Need Help 2x4 Balanced very very low output

[almat]

Hi everybody,

I received yesterday a pair of 2x4 balanced and a pair of miniDIGI to stack on.

The output level, on both boards, is very very very low, some mV despite the high level output seen on the monitor.
Same thing on analog and digital input.
-3dB output level gives 10mV.

Any clue ?

TIA
Alain

 

[CharlieLaub]

Do you have the volume control enabled but don't have a potentiometer connected? That can cause this exact problem. Read your documentation again.

 

[almat]

Hello Charlie,

Thanks for the fast reply 🙂

No pot and not Enabled 🙁

When I received the boards I first checked it.
Plugged it into a Meanwell 12V power supply.

On one of the boards the little tiny blue LED was not flashing at all, tried the reset button, unplugged, plugged ...
Imho the board is out, I can connect to but for example a +16dB EQ gives a measured +3,5dB at the output ...

Tried the other one with and without the miniDIGI, Analog and I2S Input, same thing, a very low output, typically 10mV for a -3dB monitor.

I have a 2x8 and had some 2x4 nothing to compare.

Alain

A view of the boards while checking

 

[CharlieLaub]

What master/slave jumper settings are you using on each board. I use a pair of miniDIGI + 2x4 balanced in some active speakers I built but it took me a long time to figure out the jumper settings. The manuals are totally confusing, and even the miniDSP forum and emails to the techs was no help. I'm fed up with miniDSP after that frustrating episode. 😡

If you look in the Hardware forum on the miniDSP web site, you will see many posts about people having problems getting this pair of products working. There is a long thread from me sometime last year, but more recently. I would not bother posting there, as you have to wait one or two weeks for a reply if you are lucky enough to get one at all.

Anyway, I set both jumpers to "slave" and that seems to work for me.

It's certainly possible that one of your board is dead...

 

[almat]

Hi Charlie,

I think the jumpers affair is "clearly" fixed, not explained, in the Jumper chart - 4way configuration :
https://www.minidsp.com/images/documents/Jumper%20chart%20-%204way%20configuration.pdf

Jumpers are set to Slave on both miniDSP and minDIGI.
That's the way I use it.

It's certainly possible that one of your board is dead...
I am pretty sure indeed 🙁

Alain

 

[Davey]

Do you have the volume control enabled but don't have a potentiometer connected? That can cause this exact problem. Read your documentation again.

Actually, no. If the volume control is enabled in software and you have an attached control at CCW or a disconnected control, the output channel indicators will drop to reflect the actual (low) output voltage.

Alain,

Are you sure you don't have a connection issue on the outputs? If using an unbalanced interface, you would utilize the "S" and "+" outputs. Is that how you're configured??

Dave.

 

[almat]

Hi Davey,

Alain,
Are you sure you don't have a connection issue on the outputs? If using an unbalanced interface, you would utilize the "S" and "+" outputs. Is that how you're configured??
Dave.

Absolutely.
S and - wired, unbalanced signal between S- and +, inputs and outputs
And I also measured S+ and S- of each of the four outputs without any wire

Did it with I2S input too.

I try again 5 minutes before this reply, analog and I2S inputs, same result.

It's very strange that the both boards act as the same.
I am pretty sure that the "unflashing led" board is out, so it should lead to non operational outputs, but the other one is quite a mystery.

My 2x8 is working nicely on balanced outputs.

 

[Davey]

Just for grins, I would try removing the S/- jumper, and make your connection just to the S/+ connections. There's no reason for that jumper on the output connectors.....only the inputs.

Dave.

 

[almat]

Hi Dave,

Thanks for replying.🙂

As I previously told I have also measured all the S+ and S- without any wire on
Same result.
🙁

I think I'll buy a 2x4 in a box at my French reseller site to compare with these boards.

 

[Davey]

Sorry, yep you did mention measuring individual connections.

Still very puzzling that you would have two boards fail in (seemingly) the same way.
Since the output indicators in your plugin indicate a good signal, it would seem the issue is external to the DSP chip and located somewhere in the analog output circuitry.

Dave.

 

[almat]

Still very puzzling that you would have two boards fail in (seemingly) the same way.
Since the output indicators in your plugin indicate a good signal, it would seem the issue is external to the DSP chip and located somewhere in the analog output circuitry.

On one board the DSP may be faulty too, although I can connect to without any problem.
I think I have to investigate around the output ICs but measurements are not very easy with SMD ICs.
For the moment I am waiting for the miniDSP team reply, on the miniDSP forum, before any other attempt.

As I said previously I bought today a 2x4 in A Box, to compare.

Alain