Schiit Magni Headphone Amplifier
Jan 26, 2013 at 3:40 AM Post #1,051 of 2,252
Quote:
is it just me or is there a quiet staticy sound every now and then>

probably.  For those following my feedback ground loop buzz/hum issue I did some more testing tonight looking at every combination of magni and cable box both straight into wall/power strip/different combos.  Also tried with my bluray player running HDMI into TV and then using amp out from TV to magni and still get horrific buzzing.  With the bluray, it only happens when the disc is playing something, so when I skip to the next scene it stops for that brief period where disc is finding new location.  Plugging the source device into same circuit as my magni doesn't do anything.
 
Perhaps more interestingly, the buzzing/hum is almost inaudible when using my D2000's but is loud as hell when using my Mad Dogs.  In both of these cases when I touch/palm the magni, the buzzing is reduced significantly.  Is there something about the sensitivity/impedance/design of the T50rp that makes the buzzing so much more audible?  
 
I am awaiting a ground loop isolator which will be here tuesday and will report back if that helps.  Will stick that between my source and magni. 
 
Jan 26, 2013 at 4:40 AM Post #1,053 of 2,252
Quote:
probably.  For those following my feedback ground loop buzz/hum issue I did some more testing tonight looking at every combination of magni and cable box both straight into wall/power strip/different combos.  Also tried with my bluray player running HDMI into TV and then using amp out from TV to magni and still get horrific buzzing.  With the bluray, it only happens when the disc is playing something, so when I skip to the next scene it stops for that brief period where disc is finding new location.  Plugging the source device into same circuit as my magni doesn't do anything.
 
Perhaps more interestingly, the buzzing/hum is almost inaudible when using my D2000's but is loud as hell when using my Mad Dogs.  In both of these cases when I touch/palm the magni, the buzzing is reduced significantly.  Is there something about the sensitivity/impedance/design of the T50rp that makes the buzzing so much more audible?  
 
I am awaiting a ground loop isolator which will be here tuesday and will report back if that helps.  Will stick that between my source and magni. 

hmm i was playing around a bit and i realized that it's from my powerline adapter
im on the 3rd floor of my house and the router is downstairs so i use powerline networking to get good internet speeds
it seems the static happens everytime something is loading
 
Jan 26, 2013 at 5:20 AM Post #1,055 of 2,252
I am confused guys. According to the specs Magni can deliver 260mW to 300ohm [HD650] vs E9 16mw. Then how come my Magni is delivering far less power to my HD650. The power[sound pressure] which E9 delivers at 1 o'clock Magni delivers at 4. I am using a step down Voltage converter to work with 240V. Any suggestions guys.
 
Jan 26, 2013 at 7:00 AM Post #1,056 of 2,252
E9 low gain is 10 dB, high gain is about 17 - 18 dB. Magni's fixed gain is 14 dB.
 
 
Looking at the specs of the Magni again, I'm again wondering if it can handle (standard) 2 V sources.
Because: Maximum Power, 600 ohms: 130mW, so output voltage is 8.83 V, divide by the gain and you get the max input 1.77 V.
 
The Asgard specs say 20Vpp output, so 7.07 V, divide by the gain and here the max input is 1.41 V.
 
In both cases the volume control seems to sit in front of the gain stage so it will amplify the attenuated signal, but I'm still wondering why this gain was chosen if there's clipping (or lots of distortion?) with 2 V sources before you reach full volume?
 
 
edit: E9 can deliver about 160 mW into 300 ohms, that's more than enough.
 
Jan 26, 2013 at 7:56 AM Post #1,057 of 2,252
Buy one, see if what your question affects fidelity, post your results, return if unsatisfied with results
 
Jan 26, 2013 at 8:12 AM Post #1,058 of 2,252
Or just ask people in the community that own one and save ~$90 in shipping here and back plus the cost of a step down transformer.
wink.gif

 
Anyway, I don't want/need a Magni.
 
Jan 26, 2013 at 10:14 AM Post #1,059 of 2,252
Quote:
Looking at the specs of the Magni again, I'm again wondering if it can handle (standard) 2 V sources.
Because: Maximum Power, 600 ohms: 130mW, so output voltage is 8.83 V, divide by the gain and you get the max input 1.77 V.
 
The Asgard specs say 20Vpp output, so 7.07 V, divide by the gain and here the max input is 1.41 V.
 
