First off, a mighty THANKS!!, and a well deserved round of applause for Prehistoricman for this latest update to the XP-ALL.
Managing to reverse engineer the Digitech .bin files, he rearranged the code, allowing each mode to now retain whatever user presets one wishes to save in any mode. Each mode will now retain those presets in memory, regardless of what presets are programmed in other modes.
This, is a major advancement in the project. Previously, the user presets section of the XP-ALL+ was rendered useless, due to the fact that only one section of memory was being used by all the modes. Since some modes had more/less presets than other modes, and some modes had preset numbers that did not exist in other modes, saving user presets would sometimes overwrite saved presets in other modes, or sometimes create errors that would require factory resets.
The new code, baptized "XP-ALLin", has been tested on my XP-ALL+ platform (converted XP-200), and is fully functional.
The updated XP-ALL build document can be found here;
https://drive.google.com/open?id=1aIbRsYi9-_odxECMjSIw4PFZCpxpx_GD (https://drive.google.com/open?id=1aIbRsYi9-_odxECMjSIw4PFZCpxpx_GD)
The new XP-ALLin .bin file (for XP-ALL+ 27C1001 application) can be downloaded here;
http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=53391&g2_GALLERYSID=b9edd9290db937f0dfd0be36edb4e9a4 (http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=53391&g2_GALLERYSID=b9edd9290db937f0dfd0be36edb4e9a4)
Prehistoricman's video on how the Digitech code was reverse engineered, and modified to all for user presets to be saved, can be viewed here;
When we initially released the XP-ALL, there were two functional drawbacks; the loss of stereo output in 100 mode, and the inability to securely store user presets in all modes. While the relay workaround solved the stereo issue, the XP-ALLin now addresses the user presets problem of the XP-ALL.
Coming soon - replacement of the preset mode switching with a rotary switch, to a footswitch style mode switching.
Regarding stereo output for the XP-100 mode, this is the bottom line:
Don't hold your breath. I'll have a real crack at it in a couple of weeks when I have my EEPROMs and a programmer.
The DSP controls stereo output and there is very little documentation on the internet about the DSP. That's the big issue with the XP-100 stereo output.
However, I'm pleased with the current progress. Big props to digi2t and Govmnt_Lacky for doing all the work towards the XP-ALL. They're still the true heroes here :)
Some really excellent work from all you folks, this is an absolutely amazing development for the XP! Am I right in saying if you already have the XP-All mod installed the new rom should work without an issue?
Quote from: MüThing on January 15, 2018, 10:44:19 PM
Some really excellent work from all you folks, this is an absolutely amazing development for the XP! Am I right in saying if you already have the XP-All mod installed the new rom should work without an issue?
Yes. I currently have the new XP-ALLin chip running in my XP-ALL+ unit. It was a straight swap out. I do recommend doing a factory reset once the new chip is in however.
I've done a complete shake down on it;
- tested all modes for user preset memory retention.
- memory retention when other mode user presets changed.
- no problem in saving presets in non-linear fashion (they don't have to be in an ascending /descending order).
- complete functionality of all factory patches.
Nothing out of the ordinary has popped out to date. No C5 or C7 errors at all. Same 'ole XP, just better.
I don't even do digital stuff, but I want you all to know I think this is remarkably cool 8)
I believe this will only work with the "+" models. It will not work with the stacked EEPROM conversions.
Correct me if I am incorrect.
If you have a stacked EEPROM model then you will need to convert to th single 27C1001 version.
Quote from: Govmnt_Lacky on January 16, 2018, 11:52:33 AM
I believe this will only work with the "+" models. It will not work with the stacked EEPROM conversions.
Correct me if I am incorrect.
If you have a stacked EEPROM model then you will need to convert to th single 27C1001 version.
I think it would work with the stacked chips. Since each .bin file is modified individually, once the stack is assembled, it should work. After all, the XP-ALL+ is simply the same four .bin files, but all together on one chip.
The pain with the XP-ALL is that you need to either disassemble and reprogram your stack, or make a new stack altogether.
