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Post by humpink on Sept 4, 2021 20:50:51 GMT
Finally got my lazy ass up and figured out how to connect the Z-DSP Cards to the MultiFX Module. This is possible since both the Z-DSP and the MultiFX use the SPIN-FV1 DSP. No videos or audio examples jet, just wanted to share the current state for now:  Basically, all you have to do is to remove the effect EEPROM from the MultiFX and then connect it with 4 wires to the Z-DSP card:   This shows how the card is internally wired. It seems like it is protected when you insert it upside down, the EEPROMs then just get disabled. (I didn't try this yet.) Pin 4 on the text side of the card (where ZVRB90 is written) is connected directly to VCC. The corresponding pin 3 on the IC side is not connected to anything. So when making a module out of this you could for example feed this pin to the input of a switch which enables the original eeprom when no card is inserted. It also seems that both EEPROMs are not write protected.  This shows which pins of the card are connected to the multifx ic socket. (just the pins with 1,2,3,4 next to it.) The colors of the wires don't match the colors of the drawing, which ist stupid, but it works.  The Socket for the card is this one: www.mouser.de/ProductDetail/TE-Connectivity/5650118-3?qs=00VrTUkr5sBqDKE2vX0kgg%3D%3DIf you try this, do it at your own risk, if you are doing it wrong it will maybe fry your whole system! |
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Post by humpink on Sept 4, 2021 20:52:35 GMT
And another warning to be sure  The drawings may contain errors, especially the text eeprom part, i didn't test that yet. |
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Post by rockysmalls on Sept 4, 2021 21:35:23 GMT
And another warning to be sure The drawings may contain errors, especially the text eeprom part, i didn't test that yet. wow! hack-tastic.... and not so difficult to put the socket in a blank module next to the multifx... there are some great reverbs in the z-dsp.. |
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Post by Kyaa on Sept 5, 2021 3:55:18 GMT
Ooh, wow! Dead simple, but I honestly never would've thought to have tried. Maybe I'll have to pick up a Valhalla cart (and possibly throw together an adapter board...).
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Post by admin on Sept 5, 2021 8:23:08 GMT
Wow, this is hacking on another level! Also I find it amazing that these cards cost as much or even more than the MultiFX module itself!
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Post by pt3r on Sept 5, 2021 11:43:27 GMT
 DIY has reached a whole new level. Very curious to hear the result.
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Post by humpink on Sept 5, 2021 13:54:37 GMT
Still trying to figure out how to keep access to the original eeprom. The effects on the chip you have to remove are the first 8. The most simple solution may be to make a custom card from this: www.reichelt.de/streifenrasterplatine-epoxyd-2-seitig-160x100mm-up-732ep2-p23957.html?&trstct=pol_2&nbc=1Just cut it to the right dimensions and then solder the original eeprom to it. I am also thinking about if it is a good idea to leave the text eeprom pins floating. Text CS could be directly connected to 5V (it already is connected to 5v if you insert the card wrong, this disables the text eeprom). Text SI (serial input) could just be connected to ground via a resistor, i think that will also work for Text SO (serial output) and Text SCK (clock) Then, when you insert the card the wrong way, FX SCL and FX SDA will also be connected to ground via the resistors, which is ok i think? Any opinions on that from someone with more electrical knowledge than me? |
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Post by humpink on Sept 5, 2021 13:57:10 GMT
DIY has reached a whole new level. Very curious to hear the result. Thanks, but i think the stuff other people in the forum have build is far more impressive, at the end of the day it's just 4 wires |
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Post by humpink on Sept 7, 2021 20:26:39 GMT
So after doing some research, it turned out that you should never leave cmos inputs floating. (that can lead to higher current consumption and, in worst case, destroy the ic). So you always have to tie them either to ground or to vcc via a resistor. When the pin is not connected to anything else then you can omit the resistor. Outputs can be left floating, on combined i/o pin it depends on the initial state of the pin. (i think?) So i decided to do the wiring like this. The wiring on the adapter pcb is shown on top. Below that the card pins are shown. All inputs are directly tied to either ground or vcc. Screenshot 1 shows the card pins when the card ist inserted the right way:  Screenshot 2 shows the card pins when the card ist inserted the wrong way (upside down):  The second card pin on the upper left is an output when the card is inserted right, and a combined i/o pin when the card is inserted wrong. So i tied that to ground via a 10k resistor to be sure. So this should disable the text eeprom (which is not needed) in both cases and also make sure that neither the text eeprom nor the fx eeprom get's damaged? Any comment's or warnings on this before i try this out? |
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Post by pt3r on Sept 8, 2021 5:15:41 GMT
Not really since I still don't understand what exactly is happening. Good luck though, going where none of us went before.  |
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Post by humpink on Sept 8, 2021 21:10:29 GMT
Prototype finished. Everything seems to work fine, nothing get's hot and nothing smokes. Putting in the card upside down doesn't seem to damage anything, but i can't check the text eeprom since i don't own a z-dsp any more. The effect order is a little weird, the card effects are not the first 8 but somewhere in between, still have to figure that out. I will upload a sound demo and the wiring in the next couple of days, and then make the card for the original fx chip.   |
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Post by robertlanger on Sept 9, 2021 14:04:09 GMT
Prototype finished. Everything seems to work fine, nothing get's hot and nothing smokes. Putting in the card upside down doesn't seem to damage anything, but i can't check the text eeprom since i don't own a z-dsp any more. The effect order is a little weird, the card effects are not the first 8 but somewhere in between, still have to figure that out. I will upload a sound demo and the wiring in the next couple of days, and then make the card for the original fx chip. View AttachmentView AttachmentAwesome! I was thinking about this possibillity since the beginning of MULTIFX; great to see you have done it! The effects order is indeed weird; this has to do with the fact, that the 16 MULTIFX programs are a mix of the internal and own FX programs, but I wanted to have them sorted by FX type (first reverbs, as second the delays ...) |
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Post by NightMachines on Sept 9, 2021 14:11:05 GMT
This is so cool! I was wondering how easy it would be to create your own Spin DSP chips for swapping, but an adapter for the Z-DSP cards is even better |
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Post by humpink on Sept 14, 2021 15:44:20 GMT
So for those who are willing to try this out, this should make the wiring a little bit clearer:  Mind that i have no electrical knowledge at all, so try this at your own risk.The connections to the multifx are there for obvious reasons i guess The other ones are there to set the remaining inputs of the chips to either 5v or ground, so that they don't float. (a couple of them are connected to vss or ground by the internal wiring of the card) The 10k resistor is there to connect a special pin to ground, which can be either a combined i/o pin or an output pin, depending on the orientation of the card. So for that reason i used the resistor to be on the save side. It probably isn't needed at all. |
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Post by humpink on Sept 14, 2021 15:47:03 GMT
Prototype finished. Everything seems to work fine, nothing get's hot and nothing smokes. Putting in the card upside down doesn't seem to damage anything, but i can't check the text eeprom since i don't own a z-dsp any more. The effect order is a little weird, the card effects are not the first 8 but somewhere in between, still have to figure that out. I will upload a sound demo and the wiring in the next couple of days, and then make the card for the original fx chip. View AttachmentView AttachmentAwesome! I was thinking about this possibillity since the beginning of MULTIFX; great to see you have done it! The effects order is indeed weird; this has to do with the fact, that the 16 MULTIFX programs are a mix of the internal and own FX programs, but I wanted to have them sorted by FX type (first reverbs, as second the delays ...) It took a while until i figured out that the first two reverbs are not from the dsp card but from the multifx |
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DIY has reached a whole new level. Very curious to hear the result.
