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Received my Opus and LCDPS kits today. Well put together, it's nice that you put labels on the loose components. :) Brian Donegan wrote:findbuddha wrote:
Does the Opus pop its outputs at turn on/off? I might need to power some relays as well.
Nope. I've hooked up my LCDPS and one Opus, to test. I2S is coming from a miniDIGI board ( http://www.minidsp.com/onlinestore/details/49/14/i/o-cards/minidigi). I'm still waiting on my balanced input amps to arrive, so to test the popping situation I plugged the output of the Opus into a line input of my RME FF400 soundcard. I can monitor the input visually and by routing to headphones. With the miniDIGI left off, switching the Opus on and off produces a small 'squelch'. This may be quiet enough for my needs, I'm not sure yet. My tweeters are 113db/W sensitive. With the miniDIGI turning on and off at the same time as the Opus, there is a much louder 'pop' at turn on and off. It's not as loud as some opamp pops I've heard, but it's probably too loud for my needs. Any suggestions? Cheers :)
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You are testing with SE (+Out and GND only) or Balanced into the sound card?
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Balanced. I've checked connectivity between the output terminals of the Opus and the far end of my balanced cable.
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I've checked with a multimeter, there's definitely voltage at the outputs when switching on/off.
I'm sure I'd get a better measurement with a scope, but roughly (with xlr cable connected, but measured at the Opus terminal block).....
On: +500mV
Off: -200mV
It's the same polarity for both + and - outputs, so it wouldn't seem to be a balanced/SE issue.
Should I have the G pin on PCM_IN connected? I had it connected to ground on the miniDIGI.
Thanks :)
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Hello Brian :)
I don't think it's fair to ignore me after I bought your products based on what you said....
If the Opus does indeed pop as normal, can you please assist me in working around it?
Is it safe to short the outputs to ground via relay?
Thanks
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I don't think anyone meant to ignore you.
I have never had the Opus pop when used balanced out, nor anyone else I can think of. So I would start to suspect some sort of correctable issue. Could be any number of things, ranging from power supply collapse to PCM data.
Try to isolate and test. Do you have another source?
You should definitely connect the ground pin on the PCM input.
As always, pictures can help us spot problems.
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Thankyou very much for your response, and I apologise for suggesting I was being ignored. I waited patiently and noticed you and Brian replying to other posts, but not this one.
I will test soon with my other Opus boards (which I have assembled since the first one), and work from there.
:)
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