Quote from: digi2t on January 16, 2018, 06:42:22 AM
Yes. I currently have the new XP-ALLin chip running in my XP-ALL+ unit. It was a straight swap out. I do recommend doing a factory reset once the new chip is in however.
I've done a complete shake down on it;
- tested all modes for user preset memory retention.
- memory retention when other mode user presets changed.
- no problem in saving presets in non-linear fashion (they don't have to be in an ascending /descending order).
- complete functionality of all factory patches.
Nothing out of the ordinary has popped out to date. No C5 or C7 errors at all. Same 'ole XP, just better.
Lovely, lovely, lovely! ;D I'll be digging out the MiniPro and putting my XP back to work on my board.
Quote from: digi2t on January 16, 2018, 12:00:31 PM
The pain with the XP-ALL is that you need to either disassemble and reprogram your stack, or make a new stack altogether.
This was more of the reasoning I wanted to convey. :icon_redface:
If you are going to disassemble a 4 chip stack to do this and then re-assemble it.... you might as well convert to the 27C1001 anyways ;)
I found out the importance of decoupling yesterday. I received my extra RAM chips, solder suckered all the holes in the board and added sockets for them. Upon adding the extra RAMs, my Whammy didn't quite work as I remembered. The frequency of the pitch shift would oscillate quite badly, and I couldn't push the pedal far enough to get the entire shift. (On this note, why is the expression pedal LED powered by the digital 5V?) The signal LED was also behaving slightly weirdly.
I tried to do some decoupling. I had a couple of ceramic 2.2uF caps but it's still 5x less capacitance than the tantalums that should have been there. I added a cheap Chinese 470uF electrolytic and it didn't help. Then I replaced it with a 3.3mF electrolytic and it worked great! I suspect the lower ESR of the huge cap is what did the trick. The designers wouldn't have asked for tantalums if they didn't need to. However, I still plan to test out some higher capacity MLCCs as these would be smaller than the tantalum.
Yep! If you install the 3 additional RAM chips, you definitely want to install C61, C64, and C65 or else there will be some "issues."
Unrelated, but important nonetheless, when doing mod work on these units. A factory reset and calibration should be done before using the unit.
Factory Reset/Pedal Calibrate -
- To reset the User programs to their factory settings and calibrate the expression pedal, with power off, press and hold the <BYPASS/(Hold)TUNER> foot switch, and apply power to the unit.
- Wait until the letters rS appear in the display and release the foot switch.
- The display will now show: Pd and CA , indicating that you are in pedal calibrate mode
- Once Pb appears, rock the pedal back and press the <BYPASS> foot switch.
- When PF appears, rock the pedal forward and press the <BYPASS> foot switch.
- SA will next appear in the display to confirm the pedal is now calibrated.
I myself, as well as one or two others that have done these mods, have encountered the units doing "weird things" after a mod. A simple factory reset has cleared things up in some cases.
What kind of weird? I'm interested.
Quote from: Prehistoricman on January 19, 2018, 01:32:22 PM
What kind of weird? I'm interested.
Patches not loading (dead air), patch working but not modulating with the treadle, were two that come to mind.
Update on the decoupling issue:
Wasn't actually decoupling. I scoped the power supply after adding a considerable amount of SMD ceramic caps (9) and found that there was a 0.5V dip at 50Hz. This led me to believe that the input cap wasn't holding enough juice for the next cycle of the mains supply. I doubled the capacitance of the input cap and it works fine.
Quote from: Prehistoricman on January 23, 2018, 08:07:46 PM
Update on the decoupling issue:
Wasn't actually decoupling. I scoped the power supply after adding a considerable amount of SMD ceramic caps (9) and found that there was a 0.5V dip at 50Hz. This led me to believe that the input cap wasn't holding enough juice for the next cycle of the mains supply. I doubled the capacitance of the input cap and it works fine.
Which input caps were you having trouble with? C?
C39
I suspect the issue might have something to do with the fact that I'm using my own power adapter (a 9V transformer made in '92 in England!). It outputs exactly 9VAC and I suspect that a stock power supply outputs a bit more than that.
