really old easyvibe pcb layout

[mantella]

I have this pcb made, and managed to decipher the layout:



I got the whole circuit put together. However, when I compare it to John's original schematic (http://www.hollis.co.uk/john/easyvibe.jpg) I notice that there are diodes missing next to the depth pot. I got the pedal to work, but it sounds more like a tremolo than a vibe sound. Would the missing IN914's be the issue?

Thanks.

[enquiryband]

most vibratos aren't actually true vibrato. a real circuit vibrato that bends the sound is hard to do.

reading is your best friend. read all about this here. i came across it while trying to research my vintage amp. http://www.vibroworld.com/magnatone/vibrato.html

[RedHouse]

most vibratos aren't actually true vibrato. a real circuit vibrato that bends the sound is hard to do.

reading is your best friend. read all about this here. i came across it while trying to research my vintage amp. http://www.vibroworld.com/magnatone/vibrato.html

Dude, the Easyvibe is not really a "vibrato", it's a IC based version of an early phase shifter (ie; Univibe) but really much more like a 4-stage Phase-100

But as you said, reading truly is your best friend, you can read here on this firm many posts about the EasyVibe.
(search is also your best friend)

[mantella]

thanks guys, I actually realized I had read the scheme wrong. I see that on John's schematic he has the ldr's in a different place than the led's that are driving them. Once I figured that out, I could see where the other diodes should go. So I got the univibe sound I was looking for. I swear, sometimes it's good when things go wrong, because it forces me to really analyze the circuit. I end up understanding things far better than when I'm able to just slap the components on the boards and everything goes right the first time. Though, that's far less frustrating ;-)

I built the "newer" version of the easyvibe too (http://www.geofex.com/PCB_layouts/Layouts/easyvibe.pdf), but wanted to try this one out as well. No real difference, but the trimpot I used on this one seems to affect the sound much more dramatically than the other.

Thanks again.