[Neoneo]

my nuprime stream 9 is connected to my nuprime x9 dac via hdmi.

i have a problem with my nuprime dac x9 which is plugged into my anthem mrx 1140 home theater amplifier. when i put the nuprime dac x9 in "fixed", and i use the analog rca output to connect it to my home amplifier anthem cinema to listen to music (quobuz, Amazon music and tunein), I have the sound which saturates a little, like a distortion, which increases with the volume of the Anthem.

Should the volume of the external dac nuprime be lowered?

is this problem due to the fact that the rca output of the nuprime dac x9 is at 4V rms?

Thank you for your help

[rustydoglim]

Don't use the Fixed output. Since DAC-9X has memory retention for the input volume, just set the volume on DAC-9X and leave it.

https://nuprimeaudio.com/ufaqs/what-kind-of-volume-control-and-preamp-do-you-use-for-your-dac/

[Neoneo]

Thank you for your reply.

if I understand correctly I have to put the sound by switching the switch to variable? but if I put on variable the pre amplifier of the x9 is not bypassed and therefore I have to use the pre amplifier of my anthem mrx to control the volume and of the dac x9 in variable but of which I do not change the value?

so what value should I set the volume on the nuprime dac x9 to not have sound saturation?

[rustydoglim]

Please read the FAQ about volume control, whether it is "fixed" or variable, it goes through the same switching circuit.
The "bypass" is an outdated concept or only relevant in low-end design.
In the "old days" high-end preamps have a switch-resistor design for volume control and entry-level preamp has a bypass switch with analog volume pot.  Nuprime's state-of-the-art DAC with preamp uses the design as described in the FAQ where the switch-resistor circuit is implemented in a chip so there is no longer a need for a "bypass switch".
Due to the demand from some requirements, some users like to have a fixed switch so we put it there.
Or think of it such that you can have a bypass switch at any volume you want.

[Neoneo]

Ok.

Is there a specific value to which I must set the volume of the dac x9 or do I have to do it by ear?

little personal question, you don't have to answer. do you work for nuprime? are you a nuprime engineer?

thanks again.

[rustydoglim]

Is there a specific value to which I must set the volume of the dac x9 or do I have to do it by ear?

Start from mid level, by ear.

little personal question, you don't have to answer. do you work for nuprime? are you a nuprime engineer?

It is no secret here that many people know that I am the CEO 

[Neoneo]

It is no secret here that many people know that I am the CEO 

 

impressive!!

forgive my ignorance but I must say that I am new to the audiocircle forum. 

[AllanS]

I was a bit confused also.  The basic idea of a volume knob on a component DAC is something relatively new to me.  As obvious as it may seem, and is now to me, every DAC I’d ever used had a volume control.  I just didn’t know it was controlling a DAC output (eg mobile device audio).

The DAC-9X FAQ and Forum page includes a lot of helpful info.
https://nuprimeaudio.com/product/dac-9x/

This in particular discusses volume setting.
https://nuprimeaudio.com/ufaqs/if-i-am-using-your-dac-with-a-preamp-or-integrated-amp-how-do-i-set-dacs-preamp-volume/

[richidoo]

MRX1140 digitizes analog inputs.
The analog input stage is not clipping but the ADC is digital clipping.
MRX has an "input trim" function which MAY attenuate input signal in analog domain prior to conversion, in which case turning down the trim will fix the problem. But if the input trim is digital attenuation, merely for the purpose of balancing output volume levels between different inputs as I suspect then it will not help.
The MRX preamp outputs can make 5V, very robust, so the input stages are most likely equally well-designed and can handle 4v signal without clipping. But the ADC's digital full scale is calibrated to a voltage level closer to industry standard 2V in order to maximize digital S/N. Any signals which exceed this voltage level that corresponds to the ADCs full scale output will be digitally clipped.
I wrote more details and some links in your Nouveau intro thread last night
Rich

[rustydoglim]

Make sense not to use the fixed output of DAC-9X with MRX1140.

The configuration of this setup is not making the best use of the components.  Stream-9 -> DAC-9X and then ADC into a home theater amp?
May be it is time to add STA-9X to DAC-9X, route the MRX1140 L and R pre-out to DAC-9X.

[Neoneo]

Make sense not to use the fixed output of DAC-9X with MRX1140.