On a different note, my EEPROM programmer is coming along. I spent 5 hours in my university's lab today checking the timing and making code :)
(https://s13.postimg.org/ezgaw1mab/WP_20180124_16_57_32_Pro_LI.jpg) (https://postimg.org/image/ezgaw1mab/)
Excellent, glad I checked this it when I did abd found the update.
Although I do love all of the advancements that have occurred with the XP platform, it is painful to see where the prices of used or second-hand XPs have gone. Someone used to be able to get a used XP100 for anywhere from $40-70. Those days are long gone now. Going rate for them is about $125! XP200s and 400s are worse.
Hopefully, the market will settle and the prices will go back down :-\
Quote from: Govmnt_Lacky on April 03, 2018, 09:55:37 AM
Although I do love all of the advancements that have occurred with the XP platform, it is painful to see where the prices of used or second-hand XPs have gone. Someone used to be able to get a used XP100 for anywhere from $40-70. Those days are long gone now. Going rate for them is about $125! XP200s and 400s are worse.
Hopefully, the market will settle and the prices will go back down :-\
All your fault pal. ;D
Quote from: digi2t on April 03, 2018, 12:20:10 PM
All your fault pal. ;D
:kicksrocks: >:( ::) :icon_lol:
The good thing is that sales appear to have stagnated. I see the same units for sale for the same prices for weeks on end.
Only a waiting game before the prices go down... hopefully
Quote from: Govmnt_Lacky on April 03, 2018, 02:36:55 PM
Only a waiting game before the prices go down... hopefully
(https://media.giphy.com/media/3o7TKxBr7xhEgJhaFy/giphy.gif)
I bought mine for about $170 equiv. including postage and tax (cheapest to buy from the UK). Then 2 months afterwards, I saw a unit that had faulty buttons to bid on for £1. I'm reminded from this price discussion that I probably could have won it and I've been kicking myself ever since :(((
Quote from: Prehistoricman on April 05, 2018, 08:28:26 PM
I bought mine for about $170 equiv. including postage and tax (cheapest to buy from the UK). Then 2 months afterwards, I saw a unit that had faulty buttons to bid on for £1. I'm reminded from this price discussion that I probably could have won it and I've been kicking myself ever since :(((
I wonder who bought that one :icon_evil: Went for £21 in the end. I have replaced the buttons with foot switches and made a face plate like someone did on here. Halfway through the conversion to XP ALL +
Update:I have found how to modify the XP100 ROM to output in stereo! The only thing is... it's wet on both sides. I don't know how much you guys would care about having that?
My feeling is that getting wet/dry stereo out would require much more understanding of the DSP chip than I currently have. My greatest progress so far has been seeing the 4-byte instructions and the 3-byte data words that are sent to the DSP. Without info on the DSP's instruction set... it's somewhat impossible to reprogram it.
I 'discovered' this mod 3 weeks ago now but held off on an update until I heard a word from Dino. What you doing man?? :icon_evil:
Edit: :icon_eek: Turns out I didn't email Dino! Now I blame Greg for not telling me my mistake :icon_evil: Haha
Trivia:
- The mod to get wet/wet output is a change of a single bit
- The XP100's tuner mode's volume pedal is stereo wet/wet from factory because...
- All units contain the same data to send to the DSP in tuner mode
All right, I've been wanting to do this for a while and just picked up an XP100 yesterday. I can't wait to get started on this, in the very early 00's my other guitar player had a Space Station that he never used so I had it on my board for three or four years and I really miss it! Been looking to come across a cheap XP ever since you guys started this, there are two things I try not to order online and be zen about finding, used pedals and LPs, it's almost as much about the hunt as it is owning it.
I'm really looking forward to this!
Those of you that happen to have an XP kicking around... be thankful.
Used to be able to pick up a second hand XP100 or maybe even 200 for about $50-70. Can't touch one for under $150 now :icon_eek:
Did you already post the bin file for stereo wet/wet XP100? Personally I would find that way more useful than dry/wet, thanks!
Quote from: Govmnt_Lacky on September 26, 2018, 04:32:14 PM
Those of you that happen to have an XP kicking around... be thankful.
