The Evil Twins (dminner coop dual reverb)

[m-Kresol]

This is The Evil Twin, or better Twins. They were built in a labour trade with dminner over a long, long period. I think we started planing sometime in February or March. Dan did the artwork, etching and painting, I did all the electronics. It's a dual reverb with a send-return loop in between the effects and an order switcher. This means that in/out 1 can go to either effect and in/out 2 will go to the other. If nothing is inserted into the loop, they are directly in series via the switched jacks.

The dark side is a DBA reverberation machine workalike with the addition of variable decay (btdr-3h brick) and some power filtering/polarity protection. Following my labelling scheme, I call it the "Rubidium Reverb." The light side is a spring reverb using the small blue 2 spring tank by accutronics. The design is based of the reverb section of a Fender Blues junior and I had to run through 5 designs. Mostly it was about the power section, as 9V didn't give enough clean headroom for the opamp. Had to go with a charge pump in the end. Also, because of the lowered input voltage compared to a tube amp, I had to modify the gain makeup stage and added a boost to the end to get it to unity and beyond. I achieved both with a LBP1 booster. This one's called "Ruthenium Reverb."

the dark side gets quite weird on some settings (just like the original), very spacy and ambienty but can also do clean, regular reverb. very versatile. The light side has very much treble, which I couldn't alter in the end. We think that might be coherent to the spring tank due to the small size. Nevertheless, it sounds quite nice up to half of the blend knob, then it gets a bit icy for my taste.

both projects are shared on OSHpark and the build docs are linked there. I hope some of you will build either one. I also shared the order switcher with the send/return option. No idea if that could have been done with a 3pdt too, but i couldn't figure it out.

Here's mine all finished up. I obviously got the Evil Twin with a worn in finish. Both projects are designed for all board mounted pots and switches, but I had to wire some of them in. Still pretty pleased with the wiring considering what's going on in there. The spring tank is mounted to the lid of the enclosure and sits right between/above the stomp switches. Yes, you can make it warble and make noise by hitting the enclosure. To be honest, even hitting the bypass switch will give some warble, which is hardly noticable if you engage while playing though.











Dan got the Good Twin with a nice, unbruised finish.




spring tank attaches comfortably to the pcb via these connectors.


Still missing some knobs...

Group shot:


Dan should receive his shortly. I hope he'll do a demo

Lastly, I've got one Ruthenium Reverb board (spring reverb) left, which is up for grabs. 10€ including shipping worldwide. First one to speak up in this thread gets it. paypal gifted please.

[nzCdog]

Hot!  Great work in and out, sounds like an epic verb project too

[warriorpoet]

This is way too cool, man. Great work all around!

[Lubdar]

Very Nice!!!

Is that spring reverb project going to go up on your OSHPark projects?

[lincolnic]

Damn, amazing work, both of you!

[m-Kresol]

Thanks guys.
I thought I shared the spring reverb before, but obviously didn't. It's shared now and the build doc is up too

[cajone5]

WANT!  I have been trying to build myself the perfect reverb and haven't quite landed there yet.  This looks like it'd be amazing.  Excellent looking inside and out.   

[Droogie]

Dat's dope dudes!

[playpunk]

Man! What a fantastic pair of builds.


Sent from my iPhone using Tapatalk

[m-Kresol]

thank you!

the spring reverb pcb is still up for grabs 

[Boba7]

SOOO cool!!

Thanks a lot for a the detailed pictures, I just spent a long time observing them very precisely haha! What a perfect pedal. And it looks stunning.

[Bret608]

You used an actual spring tank in there? That is just nuts! Love the look, and now I am curious to hear what the original DBA circuit sounds like.

[jubal81]

Shazam! What a great project. Beautiful.


Which enclosure is that? Looks perfect.

[m-Kresol]

Shazam! What a great project. Beautiful.


Which enclosure is that? Looks perfect.

thanks, Jason. It's a 1590D. Basically two 1590BB next to each other with extra height