What is the optimal power supply voltage for the 2x4 unbalanced? USB is 5V, but I have seen various posts on the minidsp forum suggesting that 12V is better.
I measured my miniDSP 2x4.
When applying an external voltage to the green connector, I tested over a range of 10V to 24V. The required current dropped as the voltage rose, as is typical with a switching power supply. I seem to remember the total current was less than 100mA even at the lowest supply voltages.
So there really is no optimum voltage, the switch supply will take any voltage up to its rated maximum, and process it efficiently.
Hope that helps 🙂
.
When applying an external voltage to the green connector, I tested over a range of 10V to 24V. The required current dropped as the voltage rose, as is typical with a switching power supply. I seem to remember the total current was less than 100mA even at the lowest supply voltages.
So there really is no optimum voltage, the switch supply will take any voltage up to its rated maximum, and process it efficiently.
Hope that helps 🙂
.
I didn't test below 10V. I would be surprised if the 5V level was very sensitive, I haven't noticed any problems when plugging the USB plug into a power adapter which I know is closer to 4.5V than 5V 🙂
Awesome thanks for your help! I ordered a 5V switching psu off ebay earlier so hopefully that will be fine to power all the miniDSP's and a few LED's
Already well answered by Trevmar, just a short post to indeed confirm that there are no optimal voltage as the on-board switching regulator will indeed do its magic.
DevTeam
DevTeam
I have my (personal) problems with switching supplies, based on hearing experiences. May be I am an “old analog guy“. It would be nice, if minidsp could supply instructions, how to overcome their switching supplies on their boards.....
@Hm4nine,
Apologies but we're not sure to understand the question.
Are you asking how to remove the switching regulator (running @ 1.25MHz so well above audio band) to run your own linear supply for the 3.3V?
Not sure you would get a great benefit on this one...
DevTeam
Apologies but we're not sure to understand the question.
Are you asking how to remove the switching regulator (running @ 1.25MHz so well above audio band) to run your own linear supply for the 3.3V?
Not sure you would get a great benefit on this one...
DevTeam
My intention goes mainly towards the analog supply part of the output stage, where some linear opamps probably need a symmetrical supply. May be there won´t be any audible difference between switched and analog supplies for the 3.3 Volts. Because the 2x4 kit has only one supply input all internal voltages must be generated from that single voltage.
No reaction to my intentions/wishes?
Besides this - let me report some experiences:
A friend-of-mine owns the 2x8-kit. To evaluate the sonic differences he compared it with his actual equipement – say, he incorporated the kit into his preamp/poweramp audio chain.
And yes, - as awaited - he could hear a slightly negative difference when using no filters etc., just in the linear frequency mode.
But – and it´s a big BUT: having equalized audible abberations like room/speaker anomalities the result was really, really positive.
Now I think: how about to optimize the kit, e.g with the supplies? Don´t forget: here we are in a DIY-forum! Supplies cost money, and I understand that manufactures want to get the most profit. That´s business world....
Therefore my suggestions are: miniDSP should think about how trained DIY-technicians can improve their kit (probably with lots of their own money) – and of course: loosing warranty.
Nevertheless: miniDSP-products seem to be a great value-for-money!!
Besides this - let me report some experiences:
A friend-of-mine owns the 2x8-kit. To evaluate the sonic differences he compared it with his actual equipement – say, he incorporated the kit into his preamp/poweramp audio chain.
And yes, - as awaited - he could hear a slightly negative difference when using no filters etc., just in the linear frequency mode.
But – and it´s a big BUT: having equalized audible abberations like room/speaker anomalities the result was really, really positive.
Now I think: how about to optimize the kit, e.g with the supplies? Don´t forget: here we are in a DIY-forum! Supplies cost money, and I understand that manufactures want to get the most profit. That´s business world....
Therefore my suggestions are: miniDSP should think about how trained DIY-technicians can improve their kit (probably with lots of their own money) – and of course: loosing warranty.
Nevertheless: miniDSP-products seem to be a great value-for-money!!
@hm4nine,
Thanks for your comments and sharing your feedback, we're glad to hear of the successful implementation of your friend!
The miniDSP 2x4 unbalanced doesn't have any op amps so that simplifies things up.. 🙂
The miniDSP 2x4 balanced uses a low noise LDO instead of a switcher for all op amp supplies.
The miniDSP 2x8 does generate +/-15V from a switching supplies and indeed could be replaced by a linear supply if needed. There are actually a lot of DIYers out there tweaking our boards and I'm sure that we only know 1/10th of it.. 🙂 However we don't really want to get into documenting too much else we'd turn ourselves into an electronic design support office. Having to explain what's a PEQ and how to use a DSP is already a substantial task to keep up and the more questions we get (especially out of the use of the product), the higher the tech support requirements, the more expensive we'll have to sell the board. If you have some electronic knowledge, a scope and able to read some test points, there is certainly a lot of good things that can be done!
Hope this clarifies
DevTeam
Thanks for your comments and sharing your feedback, we're glad to hear of the successful implementation of your friend!
The miniDSP 2x4 unbalanced doesn't have any op amps so that simplifies things up.. 🙂
The miniDSP 2x4 balanced uses a low noise LDO instead of a switcher for all op amp supplies.
The miniDSP 2x8 does generate +/-15V from a switching supplies and indeed could be replaced by a linear supply if needed. There are actually a lot of DIYers out there tweaking our boards and I'm sure that we only know 1/10th of it.. 🙂 However we don't really want to get into documenting too much else we'd turn ourselves into an electronic design support office. Having to explain what's a PEQ and how to use a DSP is already a substantial task to keep up and the more questions we get (especially out of the use of the product), the higher the tech support requirements, the more expensive we'll have to sell the board. If you have some electronic knowledge, a scope and able to read some test points, there is certainly a lot of good things that can be done!
Hope this clarifies
DevTeam
Hopefully you don't mind me adding my question to this thread.
With the 2x4 balanced board what is the minimum operating voltage recommended? Is there any issues if the voltage dips below 12V?
I've already asked this on the minidsp official forum, but I'll ask here too, since there are many experts.
I have noticed a general worsening of the sound quality by putting the minidsp between dac and speaker amp. Ofc it also brought a big improvement, by allowing me to better integrate the speakers with the subwoofer, but I feel the sound is dirtier, noisier with the usb power. I would therefore like to try with a cheap but decent quality psu.
How about this one? EU 5V DC 2A High Quality regulated power supply adapter 2.5x5.5mm | eBay
Ofc I have to cut the tip of the cable, to fit it in the phoenix connector, but do you know how I can find which is the + and which is the -?
You also said there is no difference with psu voltage, but do you suggest me the one I linked over, to this one EU 12V 1A regulated power Supply adapter high quality | eBay ?
I have noticed a general worsening of the sound quality by putting the minidsp between dac and speaker amp. Ofc it also brought a big improvement, by allowing me to better integrate the speakers with the subwoofer, but I feel the sound is dirtier, noisier with the usb power. I would therefore like to try with a cheap but decent quality psu.
How about this one? EU 5V DC 2A High Quality regulated power supply adapter 2.5x5.5mm | eBay
Ofc I have to cut the tip of the cable, to fit it in the phoenix connector, but do you know how I can find which is the + and which is the -?
You also said there is no difference with psu voltage, but do you suggest me the one I linked over, to this one EU 12V 1A regulated power Supply adapter high quality | eBay ?
Unfortunately it's not in a case 🙁. Do you hear differences between this and usb power?
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