Used to be able to pick up a second hand XP100 or maybe even 200 for about $50-70. Can't touch one for under $150 now :icon_eek:
I got mine for $100 at Sam Ash, I figured that was fair enough.
Hello y'all! I should really enable notifications...
I never uploaded/finished the wet/wet binary because of lack of interest. Now that a couple of you are here, the XP100 modded wet/wet can be found here:
https://www.aronnelson.com/DIYFiles/up/xp100_whammy_eprom_new_-_mod_%2B_wetwet.txt
The file extension is txt because I wasn't allowed to upload .bin
Please do report back if this worked correctly - I have my own testbench but I don't trust myself!
I am still investigating the mystery TMS57070 DSP chip. Yesterday I found a way to get all 3 XP100 effects on the pedal at the same time. Cool stuff.
Thank you! I'll report back as soon as I can.
So I just ordered the OSH park PCB for the conversion.
Do any of you folks that have done this already have a reliable/preferred source for the ram and eeprom stuff? I'm not super fond of ebaying chips.
Quote from: wavley on October 09, 2018, 03:51:50 PM
So I just ordered the OSH park PCB for the conversion.
Do any of you folks that have done this already have a reliable/preferred source for the ram and eeprom stuff? I'm not super fond of ebaying chips.
The EEPROM chips I have used many different vendors. My RAM chips I used to get from a specific eBayer but sadly, they have been "away" for several months and I fear that they will not be back :icon_cry:
Kinda bummed because they had great prices and I never got a bad chip from them.
I bought 5 chips from https://www.ebay.co.uk/usr/cayin35
All of them worked but one of them was slower than the rest. Not a big deal especially when you get 5 pieces.
Sadly for you, I don't think they deliver to the US.
Quote from: wavley on October 09, 2018, 03:51:50 PM
So I just ordered the OSH park PCB for the conversion.
Do any of you folks that have done this already have a reliable/preferred source for the ram and eeprom stuff? I'm not super fond of ebaying chips.
Check out the Dead End FX store. We offer the adapter boards, as well as an EPROM burning service. I test all EPROM's before shipping.
https://www.deadendfx.com/product/xp-all-adapter-board (https://www.deadendfx.com/product/xp-all-adapter-board)
https://www.deadendfx.com/product/xp-all-chip-burning-service (https://www.deadendfx.com/product/xp-all-chip-burning-service)
Try Jameco for the SDRAM.
https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&freeText=41464&langId=-1&storeId=10001&productId=41574&krypto=UI1Oux8BxV2jO6bwif4E4RAUB5cNLakb2mU0v1wx3QEwbDRmrPFq2p42Q9IYKVMIg%2FDrO7nZzGzvLmp1tCoiPeauJTU9bI7VDWvRTEUyxRE%3D&ddkey=https%3AStoreCatalogDrillDownView (https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&freeText=41464&langId=-1&storeId=10001&productId=41574&krypto=UI1Oux8BxV2jO6bwif4E4RAUB5cNLakb2mU0v1wx3QEwbDRmrPFq2p42Q9IYKVMIg%2FDrO7nZzGzvLmp1tCoiPeauJTU9bI7VDWvRTEUyxRE%3D&ddkey=https%3AStoreCatalogDrillDownView)
Quote from: digi2t on October 10, 2018, 06:43:21 AM
Quote from: wavley on October 09, 2018, 03:51:50 PM
So I just ordered the OSH park PCB for the conversion.
Do any of you folks that have done this already have a reliable/preferred source for the ram and eeprom stuff? I'm not super fond of ebaying chips.
Check out the Dead End FX store. We offer the adapter boards, as well as an EPROM burning service. I test all EPROM's before shipping.
https://www.deadendfx.com/product/xp-all-adapter-board (https://www.deadendfx.com/product/xp-all-adapter-board)
https://www.deadendfx.com/product/xp-all-chip-burning-service (https://www.deadendfx.com/product/xp-all-chip-burning-service)
Try Jameco for the SDRAM.
