DigiTech XP-100 question

[aran.e666]

Hey guys

Ok so i'l get straight to the point and not justify why i am doing this: i am going to attemp the impossible. A complete DIY xp-100. I've done research and I'm confident it's doable. The thing I'm not so confident on is the digital side. I get that the EPROM contains the firmware/code for the effects but what i need to know is what else has firmware/is custom programmed? More importantly, does anyone have the other firmware? I have had no luck from messaging a few people who are known for modding xp-100s so i don't expect much more insight here (no offense  )

[Muadzin]

Applause and respect to your DIY spirit. But why the XP-100? I have one and having tested it against the WH-1 and WH-4 I find it much the lesser of the three.

[aran.e666]

Totally agree that the whammy is much superior to the XP-100 however i cannot find any schatics for the whammy plus it uses even more obsolete parts. Since its also slightly different i assume it will have different firmware that nobody has. I would make one instead if anyone had a schematic but i think if i could make anything at all, it would be the xp-100 since its the pedal that has most information on it.

[wgc]

I don't know too much about it but maybe look deeper into the fv-1.

Rather than copy the digitech circuit, see if you can build an fv-1 circuit and get programs you need to do what the digitech does?

[wgc]

Maybe this will help, old stuff though. Your post piqued my curiosity and I did a quick google.

http://www.diystompboxes.com/smfforum/index.php?topic=85321.0

[aran.e666]

appreciate the reply, i took a look into the fv-1 and it looks quite promising for what i want to do however the reason its more ideal to try and clone the xp-100 is because i already understand the circuit (and have lots of the digital stuff from a POD). looking deeper into the fv-1 makes me think it would actually be significantly easier to make a pitch shifter but after going through the link, it seems it suffers from bad lag. i'l keep my eye on the fv-1 in case i can't make the xp-100.

also for anyone else who might see this, when i say 'XP-100' i generally mean i am making an XP-xxx circuit (they are all the same with the only difference being that different code is flashed onto the EPROM)

[aran.e666]

right, i just found a link to an old thread where someone asks how a whammy works and i found a massive detailed reply explaining the use of SOLA and PSOLA. i actually found a PSOLA audio shifting algorithm in C++ but i highly doubt it would work with an XP-100 as there are other programs on the XP-100. not only that but im not too sure how it would interact with the other IC's etc.

[Muadzin]

Totally agree that the whammy is much superior to the XP-100 however i cannot find any schatics for the whammy plus it uses even more obsolete parts. Since its also slightly different i assume it will have different firmware that nobody has. I would make one instead if anyone had a schematic but i think if i could make anything at all, it would be the xp-100 since its the pedal that has most information on it.

If that is what you want to do go for it! I'm sure the build report will look awesome. Me, personally? I would just buy a 2n hand WH-4. These days they're probably dirt cheap to be had.

[aran.e666]

To be fair, i probably should if anything make a digital pitch shifter since thats really all i am after. I would buy a second hand wh-4 but where i live im looking at minimum  £80 (about $105). Since i have most of the digital ICs i would in theory be making the pedal for cheaper.

[aran.e666]

after digging deeper into one of the unobtainable components, it seems that it is a 24 bit DSP with onboard ROM  . at this point i think i better give up because there is no way to get the firmware thats flashed on that ROM. i think i will probably just make a digital pitch shifter. another option i thought about was buying an xp-100 someday then copying all of the programmed ROM so that i can duplicate the build. so pretty much like how people copied the code from the EPROM (for the XP-all mod). my only constraints with that are 1. i can't afford one right now and 2. how would i get it onto my computer? i thought about using a USB reader interface but i would have to firstly figure out the ROM's location then figure out how to actually read it via the USB adapter.