# 2hp — Turing Machine - [Manual PDF](../../manuals/TM_Manual.pdf) --- [Manual PDF](#) # Using the 2hp TM to Create Melodic Material The attached manual is for the **2hp TM**, a compact probabilistic random sequencer/CV generator. On its own, it does not quantize pitch, clock itself, or generate gates for note articulation beyond responding to an incoming trigger. But as a melodic utility in a Eurorack system, it can be very effective when paired with a **clock/trigger source**, **quantizer**, **VCO/voice**, and optionally **sample & hold, slew, logic, or modulation**. ## What the module does The **TM** outputs a **0–5V random control voltage** at its **OUT** jack whenever it receives a trigger or gate at **TRIG**. Its key idea is that it does not behave like pure chaos all the time. Instead, it stores a sequence of step voltages and uses a **probability control** to decide whether each step changes or remains the same as the sequence advances. ### Core controls - **TRIG input** - Advances/generates on incoming trigger or gate - Threshold: **2.5V** - **PROB knob + PROB CV** - Far left = **100% probability** of generating a new random voltage for the active step - Far right = **0% probability**, effectively locking the existing sequence - **STEPS knob + STEPS CV** - Sequence length from **1 to 32 steps** - **AMP knob** - Scales output range from **0V to 5V** - **OUT** - Random/stored sequence CV output, **0–5V** ## Musical interpretation This is best thought of as a **Turing Machine-style looping random melody source**: - At high probability settings, the melody changes constantly. - At low probability settings, the melody becomes increasingly repeatable. - At 0% probability, it acts like a locked sequence. - Changing **STEPS** changes phrase length. - Changing **AMP** changes melodic range before quantization. That makes it very useful for: - generative melodies - evolving basslines - semi-repeating motifs - controlled random transposition - modulation of melodic parameters --- # How to patch it for melody ## 1. Basic generative melody patch ### Patch - **Clock/trigger source** → **TM TRIG** - **TM OUT** → **quantizer IN** - **quantizer OUT** → **VCO 1V/oct** - Same clock or a related gate pattern → **envelope/gate input** - Envelope → **VCA** - VCO → **filter/VCA/audio chain** ### What happens Each trigger advances the TM. The output voltage is quantized into musical notes, giving you a melody. ### Suggested settings - **PROB** around 9–12 o’clock for evolving repetition - **STEPS** around 5–8 for short melodic phrases - **AMP** around 10–1 o’clock to keep pitch movement in a usable range ### Why it works The quantizer turns the TM’s raw random voltages into scale tones. The TM’s probability memory gives the result more structure than pure sample-and-hold randomness. --- ## 2. Locked looping melody ### Patch Same as above. ### Settings - First, turn **PROB** left so new values are written often. - Let it run until you hear a phrase you like. - Then turn **PROB** fully right to **lock the sequence**. ### Result You now have a repeating melodic loop with up to **32 steps**. ### Performance trick Momentarily bring PROB left to let a few notes mutate, then return right. This gives subtle phrase evolution without losing the identity of the melody. --- ## 3. Controlled random bassline ### Patch - Trigger sequencer / clock divider → **TM TRIG** - **TM OUT** → quantizer set to minor pentatonic / minor scale - Quantizer out → bass VCO - Gate pattern → envelope → VCA ### Settings - **STEPS**: 4–8 - **AMP**: low to medium - **PROB**: low, around 1–3 o’clock if you want mostly stable looping with occasional mutation ### Result Because the output range is reduced with **AMP**, the quantizer sees a narrower CV span, which often creates tighter melodic contours suitable for basslines. --- ## 4. Melodic phrases with variable length ### Patch - Clock → **TM TRIG** - Slow LFO / random CV / sequencer row → **STEPS CV** - **TM OUT** → quantizer → voice pitch ### Result The phrase length changes over time, causing the melodic cycle to shift. ### Musical use This is great for: - non-repeating ambient melodies - phase-like pattern changes - evolving techno arps ### Tip Subtle modulation of **STEPS CV** tends to be more musical than wild jumps. --- ## 5. Varying predictability over time ### Patch - Clock → **TM TRIG** - Slow LFO, envelope, or another random source → **PROB CV** - **TM OUT** → quantizer → oscillator pitch ### Result The melody moves between: - highly unstable / novel - semi-repetitive - fully locked ### Musical use This is one of the strongest features of the module. You can automate tension and release: - verses: lower probability, more repeatability - transitions: higher probability, more mutation - breakdowns: fully random - choruses: locked phrase --- # Best companion modules for melodic use Since TM is only one module, the "used together" part really means how it works alongside other common Eurorack categories. ## 1. Quantizer This is the most important partner. TM outputs **continuous random CV from 0–5V**, not discrete musical notes. A quantizer converts that into a scale. ### Good uses - Major/minor tonal melodies - Pentatonic ambient lines - Modal sequences - Arpeggio-like note sets ### Tip If the quantizer supports transposition, feed a second CV source into transpose for harmonic movement while TM handles