https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&freeText=41464&langId=-1&storeId=10001&productId=41574&krypto=UI1Oux8BxV2jO6bwif4E4RAUB5cNLakb2mU0v1wx3QEwbDRmrPFq2p42Q9IYKVMIg%2FDrO7nZzGzvLmp1tCoiPeauJTU9bI7VDWvRTEUyxRE%3D&ddkey=https%3AStoreCatalogDrillDownView (https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&freeText=41464&langId=-1&storeId=10001&productId=41574&krypto=UI1Oux8BxV2jO6bwif4E4RAUB5cNLakb2mU0v1wx3QEwbDRmrPFq2p42Q9IYKVMIg%2FDrO7nZzGzvLmp1tCoiPeauJTU9bI7VDWvRTEUyxRE%3D&ddkey=https%3AStoreCatalogDrillDownView)
HOW DID I MISS THE ADAPTER BOARD ON YOUR PAGE!!!! :icon_redface:
I was planning on using your chip burning service and even though I love OSH Park I would have rather given money to you!
That's ok, there's more boards I'll probably be buying from you when I get the chip. Any idea on the ETA of the Meaty Balls, I'm in love since I repaired one for Steve West (Pavement/Silver Jews), I didn't want to give it back.
Quote from: wavley on October 10, 2018, 09:50:59 AM
Any idea on the ETA of the Meaty Balls, I'm in love since I repaired one for Steve West (Pavement/Silver Jews), I didn't want to give it back.
Meaty Ball have been ordered and should be here in a week or two.
Quote from: Prehistoricman on September 29, 2018, 07:51:07 AM
Hello y'all! I should really enable notifications...
I never uploaded/finished the wet/wet binary because of lack of interest. Now that a couple of you are here, the XP100 modded wet/wet can be found here:
https://www.aronnelson.com/DIYFiles/up/xp100_whammy_eprom_new_-_mod_%2B_wetwet.txt
The file extension is txt because I wasn't allowed to upload .bin
Please do report back if this worked correctly - I have my own testbench but I don't trust myself!
I am still investigating the mystery TMS57070 DSP chip. Yesterday I found a way to get all 3 XP100 effects on the pedal at the same time. Cool stuff.
Question on the wet/wet code. Does it also contain the preset memory mod of the XP-ALLin code?
Quote from: digi2t on October 10, 2018, 01:14:51 PM
Quote from: wavley on October 10, 2018, 09:50:59 AM
Any idea on the ETA of the Meaty Balls, I'm in love since I repaired one for Steve West (Pavement/Silver Jews), I didn't want to give it back.
Meaty Ball have been ordered and should be here in a week or two.
This is great news, sounds like about the time I'll be getting chips and mailing them to you.
Quote from: digi2t on October 10, 2018, 01:14:51 PM
Question on the wet/wet code. Does it also contain the preset memory mod of the XP-ALLin code?
Yes.
Quote from: Prehistoricman on October 10, 2018, 07:38:05 PM
Quote from: digi2t on October 10, 2018, 01:14:51 PM
Question on the wet/wet code. Does it also contain the preset memory mod of the XP-ALLin code?
Yes.
So, with this code I no longer need to stuff the relay on the adapter pcb?
Got everything but my adapter pcb's (I think they shipped, I'm bad about going to my mailbox) so I'm going to start on this soon.
Crazy idea, but is there any way to do the WH-1 code for the Whammy part instead of the XP version, I've got a 3/4 working one (white noise follows the notes, I think there may be some corruption going on) and there's just something about it that seems better than the others I've tried. The whammy just doesn't suit my playing style, but after playing the WH-1 I could see using it.
Quote from: wavley on October 24, 2018, 02:51:49 PM
So, with this code I no longer need to stuff the relay on the adapter pcb?
Correct. We have a wet/dry code in the works too!
Quote from: wavley on October 24, 2018, 02:51:49 PM
Crazy idea, but is there any way to do the WH-1 code for the Whammy part instead of the XP version, I've got a 3/4 working one (white noise follows the notes, I think there may be some corruption going on) and there's just something about it that seems better than the others I've tried. The whammy just doesn't suit my playing style, but after playing the WH-1 I could see using it.
The WH-1 runs on completely different hardware. To transfer the algorithm (with our current knowledge) would be impossible.
