Electric shock problems with LiTe DAC-AH

[guzziguy]

I recently sold my DAC-AH to a fellow HC'er. It arrived in good shape, but he had the following issues with it:

Hi Ken,

Once again, I'm sorry about this whole thing, and I really hate to do it. Well the DAC-AH worked great right when I took it out of the box. I hooked it up to my AEX and Lunchbox and jammed away with it for about 50 minutes, which was when I turned it and the lunchbox off, and picked it up to move it. I noticed that my hand was tingling when I picked it up, so I set it back down, and put my hand on the dac-ah case again, only this time to get a very strong electric sensation up my arm and all over my body. So I unplugged the whole thing and moved it after.

The next day, I plugged everything back in, and noticed that the interconnects were twisted up, so I reached behind the dac-ah to unplug them, and right when I touched the plug on the interconnect, I got an even more intense shock and literally jumped a mile. Needless to say, I knew something was wrong, and didn't touch it until yesterday, when I took it to about 5 of my EE friends, who all took varying looks at it, only to reassure me that it was fine.

So I went to RatShack and bought a new powercord and interconnects, plugged the bad boy into a different outlet, and bam, hit again. So now I'm too scared to do anything with it and I don't think I should keep shocking myself like this, so I guess that brings us to here. I'm almost scared to say that you should try and replicate the problem, because I'm honest to god worried about the electrocution possibility here. If you got some people you know who know this kind of stuff, then I'd rather have you take a look at it than anything.

I received it back today, again in good shape. I briefly powered it up without making any audio connections and there was no tingling or any other feeling of electricity. I touched the case in multiple places, including the RCA sockets. When I was using the DAC, I never had any electrical problems. One difference is in how we used it. The buyer used an optical connection between his source and the DAC whereas I always used a COAX connection.

I'd like to debug this without electrocuting myself. I have only very basic electric circuit knowledge and definitely need some help. Could anybody suggest what is happening here? Why did the buy have problems, even after changing power cord, electrical socket and RCA interconnects?

Thanks in advance for your help.

[luvdunhill]

it's possible that the coaxial cable is using the ground of the connected component. Since the optical cable has no such provision, that might explain things.

[ojnihs]

heh, i already discussed it with these guys here Ken

[ojnihs]

it's possible that the coaxial cable is using the ground of the connected component. Since the optical cable has no such provision, that might explain things.

man if that's it i'm going to kill myself

[jinp6301]

it's possible that the coaxial cable is using the ground of the connected component. Since the optical cable has no such provision, that might explain things.

yup what I was thinking

but i'm using the optical out for my lite dac and it doesnt want to kill me Maybe the mods use the case as ground?

[guzziguy]

heh, i already discussed it with these guys here Ken

Oops, how did I miss that thread? Or did you do it via PMs?

[ojnihs]

Oops, how did I miss that thread? Or did you do it via PMs?

no worries, i discussed with a few guys here. title doesn't match the discussion

[dc]

my DAC-AH appears to have a ground loop but only with 1 of my amps and doesn't shock me

solution so far has been simple - don't use it with the offending amp. didn't fancy their sound together anyway

i too use optical, i'm going to try it with coaxial and see if it resolves that problem

[ojnihs]

my Capitole has no issues with the optical input. just though i would throw that out for you, David

thanks reks

seeing as there are quite a number of people who really like the lite dac ah and lunchbox combo, i find it difficult to say that there's a problem with the combo. i've been using my 0404 usb with my lunchbox lately, and i've had no problems there.

[ojnihs]

can you go coax? be worth trying.

i could but would require buying a toslink to coax converter to use with my AEX

[ojnihs]

hmm, not sure that would fix the issue. can't go from your computer to the 0404 to the DAC Ah to the amp?

i never thought of that. guess that would mean i'd have to use macbook -> usb -> 0404 -> coax -> dac-ah -> lunchbox. that's an interesting proposition.

question is, will coax solve the problem or not. for all we know, if guzziguy can't replicate the problem, it could be my lunchbox.

[Dusty Chalk]

[ojnihs]

does David have a dirt floor?

heh

[aerius]

A possible idea, from when I had a ground loop in my system. Get a wire and tie the chassis of the DAC to a ground point on the amp. Try at own risk, not responsible for fires and damaged components.