DOD Phasor 201

[Greedy_Fly]

http://www.ampage.org/schematics/dod201.pdf

[Neil mcNasty]

Say what?
That's all there is inside this one.
This has to be the lowest part count I've ever seen for a phaser!
This should absolutely be doable on vero.
I'll get straight to it, and see if I am capable of making something out of this.

Do you know if this is the original or the reissue?

I got the original and it is one of my most cherished pedals. I've also considered to buy the reissue as well, since it is dirt cheap!
It sounds great, and can reproduce that lovely Led Zeppelin phasing sound that we have all love so much...

[Frank_NH]

Apparently, this is similar to the MXR Phase 45:

http://schems.com/Schematics/Phasers/DOD%20Phasor%20201%20or%20MXR%20Phase%2045.gif

There is a layout here for the Phase 45 so maybe it could be modded to a 201?

[Neil mcNasty]

Thanks for the tip about the MXR 45
Strange thing though... In my opinion they do not sound very similar.
I've never liked the MXR 45 very much, but I love the DOD201.
It's going to be interesting figuring out the differences...

I hope to have some update on this by tomorrow morning.

[Frank_NH]

Check out the schematic I linked to - it marks the differences between the 201 and the Phase 45.

[Greedy_Fly]

Dod phasor 201 has single dip-14 chip.... And the phase45 - two dip-8 chips....

[Frank_NH]

The single chip is likely a quad op amp like a TL074.  So that would be equivalent to two duals (TL072).  

[Neil mcNasty]

Thanks to Frank and his link to the schematic that shows the differences between MXR 45 and DOD 201, this was a much more simple task than expected.

I have colored the parts that differ from the MXR 45 slightly different, so that those of you who have built the MXR 45 can replace the components needed to transform it into a DOD 201.

Please note that I have left a 10uf cap that is not originally in the DOD 201, but I suspect that it is a power filter that does not affect the sound. The cap is the semi-transparent one in the upper right corner.

I also moved 2 components in the upper right corner) + ground connection in order to get the 100R resistor in there + get both +9v and Ground on the same side of the vero (I don't like Ground and Voltage on separate sides of the vero)
Also note that there is a 47nf cap (right side, middle section) that is not present in the DOD 201 design (if you are modifying a MXR 45)

In the schematic it says TL072, but I decided to use the NE5532 as in the MXR 45 layout.
Also: according to the MXR 45 layout; the JFET's can probably be substituted with 2N5458 if you do not have any matched 2N5952

I hope that I got everything right.
Enjoy!

[Greedy_Fly]

I would just like to vero with one 14-dip chip! )

[Frank_NH]

Thanks Neil!!  I vowed not to build any phasers since I already have a vintage Small Stone, but this one has me intrigued.  And the vero is square!  Bravo.