It's within the realm of possibility to run both in the same box and then use a controller/mod to switch to the WH-1 signal path.
Your issue with the WH-1 sounds like a bad connection to RAM.
Hello.Is the wet/wet bin for the 27001 chip or just the wh100 rom that needs to be compiled with the rest?
How is the wet/dry coming along?
Quote from: mitchschaft on August 05, 2019, 01:05:35 AM
Hello.Is the wet/wet bin for the 27001 chip or just the wh100 rom that needs to be compiled with the rest?
Just for the XP-100. If you know how to use a hex editor, it's a very simple task to either stick the bins together or to replace the old XP-100 code (it's at the beginning of the combined file). Otherwise, I can do it for you.
Quote from: mitchschaft on August 05, 2019, 01:05:35 AM
How is the wet/dry coming along?
That's weird... I was convinced I had released it already.
I'll check out my bins and see if it's ready for release. I made the code modifications successfully, but there are a couple more steps before I can put it online.
At the time that I discovered wet/dry, I was basically hitting random buttons with regard to making the mod. I've since found out what most of the instructions do and now I'm more sure that it works and is stable.
That's good to hear. Maybe I overlooked it. I just now got around to installing the XP-ALLin rom. I took a bit of a break the last year. Today I started looking into Diptrace to learn how to make a PCB that incorporates the PIC for the momentary switch so I can ditch the rotary and relay. I don't know if you guys have messed with that yet.
I found this flash eprom board on oshpark. I wonder if that guy got around to doing anything with it.
https://oshpark.com/shared_projects/MulhqGKj
(https://i.postimg.cc/p5TJP4Wp/osh-flash.jpg) (https://postimg.cc/p5TJP4Wp)
XP100 modded dry/wethttps://www.aronnelson.com/DIYFiles/up/xp100_whammy_eprom_new_-_mod_%2B_drywet.txt
As before, it's a txt so you may need to rename that for whatever flashing tool you may use.
Quote from: mitchschaft on August 05, 2019, 05:32:54 PM
https://oshpark.com/shared_projects/MulhqGKj
(https://i.postimg.cc/p5TJP4Wp/osh-flash.jpg) (https://postimg.cc/p5TJP4Wp)
Pretty cool. I considered doing something like this but by making a foray into the world of WiFi. I thought it would be neat to be able to flash the chip in my XP100 while sitting at my PC. The XP100 would power whatever networking chip it was (probably ESP8266). I was doing a lot of chip flashing back then (with my DIY programmer :icon_mrgreen:) so it could have been worth it.
Is there a step by step tutorial? Where do I get the parts/boards? Which ones should I use? Thanks
Quote from: lewsidiusmaximus on September 06, 2021, 07:43:33 AM
Is there a step by step tutorial? Where do I get the parts/boards? Which ones should I use? Thanks
Chip burning service;
https://www.deadendfx.com/category/service (https://www.deadendfx.com/category/service)
Code download, if you have your own burner (assembled for 27C1001 chip);
https://drive.google.com/open?id=1nwHOxD5Mulv5Ccg7hW1dxjgvDdsJVuAb (https://drive.google.com/open?id=1nwHOxD5Mulv5Ccg7hW1dxjgvDdsJVuAb)
27C1001 adapter board;
https://www.deadendfx.com/product/xp-all-adapter-board (https://www.deadendfx.com/product/xp-all-adapter-board)
Build document;
https://drive.google.com/open?id=1aIbRsYi9-_odxECMjSIw4PFZCpxpx_GD (https://drive.google.com/open?id=1aIbRsYi9-_odxECMjSIw4PFZCpxpx_GD)
Sorry, apart from the adapter board, we don't supply parts.
EDIT: oops I got it, the LED needs to be pointed off center to calibrate for some reason that works. nevermind!
I just discovered the craziest thing , I'm reporting this on 2 different XP-ALL builds using codes titled:
xp400__reverberator_eprom_new.bin
Etc and it is loaded on an EPROM stack.
