The New Hypex Fusion Plate amps

[mattsk8]

I have a spdif connection of about 5 meters (17 feet) between both amps. No problems.
Do use a 75Ohm coaxial (spdif) cable.

Thanks! Will confidently move forward with it then

 

[fedde]

Why do you recommend the amp volume over the source volume?

Because I expect the internal precision of the DSP to be higher than the max 24 bits the spdif provides. This way, quantisation issues could be less...

By the way, I did not find any solid information about internal precision and what you need to do to avoid clipping (e.g. can a boost filter clip the input signal and what is the role of internal volume in this?).

Fedde

 

[Shutdown98]

By the way, in the meantime I received a response from Hypex support. It is possible to change NCxxx amp channel gain by changing one resistor. Of course, this totally invalidates the warrenty and reduces Max power and so, but it could be a way out in case noise needs to be reduced further...

Fedde

What would be the benefit of a resistor to reduce gain vs lowering gain in dsp?

 

[Julf]

What would be the benefit of a resistor to reduce gain vs lowering gain in dsp?

Reduces impact of DAC and amp noise on the output. There is a also a theoretical benefit in that it increases negative feedback so might lower distortion and non-linearity.

 

[fedde]

Yes, and it would have less bit loss at lower volumes. So in general it will improve SNR...

Fedde

 

[Shutdown98]

Ok... Interesting
I have my amps a year now.
Perhaps i just might go for that...
Any details on the resistor and the value needed?
For tweeter a 5dB lower gain would be usefull.

 

[Julf]

Any details on the resistor and the value needed?

This information is originally for the UcDs, but applies to nCores as well: https://www.hypex.nl/img/upload/doc/an_wp/AN_Voltage_gain_hypex_modules.pdf

 

[fedde]

Yes, it is about Rg. I want to double check with Hypex whether I can share the data widely...

Fedde

 

[Shutdown98]

Thnx for the info!
I am not that technical... But i can solder.
If the resistor is relative easy to replace and someone can pinpoint it... I can give it a try.

 

[Julf]

Thnx for the info!
I am not that technical... But i can solder.
If the resistor is relative easy to replace and someone can pinpoint it... I can give it a try.

It will be a SMD resistor. Not impossible to hand solder, but you can easily damage the PCB.

 

[jcga]

Hypex HFD 4.95 software & 1.41 firmware

Hello all,
I've just noticed an new release of the HFD and firmware from Hypex.
I updated my two FA503 to the latest 1.41 flat EQ firmware and started the new HFD 4.95.


Has anyone been able to get into the new input equalizer ? When I click on it nothing happened and of course I'm not able to add any correction

 

[paalj]

Hi,
The new on/off calibration is explained with one slave and one master. I have 3 slaves and one master. How is this done?.

 

[fedde]

Dear all,

Hypex is ok with sharing the data, so hereby. First the disclaimer: you are on your own if you destroy your PCB by modding, so your warrenty will be gone.

You can change the resistors with circles on the attached image on the NC252MP board. The resistor (Rg) is part of the differential input buffer stage. For the Fusion 253, the resistor values are:

Rf = 3k3, Rg = 1.8k (Rg = R76 and R162)

See manual posted above how to calculate the gain. If you want to lower the gain, you need to raise Rg.

On the NC100HF tweeter board, you need to look for R76. The resistor values are the same there...

Have fun!

Fedde

 

[Shutdown98]

If i do the math with the current resistor values i get a outcome of 21.
If i raise Rg from 1k8 to 2k2 i get a value of 18.
But that is the value Av.

If i want the gain to be lowered bij approx. 5 or 6 dB.
What value of Av do i need?

(In this electronics Area i am totaly lost )

 

[ds23man]

Please use a series resistor, you will get a form of current drive which reduces distortion!

 

[Julf]

If i do the math with the current resistor values i get a outcome of 21.
If i raise Rg from 1k8 to 2k2 i get a value of 18.
But that is the value Av.

If i want the gain to be lowered bij approx. 5 or 6 dB.
What value of Av do i need?

For a 6 dB lower gain, you need Av to be half of the original value, so 10.5.

 

[Shutdown98]

Please use a series resistor, you will get a form of current drive which reduces distortion!

You meen that Rf and Rg must be the same value?

 

[Shutdown98]

For a 6 dB lower gain, you need Av to be half of the original value, so 10.5.

Thanks...
Means that Rg mus be 3k9 (11,42Av) or going to 4k7 makes Av = 9.47.

 

[ds23man]

You meen that Rf and Rg must be the same value?

No, between the amp and driver. Also the limitersettings wil not correct anymore if you change the gain of the amp....

 

[Shutdown98]

I misunderstoud "series resistor".
It is the way the resistor is build to get the desired value. (As there are also parallel resistors).

Getting confused about the options of all types of resistors...
Can anyone advise one?

I do not use the limiter in the amp.