Wall wart question
Sep 10, 2009 at 3:06 AM Thread Starter Post #1 of 5

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Just a quick question, I'm looking to buy a 24vdc 800mA wallwart to go with my M3/tread amp - problem is that I can't find one that isn't earthed.

do not use a power supply that has its V- output connected to the "earth" pin of the AC plug. This is because V- is used as the negative DC rail on the M³ amplifier, and the signal ground is synthesized by an onboard TLE2426 rail splitter chip

Question is whether it's possible to simply reterminate the cable omitting the earth wire without causing any other problems I'm not aware of.

Thanks.
 
Sep 10, 2009 at 4:00 AM Post #2 of 5

FallenAngel

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Many ways around this and a couple of things to note.

1) Tread can accept AC input, you can use that.
2) M3 does not need 800mA, 500mA is plenty.
3) You aren't really using a power supply that connects V- to ground, don't connect TREAD V- output to ground and you're fine.
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Buy yourself any AC or DC wallwart, there are plenty out there.
 
Sep 10, 2009 at 7:43 AM Post #3 of 5

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Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif
2) M3 does not need 800mA, 500mA is plenty.


That's kind of what I'm wondering about, the M3 has a current draw of about .3A depending on bias settings and I'm probably losing about .1A across the tread - basically I don't think there is a great deal of headroom with 500mA. The HD600's I've got are also reasonably hard to drive.

So yeah not sure, but the headphones sound pretty good as it is and if the consensus is that 500mA is fine I'll go with that.
 
Sep 10, 2009 at 7:54 AM Post #4 of 5

FallenAngel

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Uhm... how are you "losing 100mA across the tread"? You don't lose current.
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As for HD600, at 300R, they're actually MUCH easier to drive and require considerably less current than something like a 25R Denon. That M3 will stay in Class-A no matter the load anyway, so no worries. They do require more voltage, but that's taken care of.
 
Sep 10, 2009 at 9:42 AM Post #5 of 5

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Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif
Uhm... how are you "losing 100mA across the tread"? You don't lose current.
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As for HD600, at 300R, they're actually MUCH easier to drive and require considerably less current than something like a 25R Denon. That M3 will stay in Class-A no matter the load anyway, so no worries. They do require more voltage, but that's taken care of.



Thanks for the correction fallenAngel, I get a little confused with the relationship between voltage and current - my electrical knowledge could probably fit on the back of a postage stamp anyway
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