Emma - DB-1 DB-2 DiscumBOBulator

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
Mbas974
Resistor Ronker
Posts: 281
Joined: 29 Aug 2011, 13:13
Has thanked: 33 times
Been thanked: 38 times

Post by Mbas974 »

Wow, looks not really hard to build... :-)

but, what are the boxes called "1" (INV_XX).
I image it's a sort of logic port.

Any idea what could be the chip involved ?

roseblood11
Tube Twister
Posts: 1857
Joined: 23 Aug 2008, 15:21
Has thanked: 289 times
Been thanked: 256 times

Post by roseblood11 »

I just realized that there is a second version of this pedal, and I hope we'll get this traced.
The first version was based on the MXR envelope filter, with some mods, maybe with additional buffer(s). Clones of the MXR that had the mods described on tonepad sounded more or less identical.
https://m.youtube.com/watch?v=40cPxO1AzWQ
http://www.emmaelectronic.com/discumbobulator/

User avatar
modman
a d m i n
Posts: 4548
Joined: 19 Jun 2007, 17:57
Has thanked: 3182 times
Been thanked: 660 times

Post by modman »

I merged all Emma - DiscumBOBulator post into one thread because all the schematics have dissapeared as well as all gutshots.
Please use the attachment function to preserve shit for posterity! thanks
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

POTL
Resistor Ronker
Posts: 303
Joined: 26 Sep 2016, 04:11
Has thanked: 60 times
Been thanked: 59 times

Post by POTL »

Image

not verified!

Image

Image
Attachments
Emma_DiscumBOBulator.jpg

rs
Breadboard Brother
Posts: 70
Joined: 01 Dec 2007, 15:40
Has thanked: 84 times
Been thanked: 5 times

Post by rs »

Here are some guts i've found a while ago.
I'm still trying to figure this one out.

Cheers.
Attachments
jtngov08datbmnqemyey.jpg
17934038_1680395775588020_6850852464984326144_n.jpg

User avatar
chicago_mike
Tube Twister
Posts: 1759
Joined: 03 Jul 2008, 05:38
Has thanked: 20 times
Been thanked: 288 times

Post by chicago_mike »

For the input and output caps in the Emma, I just used .022 Panasonics. sounds fine!
Skyline FX 2013

rs
Breadboard Brother
Posts: 70
Joined: 01 Dec 2007, 15:40
Has thanked: 84 times
Been thanked: 5 times

Post by rs »

Hi Mike, wich schematic did you use? Im getting strange noises. Have to check it latter. Thanks.

roseblood11
Tube Twister
Posts: 1857
Joined: 23 Aug 2008, 15:21
Has thanked: 289 times
Been thanked: 256 times

Post by roseblood11 »


roseblood11
Tube Twister
Posts: 1857
Joined: 23 Aug 2008, 15:21
Has thanked: 289 times
Been thanked: 256 times

Post by roseblood11 »

Just ordered version 2. I will post photos and schematic next week

roseblood11
Tube Twister
Posts: 1857
Joined: 23 Aug 2008, 15:21
Has thanked: 289 times
Been thanked: 256 times

Post by roseblood11 »

Version 2 is all smd.
As my wife is in hospital, I won't have time to do the tracing myself but I will take some macro shots.
The pedal doesn't sound better than the old version, but it might have more headroom, as it can be used with bass or power humbuckers without any distortion.
The clean boost is a useful addition, but there should be an option to change its position in the signal path: Often, it would be more useful, if the boost was directly behind the output of the wah circuit, so that the wah's bypass switch would switch both effects at the same time.
Attachments
IMG_20190917_182934.jpg

roseblood11
Tube Twister
Posts: 1857
Joined: 23 Aug 2008, 15:21
Has thanked: 289 times
Been thanked: 256 times

Post by roseblood11 »

Hi Res pictures...
https://www.dropbox.com/s/7nuueym110d86v2/emma.zip?dl=0

Unfortunately, I won't have time to draw the schematic. Maybe someone else will do that?

What more is needed?

roseblood11
Tube Twister
Posts: 1857
Joined: 23 Aug 2008, 15:21
Has thanked: 289 times
Been thanked: 256 times

Post by roseblood11 »

This is a bigger version of Bernard D'Uurs scheamtic of the old version DB-1.

Maybe it's helpful...


Any ideas on how to get the values of those smd capacitors? They aren't labeled...
Attachments
Emma - DiscumBOBulator.JPG

roseblood11
Tube Twister
Posts: 1857
Joined: 23 Aug 2008, 15:21
Has thanked: 289 times
Been thanked: 256 times

Post by roseblood11 »

I had to return the pedal today.
But the pictures should be all that is needed to draw a schematic.

Post Reply