Lehle / RMI Sonic Spark

This pedal is from a line of pedals that were made by the German company Lehle for the Luxembourg based company RMI (Ruppert Musical Instruments).
The Lehle RMI Sonic Spark is smaller than I thought it would be. It feels and looks high quality. What I really like is the recessed knobs – a thing that should be more common. What I don’t like so much is that the lower knob row is rotated 180°. Also, the pedal lights up white when power is connected and blue when it is engaged – it’s a bit weird and you have to remember white is off and blue is on. The gain knob seems to control the (surprise!) gain – but it is the only knob that does volume, too. So if you want “high gain” you’ll have to compensate for the bump in volume.

The other knobs will require some reading into, but I turned knobs until I liked what I heard.

With the pedal switched on, you get a kind of dirt, but I will have form some very weird couples with words here.
The added dirt gives a certain warmth, by adding harmonics and overtones. The overall sound gains a colder sounding surgical precision.
It feels modern and vintage. Imagine a vintage style bass sound that sits perfectly well in the mix and then imagine what was considered ultra modern in the 90’s, like a dual humbucker active 5 string played into a solid state amp and a cab with a tweeter.
Now take what makes out these two tones, snip off all the rest and then mush them together.
Does that make any sense?
Play a double stop in the 12th fret – there is that singing voice with the notes clearly audible and separate, but the dirt content hovering above, blending into a single note with that pleasant warmth.
Go down the fretboard and play a lick, there’s less audible dirt and the highest mids/lower highs are quite pronounced and there is a certain dry’ish voice enhancing the bass registers. It has that while at the same time it tries for a warmth in between.

Does it make dead flats sound more lively? It absolutely does.
The manual says that Gain is basically the master knob. The boost on tap is strong enough to drive a power amp and noon is neutral.
So we still have Enhance, Intensity and Bright/Deep.

Rename these to Gain and Mix and it’s smooth sailing.
Enhance does set the amount of sonic sparks, Intensity is a dry/wet blend. Bright/Deep seems to be a tilt EQ, which needs further inspection since I doubt at this point that it works after a linear fashion.
[…]
Having done such further inspection, I am at a loss. I will safely claim that it does work as some kind of tilt EQ and that the workings of the knob are by no means linear, at least not if you use your ears. When you go towards the bass side, there is some enhancement of bass and some reduction of treble content audible. However, about two thirds of the travel, you seem to reach the spot where it’s most muffled – when you go past that it feels like treble content is coming back again.
The whole thing became a lot easier and more enjoyable when I gave up understanding that particular knob and did what I usually do – searching the sweet spot, using my ears. Just turn small increments and listen. If it gets better, go on. If it gets worse, go in the other direction – until you’re there.

The Lehle RMI Sonic Spark is a weird pedal. But weird in the best of ways. It is one of those devices you drop into your chain, set a few knobs and what you get is more sound. More Better. It’s not a simple bathtub EQ that will make your bedroom tone more shiny but drops out in a mix. It really works in all kinds of circumstances. I used it to push a preamp that was set on the brink of breakup over the edge and my sound gained a jagged edge that felt dangerous. At the same time, you can run the enhancement a little bit lower and your sound gets a few hundred dollars more expensive, even if you’re after a clean sound, this thing can deliver something you’ll enjoy.

These are discontinued and not easily found, but those I’ve seen on offer were sold at €200-250,-
I feel that this is a sleeper pedal that would get more attention if more people tried it.
If you ever run across one, don’t hesitate. Snatch it up and bring it home.