Okay. I really didn't expect my bitstreams to look as cleanly as they were burned on my test-CD, but I really dit NOT expect them to be -that- bad. 22.5 KHz square wave: (101010101....): Looks workable. My discman transforms it into some sort of sinus, as expected. I know now that my discman uses 8 times oversampling.. 11 KHz square wave (11001100...): Ditto. 2.2 Khz square wave (11111111110000000000....): Boy, what an overshoot! Then again, since the lowest spike hardly reaches 3/4 of maximum, it should be filtered out by an infinite amplifier. A-symmetrical stream #1: (110110110110110): The rising and falling edges of the signal are not as steap as they should be. Output level is not at maximum at the first '1'. This means that the 0v-passage will be to late. Once amplified, this means that the 0-pulse is too short. Manageable though. A-symmetrical stream #2: (001001001001001..): Yes, that's exactly the opposite as above:) The only reason I included this pattern was to see if the DAC and/or digital filter of my discman is symmetrical. It is. The result is exactly the same as above, with the difference that the 1-pulse is too short now. A-symmetrical stream #3: (101000): This one is totaly devastated. It hardly represents the signal it's supposed to be; there are -0v crossings where there shouldn't have been; the peak values of the signal follow a strange sinus. I'd be really surprised if a simple amplifier would be able to correct these errors. Seeing this mess, I don't think that it will be possible to record different data on the left- and right channel. This signal is hard enough to repair (if that's even possible!) -without- any crossover from the other channel. I will try to build a working amplifier anyway next weekend (If I'll be able to find some time;), but I wouldn't be surprised if the data rate needs to be reduced drastically. Furthermore, I don't know if it is only my discman messing up things like that. I intend to run some tests on other discmans too, but I don't really expect other results. Furthermore, what's the use of a scheme that will work on some discmans, but won't at others? %s/discman/cd-player/g, if you want - I used the line out.. Kind regards, Martijn -- Martijn van Buul - Pino@dohd.cx - http://www.stack.nl/~martijnb/ Visit OuterSpace: mud.stack.nl 3333 finger firstname.lastname@example.org for my public key block - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail email@example.com.
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