*Comparison and Review* Magni/Modi vs O2/ODAC
Jan 19, 2013 at 12:52 AM Post #241 of 452
I use thick Velcro, specifically something like this http://www.velcro.com/Products/Ties-and-Straps/Ties/One-Wrap-Tie-Rolls.aspx

I have a piece between the units, and a wrap around them. It's thick enough to basically be feet; keeps the O2 off the table and the ODAC from sliding on the O2. It can also be taken apart and the units separated without leaving any trace since it isn't adhesive.
 
You can see it in the background here (with a velcro-wrapped cable on top so I can carry it around):
 

 
Jan 19, 2013 at 1:42 AM Post #242 of 452
Quote:
I use thick Velcro, specifically something like this http://www.velcro.com/Products/Ties-and-Straps/Ties/One-Wrap-Tie-Rolls.aspx

I have a piece between the units, and a wrap around them. It's thick enough to basically be feet; keeps the O2 off the table and the ODAC from sliding on the O2. It can also be taken apart and the units separated without leaving any trace since it isn't adhesive.
 
You can see it in the background here (with a velcro-wrapped cable on top so I can carry it around):
 

Woah that's pretty clever. I might give that a try instead!
 
Jan 19, 2013 at 2:10 AM Post #243 of 452
Woah that's pretty clever. I might give that a try instead!


Check out the Velcro One Wrap Straps that have the hole at the end to run the strap through:

http://www.amazon.com/Velcro-Wrap-Strap-2-Inches-Pack/dp/B0057564NK/

Those are a little long at 15", but you can trip then end down.
 
Jan 19, 2013 at 3:19 AM Post #244 of 452
Quote:
It's simply the quiescent current in the output stage--in the case of Magni, about 30mA--hardly enough to really get warm. P= IV, where I is .03 and V is 30V--so it dissipates about 2W at idle from 2 channels. I forgot the actual FLIR numbers, but it runs something like 27C in a 20C room.

 
Don't forget the regulators.
biggrin.gif

 
After a 30 minute warmup (and measuring immediately after removing the top cover), the regulator cases were running around 140F (60C) and the output devices around 150F (66C). That's enough to make the top cover feel warm, but certainly not hot.
 
Top cover with Magni off was 72F. After idling for about 30 minutes, it rose to about 84F. Warm to the touch, but not even body temperature. So no reason for anybody to fret.
 
Oh yeah, while you're here, my Magni has a problem. Whenever I turn the knob all the way to the left, I get no sound. What's up with that? Can I get a new one?
tongue.gif

 
Have a great weekend, Jason!
 
se
 
Jan 19, 2013 at 4:01 PM Post #249 of 452
Quote:
Oh yeah, while you're here, my Magni has a problem. Whenever I turn the knob all the way to the left, I get no sound. What's up with that? Can I get a new one?
tongue.gif

 
se

 
Yeah, I've heard of that problem. About 99.8% of the Magnis have it, unfortunately. I've heard it's a relatively common problem with other amps.
 
Despite that, we'll put our entire engineering team on it and see if we can develop a fix. I believe Dave (our DSP and microcontroller wizard) could probably work up a PIC-based control system that would, say, allow you to get full volume at the touch of a button even with the pot fully to the left. Of course, that may not be the best solution, unless you want a special "destroy my headphones" function.
 
(Actually, the first preamp I designed for Sumo had the pot wired backwards on the prototype PCBs. So, in that case, you'd have plenty of output at full left, especially with 20dB gain and +/-35V rails. Hello, voice coils.)
 
Schiit Audio Stay updated on Schiit Audio at their sponsor profile on Head-Fi.
 
https://www.facebook.com/Schiit/ http://www.schiit.com/
Jan 19, 2013 at 5:36 PM Post #250 of 452
Quote:
 
Yeah, I've heard of that problem. About 99.8% of the Magnis have it, unfortunately. I've heard it's a relatively common problem with other amps.
 
Despite that, we'll put our entire engineering team on it and see if we can develop a fix. I believe Dave (our DSP and microcontroller wizard) could probably work up a PIC-based control system that would, say, allow you to get full volume at the touch of a button even with the pot fully to the left. Of course, that may not be the best solution, unless you want a special "destroy my headphones" function.

 
Not to worry. I just took it out to the shop and monkeyed around with it for a bit. Got it working perfect now. 
 

 
 
Quote:
 
(Actually, the first preamp I designed for Sumo had the pot wired backwards on the prototype PCBs. So, in that case, you'd have plenty of output at full left, especially with 20dB gain and +/-35V rails. Hello, voice coils.)

 
Did something similar to that myself once. Was picking bits of wire and polypropylene out of my teeth for a week. Oops.
redface.gif

 
se
 
Jan 19, 2013 at 5:40 PM Post #251 of 452
I love it! The alternate-universe Magni...
 
Schiit Audio Stay updated on Schiit Audio at their sponsor profile on Head-Fi.
 
https://www.facebook.com/Schiit/ http://www.schiit.com/
Jan 19, 2013 at 7:16 PM Post #253 of 452
Quote:
Quote:
It's simply the quiescent current in the output stage--in the case of Magni, about 30mA--hardly enough to really get warm. P= IV, where I is .03 and V is 30V--so it dissipates about 2W at idle from 2 channels. I forgot the actual FLIR numbers, but it runs something like 27C in a 20C room.

 
Don't forget the regulators.
biggrin.gif

 
After a 30 minute warmup (and measuring immediately after removing the top cover), the regulator cases were running around 140F (60C) and the output devices around 150F (66C). That's enough to make the top cover feel warm, but certainly not hot.
 
Top cover with Magni off was 72F. After idling for about 30 minutes, it rose to about 84F. Warm to the touch, but not even body temperature. So no reason for anybody to fret.
 
Oh yeah, while you're here, my Magni has a problem. Whenever I turn the knob all the way to the left, I get no sound. What's up with that? Can I get a new one?
tongue.gif

 
Have a great weekend, Jason!
 
se

Doesn't that happen with most amplifiers? Maybe not...my lack of experience is getting to me isn't it? XD
I always thought the volume knob is supposed to go from volume 0 to volume max.
 
Jan 19, 2013 at 9:04 PM Post #254 of 452
Quote:
 
Yeah, I've heard of that problem. About 99.8% of the Magnis have it, unfortunately. I've heard it's a relatively common problem with other amps.
 
Despite that, we'll put our entire engineering team on it and see if we can develop a fix. I believe Dave (our DSP and microcontroller wizard) could probably work up a PIC-based control system that would, say, allow you to get full volume at the touch of a button even with the pot fully to the left. Of course, that may not be the best solution, unless you want a special "destroy my headphones" function.
 
(Actually, the first preamp I designed for Sumo had the pot wired backwards on the prototype PCBs. So, in that case, you'd have plenty of output at full left, especially with 20dB gain and +/-35V rails. Hello, voice coils.)

Jason, I am proud to be your customer :D
 
Jan 19, 2013 at 11:26 PM Post #255 of 452
Schiit Audio Stay updated on Schiit Audio at their sponsor profile on Head-Fi.
 
https://www.facebook.com/Schiit/ http://www.schiit.com/

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