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Old 20th March 2011, 10:19 AM   #311
theresa is offline theresa  United States
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Finally got the balanced miniDSP working but now the output level is not being shown but the amps lights are blinking and there is plenty of bass. It worked before with the unbalanced miniDSPs. Is this a known bug with the balanced miniDSP? I liked keeping an eye on that graph when in use and it hardly ever moves.
I've checked all mute controls as well as levels. The sub is putting out quite a bit but nothing shows on either the input or output meters.
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Old 20th March 2011, 07:42 PM   #312
theresa is offline theresa  United States
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The level meters of the Advanced Two Way miniDSP software doesn't work with either my subs balanced miniDSP or the center channel's unbalanced miniDSP. This started as far as I can tell when I first hooked up the balanced miniDSP but could have been slightly before that. I've reinstalled the required software, .NET etc., and even my graphic's card's driver with no sign of what the problem might be even in the system logs.
I can live without the meters, they never came within 40db of clipping anyway but this is a mystery I feel compelled to solve.
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Old 3rd June 2011, 06:06 AM   #313
DQ828 is offline DQ828  Australia
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Default Hissing Noise In System

My MiniDSP setup is injecting a hissing noise into the system & I have no been able to work out what is causing it. I have tried it with my 2 amps & it is the same with both. I don't think it was there (cant be sure) when I was running 2xDSP 2xDigi, Now I am running 2xDSP 1xDigi.

My main (Coldamp) volume control is after the RCA inputs to the amp & before the amp modules with the Coldamp. I have it set so that I am using the last 30% of the Squeezebox volume for adjustment.

When I use the Integra Receiver as the amp, the Squeezebox it set on 100% volume & I use the Receiver volume for adjustment.

Both amps product the same hiss, except the Receiver is worse.

The DSP's channel Inputs are set with no attenuation & the DSP outputs are set to level the driver but have very little attenuation overall. So If I understand Gain Structure correctly, that shouldn't be a problem. I'm definitely not the only one that has this issue as I have read about numerous similar problems in the MiniDSP forum, I am also aware it is not a global problem

I normally run it off a 12V External Hard drive PSU, But have tried it with my 12V Kingrex Linear PSU and the noise is the same.

I have tried pulling it out of the case, triple stacked it as per instructions, shortened the link cables, & mounted it on a piece of wood as it was in the 2xDSP & 2xDigi setup.

Nothing has worked, can anyone help?
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Last edited by DQ828; 3rd June 2011 at 06:09 AM.
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Old 3rd June 2011, 06:13 AM   #314
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I had similar issue when I first tried to introduce one miniDIGI and it appeared to be due to the plug-in installation process.
Have a look at miniDSP forum but in few words, I didn't follow ALL the steps described in the installation guide. In fact I forgot only one that was to reset configuration before installing plug-in again.

Hope this helps.

Last edited by chris7916; 3rd June 2011 at 06:13 AM. Reason: typo
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Old 3rd June 2011, 07:12 AM   #315
DQ828 is offline DQ828  Australia
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Quote:
Originally Posted by chris7916 View Post
I had similar issue when I first tried to introduce one miniDIGI and it appeared to be due to the plug-in installation process.
Have a look at miniDSP forum but in few words, I didn't follow ALL the steps described in the installation guide. In fact I forgot only one that was to reset configuration before installing plug-in again.

Hope this helps.
My setup plays music ok, I think I have done the setup right, after a few tries
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Old 3rd June 2011, 10:26 AM   #316
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I had similar problems which are now solved.
Follow these steps:
1. Reduce the output volume of the miniDSP by -20 db, for all channels.
2. Make sure the units are sealed from RFI (Looks like yours are already)
3. Use a non-switch mode PS
Hope this works for you!
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Old 4th June 2011, 07:20 AM   #317
DQ828 is offline DQ828  Australia
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Quote:
Originally Posted by MattWRX300 View Post
I had similar problems which are now solved.
Follow these steps:
1. Reduce the output volume of the miniDSP by -20 db, for all channels.
2. Make sure the units are sealed from RFI (Looks like yours are already)
3. Use a non-switch mode PS
Hope this works for you!
Matt

Thanks for the input, I think reducing the output -20 db is just masking the problem that still really exists, I need to go & reread the gain structure artical in this website to check I am doing it the right way.