The configuration of this setup is not making the best use of the components.  Stream-9 -> DAC-9X and then ADC into a home theater amp?
May be it is time to add STA-9X to DAC-9X, route the MRX1140 L and R pre-out to DAC-9X.

yes thats what i was thinking. do the combo stream 9 + dac x9 + pra x9 + sta x9. on the other hand, I was thinking of connecting the pre out outputs of the anthem mrx to the rca input of the sta x9 and not of the dac x9. like that when I use the home theater to watch a movie I only turn on the sta x9. and the sta x9 connected directly to the front speakers. the dac x9 would be connected to the sta x9 by xlr. I would just have to change the switch of the dac x9 to balanced (xlr) when I want to listen to music from stream 9 and change the switch of the dac x9 to unbalanced (rca) when I want to watch a movie on with my anthem mrx 1140.

It's not a good solution for you ?

[Neoneo]

@richidoo

I'm going to adjust the value on the input trim and I'll tell you if that solves the problem.

A attenuator (passive) like this one ?

https://www.audiophonics.fr/en/rca-adapters/monacor-ila-1020-rca-line-level-attenuator-regulators-10db-15db-20db-the-pair-p-7774.html

[richidoo]

@richidoo

I'm going to adjust the value on the input trim and I'll tell you if that solves the problem.

OK thanks

A attenuator (passive) like this one ?

https://www.audiophonics.fr/en/rca-adapters/monacor-ila-1020-rca-line-level-attenuator-regulators-10db-15db-20db-the-pair-p-7774.html

You only need 3dB - 6dB max attenuation to stop the digital clipping.
Those commercial attenuators use low quality parts, not good enough for your equipment, imo.
You could DIY it with good parts, or maybe there is a audiophile version with good quality audio resistors?

If NuPrime DAC volume control is lossless then thats the easiest answer

[rustydoglim]

yes thats what i was thinking. do the combo stream 9 + dac x9 + pra x9 + sta x9. on the other hand, I was thinking of connecting the pre out outputs of the anthem mrx to the rca input of the sta x9 and not of the dac x9. like that when I use the home theater to watch a movie I only turn on the sta x9. and the sta x9 connected directly to the front speakers. the dac x9 would be connected to the sta x9 by xlr. I would just have to change the switch of the dac x9 to balanced (xlr) when I want to listen to music from stream 9 and change the switch of the dac x9 to unbalanced (rca) when I want to watch a movie on with my anthem mrx 1140.

It's not a good solution for you ?

The switch at the back of STA-9X for bal and unbal inputs is not a true preamp switch, so if you are going to use it to select between two inputs and don't mind the inconvenient of reaching behind the unit, then make sure both inputs are not active at the same time.

I suggest that you compare 1) sending MRX1140 pre-out to DAC-9X analog input;  2) the bal-unbal switch as above

[Neoneo]

Ok thank you. So plug the anthem in the dac x9 is the best solution.

[Neoneo]

MRX1140 digitizes analog inputs.
The analog input stage is not clipping but the ADC is digital clipping.
MRX has an "input trim" function which MAY attenuate input signal in analog domain prior to conversion, in which case turning down the trim will fix the problem. But if the input trim is digital attenuation, merely for the purpose of balancing output volume levels between different inputs as I suspect then it will not help.
The MRX preamp outputs can make 5V, very robust, so the input stages are most likely equally well-designed and can handle 4v signal without clipping. But the ADC's digital full scale is calibrated to a voltage level closer to industry standard 2V in order to maximize digital S/N. Any signals which exceed this voltage level that corresponds to the ADCs full scale output will be digitally clipped.
I wrote more details and some links in your Nouveau intro thread last night
Rich

you were absolutely right, I modified the trim setting of the analog rca input up to -12db and the sound is still saturating. the only option i have is to put the x9 dac on varible and lower the db.

congratulations for your expertise

[Neoneo]

May be it is time to add STA-9X to DAC-9X, route the MRX1140 L and R pre-out to DAC-9X.

But the anthem's pre out outputs can output a signal up to 5v. isn't there a risk of sound saturation occurring on the rca input of the dac x9 which is limited to 1.5 Vrms?

[rustydoglim]

But the anthem's pre out outputs can output a signal up to 5v. isn't there a risk of sound saturation occurring on the rca input of the dac x9 which is limited to 1.5 Vrms?

Usually AVP has the setting to limit the pre out signals.

[Neoneo]

Usually AVP has the setting to limit the pre out signals.

very well I will look in the parameters of my anthem to see if there is an option of this type to limit the output signal of the pre-outs

Thank you again.

[jeanluc612]

Hello,

how do I trim the input level,as I can`t find anything in the manual.

thx in advance

Peter