed as the input impedances are much higher than the DACs' output impedance and load isolation is not in context as these are not reactive loads.

 

[goodvibes]

I'm aware of that but it's the same as running 2 amps from a single preamp. You are technically correct but I've found that in practice, when done near the pre out, it can make a subtle difference. Certainly not a big deal.

 

[StanD]

  I'm aware of that but it's the same as running 2 amps from a single preamp. You are technically correct but I've found that in practice, when done near the pre out, it can make a subtle difference. Certainly not a big deal.

There is no technical reason for this. Also us carbon units are not good at comparing audio for subtle differences, especially when more than 4 seconds transpire due to our "Echoic Memory" limitations.

 

[goodvibes]

Yes, ink and probes are much more perceptive.

 

[StanD]

  Yes, ink and probes are much more perceptive.

That answer mean that you can't accept the truth about human limitations? 

 

[cel4145]

Resistors are not needed as the input impedances are much higher than the DACs' output impedance and load isolation is not in context as these are not reactive loads.

That make sense.

I've always heard that when you split the signal to two amps, what you do affect is (and I'm not sure if the terminology is right) is the strength of the signal compared to running it to only one amp. So the noise floor moves up a few db. Is that true? If so, seems like it would only affect the audio quality if the noise floor of the source (DAC) was close to audible to begin with, which should not be an issue with most modern DACs.

 

[StanD]

That make sense.

I've always heard that when you split the signal to two amps, what you do affect is (and I'm not sure if the terminology is right) is the strength of the signal compared to running it to only one amp. So the noise floor moves up a few db. Is that true? If so, seems like it would only affect the audio quality if the noise floor of the source (DAC) was close to audible to begin with, which should not be an issue with most modern DACs.

If the input impedances of the attached line inputs are much higher that output impedance then that will not be an issue. The output impedance in series with the two input impedances that are in parallel form a simple attenuator. If the DAC is 75 Ohms and the two input impedances are 10K Ohms the loss should be 0.129 dB, nothing that any human can possibly notice.
20 * log₁₀(1 + 75/5000)

 

[cel4145]

If the input impedances of the attached line inputs are much higher that output impedance then that will not be an issue. The output impedance in series with the two input impedances that are in parallel form a simple attenuator. If the DAC is 75 Ohms and the two input impedances are 10K Ohms the loss should be 0.129 dB, nothing that any human can possibly notice.
20 * log₁₀(1 + 75/5000)

Thanks. I knew you would know the math. Like many others who make claims about electronics, I don't. LOL

 

[StanD]

Thanks. I knew you would know the math. Like many others who make claims about electronics, I don't. LOL

It never amazes me how often, on the forums, someone makes an odd claim which others repeat and hold true. Once someone that understands tries to set it straight, that person gets all sorts of grief. What's more amazing how all sorts of people begin to hear things that are not possible, all based upon an unsubstantiated myth. I love it when people make up all sorts of names to describe what they think they hear. But that's what makes this entertaining, at times. I do understand the way humans work and that many truly believe their imaginations and can't get angry at it. That's why we make lousy witnesses. I wonder how many on death row are innocent? 

 

 

[cel4145]

It never amazes me how often, on the forums, someone makes an odd claim which others repeat and hold true. Once someone that understands tries to set it straight, that person gets all sorts of grief. What's more amazing how all sorts of people begin to hear things that are not possible, all based upon an unsubstantiated myth. I love it when people make up all sorts of names to describe what they think they hear. But that's what makes this entertaining, at times. I do understand the way humans work and that many truly believe their imaginations and can't get angry at it. That's why we make lousy witnesses. I wonder how many on death row are innocent? :eek:  

What do you expect when you try to refute magic, you heretic of science

 

[StanD]

What do you expect when you try to refute magic, you heretic of science

I hope that I don't get burned on a headphone stand.