I have tried a well built linear PSU but it didn't make any difference & as you say I think I have the RFI under control.

Thanks

David
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Old 4th June 2011, 10:44 AM   #318
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Default So whats the issue? Do we need a tissue?

I am still collecting parts for my multi amp horn system. I have been sitting back and following the development. Which is fortunate because they have now made a more suitable unit for me for 300$. But if its going to be a hissy piece of crap that is unfixable I need to know. So I have a vested interest in fixing this issue.

What I have been experimenting with is tripaths for bass channels. These have a rep as having similar issues. This mainly comes out of the fact they have got huge bandwidth and pick up RF on the input or cabling or I suspect thats the issue. And of course the power supply can be a input too. Now with the first tripath I built from a board. I used sealed lead acid battery for power supply as I intend to do with the crossover. And drove it directly into the input with one of my preamps. which was 600ohm impedance and a dcr to ground of maybe 30ohms. This amp was dead quiet and a real pleasant surprise sonically.

So is this what where dealing with here? Dirty supply's and highimpeadance inputs?
I am guessing these will need nice copper or mu metal cases. Forget switchers unless there hiend. Even a cheap toroidal supply will pass a lot of RF.

Input may have to be well loaded close to ground. Unused digital inputs may have to be terminated if not in use.

Is this any help? I would like to know if after I buy and set it up right that it going to be quiet. This is how I will set one up. It will be trans coupled and battery supplyed so it will be completely isolated.


Good luck guys I especially would like to hear about the new 8 way. Hell I am even thinking about using one of these on my mums new set up I am building her.

Last edited by fatbattery; 4th June 2011 at 10:46 AM.
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Old 4th June 2011, 10:55 AM   #319
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Default Some ideas

Quote:
Originally Posted by DQ828 View Post
My MiniDSP setup is injecting a hissing noise into the system & I have no been able to work out what is causing it. I have tried it with my 2 amps & it is the same with both. I don't think it was there (cant be sure) when I was running 2xDSP 2xDigi, Now I am running 2xDSP 1xDigi.

My main (Coldamp) volume control is after the RCA inputs to the amp & before the amp modules with the Coldamp. I have it set so that I am using the last 30% of the Squeezebox volume for adjustment.

When I use the Integra Receiver as the amp, the Squeezebox it set on 100% volume & I use the Receiver volume for adjustment.

Both amps product the same hiss, except the Receiver is worse.

The DSP's channel Inputs are set with no attenuation & the DSP outputs are set to level the driver but have very little attenuation overall. So If I understand Gain Structure correctly, that shouldn't be a problem. I'm definitely not the only one that has this issue as I have read about numerous similar problems in the MiniDSP forum, I am also aware it is not a global problem

I normally run it off a 12V External Hard drive PSU, But have tried it with my 12V Kingrex Linear PSU and the noise is the same.

I have tried pulling it out of the case, triple stacked it as per instructions, shortened the link cables, & mounted it on a piece of wood as it was in the 2xDSP & 2xDigi setup.

Nothing has worked, can anyone help?
Gday You want to think about shielded power supple cables. And perhaps a cmc or 2 in there. What earthing are you using? Rf can get in that way too. What input impedance are you using? Perhaps you can put a 600 ohm resister in there if you driving with op amps or buy some trans.
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Old 5th June 2011, 10:51 AM   #320
DQ828 is offline DQ828  Australia
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Quote:
Originally Posted by fatbattery View Post
Gday You want to think about shielded power supple cables. And perhaps a cmc or 2 in there. What earthing are you using? Rf can get in that way too. What input impedance are you using? Perhaps you can put a 600 ohm resister in there if you driving with op amps or buy some trans.
I'm working on a Power Board with filtering.

There are plenty of people who don't have my problem, I'm not sure if its the configuration I am using. I'll build the filter & then see how I go.
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