TDX Stereo Sound Card – Breadboard Complete

October 28, 2009

Bread Board is complete. Surprisingly all worked (well had an initial issue where i wasn’t providing +5 and -5 volts properly to the board), bit of hiss in the background, but suspect this is because its on a breadboard.

(56k Resistors still arn’t here but put some in series to get the resistence needed)

29/10/2009 – RS Stuff has all turned up, but I had forgotten to add the 56K resistors to the order…3.5mm Stereo PCB jacks also turned up…but suspect they are too close to the board to accept a jack unless at end of the card..Will be fine for breadboard and prototype, but will most likely look at some that are slightly raised to allow cable to not impact back of case. (ideally i want to use a cable from the board to the the back of the case to fit in one of the ports…but finding parts seems difficult)

Connector seems to work well with the ribbon cable and though its a bit of a tight fit on the motherboard it does fit, and didn’t need any crimps. Also started the bread board…not sure its big enough, but its what i had available :).

I have been busy getting parts together for this new project and have just ordered the following parts from RS.

  • 517-3181 – TL084I quad 3MHz 13V/uS op amp, DIP14
  • 197-2669 – 16 way turned pin DIL socket,0.3in pitch
  • 519-0316 – Dual 4-1line mux/demux,MC14052BCP DIP16
  • 135-910P – RES HYSTAB 0.25W/10K
  • 135-932P – CFR16 carbon film resistor,15K 0.25W
  • 365-4234 – NHG min Al electrolytic cap,4.7uF 50V
  • 365-4240 – NHG min Al electrolytic cap,10uF 50V
  • 122-4235 – FKS2 Polyester Cap,100Vdc,1.5nF
  • 622-4397 – Plastic film capacitor,100nF 63V 5%
  • 157-547  – MBA0204 M/F Res, 0.4W 50PPM 1% 56K
  • 289-9846 – Speedbloc(R) 10 way IDC ribbon cable,5m
  • 189-9592 – HE14 AUTOCOM cable socket 26/28awg 7W

I have also ordered a selection of connectors/headers to see what will be best for connecting to the mainboard.

Andy at work likes his circuit diagrams and has kindly drawn up a schematic and a PCB layout based on the TDX diagram and Polymorphs use of the Quad Amp. He still has to add the connector layout for the GS slots, but I am well on my way to having a bread board ready for some testing.

Version 1 Schematic and PCB Layout

I am just going to be using a single sided copper board for the prototyping stage (once breadboard testing is done) this will mean that I will not have the +5V, so will plan to add a L7805 Reg to bring the +12V down to +5V. This will mean only pins 34 and 50 will be used on the connector.

TDX Stereo Sound Card

October 22, 2009

Right on to my next project…. I am now going to attempt to make the TDX sound card i have seen in the FAQ and on Polymorph’s site.

I don’t actually need one as I already have an AE Audio Animator, but again things get older and i could also do with the external box not being on my desk. More importantly more electronics fun 🙂

I have several goals with this project

  1. Re-Produce the above using the information available and assistance from the A2 Community.
  2. Do a more complex electronic’s project
  3. Possibly look at mass production….

I will start ordering kit and getting people at work geared up to help 🙂

Things to think about….

  • Cable to GS ?
  • Audio Output ?
  • Making more than one…

J-25 Connector
1  Analog to digital in
(end nearest front of computer)
2  Analog ground
3  Waveform out
4  Channel address zero
5  Channel address one
6  Channel address strobe
7  Channel address two

Replacement GS PowerSupply – Complete :-)

October 22, 2009

Well today I completed my first electronics project :). I initially was going to just mount the regulator to the case, but someone at work suggested i use a bit of strip board as well as use relevant connector (floppy type in this case). All works. Apart from the 240Volts I got yesterday lol, it was a pretty successful little project. Photos below.

After old power supply was stripped out

New Power supply mounted including Regulator
Used existing mount point to provide a secure fixing then plastic mounts for the rest.

Used existing mounting point to mount the strip board with L7905CV regulator

Circuit diagram for the negative regulator (make sure Capacitor + is to ground)

Circuit Diagram for the MeanWell PT65B PSU

L7905CV -5 Regulator

TECHNIKA 15.4" HD Ready LCD TV (Tesco) – Model 15.4-310

October 13, 2009

Bought this from Tesco today on a bit of a whim. I have tested lots of LCDs with the GS and this is the best one yet and only £99 (is HD Ready, with VGA, component as well). I will say that the colours aren’t as vibrant as real monitor or compared to my Samsung 24inch next to it (when using Carte Blanche via VGA).

Some quick screen shots of GS/OS below.

Some screen shots of 40 column text

80 Column Text