# Derailer Overdrive



## music6000 (Feb 12, 2019)

Raw Finish with Graphic in Automotive Clear Coat.
This was a Revisit today from 6 months ago. In Buffered Bypass mode it was above Unity.
Robert (PedalPCB) suggested replacing R4 (10k) with a Link (0 ohm).
It is now at Unity in Buffered Bypass & slightly Cleaner with Drive knob in the CCW positions.
It was a Win, Win for me!!!
Mods : R4 Link (Removed 10K)
            Battery Clip & Stereo Input Jack


----------



## chongmagic (Feb 12, 2019)

Mine gets pretty loud, I have to keep the level pot pretty low. Do you see the same with your build?


----------



## zgrav (Feb 12, 2019)

Nice artwork surrounding your footswitch.


----------



## music6000 (Feb 12, 2019)

Around 10.00 O'clock. It's Ok but if I was to build again, I would use A10K Audio pot.


----------



## sertanksalot (Feb 13, 2019)

That looks top quality, well done.  You could sell it on Reverb for $$.


----------



## Andrew01 (Feb 17, 2019)

Did you use the 1,8V zener diodes?
There impossible to find here in Europe (Netherlands).
Any suggestions for a substitute?
The closest thing available would be 2,4V


----------



## music6000 (Feb 17, 2019)

I live in Australia & have to source a lot of my parts from the USA.
I wait until I need enough parts to fill maximum weight for Shipping.
This was Mouser :
610-1N4678BK
Central Semi Zener - 1N4678 BK

Robert (PedalPCB) has these in stock now as we speak. 








						1N4678 1.8V Zener Diode - PedalPCB.com
					

1.8V Zener Diode




					www.pedalpcb.com


----------



## Andrew01 (Feb 17, 2019)

music6000 said:


> I live in Australia & have to source a lot of my parts from the USA.
> I wait until I need enough parts to fill maximum weight for Shipping.
> This was Mouser :
> 610-1N4678BK
> ...



Oke, thanks.
I'm about to commence the build so that wil take way too long.
I had a source here in Holland (if it looks to good to be true.....) but as it turned out they measured 6,7 V
Still awaiting a reply from the seller.


----------



## music6000 (Feb 17, 2019)

I thought I got similar readings to you with a DCA55, 2 different manufacturers.
They have a higher zener current than most semiconductor testers deliver.


----------



## Andrew01 (Feb 18, 2019)

Oke, here' s how i tested the zeners.
Simplefied but it' s supposed to work according to what i' ve found.
I have yet to try with a 10K resistor though.


----------



## music6000 (Feb 18, 2019)

I dug up & tested 2 different types with my Peak DCA55 today & got 2.82v with both.
I then tested them as per your layout with a B100K pot in place of the resistor.
I got 1.846v with the pot adjusted at 100k on the dot.
Central Semi Zener - 1N4678 BK is what I used in my Build & one of the Zeners I tested today.
If you are getting 6.7v, They are wrong for sure.


----------



## Andrew01 (Feb 18, 2019)

music6000 said:


> I dug up & tested 2 different types with my Peak DCA55 today & got 2.82v with both.
> I then tested them as per your layout with a B100K pot in place of the resistor.
> I got 1.846v with the pot adjusted at 100k on the dot.
> Central Semi Zener - 1N4678 BK is what I used in my Build & one of the Zeners I tested today.
> If you are getting 6.7v, They are wrong for sure.



Just got word from my supplier, they're definetly wrong!
There's no supply either so it will be two weeks before the right ones are in.
The good news is they will be coming ofcourse!
Thanks!


----------



## Teddeeh (Mar 17, 2019)

Do you get any feedback with higher gain settings on this? Or is any setting- especially with high presense, hi cut all the way ccw etc feedback free? Im just trying to see if i need to trouble shoot my build..


----------



## music6000 (Mar 17, 2019)

Did you build this with the Buffered Bypass Footswitch. It actually Boosts it above Unity in Bypass mode.
A simple mod (PedalPCB) is to remove R4 - 10K & replace it with a Link.
It brings it back to Unity & minimal Gain loss.
The pedal is lucky to get to 9.00 O'clock with the Level control even after the mod.
If I were to build again I would change to A10K Audio taper.

Feedback is on the High strings with Gain maxed, Hi Cut fully CCW, Presence Sw. On, *BUT* that's extremely Bright and I would never use it at those settings.
I have also Found that some pedals with the Gain Pot maxed at the end of rotation can actually enhance (Spike) Treble like response creating Feedback.
Try backing the Gain Pot off a tad and see if it reduces treble thus reducing Feedback.


----------



## music6000 (Mar 18, 2019)

I have just changed the B10K Level Pot to A10K.
It is now a lot Smoother with Unity at 10 O'clock with Maximum Gain.


----------



## Mictester (Mar 19, 2019)

Andrew01 said:


> Oke, thanks.
> I'm about to commence the build so that wil take way too long.
> I had a source here in Holland (if it looks to good to be true.....) but as it turned out they measured 6,7 V
> Still awaiting a reply from the seller.



For 1V8, you could use an ordinary 3mm red LED.  Its forward drop will be almost exactly 1V8!  Don't use a "high brightness" or "high efficiency" type - just try an ordinary 3mm red LED.


----------

