Here’s the assembled Rollz-5 project!
The whole assembly can operate outside of its box. Here it is being tested. To the right you can see the power inlet, ground jack, and left and right quarter-inch outputs. Below those, suspended beneath the clear panel, is the hand-wired board containing the voltage regulator (Recom R-78C9.0-1.0) and output mixer. The single green jack goes to an LED driver and LED on that board for test monitoring.
I described the panel layout in more detail on this previous post. On the left are the eight Rollz LFO square wave oscillators, each with a separate fixed frequency. From top (red) to bottom (green) they go from fastest to slowest at non-harmonic intervals. Next to the right are the four AVDogs with their associated square wave audio oscillator. The oscillator output is directly available on the panel. Next come the Ultrasound modules, and finally the four Gongs. The six gray output mixer knobs are on the right.
The measured frequency range of the manual square wave oscillators is 50 Hz to 2.1 KHz. The Ultrasound oscillators are 750 Hz to 30 Khz. And (a bonus from adding inputs and outputs to the Gong) when the Gong output is patched to its own input, it becomes an oscillator with a range of 95 Hz up to 2.1 Khz. The upper frequency of the Gong is limited by a series resistor installed on the PC board, which I made different values from 47K to 470K. I will be changing the 470K to a smaller value, since it limits the upper frequency on that Gong to 220 Hz.
The added inputs and panel outputs have really enhanced the patch flexibility of this board. By accident I discovered that patching the output of an AVDog to the Gong aux input and the Gong out to the AVDog aux input makes an interesting gated oscillator. The Gong begins oscillating as the AVDog VCA opens up and then stops as it closes. Since the AVDog can have a very long envelope (several seconds long) that repeats, it results in a repeatedly rising and falling drone. And you can patch four of them all at different frequencies. All the pitches are manually tuned, so it can sound melodious if desired.
The AVDog, Ultrasound, and Gong can be patched in series in any combination with the Oscillator inserted at whatever starting point you like. For example I can route an Oscillator through a Gong then through AVDog. The switch on the AVDog input selects between the Oscillator and whatever is patch to the violet aux input jack. Being able to switch this input is useful during a performance without re-patching. A 10K ohm series resistor on each output allows for stacking outputs together to one input. I found when using the Gong aux input that if the Gong is also being triggered via the green jack, the aux input tends to overwhelm the ringing, but I can patch in one of my in-line attenuators to remedy this, if needed. I think I’ll probably use a Gong in either the ringing bongo mode or the filter mode.
The two brown Node jacks on the Rollz LFO allow ample opportunity to link it to other LFOs. The brown jacks generate short, negative-going (below zero volts) pulses that can be used to trigger AVDog and Gong and also jog Ultrasound. The orange output is a positive-going square wave, like the Rollz on Plumbutter. Using it as a trigger has subtly different effects on the AVDog and Gong.
Needless to say, I have plenty of experimenting to do with all this patching variety.
A closeup of the CGS LED driver board. These were perfect to use here. Notice the notch, cut with a Dremel tool, to straddle the solder lug on a banana jack. I used water-clear high efficiency LEDs, the same ones as used on the Quantisise, because of their low power consumption. I matched the current resistor with each color to get a more or less uniform brightness across the four colors.
Here are some photos of the assembly, prior to folding it together. This first one is just after wiring up the Rollz circuits.
This one shows all the wiring. I estimate there is more than 200 feet of wire. It took several days of work to wire it all up. I made one wiring mistake, reversing the connections to the frequency and Q pots on two of the Gongs, because I didn’t pay close enough attention to the asymmetric layout on the board. But this took only swapping six wires to correct. This pic shows the incorrect wiring!
And here is how it looks secured into the travel case, a standard tool/gun case. It pops in and out of the case with just four large screws. There is room left to store cables and the wall wart power supply for carrying. It’s waterproof, too!
Naturally I will be posting some recordings. I also plan to get a video camera soon, so I can make some demonstration videos of this and other projects.