Please help with OCD debug (VOLTAGES INCLUDED)

Started by skibum1999, October 05, 2008, 02:13:19 PM

Previous topic - Next topic

mojotron

#20
Quote from: solderman on November 17, 2008, 04:05:07 AM
Quote from: mojotron on November 17, 2008, 03:28:02 AM
I pretty much morphed my OVD build into the schematic shown here http://s197.photobucket.com/albums/aa131/veroboard/Commercial/Fulltone/OCD/?action=view&current=ocd_vero.png.

It sounded better and better as I made the changes - so I just implemented all of them - getting there form the OVD layout is not trivial.

All in all - it sounds awesome. I don't know if it's identical to the OCD - does not really matter to me - the circuit in the above link is a real keeper.  :icon_biggrin:
..
The transistor/Cap/small Diode/resistor close to the "99" on the tone pot could be this configuration.  The other two could be 2N7000 as used in my Fulldrive. One of the beige standing resistors can be the type of diode (beige looks like a resistor with one black ring I don't know what it is besides that it is a diode) that is in series with one of the 2N7000 in my Fulldrive.
Near the lover edge of the PCB you can see two standing larger diodes (probably 1N4001 or so) this could be half a rectifier.
...
This makes a lot of sense as the sound of the pedal I just made with the schematic above is dead on with the sound samples from Fulltone and Youtube. Cleans up very well, and offers a lot of dynamics. Also, the pop on the pedal I just made is hideous - deserving of special treatment - I have several things to try on that: Great pedal design though!

BTW - I love Fulltone gear - I've made copies and resold everything I ever bought from Fulltone. I once had a FullDrive 2, a DistortionPro, a 69, a 70 and traced the circuits out and they ended up being pretty much what you find from knowledge people here who have submitted schematics. Once I sold them all I had plenty of money for parts too :). The coolest stuff about Fulltone is they have the mechanical design to the point of being the best in the business on some of their enclosures and rugidization IMO - they are made for how musicians will treat them. Buy a Fulltone pedal - everyone was worth every cent I paid for them and are a great investment if you don't make your own gear - good enough to copy right down to the exact same parts, minus those funky pots. I think a lot of people focus on the electrical design and copying existing circuits... but I would say that the way Fulltone makes their stuff is great - part selection, mechanical design, the placement/spacing of the layouts... that is the bigger part of it. It's not that Fulltone designs great pedals, they deliver the designs that are floating around out there with excellent mods and excellent part selection. I wish they gave credit to the original designers because then people would see better that the total package they sell to customers is really quite nice for the price.

tehfunk

Quote from: solderman on November 17, 2008, 04:05:07 AM
Quote from: mojotron on November 17, 2008, 03:28:02 AM
I pretty much morphed my OVD build into the schematic shown here http://s197.photobucket.com/albums/aa131/veroboard/Commercial/Fulltone/OCD/?action=view&current=ocd_vero.png.

It sounded better and better as I made the changes - so I just implemented all of them - getting there form the OVD layout is not trivial.

All in all - it sounds awesome. I don't know if it's identical to the OCD - does not really matter to me - the circuit in the above link is a real keeper.  :icon_biggrin:

Hi
I donĀ“t own a Fulltone OCD myself but I own a Fulldrive 2 (MOSFET version). I have poked around a bit inside that one to find out if the "Fullclone 2" schematics that fly around the net, is correct. 
Fulltone says  that there pedals works well from 9-18V and that they are immune to goofs like connecting a wrong polarized adaptor or an AC adapter to the pedal. I will not work but it will not fry either.  In the Fulldrive there are two Si diodes (half a rectifier) that fix's this. There is also an unusual FET connected to the ON/bypass LED indicator. It seems to be connected like a millennium bypass. Even if the 3DT stomp switch is connected as you would expect. I think this is a double security to use the FET as a switch to eliminate pop clicks from the LED going on off when draining the Cap even with a 1M input resistor. This will count for the third transistor you have seen.
Se this pic on an ODC V3
The transistor/Cap/small Diode/resistor close to the "99" on the tone pot could be this configuration.  The other two could be 2N7000 as used in my Fulldrive. One of the beige standing resistors can be the type of diode (beige looks like a resistor with one black ring I don't know what it is besides that it is a diode) that is in series with one of the 2N7000 in my Fulldrive.
Near the lover edge of the PCB you can see two standing larger diodes (probably 1N4001 or so) this could be half a rectifier.

//Solderman


Solderman thank you for those interesting thoughts, but for me it was a bit confusing especially on the resistor colored and looking diode. does anyone else have any thoughts on this? My friend has an ocd I think I'm gonna go open his and write down the total number of resistors and diodes and caps etc. and get there values as best as I can and put them up here so you guys can say what you think. but that won't be for a while. I just think this is interesting.
Carvin CT6M > diystompboxes.com > JCM800 4010

The tools of the artist give you a chance to twist and bend the laws of nature and to cut-up and reshape the fabric of reality - John Frusciante