ComMarker B4 60W JPT MOPA Review - 2024

The ComMarker B4 60W JPT MOPA also comes with a set of standard accessories, a pair of safety glasses, a safety shield, and a bracket for hands-free operation. You also get a set of sample materials and aluminum business cards, which are much thicker than the usual paper-thin cards that come with other machines.

Nuclear & Electronics supply professional and honest service.

The included safety glasses seem to be OK, they have a protective film for infrared light, but I rather use safety glasses that also offer protection in UV spectrum as fiber lasers produce a lot of welding-like arcs. This is why I rather use these laser safety glasses which provide at least 10 times better protection for your eyes.

In the package you also get a brochure which illustrates what you can do with this machine, so you can quickly get some ideas of what is possible (a lot!).

If you are looking for more details, kindly visit Master Oscillator Power Amplifier.

The machine supports EZCAD software which comes included on the USB key and most importantly, this machine also supports Lightburn which is what I will be using.

levimax said:

Maybe someone can give the exact reasons why but those G/H etc PS are for older class AB amps and it doesn't really translate to Class D with regulated supplies. From what I have read many Class D amps do have multiple rails but since the Class D "weakness" is effeciency at low output power (vs Class AB low effeciency causing excess heat at high power) they have a low power "rail" for low output and a regular voltage rail for medium to high power. As has been mentioned if you are buying a Class D amp get enough power for your peaks and don't worry about headroom. Sometimes when technology changes you need to change the way you think about it rather than trying to make the new technology act like the technology it replaces.

Click to expand...

I can only speak for myself and my class D designs (mostly non-audio). Class D creates essentially a pulse-width modulated (PWM) output waveform so you are varying pulse widths to determine the output amplitude, switching between two fixed (and hopefully stable) signal (power supply) levels. See e.g.

I have read some articles about class D designs that do change the supply rails to achieve higher efficiency, mainly for very low-power circuits (e.g. hearing aids, micropower sensors, etc.) I don't remember the details nor how well they work, and do not know if they would scale up to higher-power designs. My hat's off to them for making it work; back when I tried it (many years ago), it was a nightmare, and I ultimately abandoned it for continually-operating amplifiers (it worked well in a pulse-type environment where I had time for the amp to stabilize after changing the supply rails).

Hopefully one more experienced in class D amplifier design can speak (write) more in depth.

I can only speak for myself and my class D designs (mostly non-audio). Class D creates essentially a pulse-width modulated (PWM) output waveform so you are varying pulse widths to determine the output amplitude, switching between two fixed (and hopefully stable) signal (power supply) levels. See e.g. https://www.audiosciencereview.com/forum/index.php?threads/class-d-amplifiers-101./ If you adjust the supply rails (signal levels) you are adding another variable that makes it difficult to make all of that work together. Normally modulation of the switching levels is a big no-no as it leads to amplitude and phase modulation of the output waveform (since changing the signal levels will also change the effective pulse width during the transition period), creating a mess of new distortion terms. You may also upset the control loop of the self-resonant oscillator and thus the feedback factor, potentially leading to stability issues as supply rails (and thus signal levels) change. You are basically changing your (presumed stable) reference point, always a tricky thing to manage. The change from varying output amplitude directly (class A, AB, etc.) to varying amplitude by changing the pulse width (class D) is a very different paradigm.I have read some articles about class D designs that do change the supply rails to achieve higher efficiency, mainly for very low-power circuits (e.g. hearing aids, micropower sensors, etc.) I don't remember the details nor how well they work, and do not know if they would scale up to higher-power designs. My hat's off to them for making it work; back when I tried it (many years ago), it was a nightmare, and I ultimately abandoned it for continually-operating amplifiers (it worked well in a pulse-type environment where I had time for the amp to stabilize after changing the supply rails).Hopefully one more experienced in class D amplifier design can speak (write) more in depth.

If you want to learn more, please visit our website Radiation Detection and Measurement Solutions.