In both cases the volume control seems to sit in front of the gain stage so it will amplify the attenuated signal, but I'm still wondering why this gain was chosen if there's clipping (or lots of distortion?) with 2 V sources before you reach full volume?

 
Hey all,
 
To clarify some things:
 
1. It's standard procedure in any amplifier design to choose a gain that will drive the output stage into clipping with the volume all the way up. We've been doing this since the 1980s--this is how you always do it. Why else would a "standard" preamp have 10-20dB of gain and a "standard" speaker amp have 26-32 dB of gain? To ensure you can drive the amplifier output stage far beyond clipping with a standard source. That's why you can drive Magni past clipping with a standard source.
 
2. You don't have to worry about overloading the Magni's input with any source--2V, 2.5V, hell, 5V, or even 7V, like some crazy DACs put out--the volume pot is before the gain stage, so any input is attenuated before it reaches a stage that can be overloaded. Same with Asgard. Same with every amp we design.
 
All the best,
Jason
 
Schiit Audio Stay updated on Schiit Audio at their sponsor profile on Head-Fi.
 
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Jan 26, 2013 at 10:32 AM Post #1,060 of 2,252
Quote:
I am confused guys. According to the specs Magni can deliver 260mW to 300ohm [HD650] vs E9 16mw. Then how come my Magni is delivering far less power to my HD650. The power[sound pressure] which E9 delivers at 1 o'clock Magni delivers at 4. I am using a step down Voltage converter to work with 240V. Any suggestions guys.

Even I'm planning to use the magni with a 100W step down transformer (240v in India) to drive the audeze lcd2.2...has anyone else encountered any problems with step downs...
 
Jan 26, 2013 at 11:21 AM Post #1,061 of 2,252
Quote:
1. It's standard procedure in any amplifier design to choose a gain that will drive the output stage into clipping with the volume all the way up. We've been doing this since the 1980s--this is how you always do it. Why else would a "standard" preamp have 10-20dB of gain and a "standard" speaker amp have 26-32 dB of gain? To ensure you can drive the amplifier output stage far beyond clipping with a standard source. That's why you can drive Magni past clipping with a standard source.
 
2. You don't have to worry about overloading the Magni's input with any source--2V, 2.5V, hell, 5V, or even 7V, like some crazy DACs put out--the volume pot is before the gain stage, so any input is attenuated before it reaches a stage that can be overloaded. Same with Asgard. Same with every amp we design.

Re 1, oh sorry I was thinking in terms of headphone amps with gain option where clipping doesn't occur, at least not with 600 ohm loads.
 
Re 2, thanks for confirming that.
 
Jan 26, 2013 at 11:27 AM Post #1,062 of 2,252
Quote:
E9 low gain is 10 dB, high gain is about 17 - 18 dB. Magni's fixed gain is 14 dB.
 
 
Looking at the specs of the Magni again, I'm again wondering if it can handle (standard) 2 V sources.
Because: Maximum Power, 600 ohms: 130mW, so output voltage is 8.83 V, divide by the gain and you get the max input 1.77 V.
 
The Asgard specs say 20Vpp output, so 7.07 V, divide by the gain and here the max input is 1.41 V.
 
In both cases the volume control seems to sit in front of the gain stage so it will amplify the attenuated signal, but I'm still wondering why this gain was chosen if there's clipping (or lots of distortion?) with 2 V sources before you reach full volume?
 
 
edit: E9 can deliver about 160 mW into 300 ohms, that's more than enough.

 
So the behavior I explained in my previous post (comparing with E9) is perfectly normal is that what you are suggesting ?
 
Jan 26, 2013 at 11:28 AM Post #1,063 of 2,252
Hmm sometimes mine takes a few minutes to power on,  it's been 5 so far and nothing.  Think I may have a defective one.


Haven't heard of that, does the light turn on immediately and you get no sound, or does it not power on at all?

The light on the front should turn on as soon as you flip the switch and you should get sound 5 seconds later.
 
Jan 26, 2013 at 11:48 AM Post #1,065 of 2,252
I am confused guys. According to the specs Magni can deliver 260mW to 300ohm [HD650] vs E9 16mw. Then how come my Magni is delivering far less power to my HD650. The power[sound pressure] which E9 delivers at 1 o'clock Magni delivers at 4. I am using a step down Voltage converter to work with 240V. Any suggestions guys.

Different pot tapers? Different volume controls can control the volume on different curves. Some more gradually, some earlier on.
 

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