I have ROM chips to donate to this project, shoot me an email.
OK, so on the chip transplant subject, I've been doing a lot of that. The fried 707 is working much better--to recap, first, I lost the second sound in grouped sounds, then I lost everything but kick/hitom/ride and they sounded all bent. I fried a few chips, I guess.
After swapping some chips, I now have all sounds except crash, even both sounds in a paired set (came back after replacing IC29, BTW). But they sound bent (although recognizable). Here's where it gets interesting: no crash -- I had a test pattern with a crash in it, but it didn't sound -- then as I powered down I got a brief crash as it turned off. Where it gets really interesting: the crash sound was unbent, it sounded totally normal. Odd, but seems to suggest that something is wrong with a crash related chip, doesn't it
Anybody have any ideas as to what to replace first
plutoniq9 <Plutonique9@...>
wrote:
Well, still waitin' on the eprom burner to get here from hong
kong....is it wrong to wait this long for a bong to arrive from hong
kong
hehehe, just a lil' humor....
But i haven't been idle. I programmed a VST module today that applies
Mu-law compression/expansion algorithm to samples. It will be
necessary to process all samples this way before gettin' them on the
707/727 because;
-Samples have a lot of quantized noise (like aliasing) if they aren't
compressed before converting them to 8-bit.
-707, like most 80's machines, use a combination of compression +
expansion on the samples (compansion), so it would sound real bad if
they (samples) were burned in their native linear format, because the
expansion would still be applied by the de-mux chips. That's thoses
extra "envelopes" the schematics refer to, but they apply exponential
envelopes to restore sample dynamics.
Also, when ripping sounds off eprom's, I can apply mu-law expansion to
them to restore their original dynamic content. This would be the most
accurate way to extract samples from old eprom drum machines......
I'm itchin' 4 this eprom burner to come, can ya tell
Also, does no
one have 707 eprom's to donate
Some junk/parts boards out there
I'm
broke....so i can't just grab one from evil bay :) Also, still lookin'
for v2.0 of the firmware.....maybe I'll drop a line to the AH/SDIY list.
Seeya
Ryan
Blab-away for as little as 1 ¢/min. Make
PC-to-Phone Calls
using Yahoo! Messenger with Voice.