This page aims to answer some of the most frequently asked questions (FAQ) about the MagicQuartz firmware for turntable speed control. If you have another question, please send me an e-mail. I will be happy to help.

I smell snake oil!

“Snake oil” refers to products that promise miraculous results but deliver little to no real benefit. In the hi-fi community, the similar term “voodoo” is often used to describe unscientific claims.

MagicQuartz is neither. And despite its name, no magic is used. MagicQuartz is built on proven engineering principles, precise arithmetic, and smart microcontroller programming. If you’re curious about its internals, please check out the PDF documentation. It even contains a section “Theory of Operation”.

Can you really hear the difference?

The short answer: If your turntable is already well-calibrated for accurate playback speed, you may not hear a major difference. However, the optional automatic voltage reduction can significantly reduce motor noise — especially noticeable during quiet passages.

The long answer: Motor noise aside, three main factors cause speed variations in turntables:

1. Mains frequency fluctuations: Changes can slightly affect speed.
2. Stylus friction: This decreases as the record plays, subtly altering (increasing) speed.
3. Lubricant warming: As the turntable runs, lubricants heat up, reducing resistance and slightly increasing speed.

While the first two factors usually go unnoticed, the third can be more significant, depending on the turntable. If you’re very familiar with a recording or conduct an A/B test, you might notice these subtle speed drifts. Though they occur gradually over several minutes, they are real and measurable. I have provided measurements on the downloads page that analyze these effects in detail. They are also outlined in my YouTube video.

Luckily, these speed variations can be measured and corrected. MagicQuartz offers an affordable, easy-to-use solution to ensure precise playback. If accurate speed matters to you, there’s no good reason not to use a turntable speedbox!

This is great! Where can I buy the speedbox?

I do not sell any hardware — neither a finished speedbox nor a kit. I also have no plans to do this in the near future. If you would like to own a MagicQuartz-based turntable speedbox, you will have to build it yourself. The straightforward, open-source hardware design of the MagicQuartz TechDemo could be a good basis for this.

That said, I’d love to hear from you! If you’re interested in a finished device or kit, let me know — your feedback helps me gauge demand for future possibilities. Simply drop me an e-mail.

What is the status of the project? Is it finished?

Yes, the project can be considered complete, but there will certainly be updates and improvements in the future.

How much does it cost?

The proprietary MagicQuartz firmware is currently available free of charge. All other information and resources are permanently free. The TechDemo hardware design, for example, is provided under an open source license. If you would like to activate a MagicQuartz license now, simply send me an e-mail: Contact Information

Why is it free? And why does a free software have to be activated?

Originally, I wanted to commercialize the project, as I have invested a considerable amount of time and money in it. However, after careful consideration, I have to recognize that there is currently too little market demand for it to be worthwhile. The firmware activation gives me the opportunity to possibly do this in the future. But for now, I’m perfectly satisfied with sharing it with other hi-fi enthusiasts for free. There’s no catch. Once activated, a license will stay activated for all time.

It looks as if the speed is only measured once per platter revolution. How can short-term fluctuations be compensated for?

MagicQuartz does not compensate for short-term speed fluctuations (wow and flutter). It compensates for slow drifts that occur over several seconds or minutes. The speed regulation deliberately reacts rather slowly.

MagicQuartz was developed for turntables with a rather heavy platter, where wow and flutter are inherently compensated for by inertia. And these don’t have to be high-end “oil rig” turntables — in fact, most vintage mid-range turntables should already fulfill this characteristic. Although more sophisticated means of measurement could be applied to measure and adjust the speed more often than once per revolution, it can be assumed that constantly decelerating and accelerating a heavy platter is not sensible because it may put mechanical stress on the drive.

It is good to know that MagicQuartz implements clever programming to quickly restore the speed at the beginning of a record (see documentation, parameter SaveHzAtSec) and to pause the regulation when the stop function of an automatic turntable is activated. It can also handle measurement errors efficiently.

Will MagicQuartz work with my turntable?

MagicQuartz should work with any turntable equipped with an AC motor, although certain limitations may apply. In general, the automatic speed control (“Live Quartz Mode”) works with all motor types (synchronous, asynchronous, and regardless of whether these uses phase-shifting capacitors). The electronic speed switching (e.g., between 33 and 45 rpm), the transpose function, and the automatic voltage reduction however may not fully work with asynchronous motors due to their inherent slip. Also, the electronic speed switching and transpose functions should not be used if phase-shifting capacitors are present (both on synchronous and asynchronous motors). It may be possible to modify and properly drive such a motor via a dual-phase inverter configuration. Please refer to the documentation and my tests (Downloads => Turntable-Compatibility-Chart.zip) for details.

The documentation often mentions 220V and 50Hz. Will it also work with my 120V/60Hz turntable?

Yes, of course. The nominal frequency of the turntable can be set between 40 and 70Hz (parameter DefaultHertz). The maximum voltage is determined by the hardware design and can be reduced to arbitrary lower values via the parameters VoltageMtOff, VoltageMtOn, and VoltageMtRed (see documentation).