Femtosecond Clocks

Femtosecond Clocks

Femto 140: "Huge Improvement. Transforms the DAC IV. Well worth the $4995 list price." Vince Galbo
Galaxy Femto 77: List Price $9950. DAC V Upgrade Price $4955.
“First impression: Big improvement. Sounds like analog, no grain,,,more low level resolution.“ David Chesky

Femto 33: List Price $19900. DAC V Upgrade Price $14905.

A Family of Femtosecond Clocks

Digital audio is all about timing. The further we press the limits of clock precision the better sonic results we experience. With our Femtosecond Clocks we have pushed the envelope in jitter and right to the limits.

It all starts with a crystalline material. Crystals were found to resonate at a precise frequency a hundred years ago. We have since pushed our understanding of crystal oscillation to an exact science. When the right crystalline material is cut exactly the right way, and allowed to resonate at the right temperature, a clock is created with unprecedented accuracy. (33 femtoseconds of jitter is around a third of a tenth of a picosecond - a new class of clock.)

Conventional specifications and industry buzz words just do not begin to quantify the startling results of our clock research as we move toward a whole new level of performance. Our novel clock design has never before been applied to an audio product. Unique proprietary materials are precisely fabricated in an equally proprietary clock circuit using crazy space age materials.

FEMTO 33 - This is the newest and record breaking clock with less than 33 fs of jitter. So far we have never heard it better than this. This clock has improvements in every area including clock precision, thermal management and a new effort in vibration control. Imagine, half the jitter of the well known Galaxy Femto 77 clock.

Galaxy FEMTO 77 - This is original Femtosecond clock with less than 77 fs of jitter. It has been compared and reviewed all over the world with amazingly consistent results. One is installed in every A/D converter we have sold and most of the DACs. A proven winner.

FEMTO 140 - The Femto 140 achieves much of what the Galaxy clock achieved with some fabrication economies. With less than 140 fs of jitter it is still orders of magnitude better than any commercially available audio clock.

The Femtosecond Clocks plugs into the clock upgrade header on any DAC IV, DAC V or SELECT DAC with an immediate sonic benefit. An excellent DAC clock tends to reveal the true nature of the original music. The DAC V with a Femtosecond Clock reveals fine, delicate, very dense harmonics that are accurately organized and therefore correctly reveal the true sound of the instruments and voices. The lower the jitter of the clock the more noticeable the effect with scales directly with jitter. The harmonic congestion that translates to harshness and the familiar digital "annoyance factor" is just absent. The music and instruments sound like they are coming from live mic feeds on the best recordings.

The clocks can also be installed in our Professional Studio ADC. The benefit of this clock in the ADC is even more important than in the DAC. Jitter on the recording side is permanently locked into the digital data and even a perfect DAC cannot correct it. Think of the advantage if both ADC and DAC are both timed off the same super precision clock. Wow!

The ability to recover the soundstage is closely related to the correct recovery of dense harmonic information. Because of this ability to reveal the finest resolution without any trace of harshness, the soundstage is defined to a degree never heard before. Each recording moves from venue to venue, each instrument takes its focused place in the soundstage. The combination of the dense harmonic recovery and the exceptional soundstage presentation results in a level of "believability" that has to be heard.

A personal note:

We do NOT want to push these clocks on anyone. They are expensive clocks and we do not want a single customer feeling they made a bad investment. We cannot control what a distributor or dealer will do with a customer but we publicly pledge to happily give a full refund to any of our distributors who feel the clock did not live up to their expectation. We encourage our dealers to do the same for you customers. This is an extravagant luxury for those who want to hear something new. Let me explain.
The problem in quantifying the sound is that the sonic impact is on a different vector than for example DAC level. There are two sonic vectors that are 90 degrees apart. One has to do with timing and one with accuracy. They are quite unrelated. Digital filters, upsamplers and clocks all have to do with timing. Signature - Diamond - Hybrid mostly have to do with resistor accuracy. The sonic impact of each vector are not related. The clock impacts all three levels of DAC on the timing vector only. So the clock upgrade does not make a Signature DAC into a Diamond or a Diamond into a Hybrid DAC. The clock impacts the time alignment of the sound. The more accurate the DAC, the more stunning the clocks impact.
So the impact of the clock depends on what a listener cares about. Vince (our US sales manager) wrote the description of what the clock did for the sound above. He has a pretty narrow (and super critical) focus. For him, it came down to one of his favorite recordings. When he sits off axis a particular cymbal sounds so real it sounds live. That hooked him and made him a fan. Every time he hears the recording without the clock he is sadly disappointed. He is a true audiophile. For most of us, we heard a high-res violin solo. The violin image went from an unmoving meter wide to actual size and we could see the violinist sway and turn as he played. Wow. Can't put a price on that. At that moment we changed our mind and determined to sell this clock even though the price is high. We want to hear that sound again. Irrational and reckless, but what did we work so hard for all these years for if not to indulge ourselves from time-to-time in something unique, new and wonderful.

