DIYHiFi.org

Correction to the post above: all INPUT signals to the register are switching, including output enable and clock. I can input signals to the A/D and see the bits toggle at its output (parallel output). This is tied directly to the inputs of the register. So I can see the inputs of the register switching. But the outputs seem to be oscillating, I read 300mV with my DMM. And the outcome is always logic 0.

I did these tests at low sample rates like 10k.

Out of the circuit this data register tested ok, in DC conditions (manually tested with push buttons and protoboard).

I think I´ll learn something with all this.

Best
Alex

74FCT574 should do the job though.

_________________
Antoine

There's just 1/3 of the card on that picture

_________________
Antoine

Hi Dragonmaster

When I took the picture I tought only the analog stage was at fault... since then it has turned into a mess.

It´s really a puzzle to troubleshoot this card. But I´ll manage it eventually. I grew fond of this instrument since it has helped me in many projects, not only in audio.

Dragon, do you still have yours? Is it working?

Best
Alex

Yep, still have my two cards. Still working? No idea. Not 100% for sure, they're boxed in somewhere.

_________________
Antoine

If you ever want to sell the cards I´d be interested.

I just took a screenshot of the logic analiser function, which is working fine. When I first bought this card off ebay the seller sent me the wrong logic pod, I had to modify it to correct a pinout difference.

Shown are the signals to my AD1865 dac at 24/96 non-oversampling. Note the simultaneous L/R, stopped clock operation, all lines are quiet before and after conversion.



Best
Alex

Actually, it´s 16/96 since it´s dithered... Still have to find a dither plugin that allows 18 bit wordlenght.

Speaking of dither, this is an interesting page: http://www.24-96.net/dither/

Best
Alex

I'm going into electrical engineering next semester, never know! If it turns out I don't need them, I'll tell you.
I bought a Tek 485 after I saw the cards were going to need a lot of work. It solved my problem for analog signals, but maybe the logic analyser will turn out to be useful for me as I might work with more than analog signals in the near future.

_________________
Antoine

Congrats for going to EE, great choice!

These older TEKs are great, I should get myself one. But ít´s hard to find one in good condition at a decent price down here.

Best,
Alex

Oh, I got mine dead quite cheap, but I had luck and found someone who sent me free PCBs from a unit with a broken CRT. The flyback was shot and the PSU board as well, but after a little swap, the beast came alive.

_________________
Antoine

Must have been a blast!