The Tube Screamer is one of the most modded pedals there is, and this plug‑in lets you mod the virtual circuit to your heart’s content!
With so many effects‑modelling plug‑ins available today, you might wonder why Cytomic would focus their talents on an emulation of the classic Ibanez TS808 Tube Screamer. Indeed, when I first saw their announcement, I wondered that myself — but boy am I glad that I decided to see what all the fuss was about! I started by comparing the results of placing The Scream before a Blackstar St James amp model set to the clean channel of its EL34 mode. In comparison with other drive plug‑ins, the Scream sounded more refined (to be fair, Overloud TH‑U’s Tube 9 came close), reminding me of a real Tube Screamer running into a clean amp, with the classic smooth highs combining with some mid lift and a little taming of the low end. Tweak the gain and you can go from an almost clean, warm boost to a hint of bluesy drive and then on into classic rock territory, resplendent with smooth saturation.
Tweakers’ Delight?
But Cytomic have taken things much further. First, there’s a global control panel that allows adjustment of the pre and post levels, plus the ability to mix the wet and dry sounds, which can help when a little more transient clarity is required. The ‘pedal’ itself sports the usual trio of Drive, Level and Tone knobs, but you also get a two‑position Mod switch plus trimmer pots for adjusting the working voltage and the circuitry bias. The Mod switch’s two positions access differently modified versions of the pedal, and circuit mods can be undertaken by the user without the need for a soldering iron!
Upping the Voltage appears to give a smoother sustain while Bias, which essentially offsets the centre rail voltage, produces authentically spitty and spluttery results if turned anticlockwise. For most users that will be enough, but the Mod button gets you into a world of diode swapping that can be applied separately to the Mod switch’s two positions. The available diode types are Custom (the default), Silicon, Germanium, LED, Schottky and Zener, with a number of choices for each. The Silicon category offers 13 diode choices, and there are five Germanium types. Each of the circuit’s two diodes can be changed independently, and there’s the option to place multiple diodes (of the same type) in series; a common trick is to double up just one diode, to add some asymmetry to the clipping. A further button randomises component values.
It’s a great way of designing and testing your own modded Tube Screamer before you go out and buy the bits to build one.
This tweakers’ rabbit‑hole keeps on getting deeper! Click on the Diode symbol (top right), and a Tube Screamer circuit schematic opens. Here, you can change the resistor or capacitor values — it’s a great way of designing and testing your own modded Tube Screamer before you go out and buy the bits to build one. The factory presets already include several well‑known variations on the circuit, including various TS9 models, a Keely‑modified TS808, a Boss SD‑1, an EQD Plumes and a Mesa Grid Slammer. As you select these, the circuit diagram updates accordingly. Various mods can be saved as presets to load into your next virtual design session.
Switching to HD mode, which asks more of your CPU, models the virtual circuitry as one complex large‑equation model, and includes more precise modelling of the op‑amps, including slew rate, diode capacitance and power supply sag. A bar of dots (the Explorer Bar) stores each change, allowing you to go back to earlier versions very quickly, and further diode characteristics can be imported in the Spice model format for those who wish to get super‑geeky. In stereo mode, different component variations can be added to each channel.
A Real Scream!
If you just want a great‑sounding TS808 with its familiar three knobs, that’s all you need to use. But this is so much more than a detailed plug‑in version of the beloved Tube Screamer. Not only has it been modelled in fastidious detail, but you can tweak to your heart’s content and really dig into the fine detail of circuitry design — with no risk of burning out any chips! And all this for only $29? It’s a steal!
Summary
So much more than a Tube Screamer emulation, The Scream could be as valuable to pedal builders as a design tool as it is as an effect for those wanting to shape their own guitar sounds.