The Stoel Music Systems Dual Lin/Log VCA is a versatile module featuring two voltage-controlled amplifiers with a switchable response. The logarithmic setting is generally used for audio, and the linear response is more suited to modulating control signals. However, the responses can be interchanged to generate unique effects.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high-resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Model EM1206
Size: 8 HP
The Stoel Music Systems Discrete VCF is a vintage-inspired voltage-controlled filter that uses several matched transistor pairs arranged in two sequential filter blocks. It sounds completely different from the famous east coast “Ladder” filter design. There are no integrated circuits or op-amps in this design. It has a gentle slope of 12dB per octave and features low pass and bandpass modes for added versatility.
There are two CV inputs for modulating the filter frequency. CV input 1 is full-scale for keyboard tracking purposes, and the amount of CV input 2 is adjustable with a knob. The resonance will self-oscillate except at very low frequencies. This filter is excellent for leads, basses, and percussion sounds.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high-resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Mode EM1201
Size: 8 HP
The Stoel Music Systems Buffered multiple provides precise distribution of control voltages to up to eight destinations. When splitting a control voltage, the voltage will often drop as it is divided to more destinations. This can be a significant problem, especially when controlling the pitch of oscillators. This module provides a separate unity gain buffer amplifier for each output, ensuring that splitting the signal will not affect the level. Both CV and audio signals can be distributed with this module.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Size: 4 HP
Enjoy your Eurorack system anywhere without hooking up speakers or using headphones. The Stoel Music Systems Mini Speaker is great for casual jam sessions with friends without headphones, sharing your love for electronic music with others outside the studio, in the classroom to demonstrate music and physics, or just annoying your neighbors. For large cases, two speakers can be installed for a stereo effect.
How loud does it get? This module features a 4-watt amplifier and 3” (77mm) speaker rated for 4 watts continuous, 8 watts peak. The speaker has an efficiency of 84dB @ 1 watt, measured from 1 meter away, so expect a maximum output of around 90dB at 1 meter away, or 93dB when standing about 18” away. It’s loud enough to be heard across a small to medium-sized room but not loud enough to be heard over drums or loud guitars.
How does it sound? The speaker is somewhat bandwidth-limited due to its small size but still delivers clear sound when playing back full-range music. The Eurorack case acts like a large speaker cabinet, contributing to the low-frequency response. The bass response rolls off around 200 Hz, and the high frequencies roll off above 10kHz. It can be miked up and recorded for a lo-fi effect.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Size: 16 HP
The Stoel Music Systems Dual Morphing LFO features a pair of multi-waveform voltage-controlled LFOs with cross-modulation, allowing for a wide variety of rhythmic phenomena and happy accidents.
The speed of each LFO is controllable with CV. If the CV jacks are unused, the sine output of each LFO goes to the CV control of the opposite LFO. This routing arrangement allows the output of one LFO to modulate the speed of the other. This routing is overridden by plugging a cable into the CV jack, allowing an external CV signal to be applied. The maximum frequency is approximately 120Hz.
Each LFO has saw, square, triangle, and sine wave outputs. Additionally, each LFO has a sine minus saw waveform and a sine minus square waveform. These unique waveforms create additional sound design possibilities.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high-resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker
Size: 14 HP
The Stoel Music Systems CV Source provides two adjustable control voltages, each with a course and fine control. On a 1V/octave scale, the coarse control spans over five octaves, and the fine control spans a semitone plus about 20 cents (120 cents total).
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high-resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Model EM1210
Size: 4 HP
The Stoel Music Systems Dual Ring Modulator provides two classic analog ring modulators, which also feature a multiplication mode for added versatility. Depending on the front panel switch setting, the X and X inputs either modulate or multiply each other.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high-resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Size: 4 HP
The Stoel Music Systems ADSR provides a classic synthesizer envelope. Attack, decay, sustain, and release are all controlled with knobs. The ADSR envelope output is provided in both normal and inverted forms. The manual trigger button fires off the ADSR without a gate signal present, which is excellent for playing sounds live or sorting out complicated patches.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high-resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Size: 6 HP
The Stoel Music Systems Quad VCA provides four logarithmic (audio) VCAs that mix to one common output in a compact 4HP module.
Both the audio jacks and the CV jacks are normalled from top to bottom. If a CV signal is plugged in, and the CV jacks below it are unused, the same CV signal goes to the remaining VCAs. This applies the same VCA signal to multiple signals, such as in stereo or quad-channel configurations. Likewise, when an audio signal is plugged in, and the audio jacks below it are unused, the same audio signal is provided to the VCAs below. This configuration allows for the remaining VCAs to be used in parallel. Using two VCA channels in parallel reduces the noise floor by 3dB, and using all four channels in parallel reduces the noise floor by 6dB. Please note there will be an increase in output level when VCA channels are used in parallel.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high-resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Size: 4 HP
The Stoel Music Systems Spring Reverb is a flexible spring reverb module with extended features. In addition to standard level, wet/dry mix, and tone emphasis controls, the feedback control re-introduces the reverb signal back at the input. At low settings, this increases the density of the reverb. At high settings, it will cause oscillation. The level at which oscillation occurs will depend on the reverb tank used. In addition, a 100% wet output and a feedback input jack allow for external feedback signal processing. For example, by sending the feedback signal through a filter, unique reverb textures can be created, and the feedback control can be further exploited for sound design.
