That 470pf was probably to help remove any RF, and the other early revisions are likely the same things, and probably help with noise. For TL022, yeah current was probably one reason and impedance another as they are FET inputs. I think the 022's also have input protection which the 741/1458/4558 series doesn't have. This results in failures when say in effects loops where the input swing exceeds the supply voltage and kills the op amp. I'm pretty sure this is the reason the OD-1 with the long chip would fail too. This is easy to solve with a couple of diodes connected in reverse polarity to the input supply rails. I remember one of their pedals has this, I can't remember which though, the DS-1 or SD-1 I think.
Hi Scott, thanks for watching and sharing your insights! Interesting thoughts. I'm pretty sure the 022s are regular BJT inputs... Maybe you were thinking of the 072? In any case, thanks for sharing!
@@ScottyBrockway 😄Remembering and recognizing op amp numbers and series is so difficult, I get totally confused and constantly have to check the datasheets... 😅
I have the early one! 01! =) =), I'm from Argentina and a Dude from Spain sold me the Ge-7 for a really cheap cheap price when he came to set up the lollapalooza stage here in my country. I made the 9vol and low noise mod but keeping the original components in a bag for collector reasons. The only thing I had to definitely change were the electrolytic caps, because they were causing problems due to their age.
Thanks for watching! Congrats on the 1st generation GE-7! The electrolytics will definitely start going bad for a pedal this age, so it's great that you changed them!
Regarding the 470pf cap, I agree with @ScottyBrockway comment. I experienced myself inverting a sawtooth waveshape with a TL071 opamp from a VCO that I got nasty overtones which was cured by a 47pf cap.
That 470pf was probably to help remove any RF, and the other early revisions are likely the same things, and probably help with noise. For TL022, yeah current was probably one reason and impedance another as they are FET inputs. I think the 022's also have input protection which the 741/1458/4558 series doesn't have. This results in failures when say in effects loops where the input swing exceeds the supply voltage and kills the op amp. I'm pretty sure this is the reason the OD-1 with the long chip would fail too. This is easy to solve with a couple of diodes connected in reverse polarity to the input supply rails. I remember one of their pedals has this, I can't remember which though, the DS-1 or SD-1 I think.
Hi Scott, thanks for watching and sharing your insights! Interesting thoughts. I'm pretty sure the 022s are regular BJT inputs... Maybe you were thinking of the 072? In any case, thanks for sharing!
@@arito Hrm my mistake then, I thought all the x2 series was FET, haha.
Nice analysis!
@@ScottyBrockway 😄Remembering and recognizing op amp numbers and series is so difficult, I get totally confused and constantly have to check the datasheets... 😅
@@PATRIK67KALLBACK Thank you!
I have a 902 PCB
Thanks for watching! Yes, I have since come across 902 circuits, so they are out there. Maybe it was a short lived transition circuit?
I have the early one! 01! =) =), I'm from Argentina and a Dude from Spain sold me the Ge-7 for a really cheap cheap price when he came to set up the lollapalooza stage here in my country. I made the 9vol and low noise mod but keeping the original components in a bag for collector reasons. The only thing I had to definitely change were the electrolytic caps, because they were causing problems due to their age.
Thanks for watching! Congrats on the 1st generation GE-7! The electrolytics will definitely start going bad for a pedal this age, so it's great that you changed them!
@@arito I love the channel! I learn from You man! Thanks to You =)
@@ran-diy-audio Thanks soo much! I really appreciate your kind words! Great to hear that you enjoy my videos!
Regarding the 470pf cap, I agree with @ScottyBrockway comment. I experienced myself inverting a sawtooth waveshape with a TL071 opamp from a VCO that I got nasty overtones which was cured by a 47pf cap.
Hi PATRIK, thanks for watching! Thank you for sharing your experience regarding a capacitor.