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
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.
Member
Joined 2009
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?
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
Member
Joined 2009
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.
Member
Joined 2009
it sounds great on a 9V battery!
Wow, you guys are good! I spent an entire day swapping each and every power supply in the house until I finally figured out that I can try a battery.
Dave, I swear, I thought about hooking up a battery a minute before I looked at your post. Lol. I rigged up a 9V battery and that solved the bass distortion beautifully. I am happy to say that it sounds great with the battery. I hope the linear power supply delivers a similar performance.
It turns out that I was in fact overdriving the miniDSP input with the ODAC! I got around that by lowering the software volume in Windows.
I knew about overdriving it digitally because I have some experience with DSP. I usually lower the input level by the amount of the largest EQ peak and a few dB padding. This one is easy to verify audibly.
Thank you all for helping me!
Wow, you guys are good! I spent an entire day swapping each and every power supply in the house until I finally figured out that I can try a battery.
Dave, I swear, I thought about hooking up a battery a minute before I looked at your post. Lol. I rigged up a 9V battery and that solved the bass distortion beautifully. I am happy to say that it sounds great with the battery. I hope the linear power supply delivers a similar performance.
It turns out that I was in fact overdriving the miniDSP input with the ODAC! I got around that by lowering the software volume in Windows.
I knew about overdriving it digitally because I have some experience with DSP. I usually lower the input level by the amount of the largest EQ peak and a few dB padding. This one is easy to verify audibly.
Yes, it has a jumper for selecting a 0.9V or 2V input. I am afraid the 2V might mess up the gain stage by lowering the signal too much.
Thank you all for helping me!
Using the jumper to select 2.0 volt input is perfectly acceptable. You'll lose 7db in your system gain, but that's beneficial in most cases.
With some source material (recorded at lower levels) you might find it's necessary to turn your volume control to maximum but still not achieve the playback level you want.
That might not happen....it depends upon power amplifier gain, speaker sensitivity, etc, etc.
I don't think you need to use anything fancy for a miniDSP power supply. I use an unregulated 12VDC wallwart when I use my setup.
Cheers,
Dave.
With some source material (recorded at lower levels) you might find it's necessary to turn your volume control to maximum but still not achieve the playback level you want.
That might not happen....it depends upon power amplifier gain, speaker sensitivity, etc, etc.
I don't think you need to use anything fancy for a miniDSP power supply. I use an unregulated 12VDC wallwart when I use my setup.
Cheers,
Dave.
Member
Joined 2009
Thank you everyone for the help!
I just want to post a quick update. I've been running about a week with the linear power supply recommended in post #2 and everything is well. Based on my experiences I would not recommend powering miniDSP from the computer USB port or a generic switching power supply (low noise ones might be OK).
I'm currently running it with the 2V input option because the ODAC was indeed overdriving it at .9V.
I just want to post a quick update. I've been running about a week with the linear power supply recommended in post #2 and everything is well. Based on my experiences I would not recommend powering miniDSP from the computer USB port or a generic switching power supply (low noise ones might be OK).
I'm currently running it with the 2V input option because the ODAC was indeed overdriving it at .9V.
I just purchased 2x4, but have no PSU. Did you cut off the connector as it wasn't a match for miniDSP or..?
I am using this. Doesn't cost too much but definitely a bit more
Accessory – iPower
I used it to power my minidsp OpenDRC DA-8
Nicely built, but to be honest, I haven't tried doing a A-B comparison with its original power supply...
Oon
Accessory – iPower
I used it to power my minidsp OpenDRC DA-8
Nicely built, but to be honest, I haven't tried doing a A-B comparison with its original power supply...
Oon
The 2X4 works well with any stable supply from 5 to 24 volts..... I use a 22V switch-mode supply and it's perfect. However if you are thinking of trying out the 2X4HD unit, be VERY careful! I have to admit to being careless; I plugged my 22V supply into the 2X4HD....... instant smoke!
Ouch!!!
Ouch!!!
interesting comparo of 5v usb power supplies...
A dozen USB chargers in the lab: Apple is very good, but not quite the best
A dozen USB chargers in the lab: Apple is very good, but not quite the best
...for when you want something quick.
A dozen USB chargers in the lab: Apple is very good, but not quite the best
A dozen USB chargers in the lab: Apple is very good, but not quite the best
...for when you want something quick.
Hi all
Current drawn by 2x4 MiniDSP differs depending on the voltage of the external PSU (see attachment)
There is also an issue with noise generated by the internal buck converter, see here
My stack
For 2x4 MiniDSP gain structure, please see here (go to post #21 if you have updated to plug-ins issued Mar12, 2013 and later as you should)
Signal Level in miniDSP x-over
George