I have a batch of RAM that does not seem to be an outright failure, until you try to use XP400 reverse reverb patches 40-48. in the time of 3 to 5 minutes it will shut down , reset becoming worse and worse each time until eventually it can not even run space station patches anymore. Plug in some different RAM from the same batch and the process starts all over again. It seems the RAM will behave perfect as long as avoiding the reverse reverb. It's a shame bc personally I think a few of those patches are definitely highlights for the xp400 category. I don't believe it could be any other problem than the RAM because patches do load and sound correct for a period of time and it won't crash until you've been playing for a few minutes.
Anyways I wonder does anyone have a for sure source for good RAM? It seems the ones labelled NEC JAPAN are no good. Does old RAM like this go bad over time?
Thanks for any help!
Quote from: charmonder on October 24, 2022, 02:09:39 PM
I just discovered the craziest thing , I'm reporting this on 2 different XP-ALL builds using codes titled:
xp400__reverberator_eprom_new.bin
Etc and it is loaded on an EPROM stack.
I have a batch of RAM that does not seem to be an outright failure, until you try to use XP400 reverse reverb patches 40-48. in the time of 3 to 5 minutes it will shut down , reset becoming worse and worse each time until eventually it can not even run space station patches anymore. Plug in some different RAM from the same batch and the process starts all over again. It seems the RAM will behave perfect as long as avoiding the reverse reverb. It's a shame bc personally I think a few of those patches are definitely highlights for the xp400 category. I don't believe it could be any other problem than the RAM because patches do load and sound correct for a period of time and it won't crash until you've been playing for a few minutes.
Anyways I wonder does anyone have a for sure source for good RAM? It seems the ones labelled NEC JAPAN are no good. Does old RAM like this go bad over time?
Thanks for any help!
Is this problem happening on 2 separate builds? Separate boards??
Interesting. I'll have a go with my build. I must admit, I rarely use the 400 patches. 100 and 200 patches get the most play, with the reverse tape setting on the 300.
Quote from: Govmnt_Lacky on October 25, 2022, 06:58:04 AM
Is this problem happening on 2 separate builds? Separate boards??
Yes mine and one I'm doing for a band mate. I'm reporting those results on both a v1 XP100 and v2 (no internal boot) XP100. My explanation is total speculation, but I'm wondering if those particular patches use up so much memory that it reveals faults in otherwise passable RAM (?)
Quote from: digi2t on October 25, 2022, 09:09:52 AM
Interesting. I'll have a go with my build. I must admit, I rarely use the 400 patches. 100 and 200 patches get the most play, with the reverse tape setting on the 300.
Same, thats why I'm wondering if this might have always been a latent problem as I never bothered exploring the xp400 until recently. patches#46 & 47 in particular are fun usable interesting sounds in my opinion, its 100% wet reverse with just enough time to play sensical leads. sadly those are the exact patches that are crashing my XPs and destroying my RAM
I've ordered some jameco RAM and I bought a real unaltered XP400 so I'll report some findings...
oh no! New batch of RAM from a USA distributor, reverse reverb is crashing both pedals
NEC USA 100ns
NEC IRELAND 100ns
I'm wondering if all this RAM really is suspect, I don't see how it could be a problem with the actual code because it will load the patches for a good 15 minutes initially and then thats pretty much the last of it!
Something else I was thinking the tantalum caps that go with the RAM holders... maybe I should replace that 1 original cap that was already in the units?
aha! I think I got it!
OK so first off it is entirely possible to sort out good and bad RAM. key patches are on XP300, the famous synth string patches and the warp delay patches. If your RAM is bad these will be varying degrees of noise. If you have good RAM there will be no extra noise. Listen closely to both channels. If there is just a faint detuned radio amount of noise you still have 1 bad RAM chip, keep subbing out chips 1 at a time and by process of elimination you should be able find a complete set of good RAM.
2ndly, I believe when you are using the undervolt sensor method of automatic reset, it is also important to keep the power supply very clean. I had my XP plugged directly to a non-standby switched amp. This will predictably trip the XP undervolt when I turn on or off the amp. I still can't explain why this only happens on certain reverb patches! It seems to be that simply keeping a buffer between the XP1000 and the amp prevents the possibility of accidentally crashing the XP. I should probably replace the large electrolytics in that amplifier!