Ross Distortion Project

[soupbone]

I'm building a Ross Distortion for a friend on Perfboard.Here's 2 differn't layouts i'm using;http://tagboardeffects.blogspot.com/2012/08/ross-distortion.html?m=1  http://www.home-wrecker.com/rossdist.pdf    If you look at the tagboard link,it has the "Tan" and "Black" versions.The only differences is the Tan uses two 1N270's,and the Black uses three 1n4148's.What i wanted to do,is to have both types of diodes on a dpdpt switch.That way you can have the Tan,or Black with the flip of the toggle.I found this for the diodes; http://guitarpedalbuilders.blogspot.com/2012/05/symmetrical-asymmetrical-clipping.html?m=1 I'm not sure why the middle lugs are going to the pots?Aren't they supposed to go to one-side each of the diode holes?Any help would be greatly appreciated!  

[soupbone]

I'm building a Ross Distortion for a friend on Perfboard.Here's 2 differn't layouts i'm using;http://tagboardeffects.blogspot.com/2012/08/ross-distortion.html?m=1  http://www.home-wrecker.com/rossdist.pdf    If you look at the tagboard link,it has the "Tan" and "Black" versions.The only differences is the Tan uses two 1N270's,and the Black uses three 1n4148's.What i wanted to do,is to have both types of diodes on a dpdpt switch.That way you can have the Tan,or Black with the flip of the toggle.I found this for the diodes; http://guitarpedalbuilders.blogspot.com/2012/05/symmetrical-asymmetrical-clipping.html?m=1 I'm not sure why the middle lugs are going to the pots?Aren't they supposed to go to one-side each of the diode holes?Any help would be greatly appreciated!  

For some reason when i edited my post,the home-wrecker link wasn't underlined,so that you could click on it.Let's try that again; http://www.home-wrecker.com/rossdist.pdf

[GGBB]

Internally, the diode clippers are connected to the same places as volume pot lugs 1 & 3, so I would assume the mod instructions are intended to make it easy since tacking something on to the pot lugs is easier than making the mods on the circuit board.

[soupbone]

Internally, the diode clippers are connected to the same places as volume pot lugs 1 & 3, so I would assume the mod instructions are intended to make it easy since tacking something on to the pot lugs is easier than making the mods on the circuit board.

Well,I'll be!So,are the clipping diodes in most pedals connected to the Volume Pot?

[antonis]

So,are the clipping diodes in most pedals connected to the Volume Pot?

Usually the are connected either to the closed feedback loop or right after the main gain stage...

(if there isn't any tonestack and/or recovery stage then they could be connected to the upper lug of Volume pot..)

[GGBB]

Well,I'll be!So,are the clipping diodes in most pedals connected to the Volume Pot?

I don't know about most, but I would guess usually not. The volume pot is typically the last thing in a pedal circuit, whereas the clippers are usually after a gain/drive stage and then followed by maybe another gain/drive stage or buffer/make-up stage and possibly some tone shaping somewhere along the way. In overdrives like the tube screamer the clippers are in the op-amp feedback loop. The Ross is one of the more simple distortions - in->gain->clip->volume->out - so there isn't a whole lot going on and therefore not a whole lot of options as to where to put the clippers.

[soupbone]

So,are the clipping diodes in most pedals connected to the Volume Pot?

Usually the are connected either to the closed feedback loop or right after the main gain stage...

(if there isn't any tonestack and/or recovery stage then they could be connected to the upper lug of Volume pot..)

Thanks Antonis!

[soupbone]

Well,I'll be!So,are the clipping diodes in most pedals connected to the Volume Pot?

I don't know about most, but I would guess usually not. The volume pot is typically the last thing in a pedal circuit, whereas the clippers are usually after a gain/drive stage and then followed by maybe another gain/drive stage or buffer/make-up stage and possibly some tone shaping somewhere along the way. In overdrives like the tube screamer the clippers are in the op-amp feedback loop. The Ross is one of the more simple distortions - in->gain->clip->volume->out - so there isn't a whole lot going on and therefore not a whole lot of options as to where to put the clippers.

Right on.Great info!Thanks Gord!

[soupbone]

Internally, the diode clippers are connected to the same places as volume pot lugs 1 & 3, so I would assume the mod instructions are intended to make it easy since tacking something on to the pot lugs is easier than making the mods on the circuit board.

Sorry Gord,I had one more question;On the Home-wrecker Layout,would i just leave the diode holes blank?or would i need to put a jumper in them?Thanks!

[ashcat_lt]

...or would i need to put a jumper in them?

That will cause permanent silence.


Edit - Well, semi-permanent I guess.  Until you remove the jumpers anyhow. 

[soupbone]

...or would i need to put a jumper in them?

That will cause permanent silence.


Edit - Well, semi-permanent I guess.  Until you remove the jumpers anyhow. 

So,leave em' blank i'm guessing. 

[antonis]

You're guessing right..

(or else you'll short-circuit OUT3 to GND and result at what soupbone said...)

P.S.
Consider the diode pair holes as connecting points to middle DPDT switch lugs (with no polarity either for symmetrical or asymmetrical clipping..)

[GGBB]

Consider the diode pair holes as connecting points to middle DPDT switch lugs (with no polarity either for symmetrical or asymmetrical clipping..)

Might be simpler to think of the empty diode holes as alternatives connection points instead of volume pot lugs 1 & 3.

[brianq]

Another thing you might experiment with is the IC. My Tan version has a Texas Instruments IC & the Black version has a Sharp IC. Personally I like the distortion of the Black version but the Tan version has more volume? My mod was to swap the IC,now it has better volume & saturation. Something to think about?
Good luck on your build!!! May you not have to debug!Lol

[soupbone]

Another thing you might experiment with is the IC. My Tan version has a Texas Instruments IC & the Black version has a Sharp IC. Personally I like the distortion of the Black version but the Tan version has more volume? My mod was to swap the IC,now it has better volume & saturation. Something to think about?
Good luck on your build!!! May you not have to debug!Lol

I've never heard of a Sharp IC.All the layouts i've seen used the T.I. 4558P Are they similar opamps?

[soupbone]

Thanks everybody for your help!

[brianq]

Yes the Sharp is also a 4558, I also had a Tan model with a Sylvania IC, wich I've heard is an earlier model? My Black model has two 1n4148 & one 1n4001 & is more saturated than others I've heard.
Either way the Ross distortion is definitely a good pedal...

[soupbone]

Yes the Sharp is also a 4558, I also had a Tan model with a Sylvania IC, wich I've heard is an earlier model? My Black model has two 1n4148 & one 1n4001 & is more saturated than others I've heard.
Either way the Ross distortion is definitely a good pedal...

Cool!Thanks!