Reverb tanks use electromechanical technology dating back to the 1940s, so some noise is expected, even under ideal conditions. If the case is moved while the reverb is turned up, the user may hear a loud “crash” sound. This is caused by the springs hitting the sides of its metal enclosure. This behavior is normal. When locating the reverb tank in the case, place it as far away from the power supply as possible to avoid picking up hum and noise. A switching power supply is generally quieter than one that uses large transformers. Some level of hum and noise is expected in any installation due to the nature of the electromechanical reverb spring and magnetic pickups. Experimenting with the placement and orientation of the reverb tank may be necessary to achieve the best results. Mechanical noise can be minimized by using the included mounting grommets and mounting the reverb tank away from vibration sources such as speakers or drum pads. High signal levels will also reduce the signal-to-noise ratio, resulting in better sound quality.
We recommend the following reverb tanks (not included):
9.25” long reverb tanks
8EB1C1B: Horizontal/open side down, 3 Spring, Short Decay
8EB2C1B: Horizontal/open side down, 3 Spring, Medium Decay
8EB3C1B: Horizontal/open side down, 3 Spring, Long Decay
8EB2C1A: Horizontal/open side up, 3 Spring, Medium Decay
17” long reverb tanks
4EB3C1B: Horizontal/open side down, 2 Spring, Long Decay
4EB2C1B: Horizontal/open side down, 2 Spring, Medium Decay
9EB2C1B: Horizontal/open side down, 3 Spring, Medium Decay
9EB3C1B: Horizontal/open side down, 3 Spring, Long Decay
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Model EM1207
Size: 6 HP
The Stoel Music Systems Standard VCO is a versatile oscillator with a variety of controls and outputs. Coarse and fine tuning controls are provided for a wide range of accurate tuning. The CV 1 jack follows a 1 volt per octave scale. Knobs control the scale of the CV 2 and CV 3 jacks.
The pulse waveform is a square wave with a variable duty cycle which can be manually adjusted with the pulse width knob. The pulse width can also be modulated with a signal on the PWM jack, with the depth controlled by the pulse width mod knob.
The linear FM input modulates the tuning with an LFO or another oscillator without shifting the center pitch. The linear FM knob controls the amount of modulation applied to the pitch. Hard sync and soft sync jacks are also provided.
Outputs include saw, pulse, triangle, and sine. Additionally, a sub oscillator provides a -1 octave square, a -2 octave square, and a -2 octave narrow pulse in a nod to the sub-oscillator on the SH-101.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high-resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Model EM1204
Size: 16 HP
Enjoy your Eurorack system anywhere without hooking up speakers or using headphones. The Stoel Music Systems Mini Speaker is great for casual jam sessions with friends without headphones, sharing your love for electronic music with others outside the studio, in the classroom to demonstrate music and physics, or just annoying your neighbors. For large cases, two speakers can be installed for a stereo effect.
How loud does it get? This module features a 4-watt amplifier and 3” (77mm) speaker rated for 4 watts continuous, 8 watts peak. The speaker has an efficiency of 84dB @ 1 watt, measured from 1 meter away, so expect a maximum output of around 90dB at 1 meter away, or 93dB when standing about 18” away. It’s loud enough to be heard across a small to medium-sized room but not loud enough to be heard over drums or loud guitars.
How does it sound? The speaker is somewhat bandwidth-limited due to its small size but still delivers clear sound when playing back full-range music. The Eurorack case acts like a large speaker cabinet, contributing to the low-frequency response. The bass response rolls off around 200 Hz, and the high frequencies roll off above 10kHz. It can be miked up and recorded for a lo-fi effect.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Model EM1203
Size: 16 HP
Ring modulation takes two inputs and multiples them by each other. The original signals are canceled out, leaving only sidebands that are harmonically unique and often unpredictable. Of course, any mathematical model is less than perfectly carried out in the analog world, giving each implementation a unique character. Most modern ring modulators perform multiplication with a single integrated circuit. However, the concept of ring modulation was invented back in 1934 for use in telephone lines, long before the invention of the transistor.
This module uses the original circuit arrangement where vacuum tubes and transformers perform the multiplication. The sounds of the tube circuit tend to be more harmonically rich and complex. This module excels at making bell-like sounds, edgy, FM-like bass sounds, metallic percussion textures, and otherworldly sound effects. The inputs can be used with oscillator outputs, LFOs operating within the audio range, or any audio signal. Using the same envelope to sweep the frequency of an oscillator connected to one of the inputs and the amplitude of a VCA after the ring modulator output can lead to fascinating new textures. Varying input levels also affect the overall timbre.
All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.
Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.
Model EM1205
Size: 14 HP
The Stoel Music Systems 2044 Filter is a classic 24db/octave analog lowpass filter with voltage control over frequency and resonance. The 2044 filter was used in the Korg Polysix, Korg Monopoly, Korg Trident, PPG Wave 2.3, the Emu Drumulator, SP-12, Emulator, the Voyetra 8, and several other vintage synthesizers.
Size: 8 HP