DSP Xover project (part 2)

I wonder if a template of the front pannel for this board will be available?

Yes and no.
For sure I'll make available a document with the location of each element.
But I don't know yet if I'll have the boards populated.
A sole PCB is cheaper to ship, it's all TH so easy to assemble and you can customize your project by selecting specific parts.

A front panel template means you must use the same elements as I do. For example leds: they exist in various shapes and sizes, and what model you plan using is going to impact the front panel.

Or I can make a template for a specific list of components.

Let's discuss this further here.


Great idea - save all that point to point wiring.

Yes, of course the Mute switch on the encoder is wired on the PCB. So either you'd use this one, or you'd use a regular switch.


Looks good Ulf! Thanks for posting. Hope we also see the rear panel some day ;)
 
Seems it could have been a power supply issue. At least it worked well once I changed to a switched power supply for the 5V. Thanks Nick for assisting!

Here´s how the VFD looks behind 3mm acrylic. Now, it looks dirty because of the protection film, but I think it will look really nice once it´s off. :)

attachment.php
 

Attachments

  • photo-3.JPG
    photo-3.JPG
    93.5 KB · Views: 1,513
Last edited:
Hello MellowFellow,
thank you for the compliment! The frontpanel is made by " frontplatten designer "
Schaeffer AG: Home in Germany. You make your design, they make the frontpanel.
It is not a mass- manufactured piece, you see my name on the panel. Inside i changed the couple elkos and the Opamps. It is not really necessary i think. The NAJDA ist a fine piece.
Thanks a lot for the compliment
Ulf
 
Display bug - fix posted in NUC V.1.1.2

I've been notified that there's a bug with the previous release.
This bug is related to the display routines and will show up if ... you have no display attached to the Najda.

If you have a display attached and the Najda is operating normally, then you can skip this update.

If you don't have a display attached and you have updated recently, then it might be that your Najda seems stalled. If this is the case, here's what you need to do:
- Attach a display or alternatively tie a 10 kOhm resistor between pin 14 (DB7) and pin 1 (DGND) on the display port. Now the Najda will start normally again.
- Download NUC V.1.1.2 and update the firmware to V.1.3.
- If that's fine for you, leave the resistor in place so that the micro doesn't wait for an event which is not likely to happen.

Sorry about this bug. It's related to supporting multiple display types (LCD, OLED, VFD and ... no display at all) and each configuration wants different GPIO settings.

In case of doubt, don't hesitate to contact me here or via email.

Nick
 
Has anyone used a Squeezebox Touch as a front end to the Najda? I ask as I have just done so and I get clipping on the DSP output, switching to an Apple Mac seemed to reduce the problem, currently I have set the input 'gain' to -6db. Just how much effect would reducing the 'gain' to say -12db have on sound quality or does it not matter?

The Touch has EDO / TT3.0 mods applied, normally I run it into a Bushmaster without any problems when running single driver speakers.

Connection are Optical from Touch and Mac.
 
Last edited:
Clipping in the digital domain in the input stream comes from 2 sources:

1. The signal already contains data at full scale - i.e., 0dB - and Najda is detecting this
2. Your media player is scaling the data by >0dB - i.e., it is applying gain

If you set Najda input to -1dB, then (1.) will never happen.
For (2.), check that media player's volume control is set to 100% or 0dB or OFF (whichever applies).