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Old 16th February 2013, 09:39 AM   #411
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The plugin data sheet linked above says: "Analog potentiometer control master output digital gain fader from 80 to 0dB. Disabled if no pot connected."

Couldn't find any other info about analog volume control

Just to make it clear: All signal processing (including volume control) is done in the SigmaDSP ADAU1445. Output volume control (per channel and master) is done after all the other processing (crossover, EQ) probably using the build in Sigma DSP algorithms (why invent the wheel again?) and with 28bit depth (see this post from DevTeam in the miniDSP forum) in the digital domain. More info about algorithms used you might be able to find in the ADAU1445 datasheet or in the documentation about the sigmastudio software.

Hope this answers your question.

Best regards, Daniel
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Old 19th February 2013, 02:52 AM   #412
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Analog volume controls easily outperform digital, unless the
digital control has access to the data path of the DAC
(ie is internal to the DAC)

RIGHT IN THE DAC NOT In the THE DSP LIKE MINI USES

the bits have to be added to signal before any processing is done.

thanks for the clarifying that.. info is randomly scattered around and placed in places like the plugins( software) and i looked all over to try to decipher this crap
noit to mention too many AD verisions to sort thru the data sheet.. one thing is confusing the data sheet for the ad shows only a -46 db volume limit..???

Last edited by IMSTOOPID; 19th February 2013 at 03:08 AM.
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Old 19th February 2013, 07:06 AM   #413
OllBoll is offline OllBoll  Sweden
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Quote:
Originally Posted by IMSTOOPID View Post
Analog volume controls easily outperform digital, unless the
digital control has access to the data path of the DAC
(ie is internal to the DAC)

RIGHT IN THE DAC NOT In the THE DSP LIKE MINI USES

the bits have to be added to signal before any processing is done.

thanks for the clarifying that.. info is randomly scattered around and placed in places like the plugins( software) and i looked all over to try to decipher this crap
noit to mention too many AD verisions to sort thru the data sheet.. one thing is confusing the data sheet for the ad shows only a -46 db volume limit..???
You are giving a confused impression again. When digital attenuation is done bits are removed, not added.

And digital is superior. Since we use 24 bit DACs we have at least 8 bits we can chop off without introducing a noticeable noise in relation to the output and after that the output level is too low anyway so it doesn't matter.

If we only had 16 bits then sure we would have to do it in the DAC in such a way that no resolution is lost but we don't and therefore we can happily attenuate by chopping off bits before sending it into the DAC.
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Old 19th February 2013, 07:12 AM   #414
Rob41 is offline Rob41  United States
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Rather than start another thread I figured I'd post here in the answers to your questions thread.

I just ordered a miniDSP 4x10 HD, and the UMIK-1 mic. I downloaded and installed the latest version of REW and installed the software plug-in. Now I'm just waiting for the gear to arrive.

From what I've read, all I need to supply is a IEC cord for my "boxed" unit. I keep reading posts about needing a wall wart though. The wall wart is just for the DIY set-up isn't it?
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Old 19th February 2013, 09:28 AM   #415
OllBoll is offline OllBoll  Sweden
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Quote:
Originally Posted by Rob41 View Post
Rather than start another thread I figured I'd post here in the answers to your questions thread.

I just ordered a miniDSP 4x10 HD, and the UMIK-1 mic. I downloaded and installed the latest version of REW and installed the software plug-in. Now I'm just waiting for the gear to arrive.

From what I've read, all I need to supply is a IEC cord for my "boxed" unit. I keep reading posts about needing a wall wart though. The wall wart is just for the DIY set-up isn't it?
If I remember correctly the boxed 4x10 has no internal power supply and so you need an external 12v supply.
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Old 19th February 2013, 09:31 AM   #416
minidsp is offline minidsp  Hong Kong
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@Rob41,

Welcome to the community. The miniDSP 4x10 does come with a power supply FYI. It's not internal in the box (external power brick).

Hoping this info helps.

DevTeam
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Old 19th February 2013, 03:06 PM   #417
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I'M NOT CONFUSED..
YOU CANNOT DECIMATE 24 BITS -80DB AND NOT LOSE RESOLUTION
you have to add zeros somewhere to allow the decimation back to 24 bit.
that is why the processing now is done in 32 bit or higher..


read this

http://www.esstech.com/PDF/digital-v...me-control.pdf

Last edited by IMSTOOPID; 19th February 2013 at 03:11 PM.
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Old 19th February 2013, 03:34 PM   #418
OllBoll is offline OllBoll  Sweden
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No, you can't but you are confused in the way that you think it matters.

If your gain structure is ok then full volume is maybe 120 db at 1 m. At 80 db attenuation you are down at 40 db for the main signal. Even if the product noise introduced due to resolution loss is 60 db down from main it is at - 20 db and doesn't matter.
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Old 19th February 2013, 03:46 PM   #419
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Dear IMSTOOPID,

we all understood that you don't like digital volume control for the reasons mentioned many times now. Also it is well explained how the volume control is done in the miniDSP products.

Finally its each individuals experience and decision wether he can live with digital volume control or not. So now you can decide on your own based on the information given

In my very personal experience the digital volume control as used in the miniDSP products works without noticable signal degradation given you have done your homework with respect to propper gain staging. And in the latter case it will not be necessary to reduce the gain by 80dB. Nevertheless I agree that analog volume control is still better if you need a lot of attenuation (but then you've not done your homework ).

Quote:
PROPERLY DESIGN ANALOG does not affect the s/n ratio for its full sweep range.
its constant.. if done right. s/n ration 112 db 0v out 2.8 v out 112 db!!!
I can not follow. Maybe you can explain. How is S/N ratio defined? What about resistor noise?

Best regards, Daniel
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Old 20th February 2013, 05:04 AM   #420
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the analog volume control smd resistor ladder will maintain a 112db s/n ratio from 0v to 2.5v input.. with max out 2.8/5.6v bal output.
and yes when you are mixing balanced and unbalanced gear you need at least -60 db of gain in some cases.. regardless of gain staging.. my system routinely runs at -20 db for normal listening because of the mix of 4 different amps all with different gains 23/26/29/32 and some are balanced input some are unbalanced..
each was chosen for a specific job for a specific driver and it';s power out..(and cost)

oh yea and 4 way active with speakrs ranging form 85-93 db sensitivity.. makes the whole gain thing a total cluster .lol

I would like to run it lower but I run out of gain cut on the dcx right now..
a 4 way active system gets LOUD fast with log control pots..
this is one place I prefer linear pots/.

Last edited by IMSTOOPID; 20th February 2013 at 05:17 AM.
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