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pj_rage  
#1 Posted : Saturday, June 26, 2010 11:21:27 AM(UTC)
pj_rage

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I'm running the standard buffalo II, ivy III, placid, and placid BP setup. I'm curious if I should connect earth ground (from the IEC input) to my metal case, or just leave it not connected? Also, should I connect the ground of the power supplies or anything else to the chassis grounding point? I actually haven't wired it yet, so my concerns are for safety more than noise at this point (will take care of noise when/if necessary), but of course noise is a concern as well as I'd rather do it right on all fronts from the get go. Thanks for any tips!
pj_rage  
#2 Posted : Monday, June 28, 2010 5:21:15 AM(UTC)
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I know some of you must have used a metal chassis for your buffalo dac! What did you do with earth ground?

I can't find much about it with DACs. I've seen things for amps, and even for dac/amp combo, where they connect earth directly to the chassis, then connect circuit ground to that point using a CL60 thermistor, but I'm not sure if the same rule(s) apply for DACs or not? I'm pretty sure I'm going to tie earth ground to the chassis either way, but I'm not sure if I should tie the ground output of the placid and placid BP to the chassis/earth point using a CL60 thermistor, or if this is even necessary? Or would I not tie their ground, but instead, their neutral inputs? Maybe it's enough just to connect earth ground to the chassis and do anything with the circuits at all?
PressPlay  
#3 Posted : Monday, June 28, 2010 6:17:19 AM(UTC)
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The Buffallo DAC's ground is floating so you only need to connect to earth from your IEC inlet to a point nearby on your metal chassis.

Beefy  
#4 Posted : Monday, June 28, 2010 6:33:25 AM(UTC)
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As pressplay said, just connecting the earth on your IEC inlet to the chassis is enough, and highly recommended for safety.

If you do want to connect signal ground to earth ground (but you do not have to do this), do it through a ground loop breaker - a 10 ohm 5W resistor in parallel with a 0.1µF 250VAC flame retardant capacitor.

Edited by user Monday, June 28, 2010 6:34:44 AM(UTC)  | Reason: Not specified

Iniamyen  
#5 Posted : Monday, June 28, 2010 9:53:00 AM(UTC)
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I have been thinking about this as well since I'm (still Whistle ) in the middle of my Buffalo II build.

My plan is to use a ground loop breaker (resistor + capacitor) between chassis and audio ground. This is because I am using the USB DAC module to provide a USB input option. Since the USB module's ground is connected to the rest of the "audio ground" node, this means that "audio ground" is connected to my computer's USB ground when USB is plugged in. This causes a ground loop that needs to be broken.

EDIT: And yes, you want to connect your chassis to IEC earth ground for safety. No other way to do it IMO.

Edited by user Monday, June 28, 2010 9:53:39 AM(UTC)  | Reason: Not specified

Brian Donegan  
#6 Posted : Monday, June 28, 2010 9:59:18 AM(UTC)
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I would not bother connecting the audio ground to the chassis ground.

Iniamyen, connecting to the chassis ground will not help the USB ground situation at all. The best way to deal with that (if it is in fact an issue for you) is to use the USB module's S/PDIF output and an isolation transformer to feed the Buffalo.
LeonvB  
#7 Posted : Monday, June 28, 2010 10:28:58 AM(UTC)
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Quote:
I'm curious if I should connect earth ground (from the IEC input) to my metal case, or just leave it not connected?

If you're using a metal chassis, connecting ground to the chassis is required in most parts of the world and for good reason: a loose wire could make operating or merely touching the device a very "shocking" experience.
Brian Donegan  
#8 Posted : Monday, June 28, 2010 10:33:02 AM(UTC)
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You should ABSOLUTELY connect the earth ground to the chassis. Always, and without a doubt.
Nakamichi  
#9 Posted : Friday, October 22, 2010 7:42:21 AM(UTC)
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Well, in my case the Placid/BuffaloII/IVYIII is running in a CD-Player (my nickname btw)
Removed the original D/A Board completely, built in the Placid/BuffaloII/IVYIII combo.
The player electronics and Buffallo electronics are isolated from each other, (seperated toroids, spdif also isolated)
But after the mod, the player´s logic controller went berserk.

So my Buffalo combo is sharing a case with other electronics and those have a center ground.
The Servo Boards Power Supplies are connected to it, one bipolar, one single.
The servo boards circuitry grounds is are also connected to this center ground, via 0.22uF foils.

Shouldn´t I also connect Placids to this center ground? I guess any place on the Placid´s ground plane will do it?



All the best,
Nak

Edited by user Friday, October 22, 2010 7:47:29 AM(UTC)  | Reason: Not specified

Nakamichi  
#10 Posted : Wednesday, November 17, 2010 6:04:53 AM(UTC)
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Update:
Connected the Placid´s ground to the chassis of the player using a soft connection resistor and capacitor as described in this thread.
A very slight increse in noise on the analog outputs, (mesured at about 0.0001 volts with my scope), no audible differences.
Opening or closing this ground connection during listening will result in dropouts.
The same effect as described in another thread (lightswitches turned on/off will cause muting for a second)
The Player and Buffalo are not connected to the mains safety ground, the player was designed this way, also the Buffalo´s
transformers are double isolated, so this kind of safety measure is not necessary.
But how is the SPDIF-input of the BuffaloI designed? 100nF + 75 ohm as in version one?
The Buffao is still muting for a second , when switching on other equipment or lights, but the effect has become less.
I am already using isolation transformers (PE-65612), for decoupling, will some 74Hc-type buffer help?

Edited by user Wednesday, November 17, 2010 6:05:56 AM(UTC)  | Reason: Not specified

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