Clock measurements are a tricky thing. Comparing clock measurements is nearly impossible. Everyone quotes the lowest jitter numbers they can, which are the time interval error show in this textbook illustration below. But this error is very frequency dependent so usually this number is quoted for a very high frequency, where the clock is very good. They do not mention the jitter at lower frequencies where clocks are not so good, and where jitter is more relevant to audio sound quality.

A more useful measurement is phase noise. Phase noise shows clock jitter in the frequency domain. We look at the undesired power of the clock at various frequency ranges away from the primary clock frequency. The red lines in the actual clock measurements below show the noise 1 Hz away from the clock frequency. This specification is very relevant to audio performance.

The MSB Femtosecond Clocks have amazing noise performance with a guaranteed jitter measurement at the worse case of just 1 Hz away from the ideal clock frequency. OK, so here is another pretty unbelievable jitter specification. We better stop right here and share our ideas about specifications.

Just as we broke new ground with our Ladder DAC design, 32x Digital Filters, Upsampling to 32 bit 384 kHz, and making the first 384 kHz and Quad Rate DSD USB connection, we have done something totally different and groundbreaking with this new clock. Jitter this low is very hard to measure and I am sure the mathematicians can argue about the exact test method that should be used and the exact numbers for years, but the fact of the matter is that this clock makes a huge sonic difference, and thats what counts. Our goal was great sound, not great measurements. We published what we measured with our own test system and method and I believe them to be accurate but there is a lot of variation in test methods, such as signal level and measurement frequency (we are around 25 MHz where most clocks are at 10 MHz) that skew the results dramatically so it will always be hard to make detailed comparisons. I think all our engineering critics will agree that far more important in a DAC design is where you put the clock, and how you transmit and receive the clock at the DACs themselves. The potential jitter added in these areas far exceed the clock jitter anyway. A poor implementation of this clock may add 1000 times the clock jitter to the DAC output! The DAC V was designed from the ground up with this clock in mind, so the implementation is very clean.

Here are our measurements on our top two at 24.576 MHz:

  • MSB CLOCK MEASURED:             Galaxy Femto 77    Femto 33
  • Phase Noise at 0.1 Hz                             -67 db             -72 db
  • Phase Noise at 1 Hz                                -99 db             -114 db
  • Phase Noise at 10 Hz                             -134 db             -145 db
  • Phase Noise at 1 kHz                             -157 db             -157 db
  • Phase Noise at 10 kHz*                         -157 db             -170 db
  • Phase Noise at 100 kHz*                       -157 db             -170 db
  • Guaranteed TIE (1Hz - 1Mhz)                  77 fs            33 femtoseconds**.

                           * at CMOS output levels (For reference, at normal +13 dB levels the noise would be -170 dB).
                       ** Calculated on the web site JitterTime.com


Light travels around the earth 7.5 times in one second.

How long is a femtosecond? It is one millionth of one billionth of a second. Visible light travels around the earth 7.5 times in one second. Light travels the thickness of a sheet of paper is about 33 femtoseconds! That is really a short amount of time! So the jitter of the Femto 33 clock is the time light travels the thickness of a sheet of paper. The Galaxy clock (77 femtoseconds) is the time of 2 sheets of paper and the Femto 140 clock is the time of 3 sheets of paper. What is mind-boggling is that you can clearly hear the difference these clocks make, and can clearly hear the improvement between them.

As inconceivable as it may seem, this is the precision it takes to unravel the harshness and confusion of 'dense' music like full orchestra and big band jazz. CDs are fully realized in hi resolution -- no tricks, no upsampling. Real voices, real instruments, real sound stages. So forget about measuring clock jitter in picoseconds. MSB was once again first to bring a new reference to the industry!

Don't be fooled by the 'femtosecond' clock claims by the 'me too' companies. Insist on the real thing. You will hear the difference.

Download Galaxy Femto 77 Datasheet for printing, 3.8 MB