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Hello all,

I have a PSS-480 that has a weird "intermittent percussion" problem. Triggering drums with keyboard (percussion keys) might work for a few seconds, then triggers start getting ignored. Same behavior playing built in rhythm patterns or the demo song; drums go silent for a stretch and then come back.

The PCM drum sample themselves don't get clipped off; it seems to be only the *trigger* that gets ignored sporadically.

It seems to be random, I haven't discovered a cyclic pattern or anything.

Does anyone have any clue what could possibly cause this behavior and if it's worth trying to fix? Hard to imagine old capacitors could cause it.
- I downloaded the service manual PDF, available online at many fine websites.
- This keyboard uses YM3419 (RYP7) for percussion sounds.
- When started in test mode, it passes all ROM/RAM tests. But the drop-out problem remains.

Hello, here is my demo of a very simply circuit bent Yamaha MU15 with the very cool arpeggiator of the Novation Launchkey Mini MK3 :

https://www.youtube.com/watch?v=3puDvMTIaaM

Enjoy !

This is how i did it, headphones output to the computer's microphone input, one channel. Well, better do it on cardboard and never more than two wires crossed. The resistors are 100 k and 150 ohms (a typical output resistance of a microphone), the capacitor is 0.47 uF (makes a high pass filter 3 Hz and up, to remove the microphone's power voltage). The sounds, rhythms and demos of the tlf-3215 toy keyboard recorded  https://sndup.net/8xjh . Likely also bf-430a1 and many others have the same chip. Only a noise removal was done. Headphones output was made out of its microphone input, with a 8 k resistance in series. Weirdly it also had a switch, that switches the keyboard's speakers off when headphones are connected. In case there is any use of it for anyone, thanks.



Not knowing that much about it, i would say, headphones output is not line out that corresponds to some standard. And there are two standards, some 1 V and 0.5 V, something for 600 ohms output, the computer line in i guess is the latter. I think 1000:1 voltage divider for microphone input is enough for low power devices. But may not work for all headphone outputs. If they are just attenuated by one resistor, it is good enough for headphones but may not be much for high resistance input.

The problem with headphones output is that it is not a general output, it is only for headphones. So i guess that it may be a good idea to add a resistor parallel to the headphones output, with a typical headphones resistance, say 50 ohms. Then one gets the voltage that goes to the headphones, which supposed to be mostly not more than 2 V. So 10 times attenuation should then be enough to line out, and further 100 times to microphone input. Who knows more, correct me please thanks.

I have been working on some interesting project meaning Roland MGS-1 grip for famous SH101

If you wan to know how it went let me know and I present the whole story of creating it from scractch without having the original grip at hand.

Hello all!
I have a pss 560 that I added a delay effector ( pt2399), and an input mixer to. It also could run off a usb phone charger backup battery. It was awesome! I could plug in a poly 800 and jam without an amp with nice synthy delay effects.

It suddenly started making a deep buzzing sound, and after a minute or so, stopped everything. Now, only the pilot turns on. You might say its "dead" or "bricked" I suppose.  But I'm a stubborn bastard and I want my cool jam station  back!

The 560 is nice since there are free schematics for it online. I used them to pinpoint where to run the signal into the delay circuit. Simply, it ran into the power amplifier, along with an input signal. The usb power was just a usb plug wired in the same way as the battery wires.

Im suspecting that a wire came loose and shorted something important.
t. Before it died, I played the keyboard and noticed the delay wasnt working, so maybe a wire dropped off. Then it started working again. Also it happened after I plugged in a 12v psu by mistake ( i had another pss next to it, mistaken identity)
Can anyone give me so pointers to trace the problem? I checked many of the big ICs amd they are still getting their 5v, but after that, not sure what to look for. Thank you and glad to finally join one of these groups !

The keyboard section just has keyboard stuff, the screen section has the interesting stuff, but I can't get to it! There's two little red plugs/caps, one either side of the speaker/hinge area. I've got those out by drilling a hole through the centre and prising them out with a handy implement (a thin allen key, in my case).

So now I can slightly see inside the screen area, but there still seems to be a bunch of screws holding the screen area together, but I think their heads are under the plastic screen graphic/protector.     escorts incalls

Have seen a couple of bent ones around, anyone here successfully gotten into the thing without damaging the original look of the toy?

The middle leg is ground, you need to use one of the outer legs to inject the LTC1799 signal. We usually use the one furthest from the front panel.

You can source +5v and ground from the voltage regulator. The middle regulator pin is ground.

If any one has a Tandy /Radio shack / Realistic reverb ready to bend I’ve posted a photo with some details I’ve gathered from various places that I used to bend mine. It certainly sounds better now. Did I miss anything good ? For some reason I can’t post photos as attachments which is why I’m having to use imgur.

https://imgur.com/gallery/CGjdp3d

I recently bent my Casio SA-8 using this thread as my guide, so thanks to everyone for sharing all the info.  Most things seem to work, I’m not that keen on the original glitch bend , I’m guessing it wasn’t really meant for the SA-8 ? I didn’t manage to do the power starve mod either because I couldn’t find at pot less than 1k. I did the clock mod with a 6mz crystal but to get it to work I have to put almost spent batteries in and to get the glitch to work I have to put new batteries in! I suppose the power starve would have helped with that. Has anyone swapped out the clock altogether and used a LTC1799 successfully ? I added a couple of trigger in’s that are nice to have going while messing about with the feedback mod. 

https://imgur.com/gallery/XDEset8

I’ve been doing it for about a year now and when I started this page of tips on the Circuit Benders website was invaluable for pointing about what to buy to set me on my way. I recommend a read of it if you haven’t already.

https://www.circuitbenders.co.uk/tips.html

I haven’t bent the delay pedal you mentioned but an earlier casualty of mine is a  Mimidi delay pedal. Not sure how I fried it but now the only sounds I can get out of it sound like something from the bbc radiophonic workshop. One day I will put it in a nice enclosure.

I see your message was from a few months ago so you’re probably already sorted for gear. Hope you’re managed to get something out of the pedal.