[DecentLevi]

Hello, hopefully the title doesn't make me sound like I'm fresh into the scene - but after several years into the audiophile hobby I came across an interesting scenario and would like some feedback in order to avoid damaging my equipment... or in order to 'spread the wealth' if this really is a good theory!

PS- I wanted to post this in the headphone amp section but the notes suggested I use the Help & Recommendations area - but feel free to let me know if you think I should move this thread to another section.

The question:Would it be advisable to connect the output of an amplified soundcard to the input of a headphone amp?

The scenario: Having already owned a Schiit Magni headphone amp + Modi DAC for 6 months, I just got a new laptop a few days ago. It's a Sager NP4658 and the feature relevant to this thread is that it has a "Sound Blaster Cinema Amplified Headphone output". Skeptical of how a soundcard would drive headphones versus a headphone amp, I let it sit on the back-burner for a few days and just finally got around to auditioning it yesterday - then I had a MAJOR What moment! Seriously man, the built in amplified soundcard on the laptop sounded better than my Schiit Magni + Modi combo... by a noticeable amount anyway.

After (at least an initial) A/B comparison playing the same part of the same song at a similar (perceived) volume with several pro-headphones (Beyer. DT 880 32 ohm, Shure SRH-940 with a cotton mod under the pads, Denon AH D750 & SoundMagic HP 100, my impressions are that the built in soundcard gave a sound that was more "direct" feeling versus the sound from my amp which was more like the sound is coming from a bit 'farther down the hallway', which is probably attributable to the fact that the path the signal travels in a soundcard is much less than that of a DAC+AMP setup. Furthermore the soundcard seemed to put out a sound that it maybe 5-10% more dynamic or "punchy", with about the same amount of additional detail in the texture of the highs.

Next I thought I'd try connecting my Magni amp directly to the amplified soundcard of my laptop (using a 3.5mm headphone to RCA left/right adapter) for a possible even better sound. Assuming a possible risk of overload to either of the paired components I only tested it for a moment, but WOW, I've gotta tell you it seemed to sound even better, with even better fine detail retrieval and perhaps better dynamics too... But that's it - no more connecting an amped output to another amp until I can get a good answer: Would this cause either the soundcard or the amp to overload - if not both of them? If so then is there some leeway; say for a matter of minutes, hours, etc. that I can get away with it before pushing it too far?

BTW, I've contacted the laptop manufacturer and they did not have the specs for the amount of ohms / watts of the amplified soundcard, but I do know the the Magni amp is rated at 1.2W RMS per channel while driving a 32 ohm headphone.

I think the concept of pairing 2 amps together is enticing - but is this revolutionary or just another science fail? Thanks all!

 

[bluejay]

Hey!
 
I do some sound engineering and I think this situation is similar to gain staging problems (on stage and in studio).
 
I don't think any of your electronics will "overload" and fry themselves or anything, but if you run the stage 1 amp too high, you're likely to overload/distort the system.
 
There shouldn't be any harm in running the stage 1 amp at a very low level (just to get the characteristics you're after), and then running the stage 2 amp to bring it up to the desired level.
 
Goodluck!

 

[kramer5150]

Youre touching on several discussion topics at once, but heres my $.02.
 
Amplification circuits CAN and often times do sound different.  There are HF members who can not hear the sonic differences between one amp and another and will PREECH that all amplification stages sound identical.  Which to me can not be farther from the truth, based on my own BLIND ABX testing with other members.  I don't have golden ears and suffer from high frequency hearing loss too.  But the point is just because you can't perceive a difference, doesn't mean the difference doesn't exist... because there are other people can easily hear a difference.
 
Daisy chaining amps won't hurt anything, provided you keep your volumes in check.  If you hear signs of audible clipping and distortion, you've crossed over the limit and you need to back down the offending gain stage.  One time (OK maybe a few times) I ran my Earmax infront of my Larocco PPA... even order THD feeding the PPA high current reservoir for my low-Z cans.  Not all together unpleasant sounding.  I was using the Earmax like a tube preamp.  With Amperex Holland tubes the Earmax is a closed-in sounding circuit, that contrasts to the PPA which at times has a very layered and distant sound.  It works because the Earmax likes to see the high impedance load from the PPA, and the PPA doesn't mind the low Z load from my various headphones.
 
Simple right?  All is good right?.... well not so exactly.  There is an off-beat chance your amplification circuits are presenting/creating impedance miss-matches between stages and components.  I don't know what the ill-effects are from such a scenario, but I don't think a well designed commercial product would nuke itself if it sees loads beyond what is "typical"... let others reply and correct me on any of the above though.

 

[manbear]

You're not going to hurt anything as long as you're sane with the volume. DAC's like the Modi typically output 2V, so if you set the volume on your soundcard at whatever level gives you 2V of output then the Magni won't know the difference. A little bit more or less volume won't hurt anything either. 

It sounds like you prefer the sound of the soundcard. Nothing wrong with that. I think my laptop sounds just as good or better than my main system with some headphones (usually more sensitive ones). The increased length of the signal path has nothing to do with it though--there is no analogy between a longer wire and a more "distant" sound. 

 

[billybob_jcv]

Anyone that connects an external headphone amp to the headphone jack of their PC or smartphone is daisy-chaining two amps.

 

[manbear]

Also, you're not going to fry anything. Worst case scenario is you get some distortion and have to turn down the volume.

Now if you plugged one magni into another and then another, making a human centipede of magnis, then you might break something.

 

[DecentLevi]

Hello guys, thanks for all your insight into this theory. Per your 'endorsements', I have been upping the power of my Magni amp with the amplified soundcard of my laptop, making for an amp that's probably got the refinement and detail retreival of amps worth 10x the price! I've been keeping the initial amp at power of no more than 50% and so far no distortion or hot equippment. :basshead:

Anyone that connects an external headphone amp to the headphone jack of their PC or smartphone is daisy-chaining two amps.

And about your note, Billibob. I'm not familiar with the term you mentioned daisy chaning but I can imagine the analogy. And really, what is the point you were trying to make? But for now I'm a happy daisy chainer!

 

[DecentLevi]

EDIT: This particular Amp-to-Amp setup seems to only make a noticeable difference on 1 of the 4 hi-end headphones I've tried it on, the one being the most analytical headphone; It works wonders on this one (Shure SRH 940 modded with about 1/2 inch of cotten under the pads to increase their depth)... which not only on adds texture to the treble but increases the instrument separation, dynamics and 3D imaging.

 

[Mr Rick]

Hello guys, thanks for all your insight into this theory. Per your 'endorsements', I have been upping the power of my Magni amp with the amplified soundcard of my laptop, making for an amp that's probably got the refinement and detail retreival of amps worth 10x the price! I've been keeping the initial amp at power of no more than 50% and so far no distortion or hot equippment.

And about your note, Billibob. I'm not familiar with the term you mentioned daisy chaning but I can imagine the analogy. And really, what is the point you were trying to make? But for now I'm a happy daisy chainer!

I think what Billibob is trying to say is that the signal out of any sound card is amplified. As long as you keep the output from your first stage of amplification from overloading the second stage, everything will be fine.

 

[billybob_jcv]

Yup! What he said!