I am very interested in your mods! I am wondering if there is a way to expand the keyboard's flash memory. On your blog you mention that the samples and arpeggio patterns are stored in a 16Mbit Serial flash memory (probably?). Do you think there is a way to "capture" these samples and transfer them to a bigger flash memory and then add more samples to it? I am also thinking that in this way maybe the looper recording time improves as well? As it is now if you try to use the looper function with 2 sounds + effects (e.g. a drum loop on arp. hold, a piano played live + sustain on and a motion effect) sometimes you get a "FUL" writing on the screen pretty quickly. I understand that my idea probably is much harder to implement than I make it sound to be but still I'm very curious to find out how this works even if I don't go ahead and try it. Thank you for your time!!!
Hello @Rr12NewZealand, Thank-you for you interest and the valuable suggestions. The 2Mbytes flash is used for both the firmware and the different other data like arpeggios, samples, motions effects... Your recording are also stored in Flash (at the really end, starting from @1FE050 16Mbits means the size is 1FFFFF, which means the storage for your recording is 'only' about 8kbytes Increasing this size would be possible (code patch might be needed) , but unfortunately not possible from what I could see when decompiling the firmware : (I used Guidra to disassemble the ARM code, and get a pseudo C code) The issue is that before saving your recording in flash memory, the recording is done at first in RAM, and then transfered to the flash when turning the device off. I don't have any datasheet for the main SOC YMW830-V, so I don't know the RAM size. Anyway, but from what I could see in the memory map, it seems that your recording is also limited by RAM (currently, the recording is saved in RAM between @2a1fd - @2bffc). There's still some RAM available after, but it allocated for other things. Trying to relocate this entry point much below at @30000 could be an option => This is to be investigated, but I'm not sure if RAM is still available there. TBC About Samples, in PSS-A50, they are located in the range C0800 up to 1FDFFF. There's a little spare place starting 1F2280 (up to 1FDFFF) where it would be possible to store other samples (about 48k), but the easiest is to replace existing samples because they are already map to to the voices/keyboard (even if I understood how to change and relocated them). The thing is that the Sound generator in the SOC is only able to address 16Mbits of Flash space. This is due to the fact that the Sample entry point adresses / loop / end is a multiple of 32 bytes (=0x20h); and is coded on 2 bytes : 0xffff multiplies 0x20 = 0x1fffff ... which is the max Flash size. So No way ! For fun, I could get the cat "meow" sample from a PSS-E30, put it in the A50, and play some notes with different "cat meow" tones 🙂 Maybe I'll do a video later, but this cat sample sound was initially a unique sound in the PSS-E30, not intended to be played in different tones like the sound of the "B. toys- Meowsic- Interactive Cat Piano". So the result is not so beautiful, since more samples would be needed for each bunch of 3 or 4 keys. Regards, Lionel PS. I like kiwis from your country, and eat one every day at my breakfast 🥝
I wish there was a possibility to make "sustain mod". I was thinking once about finding a footswitch that gives momentary signal on slope (on press and on release) and simply wiring the jack to the sustain button. Unfortunately I haven't found such hardware switch. Do you think there is any possibility for "sustain mod" in the future?
@dwsel thank you for your comment and interest. This is not in my priority list, but it could be done, of course, the way you described it. The only possible issue is a lack of synchro since there's no existing feedback (led for example) when sustain is activated, which could lead to an opposite behaviour in case you press the pedal, while the pss-a50 considers sustain is already on. That's why a hw+sw mod might be required. Or a mod based on a minimal midi communication on the uart port of the F30 SWLL uart port. (Less convenient on A50 since the midi uart is connected to an additional uController for usb midi _that is not present on the F30_. I think I could identify the input/output i/o registers of the SWLL in the SW, but unfortunately, they are all used. The solution would be to use a "keyboard" switch input (only 37 keys on pss series, while some input switches are still free) _same cpu used on the 61 keys PSR-F5x series_ but right now, I'm not clear with the keys management in the SW. Also, sustain feature is not yet identified in the SW since I could not yet link all the switches of the front panel to the features.
hello, I am impressed by your DIYs ! Did you manage to flash the pss-f30 content rom on the pss-a50 mother board? In this case is the pss-a50 still functional and do we have a sort of pss-a30 with velocity and midi? I also saw that on the a30 motherboard there is room for the midi shipset. Have you tried adding one?
Hello, thanks for your comment. Yes, I'm able to swap the rom since I installed a connector in order to put and remove them easier. I already wrote a few lines on this topic on my blog. Unfortunately, velocity is not managed when you put the PSS-F30 flash on a PSS-A50 Hardware. First reason for that is that the keyboard matrix is not managed exactly the same : on a A50 hardware, the F30 software only cares about the "first" switch (when you start to press the key). Velocity is based on the measurement of the time between the press of the "first" switch and the "second" switch (once the key is fully down). As a consequence, second reason is that the F30 software is not managing the two switches. My assumption is that the software is probably disabled (most probably a configuration variable set off). Turning a F30 hardware into a velocity compatible hardware would require two things : add the missing wire between the keybed PCB and the mainboard; and add 37 diodes on the keybed PCB (the keybed PCB is the same as the A50 one, except the diodes for the second switch are not mounted). Turning a A50 into a F30 is possible when mounting the F30 flash rom on it, everything works fine, midi is also working fine (except there's no possibility to change the midi settings (midi channel, enable/disable Program change, etc... like on the stock A50). Btw, midi is also available on the F30 via an UART; some people made some adaptions to add a 5 pin midi connector. Have a look on Internet. Anyway, about F30 rom on A50 hardware, one major difference because of the keys mapping : the sound comes when you start to press the key, while normally on a stock F30, the sound comes when the key is fully pressed. (And of course, the switches mapping of the front panel (volume, tempo, start/stop) is conform to the F30, means for example VOL- is mapped on Octave- of the A50). I spend a lot of time to try to retro-engineer the SW in order to try to locate the variables which could enable dynamics. My entry points for this are the data that are saved when you turn the keyboard off (could locate and isolate them), and the ARM RISC software binary that is related to the Servicing Tests programs that are listed in the Service Manual. For now, I progress slowly, but still no dynamics on F30.
