Seppuku FX

[Chankgeez]

Won't last long?



https://reverb.com/item/49881037-seppuku-mind-warp

[Pepe]

Too expensive. But it will sell.

[UglyCasanova]

That's a beaut!

[Pepe]

Sold. What about Rhys? Did anyone hear anything from him lately?

[moid]

I tried building one of these last Summer, but the damn thing refuses to work... it sits there taunting me! Maybe I'll swear at it next Summer

[Pepe]

Faulty PT2399 perhaps? These chips are a pain in the ass. I buy them from a shop that tests them before shipping, but still I have to throw away some of them, because they don't do the longer delay rates.

It made me mad when I tried to repair my Dynamic Echo Modulator two years ago: everything checked, resoldered, etc, but still no proper sound!?!?! Then lordgalvar suggested swapping the PT2399 AGAIN and then it worked. Crappy, cheap Chinese chips. But they sound great when they work.

[lordgalvar]

Yea, had the same problem with a Mind Warp. Stopped working and switched the PT2399 which made it functional (like Pepe said). There are two different PT2399 lock up things (one during power up and one that has to do with analog/digital pin grounding). I think some of this is due to variances in chips and Rhys would just swap things until it worked. On the mindwarp the resistance at pin 6 is probably low which is why some chips only work...but don't know. Just guessing based on what I have read.

https://www.diystompboxes.com/smfforum/ ... c=112755.0
viewtopic.php?f=151&t=48812

Rhys's designs are very rudimentary and probably don't provide the right power at start up always (or there is a missing jumper between grounds). Worth a try? Maybe put a 1k trimpot between the LDR and Pin6 and adjust it until it has enough resistance at start up (it should anyway but I don't know if the light is coming LED is coming on and screwing with it? I've seen some chorus pedals use a latching transistor switch to change resistance on startup).

Always check soldering too. I always miss stuff on that because my eyes suck, haha.

I've gotten some bad opamps recently too.

[Pepe]

It is also very important to try a few different LEDs. Some are too bright and some too dim so that the desired effect isn't achievable.

[moid]

Sorry everyone, I haven't been on in little while and now my PC is also going on the blink...

Faulty PT2399 perhaps? These chips are a pain in the ass. I buy them from a shop that tests them before shipping, but still I have to throw away some of them, because they don't do the longer delay rates.

It made me mad when I tried to repair my Dynamic Echo Modulator two years ago: everything checked, resoldered, etc, but still no proper sound!?!?! Then lordgalvar suggested swapping the PT2399 AGAIN and then it worked. Crappy, cheap Chinese chips. But they sound great when they work.

Yes, I've had problems with PT2399 chips before - I doubt any of them are actually made by Princeton anymore (none of the logos on mine look like official Princeton PT2399s anyway). I did try swapping out about 4 of them to see if it was just the chip (luckily i put a socket in, I kind of expect anything I build with PT2399 to go wrong the first time anyway!). Sadly the circuit made the same oddly muted (but endearing) lofi noises with each chip... so I suspect bad soldering on my part is the most likely problem.

Yea, had the same problem with a Mind Warp. Stopped working and switched the PT2399 which made it functional (like Pepe said). There are two different PT2399 lock up things (one during power up and one that has to do with analog/digital pin grounding). I think some of this is due to variances in chips and Rhys would just swap things until it worked. On the mindwarp the resistance at pin 6 is probably low which is why some chips only work...but don't know. Just guessing based on what I have read.

https://www.diystompboxes.com/smfforum/ ... c=112755.0
viewtopic.php?f=151&t=48812

Rhys's designs are very rudimentary and probably don't provide the right power at start up always (or there is a missing jumper between grounds). Worth a try? Maybe put a 1k trimpot between the LDR and Pin6 and adjust it until it has enough resistance at start up (it should anyway but I don't know if the light is coming LED is coming on and screwing with it? I've seen some chorus pedals use a latching transistor switch to change resistance on startup).

Always check soldering too. I always miss stuff on that because my eyes suck, haha.

I've gotten some bad opamps recently too.

Thanks, I have heard about the lockup issue with PT2399s and I think someone on DIYstompboxes helped me get a delay circuit working years ago by adding one... and now I have a very embarrassing admission to make - the circuit that I thought was a Mind Warp is in fact called the Sentinel (not a Seppuku circuit, but they look very similar)... however the interesting thing is you mentioned an LDR and my brain thought - what a minute, what LDR, there's no LDR in my circuit? And then I thought, hang on, how does it modulate without an LDR? So I went back to the layout I was following and there is no LDR in it. I then went to the schematic I have and the LDR appears to be a separate daughter board / different part of the circuit and whoever drew the vero layout has omitted it! So I think I may need to re-draw the layout and rebuild, because my build has flashing LEDs, but no LDR next to them!! Thanks everyone, I will return to this circuit in the Summer - I want to build a mind warp as well!

[moid]

It is also very important to try a few different LEDs. Some are too bright and some too dim so that the desired effect isn't achievable.

Thanks Pepe, good point - but I reckon me not having an LDR to see the LED is likely to be having a severe effect on the sound!!!

[Pepe]

A very odd Seppuku model turned up in Japan:


https://www.ebay.com/itm/115248878232

MD Warp? A Mind Warp in a big enclosure with a failed Kompakt Kassette design?

[UglyCasanova]

Hmmm, idk. It's one knob shy of the DLFO. Intriguing as always, but no funds

Edit: especially not that sort of funds

[Pepe]

And it's not for sale anymore. I don't know if it was sold somehow, but this oddball has gone.

[Pepe]

War is around the corner, so I bet this seller from the Ukraine wants to go sure that he can buy enough gasoline to leave the country ...
Octave Synth for 700 USD in Kiev:


http://www.reverb.com/item/51109877

[Chankgeez]

Not sure it has anything to do with wartime evacuation, that shop's prices are on the high side normally.

Hope they stay safe though.