The Atelier Robin F100 series consists of the F125, F165, F170, and F175. The first three look the same and have identical features, except for the number of output channels. These quiet, compact, well- designed machines run standalone or from the versatile software that allows you to control every aspect of the output.

These three machines produce only square waves, but since those are the ones most often used in rifing, the lack of sine or other waveforms shouldn't be an issue. The F175 is a smaller, newer, more expensive model that outputs any desired waveform. This discussion is about the first three, particularly the F165, which is a popular compromise between the simplicity of the F125 and the extra expense of the F170.

The number of outputs available in each machine is as follows:

Since this machine works so well, and my interest is in disclosing shortcomings users may not be aware of until it's too late, I don't have a lot to say about it. It does what it's supposed to do — and more — unobtrusively and with no aggravation.

(For those desiring more power, it's not clear this is necessary; resonance is the important factor, not power. However, a "10-watt amp" available from Pacific Health Products and sold for use with the F100 series is only an audio transformer, not a true 10-watt amp. It steps up the voltage, which decreases the current and therefore the power, or wattage.)

One minor point is that the Atelier Robin website and documentation don't mention a warranty. According to an email from the manufacturer, it's one year parts and labor.

Software

The software, while requiring a short learning curve if you wish to write programs, is extremely versatile, using English-based commands and allowing you to specify settings for every frequency or group. You can write the programs in the software window or in Notepad; it's easy to paste in, rearrange, or manipulate lists of frequencies or remove them to sort in Word or Excel. The software is available on the Atelier Robin site (a Mac version is also available), along with documentation.

A sample F100 program for XDR-TB by Jeff Sutherland, released on a Creative Commons license

The software has the features often used in rifing, such as sweep, converge, fuzz (a type of sweep), pulse (gating), and duty cycle. It also has positive offset (the default) and the ability to create repeat loops.

A noteworthy feature not available elsewhere, to my knowledge, is variable background frequency (vbackfreq), which produces outputs on the secondary channels based on whatever frequency is running on the main channel — a percentage and/or a fixed number of hertz. (It can also remain constant.) 

Jeff Sutherland uses this in all his programs. In the sample F165 program in the screenshot above, the main frequencies have been assigned to channel c, since this has the highest frequency range (50 MHz, compared to 3.9 MHz for the other two). The variable backfrequencies have been assigned to the other two channels (a and b, lines 5 and 6). These output a percentage of the current main frequency based on what Sutherland calls scalar octaves, which he has found more effective than harmonic octaves (factors of 2). Scalar octaves are a natural logarithmic function of the main frequency: exp(3), or 0.049787068, and exp(6), or 0.002478752. The zero following these on each line indicates that no fixed constant is added after computation of the percentage. The 66.6 after the zero is the duty cycle, obtained by dowsing. 

Similar variable functions are available for overall duty cycle and pulse (gating).

If there are any drawbacks to this generator, I have yet to find them. The software is the key to its versatility — it's intelligently designed, completely configurable, and the machine implements the program reliably. You can set it and forget it. The price is very reasonable. It may not be as flashy as other machines, but if you're looking for utility and value, this is the one to get.