The Inventions 1981 DRV is a modded Rat, and it's a pretty nice one. If you wanted a more 'hi-fi' Rat, this would be it.
It runs at 18v, which undoubtedly helps with the more open sound/dynamics compared to an original Proco Rat. There's also a slight boost before the main op-amp, where the drive takes place. An op-amp also replaces the simple JFET buffer found on the output of the original Rat.
It's running buffered bypass and should be easy enough to convert to true bypass if that's your preference.
Schematic available at Pedal PCB
INVENTIONS 1981 DRV - VERO LAYOUT
hi there. is this layout verified ? i am going to build this on the next few weeks.
ReplyDeleteHello Angel. I’ve not built this one (yet) but I do generally check my layouts pretty well. I’ll give it another once over and post again once I’ve done this. Otherwise, maybe head over to dirtbox layouts, as there’s most likely a layout for this there that someone has tried and tested. Thanks for dropping by, Andy
DeleteI checked it again, and it looks fine. No guarantees, but I would happily build it and expect it to work. It’s not a monster layout, but be careful with the cut / joins under the TL074.
ReplyDeleteYep it works! Cool distortion, lots of sustain -> Test video: https://youtu.be/OWyHAaWo2t4
ReplyDeleteCool, thanks Felipe - appreciate the video too
DeleteHi Andy, First of all thank you for your work and second I found that I have a problem, when the pedal is bypassed it adds a second distorted note to the dry signal. Sound is very low but noticeable and seems to be an octave higher. I don't know what it could be but maybe a quick solution is to change it to true bypass, what do you think?
Deleteit's me in the comment above 😄
DeleteHi Felipe,
DeleteChanging to true bypass will avoid the problem.
Hard to say what the cause might be. I suspect signal might be bleeding across into the buffer from the other side of the opamp. Just see what happens if you add more cuts under the opamp on the buffer side (next to pins 1, 2 & 3). Bit of a long shot, but it's a quick and easy thing to try.
Hope that helps
I tried your suggestion but no success🤷♀️so it is true bypass now. Can i get rid of the 470Ω, 1k resistors and the 4,7uf cap cutting the jumper at pins 3-5?
Delete🤔 yes you can remove the jumper. You still need the 1k on the input. Maybe you meant the 100k on the output cap to ground?
Deleteoh yes you are right👍
DeleteThank you for the layout!
ReplyDeleteHello,
ReplyDeleteI made a slightly more compact layout using yours : I wanted to avoid the small cut and dual links into a single hole under the TL074, and managed to remove a couple cuts and 3 columns, too.
I am sharing the layout below, but I haven't tried it yet (hopefully I didn't make any errors) :
https://i.imgur.com/5lqAMZZ.jpeg
Best way to find out is to build it
Delete