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Hey!
First, thanks for the quick delivery, I recieved everything (2 DACs, USB & LCPS) yesterday. I put the p/s together this morning, but before I wired it up I just wanted to check some basics out.
What kind of power supply is best for the LCPS? And what tolerance does it have in what it takes?
I read in the forums that one pot should be set for 7.5V and one for 5V, do i then just connect to both DACs from the power supply, 7.5V to 'g' & 'VA', and 5V to 'g' & 'VD'?
From the USB card, i'm sending (With the jumper set to I2S), Digitial out & ground to the 2 DACs ('DIN' & 'G'), does it matter about daisy chaining or should i set them both straight from the USB card?
Finally, for dual mono mode I set the DIFFHW to high, mono to hi/lo for each channel, then I have the PS connected, digital input to DIN/G, Left- & right+ wired as XLR +, Left+ & Right- as XLR-, and both grounds together for ground. Is that everything? I don't need to connect anything to 'BCK', 'SCK', 'LRCK' etc?
Apologies in advance for very basic questions, but I don't want to screw up :)
Thanks!
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Rank: Administration
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Quote:What kind of power supply is best for the LCPS? And what tolerance does it have in what it takes? You want either one dual secondary transformer or two single-secondary transformers (center tapped transformers will not work with the LCPS). Each secondary should be rated for 8VAC - 15VAC, and be able to deliver at least 300mA. Quote:I read in the forums that one pot should be set for 7.5V and one for 5V, do i then just connect to both DACs from the power supply, 7.5V to 'g' & 'VA', and 5V to 'g' & 'VD'? Each side should be set for 7.5V. For the current and future round of DAC boards, we changed both analog and digital portions of the DAC to run at 5V to make it more widely compatible with other receivers. The DAC's onboard voltage regulators and smoothing caps make it safe to share analog and digital supplies (verified with Wolfson engineers). Therefore, you can also use one side of the LCPS to power both analog and digital portions of each DAC board (one supply per channel). Quote:From the USB card, i'm sending (With the jumper set to I2S), Digitial out & ground to the 2 DACs ('DIN' & 'G'), does it matter about daisy chaining or should i set them both straight from the USB card? I2S is made up of 5 signals, three clocks, data, and ground. You will need to also wire up the BCK, SCK and LRCK from the USB receiver to each DAC. Either method of wiring them is fine (daisy chaining or direct). As for dual-mono wiring, not sure off the top of my head, but should be outlined in the DAC manual. I'll check and update my reply in a bit (need to make some lunch for the kids ;) ). Edited by user Saturday, September 22, 2007 8:48:29 AM(UTC)
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Rank: Member
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Joined: 8/12/2007(UTC)
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OK thanks, I have it ready except for a power source now. (I think :) I looked around and found a few different options, just wondering what you'd recommend? http://www.rsonline.se/c...=I18NAll&Ntt=804-975http://www.rsonline.se/c...I18NAll&Ntt=223-8465http://www.rsonline.se/c...I18NAll&Ntt=223-7894I think the only difference seems to be they can handle more levels of current, but as they're all above 300mA, I guess any is ok? Do you think magnetic fields from it can introduce hum to the DACs? I will have the transformer and the LCPS in a seperate enclosure from the DACs/USB card, so I suppose that is not a major problem? Sorry to be asking so many questions, but I want to make sure I order the optimal part! Thanks again, Tomas Edit Here's the work so far, I've used ridiculously thick cable as it was all I had and I was impatient to get started. All it needs now is some power and two XLR sockets! Also maybe you can see the orientation of the two variable resistors? I was wondering if that was correct, I would have guessed from the circuit board print that the actual screw would be to the bottom of the board (with respect to the text), however on the LCPS_Proto.jpg it was orientated to the top, so I soldered it that way instead. Edited by user Sunday, September 23, 2007 9:38:55 AM(UTC)
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Rank: Administration
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I'd got for the second transformer you listed, the 2 x 9V 15VA toroid.
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Since both supplies are set at 7.5V (I was reading the DAC manual and it still says 5V for the digital leg), I suppose the other digital boards would also run at 7.5V: Metronome and the Toshlink module?
Thanks...
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Rank: Administration
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Joined: 10/24/2006(UTC)
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I would use 7.5V for both analog and digital. I have actually been using 5V vregs for the digital side of the DACs so they would be more widely compatible with other receivers that may be running 5V. This will probably change with the next generation of DACs (not sure if the WM8741 is 3.3V compatible, have to recheck).
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