please help me to calculate/guess Vrms input?

[AndrewT]

Vpk you mean Vpeak this inculde the Vdc ?
VM is Vmax without a Vdc component

do they?
You may have convinced yourself, but not me.

 

[gumo73]

do they?
You may have convinced yourself, but not me.

Is a small advance for Brazilian user ... i think is not important how do you call a value

 

[AndrewT]

It is very important on a technical Forum that is trying to convey technical information.

The technical language has to be learned and used.

An example.
In ignorance I used to write db for decibel, until a Member reminded me that the bel is after Bell and being a proper name must always use a capital (upper case) letter as in C for Celcius/Centigrade or W for Watt. decibel is thus dB and no full stop because a unit must not be followed with a full stop. Some convention and I don't know why.

 

[gumo73]

It is very important on a technical Forum that is trying to convey technical information.

The technical language has to be learned and used.

An example.
In ignorance I used to write db for decibel, until a Member reminded me that the bel is after Bell and being a proper name must always use a capital (upper case) letter as in C for Celcius/Centigrade or W for Watt. decibel is thus dB and no full stop because a unit must not be followed with a full stop. Some convention and I don't know why.

Ok but this is an help forum i think....

 

[AndrewT]

So I offered help.
Vpk is the term we use.

And you rejected that advice.

 

[gumo73]

So I offered help.
Vpk is the term we use.

And you rejected that advice.

I don't reject anything.. In in Italy is a different name of values but is the same calculus
Be quiet with your helps...write what do you think correct...🙂

 

[bentsnake]

Be quiet with your helps...write what do you think correct...🙂

Parla in modo tranquillo. = Speak in a quiet way.

Parla in modo delicato. = Speak in a gentle way.

Parla in un modo gentile. = Speak in a kind way.
​

Penso che sia divertente per dire che.
.

 

[STAryo]

Hi,

I am no DIYer and trying to understand some distortion in the MiniDsp. I hope someone could explain me the followings taken from Mytek engineering manual:-

Average level (0 VU) = +4dBu= 1.228 VRMS on XLR (between pin 2 and 3)
Output trim (adjustable in menu) = -18dBFS
Max output (sinewave) 9.79V RMS or 13.84V Peak or 27.69 V Peak to peak
(Voltage swing)

I understand all the calculations mentioned therein except I do not know how 1.228VRMS changes to Max output 9.79V RMS (sinewave).

My problem is the Minidsp (mine is the Miniambio version). To avoid distortion I have used the internal jumpers of Mytek to change the output to 0.302VRMS. I thought this was low enough for the 5V USB power MiniDsp and yet I am still facing distortion.

I have changed the internal jumpers to 0.9 and 2.0 V rms and yet the distortion is still there unless I use the volume control of Mytek to bring down the volume.

Why is it still distorting despite the output is only 0.302VRMS while the input of Miniambio is 0.9Vrms?

Thanks

 

[AndrewT]

The manufacturer has given the maximum as 9.79Vac
That same manufacturer has assumed that the average levels through the system will be 1.228Vac.
This means they have assumed that the max:average ratio is -18dB

This is just one ratio. Many other ratios could have been used. The average😛eak of music/audio files is reputed to vary from -6dB to -30dB. -18dB is just a reasonable middle ground in that range.

while the input of Miniambio is 0.9Vrms?

maybe it's your input that is too high.

edit:
I remembered the disable smilies AFTER I saw the default yet again.

 

[STAryo]

Thanks AndrewT, but would we be able to make an educated guess as the which serried would be ideal?

Mytek. MiniDsp
1) 0.618 vrms. A) 0.9 vrms
2) 0.302 vrms B) 2vrms

The output of the miniambio is 0.9vrms irrespective of either choice.


Sent from my iPad using Tapatalk

 

[AndrewT]

I don't know how minidsp works.

 

[STAryo]

I am now listening with Mytek at 0.302 V RMS and Miniambio with 0.9Vrms input. With Mytek volume control. Miniambio is also connected to the preamp.

Thanks AndrewT for you attention.


Ambio

 

[jinja]

can you check the input levels on the miniDSP software to see if the level is too high? (run the software while usb connected computer -> miniDSP and click synchronize to see the live readings for input and ouput gains).

 

[STAryo]

Yes, it clips. I believe the signal is above 2V.


Ambio

 

[jinja]

do you have the minidsp 2 x 4, or the minidsp 2 x 4 'balanced? (because the balanced one has a jumper to switch the input to 2V)

also is the input your connecting to the minidsp a balanced line or not?

EDIT: sorry, just realized both models have the same facility on input, its the output that is limited to 0.9Vrms on the non-balanced model. Also reread the thread and saw you've tried this! 😱

 

[STAryo]

do you have the minidsp 2 x 4, or the minidsp 2 x 4 'balanced? (because the balanced one has a jumper to switch the input to 2V)

also is the input your connecting to the minidsp a balanced line or not?

Mine is the Miniambio which is almost identical to the Minidsp except additional RACE function. I do use the internal jumper and it was set to 2V. I have issues with the SACD player. Problem starts with Mytek DAC which according to the notes, the output is over 6V. Those figures are given for XLR output...I quote from the page

Average level (0 VU) = +4dBu= 1.228 VRMS on XLR (between pin 2 and 3)
Output trim (adjustable in menu) = -14dBFS
Max output (sinewave) 6.14V RMS or 8.68V Peak or 17.37 V Peak to peak

No idea how 1.228VRMS became 6.14Vrms. According to AndrewT, this value seemed to be given by the manufacturer. That's where the confusion.