CD723 Hack, did someone download it?

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I was very interested when I read that it is possible to turn off oversampling in the Philips CD-723 and the likes, but now that I have a CD-723 ready for surgery... I can't find the source code to program the hacker!

It was discussed here Thread on 723-Hacker , but the site is now unavailable :bawling: :bawling:

Did someone save it? I'd really appreciate.....


Actually he is the first person I contacted (trough the mail service of the forum) but didn't get a reply, so I asked here.

As for programming, if someone already has a excess Atmel chip and is willing to program it for me it would be really great (of course he'll be rewarded for that ;) ) , otherwise I'll have to go and search for a chip and dig up my old Willeprom programmer (DIYed) that IIRC can program these chips.


Great news!

A few days after my las post on this thread Robinet replied me and sent me the file with all the info needed.

Today I got my Atmel chips and, after finding that at my workplace we have a programmer that supports it.. I quickly assembled the board and tried it: success!! It worked a charm.

Here is a piccy of the hacker in action:


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tschrama said:
How much did you spend for this project? Could you eleaborate a bit... seems like an interesting project..

As my signature suggests I like to be cheap ;-)

The CD723 was about ˆ40 (ebay)
The Atmel chip is very cheap and the circuit uses 5-6 components

The most costly thing is Thorsten's designed output stage for TDA1545A, that can cost up to 100 or more ˆ depending on the components you use. I already had almost everything in stock (including some beautiful Mullard E88CC NOS) so I didn't break the balance.

A description of Thorsten's original modification is here: , be warned that for NON-OS you have to change some values as T. discussed in a earlier thread.

BTW I actually found a credit for T. in this webpage, but it is hidden by its crazy layout.

The hacker allows you to use the TDA1545A in NON-OS mode, but also to throw in a TDA1541A (it programs the SAAxxx chip to output IIS !!), so you only have to choose what to do!

Another thing to do is to tweak the PS as suggested in many places (Nuuk's site and others)

Hope it is enough!


ash_dac said:

Is programming the microcontroller a relatively simple task?

I have a cd723, and also a cdpro mechanism that is gathering dust.



It is pretty trivial, since the hex file has already been compiled and is ready to be "burned" into the uC. You just need to have a suitable programmer and a chip (AT90s1200)


Nuuk said:
Andrea, I have a second CD723 here waiting for modification. It cost me just one penny on Ebay so I guess it truly qualifies for your 'frugal-phile' tag! ;)

Now, if only I could buy some cheap time on Ebay too.....:(

Hello Nuuk,
unfortunately the spare chip I got is already spoken for. :bawling:
If you don't succeed in buying some time on Ebay soon :D next time I make a order to my supplier I can add another AT90S1200 for you, or if you have one you can send it to me and I will program it and send it back to you.


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