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hkminn  
#1 Posted : Sunday, June 28, 2009 5:52:43 PM(UTC)
hkminn

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I connected B32s to a PC sound card with I2S and wondering if I could isolate the signal ground using transformers. (I guess I need 3 transformers)

Thanx
Russ White  
#2 Posted : Sunday, June 28, 2009 7:35:27 PM(UTC)
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Sure, you could do it if you want. :) You would need three transformers.
hkminn  
#3 Posted : Sunday, June 28, 2009 7:57:22 PM(UTC)
hkminn

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Could you provide some circuit examples?

Thanx
Hongki
Russ White  
#4 Posted : Sunday, June 28, 2009 8:03:51 PM(UTC)
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I have never tried it, but I imagine it would not be hard.

You could use the same trafos we use on the MUX. Just tie one end the secondaries to GND and the other to each of the input signals.
hkminn  
#5 Posted : Sunday, June 28, 2009 8:49:46 PM(UTC)
hkminn

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Don't you think some capacitors are needed somewhere in the circuit maybe?
I am worried about DC elements in the signals, but I have very limited knowledge in Electronics.

Can anybody help please?

Thanx
Russ White  
#6 Posted : Monday, June 29, 2009 4:58:30 PM(UTC)
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Sure, I would use one. For an example look at the MUX schematic. The value is not terribly critical, but I would not go lower than about 47nf. 100-220nf should work fine in series with the primaries.
hkminn  
#7 Posted : Tuesday, June 30, 2009 6:28:55 PM(UTC)
hkminn

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Hi Russ,

I tried with transformers and 220nf capacitors.
First, I connected 3 primaries to dclk, D1, D2 and tied 3 secondaries to the GND, and no sound. Then I disconnected the GND and separated the secondaries, then I got some sound with a lot of noise. So I tried with secondaries to different ground points, I finally got some music only when I connected the secondary for D2 to chasis and the other two tied together and grounded to my body.

Could you give me some advise how to ground the cable? I don't want to hold the cable when I listen to music. :)
I am using standard CAT5 Lan cable and each signal has its own ground connection to the soundcard.

Thanx.
Russ White  
#8 Posted : Tuesday, June 30, 2009 6:45:04 PM(UTC)
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Only one end of each secondary to gnd, the other to the input signal. The secondaries should not be "joined" except that one end of each is to GND.

One end of the primary has to be to source return or source GND as well.

Edited by user Tuesday, June 30, 2009 7:21:17 PM(UTC)  | Reason: Not specified

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