A long time ago, I made a series of mods to my EHX Enigma Q-Balls envelope filter pedal, and posted briefly about what I'd done. Occasionally over the years a few people have asked for more details as they wanted to do the same mods, and each time I have had to struggle to remember, or open it up to remind myself. So I thought it might be good to document these mods for anyone that's interested; hence this post.
I thought (and still think) that the Q-Balls is an excellent and under-rated envelope filter pedal, but it has a few features that are less than ideal, and other features that I wanted but felt were missing. These all turned out to be easily addressable.
None of these mods are at all electronically complex - just as well, since my electronics skills are weak now, and were even weaker back then. So these are largely mechanical hacks, just breaking into the circuit at obvious suitable points to make the changes I wanted.
So, in order of likely general usefulness, the mods I made were:
All of these modifications worked exactly as intended, with no obvious downsides. None of them were very difficult to do. The hardest part was probably removing the PCB from the case (and replacing it), as it's fitted pretty snugly and a certain amount of force was required, which was slightly nerve-wracking.
I'll make a separate post for each of the mods, to avoid turning this into a giant slab of text and pictures. Hope somebody may find it useful!
I thought (and still think) that the Q-Balls is an excellent and under-rated envelope filter pedal, but it has a few features that are less than ideal, and other features that I wanted but felt were missing. These all turned out to be easily addressable.
None of these mods are at all electronically complex - just as well, since my electronics skills are weak now, and were even weaker back then. So these are largely mechanical hacks, just breaking into the circuit at obvious suitable points to make the changes I wanted.
So, in order of likely general usefulness, the mods I made were:
- ADDING AN OUTPUT LEVEL CONTROL
A frequent complaint about the Enigma is that at most settings, its output level is louder than the bypass signal. So I added an output level control.
- ADDING AN EFFECTS LOOP
Envelope filters sound great with distortion/fuzz added. But there's a problem - the effect sounds more intense with the distortion placed before the filter effect, but since the distortion flattens the dynamics of the input signal, the effectiveness of the filter pedal's envelope follower is heavily compromised.
The solution is to put the distortion after the envelope follower, but before the filter effect - ie somewhere in the middle of the envelope filter's circuit. The Enigma does have its own built-in distortion effect placed suitably in the circuit, but it's quite limited, and it's nice to be able to use your own choice of distortion or fuzz effect.
To achieve this requires the envelope filter pedal to have an effects send/return loop between the envelope follower circuit and the filter circuit. The EXH Q-Tron+ has this feature, but the Enigma doesn't. So I added one.
An added bonus feature of doing this is that you can trigger the filter effect with any signal - not just the main input - by plugging the signal to be filtered into the return socket, and a trigger signal into the main input socket.
- MAKING THE EXPRESSION INPUT FOOTSWITCHABLE
The Enigma has an expression input socket that allows the filter frequency to be swept manually using a standard expression pedal or similar. This is a great feature, but it's activated by the physical act of connecting a jack plug to the expression socket. This causes the expression input signal to override the Enigma's envelope follower, which is thus completely deactivated until the jack plug is removed from the expression input socket.
This is often not very convenient, especially if the Enigma is attached to a pedal board, where access to its sockets may be blocked by other pedals. So I added a footswitch to toggle the control of the filter frequency between the Enigmas's envelope follower and the attached expression pedal. I also added an indicator LED to show when the external expression input is active.
[ Personal rant: internally disabling features of a pedal when a certain jack socket is used - such as the expression socket in this and many other cases - is a design feature common to many pedals that is simply dreadful for usability, and manufacturers need to be told to stop doing it. Why would they do this?! Have they never seen a pedalboard?! ]
- ADDED DUPLICATE/PARALLEL INPUT & OUTPUT SOCKETS ON THE REAR EDGE OF THE ENIGMA
This was just a trivial addition to satisfy my own personal preferences/requirements.
All of these modifications worked exactly as intended, with no obvious downsides. None of them were very difficult to do. The hardest part was probably removing the PCB from the case (and replacing it), as it's fitted pretty snugly and a certain amount of force was required, which was slightly nerve-wracking.
I'll make a separate post for each of the mods, to avoid turning this into a giant slab of text and pictures. Hope somebody may find it useful!
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