note selection. --- ## 2. Clock / trigger source TM needs external timing. ### Good trigger sources - steady clock for regular melodies - Euclidean trigger generator for asymmetrical note timing - gate sequencer for rhythmic melody placement - clock divider/multiplier for slower or faster melodic movement ### Tip Changing the trigger rhythm changes the perceived sequence as much as changing the pitch data. --- ## 3. Oscillator or complete synth voice Once quantized, TM can drive: - a sine or triangle oscillator for simple melodies - a wavetable VCO for animated lead lines - a complex oscillator for experimental phrases - a full voice module for compact patches --- ## 4. Envelope + VCA TM does not produce note gates for articulation by itself beyond reacting to incoming triggers. So you usually pair the same trigger source, or a related rhythm source, with an envelope/VCA path. ### Patch logic - trigger source branches: - one copy to **TM TRIG** - one copy to **envelope gate** - TM controls pitch - envelope controls note articulation --- ## 5. Slew limiter / glide Placing a slew after the quantizer or before the oscillator can create: - portamento - gliding random melodies - smooth ambient pitch transitions Very effective for generative melodic textures. --- ## 6. Sample & hold / switch / sequential switch These can further structure TM’s output. ### Ideas - Sample the TM less often than it is clocked - Alternate between TM and another sequencer - Use a switch to route TM to different voices - Create call-and-response melodies --- ## 7. Precision adder / offset Since TM outputs 0–5V, you may want to control register. ### Uses - transpose the melody up/down - constrain the note center - combine TM with another sequencer row - create harmonic movement over a static TM phrase --- # Practical melodic patch examples ## Patch A: Ambient generative lead - Slow clock → **TM TRIG** - **TM OUT** → quantizer set to Dorian - Quantizer → VCO pitch - Same clock → envelope - Envelope → LPG/VCA - Slow triangle LFO → **PROB CV** - Slow random CV → **STEPS CV** ### Outcome A self-evolving melody with recurring fragments and shifting phrase lengths. --- ## Patch B: Techno riff generator - 16th-note trigger pattern → **TM TRIG** - **TM OUT** → quantizer in minor scale - Quantizer → acid-style VCO pitch - Trigger pattern → short envelope → VCA/filter env - **PROB** low enough to preserve groove - **STEPS** at 8 or 16 ### Outcome A stable but mutable riff generator. Great for live performance by nudging PROB. --- ## Patch C: Bass + lead derived from one source - Clock → **TM TRIG** - **TM OUT** multed to: - quantizer 1 → bass oscillator - quantizer 2 or shifted copy → lead oscillator - Use different trigger divisions for each envelope ### Outcome Correlated melodic layers from the same evolving sequence. --- ## Patch D: TM as melodic modulation, not primary pitch Instead of controlling oscillator pitch directly: - **TM OUT** → quantizer → oscillator FM amount CV - or **TM OUT** → filter cutoff CV - or **TM OUT** → wavefolder symmetry ### Outcome You preserve a fixed melody elsewhere while TM adds pseudo-melodic internal motion. --- # Strengths of the TM for melody ## 1. Repeatability without rigidity It sits between random source and sequencer. ## 2. Excellent for live improvisation One knob move on **PROB** can move the patch from chaos to motif. ## 3. Compact At **2hp**, it gives a lot of melodic utility in very little space. ## 4. Good phrase control **STEPS** from **1–32** lets it do anything from drones to long evolving patterns. ## 5. Range control via AMP This is deceptively useful. Lowering amplitude before quantization can keep melodies focused and musical. --- # Limitations to keep in mind ## 1. No built-in quantizer You will usually want an external quantizer for tonal melodies. ## 2. No internal clock Needs external triggers. ## 3. No explicit reset input This means phrase alignment with other sequencers may be less exact than with a traditional sequencer. ## 4. Output is unipolar 0–5V Depending on your oscillator and quantizer, this can span a wide register. You may want attenuation, offset, or transposition management. --- # Best workflow for composing melodic parts A strong musical workflow with TM is: 1. **Clock it** 2. **Quantize it** 3. **Set a musical scale** 4. **Adjust AMP** for range 5. **Set STEPS** for phrase length 6. **Set PROB** for stability vs mutation 7. **Lock** the sequence when you find a phrase you like 8. Modulate **PROB CV** and **STEPS CV** slowly for long-term evolution This makes TM especially strong for: - ambient - Berlin-school style generative sequencing - minimal techno - experimental tonal patches - evolving soundtrack textures --- # Summary The **2hp TM** is best used as a **probabilistic CV melody source**. It becomes a powerful melodic tool when combined with: - a **trigger/clock source** - a **quantizer** - a **voice or oscillator** - and optionally **CV modulation, slew, switching, or transposition** Its musical sweet spot is generating phrases that feel **alive, semi-repeatable, and gradually mutating**, rather than fully programmed or fully random. If you want, I can also turn this into: 1. a **patch recipe list**, 2. a **beginner-friendly explanation**, 3. or a **“best companion modules” table**. [Generated With Eurorack Processor](https://github.com/nstarke/eurorack-processor)