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-   -   How is everyone powering their MiniDSP? (http://www.diyaudio.com/forums/minidsp/219611-how-everyone-powering-their-minidsp.html)

Lutjanus 12th September 2012 08:44 PM

How is everyone powering their MiniDSP?
 
How is everyone supplying power to their Minidsp?

I trialled using the USB port on my Blu Ray player and it seems to work. The player is set up on a home network and powers up when I select it from the wifi remote.

It doesn't seem to introduce any noise either.

CharlieLaub 12th September 2012 08:54 PM

Quote:

Originally Posted by Lutjanus (Post 3162526)
How is everyone supplying power to their Minidsp?

I trialled using the USB port on my Blu Ray player and it seems to work. The player is set up on a home network and powers up when I select it from the wifi remote.

It doesn't seem to introduce any noise either.

That would depend on which MiniDSP you have, the 2x4 versus 2x8 board or 4x10/8x8, etc. which are larger.

FWIW, I have been using an inexpensive but nice regulated 12VDC wall wart that I purchased from Jameco Electronics:
DDU120050F0981: JAMECO VALUEPRO: Power Supplies & Wall Adapters

I cut off the connector, used a DVM to figure out + and - wires, and then connected it to the screw terminals (I am using a 2x4-in-a-box).

I highly recommend this power supply for the MiniDSP 2x4 units.

-Charlie

jrenkin 12th September 2012 10:01 PM

I have a 2x4 in a box. I tried to use a twisted pear bipolar power supply (older version), plus side at 5.3V (also powering a JK modded hiface) tied to the screw terminals. Super noisy. Unusable. So now I have used the USB to mini USB from my laptop, which works great, no noise, only problem is then my laptop is next to my system, not me. Next try has been an old iPod USB wall wart I had lying around, also USB to mini USB. Also quiet and easy. So that is what I will stay with.

Ryssen 13th September 2012 09:51 AM

I have a nanoDigi that I use the original wallwart,Wonder if I would bennefit driving it from a 12v battery?

boris81 8th October 2012 10:36 PM

USB power from my computer was bad.
I tried a phone charger which was still pretty bad but usable.
Now I'm using a 24V switching regulated power supply and it's the best of the 3 but still not transparent. The noise floor seems higher and bass transients are distorted.
POWER SUPPLY, WALL ADAPTER/TRANSFORMER SWITCHING,REGULATED,24 WATT,24VDC@1A,2.1MMX5.5MM,CENTER POSITIVE,UL/CSA

It seems that miniDSP (2x4) is very sensitive to the power supply (at least in my house) but the manufacturer does not recommend any PS features in particular. Is the power supply I have any different than the one recommended in post#2? What are desirable features?

CharlieLaub 8th October 2012 10:56 PM

Quote:

Originally Posted by boris81 (Post 3194295)
USB power from my computer was bad.
I tried a phone charger which was still pretty bad but usable.
Now I'm using a 24V switching regulated power supply and it's the best of the 3 but still not transparent. The noise floor seems higher and bass transients are distorted.
POWER SUPPLY, WALL ADAPTER/TRANSFORMER SWITCHING,REGULATED,24 WATT,24VDC@1A,2.1MMX5.5MM,CENTER POSITIVE,UL/CSA

It seems that miniDSP (2x4) is very sensitive to the power supply (at least in my house) but the manufacturer does not recommend any PS features in particular. Is the power supply I have any different than the one recommended in post#2? What are desirable features?

This supply is at the extreme maximum rating for supply voltage for the unit (5VDC min 24VDC max) as recommended by "the manufacturer". I DON'T recommend using this voltage supply - higher voltage is not better. Get a regulated linear supply for $12 like I suggested in post #2. It is likely to have lower noise than the switching supply... don't just throw some random crappy wall wart on there as a power supply, either. You need a clean, quiet, regulated supply if you want to get the most out of the unit.

If you are having distortion on signal peaks, you are probably overdriving the MiniDSP. These will not perform like analog stages, which often have 15V rails. This is a digital product that runs internally at 5V. If you exceed the rated input voltage (0.9V RMS, 2.5V peak-to-peak) it will cause distortion when the input stage goes above 0 dB. This means you may need to increase the gain of your amps. If you drive this from a preamp that can output 5 volts or more (not unusual), you have the capability to easily over drive the A-to-D converter and this will cause very noticeable distortion.

-Charlie

boris81 8th October 2012 11:09 PM

Thank you Charlie!
I will try the power supply you suggested, thank you for explaining in detail.
I don't think that I'm overdriving the miniDSP, I'm using the ODAC in front of it.

Davey 8th October 2012 11:27 PM

Quote:

Originally Posted by boris81 (Post 3194337)
Thank you Charlie!
I will try the power supply you suggested, thank you for explaining in detail.
I don't think that I'm overdriving the miniDSP, I'm using the ODAC in front of it.

You could be....depending upon where your volume control is. The ODAC outputs approximately 2V RMS for 0dbFS recorded material. You'd need to attenuate its output by a minimum of 7.0db to assure no possibility of overdriving the miniDSP inputs.

There's also programming to consider. Any EQ boosts above 0db in combination with input voltages near 0.9 VRMS will cause the unit to clip also.

For those interested in evaluating noise of the miniDSP, I suggest to run it temporarily on a 12 volt battery. This will give you a feel for the output noise it will exhibit with a good quality power supply.

Cheers,

Dave.

CharlieLaub 9th October 2012 12:29 AM

Quote:

Originally Posted by Davey (Post 3194356)
Any EQ boosts above 0db in combination with input voltages near 0.9 VRMS will cause the unit to clip also.

GOOD POINT!

For instance, a 6dB boost is increasing the voltage gain by 2x.

-Charlie

theAnonymous1 9th October 2012 01:55 AM

I thought the new version can take a 2Vrms input?


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