Interesting mod to Surf PI for VCO option

[kt315]

What is VCO sound?

PEEEUUU.... PEEEEUUUU....

[Andi68]

OIIINGGG, OIIINGG....

[nonkapo]

No its done as i said and the difference is that now you have vco sound ie the tone changes pitch the closer the metal is to the coil instead of just NUURRRRRR!!!!

Then it means I've done something wrong. What I do is to disconnect ground lead of c16 coming from pin5 of the 555 timer and connect it to pin7 of lm358. right?

[dime196604]

PEEEUUU.... PEEEEUUUU....

Ok. whatever that means

[nonkapo]

I gues this one works only on surf pi pro with the 555 and7660 sinchronized🙁

[qute1]

No i wouldn't do it on pi pro as subtly different but it works fine on surfpi longboards i have it on 3 now it just changes nuuurrrr sound to peeeuuu ie the tone rises as the object comes closer to the coil instead of nuuurrr (which really gets on your wick after a while)......
i wouldn't say it was as good as "proper" vco but certainly a very cheap mod that genuinely improves the sound quality.

[nonkapo]

Do you mind uploading video when you have time? Both my surfs are longboards modded with pro components but only one have sincro.I try the VCO mod only on the sincronized board.

[qute1]

nope don't do videos sorry but all i can say is it works on stock silverdog 1.2 surfpi just fine (no other mods as rest is fine).... sorry but thats all i got.

[Suvabard]

Just disconnect the C16 from the GND and connect it with pin 7 of LM358 to have a VCO audio

Poor mans vco

Anyone had luck with this? Does nothing on mine.

[nonkapo]

Same here. It’s too simple even for dilettante to consider I’m doing it wrong

[Suvabard]

Same here. It?s too simple even for dilettante to consider I?m doing it wrong

Just a thought - do you have the NE555 or the TLC555 installed in position U1? My board uses the NE555 and the VCO mod doesn't work- maybe this is the reason. I have a TLC555 spare and will swap it out soon to test.

Where did you get your board/ kit? I see the silverdog kit currently uses the NE555D.

Here's the longboard schematic that calls for the TLC555: https://diydetector.co.uk/store/inde...d_attachment=4

[nonkapo]

Yes, i use NE555, but as per what i know, the only difference is the tech. TLC must be CMOS version of NE555 right? So the question why still remains;-). The board is exact copy of the Silverdog longboard.
Anyway, thanks for the tip. Will try and report the results later.