New ADB Soundbox replacement

Started by barcher174, March 04, 2018, 01:46:41 AM

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barcher174

All,

I'm very pleased to say I have a fully working board:

The standard board with no sound (Will pass the sound test and not lock up!)



The board with stereo output configured:



The board with mono output for a built-in speaker:


The width of the board is nearly identical to the original soundbox board, so it should easily fit in a 3d printed enclosure. To my ear it may sound better than the original, but I'm biased.

nextchef

Nice work Brian!  Combine this with some of the 3d-printed enclosures and we now are very close to a complete replacement for the soundbox.

If you have it configured with an attached mono speaker will it be disabled if you plug in external speakers?

barcher174

The audio amps run independently of each other so they will both run together. You could easily add a switch for the speaker. The sound is running on the very common I2S protocol so it would be trivial to adapt to any number of off-the-self solutions. I chose the adafruit I2S audio amps because they are easy to source and <$10. I would be hard pressed to build my own solution for cheaper and it keeps this board easy to assemble (Everything is through hole).

barcher174

Did some additional testing today. VGA works perfectly, as does ADB. If you boot without the NeXT ASIC installed, the sound test will still fail, but everything still works as expected (except sound). So the board on its own can still revive turbo systems if you don't care about sound.


Rob Blessin Black Hole

Cool Brian, I found a box of NeXT Soundbox shells as well that was marked printer trays, no faceplates still a good find.
Rob Blessin President computerpowwow ebay  [email protected] http://www.blackholeinc.com
303-741-9998 Serving the NeXT Community  since 2/9/93

krazycat

Quote from: Rob Blessin Black Hole on September 07, 2019, 08:17:36 PMCool Brian, I found a box of NeXT Soundbox shells as well that was marked printer trays, no faceplates still a good find.

Rob, If you need them, I still have about ten fronts printed in 3D, compatible with the original shell


Rob Blessin Black Hole

Hello : Yes I can use those shell fronts! Best regards Rob Blessin
Rob Blessin President computerpowwow ebay  [email protected] http://www.blackholeinc.com
303-741-9998 Serving the NeXT Community  since 2/9/93

barcher174

I have a couple soundbox boards which are beyond repair that I've been using for donor parts. I created a PLCC to DIP adapter to use the ASIC from these boards as well. Both nonADB keyboard and sound are working.



Not a practical solution, but I was curious to see if I could.

nextchef


mattsoft

Does the VGA still require sync on green or do you have a sync separator so you can use RGBHV monitors?

barcher174

The sync signals are broken out for mono systems, so no SoG requirement. 

mattsoft

Quote from: barcher174 on October 23, 2019, 10:28:02 PMThe sync signals are broken out for mono systems, so no SoG requirement. 

Woo-hoo! Very nice!

msch

Hi Brian,
I recently bought a NoSoundADB v3.0 from Rob Blessin (for use with Luciano's excellent Sounbdbox replica case).
Do You have any documentation for it?
There is a 3-pin header ("J1") and 6-pin header ("MONO") on the board.
Which mono circuit do I need to use the mono output?
What is the difference between revisions V2.2 and 3.0 of the PCB?
I hope You can help.
Thanks again and cheerio!
Mathias

edit: is this the right mono Amp?
https://www.adafruit.com/product/3006
Best regards

Mathias

barcher174

1) J1 is a breakout of the -12V line. You can put a load resistor or bulb there to boot a cube which requires a Meagpixel.
2) Yes, this is a proper Mono Amp: https://www.adafruit.com/product/3006
3) The port layout was cleaned up a bit.

No documents yet. But the full schematics are here: http://www.nextcomputers.org/forums/index.php?topic=4369.msg25569#msg25569

msch

Thanks. What do You recommend for the ,,load resistor" exactly? As I understand, a load resistor is a descriptor for an electronic part with specific characteristics. Which part should I use to boot a cube?
Best regards

Mathias