RK10 — a serious power supply plus a complex controller for Metasonix modules.

The RK10 is a power supply capable of running up to fourteen random Metasonix RK tube modules, with CV/gate controllers included. The controller section is very similar to the controller built into the previous T1 Synthesizer. We are making it in this form due to repeated demands for the control section of the T1 as a Eurorack module. Plus unending requests for a heavy-duty power supply that will run our modules. The RK10 produces +12v at 8 amps and -12v at 2 amps absolute maximum; the +12 supply has more capacity because the heaters of the tubes in RK modules are always powered from the +12v supply, and draw a LOT of current when started cold. Once the tubes are at operating temperature, the power supply will be running at far below its maximum ratings. It will also power conventional solid-state Euro modules if desired. The RK10 is one of the most powerful Eurorack supplies ever offered and is intended specifically to run our RK modules.

Unlike other Euro power supplies, the RK10 also contains:

1. a one-octave keyboard intended to control the Hz/v Metasonix RK7 VCOs and any other VCOs The keys can be individually tuned to ANY scale within the range of the VCOs, plus a keydown produces a gate signal to trigger external envelope generators. CV output range is roughly 0.5 to 2.5 volts. Gate output is 0-10v. The keyboard will also operate conventional solid-state VCOs and other modules.

2. a 50mm ribbon controller connected in parallel with the keyboard. It may be used separately or as a pitch-bend control in parallel with the keyboard. Range is roughly 0.5v to 4v.

3. An 8-stage analog sequencer. Turning the control for each stage fully down disables and skips that stage. Allowing rests to be inserted. Output voltage is roughly 0-8 volts. A clock output of 0-10 volts is also produced. The sequencer has a RUN/STOP switch to stop it on the current stage, plus an optional clock input that needs at least 0-8 volts to clock the sequencer. A run/stop switch and input can be used to stop the sequencer at any stage; the control input accepts 0-8v and is RUN=low, STOP=high.

4. finally there is a separate pressure controller producing 0-5v CV.

The RK10 supply should run up to fourteen random RK modules. With an exception; the RK8 Filterwall uses much more tube heater power than the other RK modules, so an RK10 should be limited to running a maximum of two RK8 modules along with others.

We DO NOT recommend trying to run our older R-series modules on the RK10. They draw considerable current from both the +12v and -12v rails, and the -12v supply in the RK10 is limited to 2 amps. It SHOULD run at least two R-51, R-52, R-53 or R-54 modules; we have not tested this yet. Try it at your own risk. The switching power supplies of the RK10 have overcurrent protection so damage with an overload is very unlikely. Don’t even think of running an R-55 VCO because it needs very high current 5v power. The R-56 and R-57 are probably workable but again, hasn’t been tested yet.

There was no room left on the RK10 board for an envelope or LFO. The sequencer is your LFO, dude. The RK10 gate outputs can trigger any conventional Euro envelope generator. They ABOUND. Sequencer and keyboard/ribbon gate outputs are combined into the Combination Gate output, to insure a gate is available no matter how the RK10 is configured.

Apart from the 14-position bus board, there are two additional 10-pin power headers on the back of the RK10 module. They also carry +12 and -12 power and may be used to run additional modules (within the limits of the power supply!!) INSTALLATION IN YOUR EURO CABINET IS REQUIRED. The power bus board is mounted on six M3 standoffs; you must drill holes in your cabinet to fit. A drill guide and assorted M3 screws are included.

Generally the RK10 (like the other RK modules) is a weird abnormal device. “Conventions” are not followed. A bit like an evil Music Easel controller. Tubes are little bastards that waste power and change in electrical characteristics as they age. This is why many controls have large “dead areas” in their ranges; we have to allow for tube drift and aging. Boo hoo if you don’t like it. I don’t care. Huff some more spray paint.


Specifications: the module is 40hp wide and will fit in most shallow “skiff” cabinets, although a larger cabinet is strongly suggested. It uses an external Delta Power 12v power supply “brick” which is very large and heavy, because it’s the QUIETEST 10-amp power supply we could find. It is “medical grade”. The power brick connects via a 2.1mm barrel connector. A power cord for North America is included, if you are in another country, an IEC-ended mains cable must be obtained locally. It may also be powered from a large 12v battery or other suitable source of CLEAN 12vDC power. The RK10 includes a Tiptop power bus board which connects to the module via a very heavy power cable. This Tiptop board contains a low-power +5v regulator whose use is optional (DO NOT try to use it to power an R-55 module). The typical noise riding on the +12 and -12 lines is 50 mV or less, average. Yes, it runs on any AC mains power from 100v to 240v.

Dimensions in packaging 16x4x4 inches (40.6×10.2×10.2 cm), weight 4.4 lb (2 kg). Installation and cabinet modification is required.