RS909 - Keyboard Tiptop Audio - Free user manual and instructions

Product Type	Eurorack Synthesizer Module
Brand	Tiptop Audio
Model	RS909
Width	8 HP (approx.)
Height	3U (128.5mm)
Depth	30mm (approx., with power cable)
Weight	Approx. 100g
Power Supply	Eurorack +12V / -12V (typical 30mA each)
Inputs	Gate In (trigger/gate), Accent In (gate/CV)
Outputs	RS Out (audio), MixBus (via jumper)
Main Function	Clone of TR-909 Rimshot sound generator with added oscillator controls
Controls	Level Knob, Accent Knob, OSC-1 Knob, OSC-2 Knob
Special Feature	Independent accent level per module; MixBus jumper for integration with MIXZ
Original Sound Reference	Dot on OSC knobs indicates original TR-909 setting
Construction	Analog circuit, SMT manufacturing
Dimensions (exact)	Not specified; typical Eurorack module size
Maintenance	Clean with dry cloth; avoid moisture and static
Safety	Connect only to Eurorack power bus with correct polarity; do not exceed rated power
Repairability	No user-serviceable parts; contact Tiptop Audio for support
Included Accessories	Power ribbon cable, mounting screws (may vary)

Frequently Asked Questions - RS909 Tiptop Audio

How do I get the original TR-909 Rimshot sound?

Set the OSC-1 and OSC-2 knobs to the dot on the panel. This marks the original 909 frequency. Then adjust Level and Accent to taste.

What does the Accent input do?

The Accent In accepts a gate or CV signal. When connected, it dynamically varies the output gain. The Accent Knob sets the intensity of the accent effect. If nothing is connected to Accent In, the Gate In is normalized to both inputs, making the Accent knob act as a fine gain control.

Can I use CV on the Accent input?

Yes, the Accent input accepts CV (0-10V typical) for continuous variations in accent level. The knob then controls the sensitivity, allowing greater expression.

What is the MixBus jumper for?

The MixBus jumper connects the RS909 output to the internal MixBus of the MIXZ mixer module. If you don't use MixBus, leave the jumper on a single pin (either pin) to avoid short circuits.

What are the power requirements?

The RS909 requires +12V and -12V from a standard Eurorack power bus. Typical current draw is around 30mA on each rail, but check the manual for exact specs.

What are the dimensions of the RS909?

It is a 3U Eurorack module. The exact width is not specified, but it is estimated at 8 HP (approx. 40mm). Depth is typically around 30mm including the power cable.

How do I integrate the RS909 with other Eurorack modules?

Connect a gate output from a sequencer or trigger source to the Gate In. Route the RS Out to a mixer or VCA. For accent, use a separate gate or CV source (e.g., from a sequencer accent track) into the Accent In. The module also works with the MIXZ via the MixBus jumper.

How do I clean and maintain the module?

Use a soft, dry cloth to clean the front panel. Avoid liquids and abrasive cleaners. Keep the module in a dust-free environment. Ensure proper ventilation inside the case.

What safety precautions should I take?

Always power off your Eurorack case before installing or removing modules. Ensure correct polarity when connecting the power cable (red stripe indicates -12V). Do not exceed the module's rated power draw.

Can I use the RS909 outside of a Eurorack system?

The module is designed for Eurorack format and requires a ±12V power supply. It cannot be used as a standalone device without a compatible case and power source.

USER MANUAL RS909 Tiptop Audio

The RS909 is Roland's TR-909 analog Rimshot sound generator adapted for modular synthesizer use. The front panel contains all of the controls found on the original TR-909 drum machine, allowing you full control over the sound's volume levels to mix with other drums, and accent levels. In addition to those original controls we have also added control over the two internal oscillators, further enhancing this circuit.

About the Making of the RS909.

The RS909 is a one-to-one clone of the original circuit found in Roland's TR-909 drum machine. During the design phase, we created additional features only when implementation would not compromise the original signature sound, or add excessive costs. Cloning a circuit that was designed and produced in the 80's was not an easy task. A variety of obstacles including availability of the original parts, the modern SMT manufacturing process, the differences in +/-12V Eurorack power versus the +/-15V of the original 909, and far many more were addressed in the creation of this module. To learn more about the process of remaking the sound generators in this series please refer to the BD808 user guide.

Let's get started.

To start using the RS909, just plug a gate signal into the GATE IN, plug the RS OUT to your sound system, set the LEVEL half way and Accent to max, set OSC-1 and OSC-2 to max, pointing at the direction of the 909 dot on the panel.

Dynamics and Gain:

Accent and Levels:

Dynamic Accent and Level control of any drum sound in the mix is a big part of making a beat sound right. Dynamic Accent provides emphasis on a particular note through loudness. In analog circuits like the RS909, the accent pulse physically "hits" the internal envelope circuit harder and provides not only a louder sound but also slightly more attack (much like if you were to hit a real drum harder or softer with a drum stick).

While the original 909 has one global accent knob for setting accents levels for all of its sounds, the RS909 (and all other drum modules in this series) offers an independent accent level control. This feature adds to a clear work flow than what was possible with the original machine.

Accent Explained:

The accent input can be driven by either a gate/trigger or CV signal. While the accent input is not in use, the incoming gate input is routed (normalized) to both the accent input and the gate input. This serves for two purposes:

1. To allow you to reach the hottest drum sound possible even when there is no accent input signal connected.
2. It makes the ACCENT knob act as a fine control of the output gain level. This is very useful in situations where the level knob range is too coarse for setting precise levels in a mix with other drum sounds.

Connecting a gate or CV signal into the accent input will break the internal routing mentioned above and will allow for independent control over accent regardless of the incoming gate signal. In this case as long as there is no accent signal present, the drum sound will be set to the minimum accent level set internally, and once the accent input gets hit by a gate or CV signal, the drum sound will get louder in proportion to the accent level set by the accent knob. In short: the higher the knob setting, the larger the difference will be in gain levels between the accented notes and the un-accented notes. Using CV allows for even greater variations.

OSC-1/2 Explained.

The knobs labeled OSC-1 and OSC-2 control the frequency of two of the oscillators out of the total 3 oscillators in the RS909 circuit. A dot on the scale indicates the setting of the original 909 machine, at this point the sound is same as the original.

Moving the knobs the other direction will change the frequency of these oscillators and give more variations to the sound.

MixBus jumper.

Setting the jumper on the two pins will connect the output of this module to the MixBus of the MIXZ mixer module. If MixBus is not used please keep the jumper only on one pin, either pin is fine. For more information on MixBus please see MIXZ user guide.

TIPTOP audio

www.tiptopaudio.com/909-2