Thank you for this detailed response. Perhaps activating the velocity in the F30 ROM is impossible if the code is not present. It may be a simple variable to toggle but it can also relate to code not compiled by a simple #define PSS_A50 (for example).
Nice work. I have just bought one of these and hope to do two mods, one is to change it to use usb c and the other was to add a full size Jack to plug into a guitar amp or some other equipment. I was going to just use two resistors to combine the left and right channels as a crude stereo to mono mixer, but if I'm understanding correctly thats not necessary. Do you you have any tips about getting a line level out? Many thanks
Hi, thank you for your comment. In my very first video about this topic (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-cwDBfVab3vc.htmlsi=fxfCHokF3GXue6Zq) one guy commented his work about a modification to add some li-ion bat ( @sathish6601 ). If I remember well he also drop a comment on my blog) To get a line level line, just know that the volume level is changing depending on the user settings (vol+ vol- keys). No way to change this since the level is not a fix value at the SWLL chip output, it depends on the volume set by the user.
Hello, i am looking for a way to just use it as a midi keyboard (without the top panel). But the power button is on the top panel, is there a way to use it without the top panel and that's it's always 'on' when i plug in the usb into my computer? Thanks so much for your help!
Hello, currently, when you plug the keyboard on the USB port, the keyboard does not switch on automatically (batteries present or not don't change anything). If you plug in the usb cord while the on button is pressed and stays pressed, the keyboard turns on and stays on (especially if you disable the "auto power-off" feature). The on/off push is a direct push (not a multiplexed push). Pressing the push means put a wire on the ground. Therefore if you short-circuit the related wires on the right connector, it might work as expected. The connector is "CB301", and pins are n°3 (Gnd) and n°4 (goes to an input on the micro-controler). FYI, pin n°1 is the coloured wire on the left. Having these pins shorted permanently shall not affect the HW durability. About the SW, I don't know how it behaves if this signal is LOW permanently. Kind Regards.
I dont unbderstand zhis mod. If i use only the internal speaker its mono defaault right? It has only one speaker right? If i connect to an external device it can sound stereo via the 3,5 jack right? Then why bother to mod if it has only one speaker?
Correct, no change and no difference with the internal speaker. But about the jack output there's a major difference : normally, the pss series provides sound on both left and right, BUT the audio signal IS EXACTLY the same on both. It means the signal is biaural (twice the left channel in your headphones) but not stereo. My mod brings the real right channel from the sound generator to the jack. With this mod, the sound is now real stereo, because the audio that comes out of the sound generator is not exactly the same on left and on right channel.
Es Brutal para componer. Le falta un banco de rec más para verse y otro para bridge..... y lo rompería.... de cualquier modo el instrumento ya es genial
Awesome work, is it ready to sell? I would be interested in buying the pcb, I have good soldering skills but I'm lost if I have to design it myself! I've read your entries but still found no info on where or how to buy it. Thank you!
The similar product: the SHS-300 which has only 12 voices (no arpeggiator and recording functions but instead JAM Mode) is capable of outputing Stereo from its PHONES jack by default (without modification).
Correct ! It's based on the same sound processor YMW830-V. This time, Yamaha decided to implement the full stereo. I just wonder why the decided stereo for a keytar and mono for a keyboard ?! Have a look on this hack : the guy turned his keytar in a foldable instrument : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-N2bTYpMBbag.html
Unfortunately, you can only record one phrase, up to 700 notes. Also, there is no way to save and restore recorded MIDI data. It's a basic keyboard, but the sounds are respectable and the keyboard has velocity, which is a good point in this price range. Unfortunatly, the sound was mono, that's why I developped this stereo mod. Only adds the right channel, but no additionnal features... for now...
@@LionelN , following tightly your project. The keyboard has TONS of possibilities, but without stereo sound it's just kinda lame. Your mod revives it totally ))
@Sergey, in case you missed the BT mod : darekasan-net.hatenablog.com/entry/2021/08/23/184924 (use Chrome translate feature to read it in your language)
@@sathish6601 You can find it in the service manual of the PSR-F50. Since it's a Yamaha copyright, I can't share it. As I did, you can find it on the internet if you Google something like "PSRF50 YAMAHA Service Manual download".
@@LionelN Hi Lionel I started doing the mod. Have a doubt if its already stereo-wired cos in PSR F50, only a dual opamp is used for stereo output. PSS A50 also has a dual opamp. Can you help. Thanks.
