DSP Xover project (part 2)

[elektrodepp]

Originally Posted by 30m20

@Shaun: Yes, I have firmware version 1.3, too - tried always to get the latest tricks from Nick.
@Shaun: Yes, decimation would have been a big step forward. First of all it is sad not to hear good news from Nick, but second to this it is sad that noone can continue his great work.


Power on/off process often requires two steps, if software is involved. I tried to manage this with the raspberry, succeeded....but only until volumio had to be updated. So I guess we have to live with this.


Najda is a bit shy: when I turn on power amps after Najda, there is a beep from the notebook running NUC, and Najda disconnects. Once understood I can deal with this.
@Vinylnvalves: This happens, when Najda is connected via analog input to my measuring equipment. Turning on the IMP after Najda is not healthy...



A strange thing is this: My speakers have a response nearly absolutely equal - measured using the analog input. Hearing music afterwards via digital input (coaxial S/P-DIF), I need to shift balance 2dB to the right.

Speedysteve7 had a similar theme a while ago but blamed it on the raspberry (connected via I2S!) or volumio, if I remember well.

Hi all
This is Josh from germany and i am a newbie with my Najda.
You wrote „firmware 1.3“ - is it correct, or do you mean the board version ?

Thanks

[elektrodepp]

Originally Posted by Shaun

I am in the process of resurrecting my Najda. Have confirmed that it works again. I have V1.1 board. I have a few questions:

1. Has anyone here used Najda over an extended period of time? Have you encountered any issues, such as data corruption (required a re-flash or re-configuration)? If so, what version do you have?

2. What is the latest firmware? I have 1.3.

Hi Shaun

Can you supply my with firmware version 1.3 ?

Thanks Josh

[Shaun]

Originally Posted by elektrodepp

Hi Shaun

Can you supply my with firmware version 1.3 ?

Thanks Josh

It's backed up on this page:

WAF-Audio

When you run NUC it will detect the firmware version and then update it if necessary.

[Shaun]

Originally Posted by Shaun

When you run NUC it will detect the firmware version and then update it if necessary.

Just to clarify: it seems that the firmware update resides within the NUC application.

[30m20]

Originally Posted by vinylnvalves

What’s a CD ... CD player went about 10 years ago.. all streamed music nowadays. I will download a test signal.
Impedance mismatching is the same as for any driving load. Understanding Impedance

Don´t worry, I stream, too, but since I realized that I sold my turntable too early, I keep my ReVox tape deck and my CD-player. Why sell for nearly nothing?
Thanks for the link to that article, nice to read with a cup of tea and cake - but I knew what impedance is. My (rethorical) question was how to solve the problem in the real world of Najda analog-in.
I have measured the balance via S/P-DIF, everything o.k., seems to be a room reflection that I underestimated.



Any idea why a positive post-gain "is the clue of an improper gain structure", as Nick wrote?

[jbator]

Originally Posted by 30m20

Like certainly others, I found out, that a 48 dB-filter at say 5KHz needs a pre-gain of -8 or -9 dB to avoid clipping. Why not push a bit upwards again with a positive post-gain (to avoid to have to attenuate the other channels to the same lower level -> lose resolution)?

6dBa is one bit so I don't mind. If you do this on digital level there will be some clipping. If you want to heave similar signal level you can boost it in attenuator config (in analog domain).

[30m20]

@jbator: Yes, I know how to workaround practically. It is only a question of interest, why Nick wrote this - or in other words: why not correct via positive post-gain?

[fluid]

The point he was trying to make is that adding gain back afterwards suggests you took too much away in the first place, therefore bad gain structure.

[piecor]

not sure if this is of interested but the last backup of the (now expired) WAF website dates back to 01-Sept-2019 and it's here


WAF-Audio

[shining31]

Originally Posted by jbator

6dBa is one bit so I don't mind. If you do this on digital level there will be some clipping. If you want to heave similar signal level you can boost it in attenuator config (in analog domain).

Do you have guys explanations on that? I don't understand why with thé minidsp I don't have to lower thé input signal to avoid clipping when I add a high-pass for examole