In A Blind Sound Comparison, People Can’t Tell The Difference Between A Sequential Prophet-5 Rev 3 & Rev 4

One of the most hotly contested questions about Sequential’s Prophet-5 Rev4 synthesizer is how close it sounds to the classic Rev3 original, which sells for about $5,000 more than a Rev4.

To help answer this question, synthesist Alex Ball recently shared a blind test, embedded above, comparing a vintage Prophet-5 Rev3 against a new Prophet-10 rev4. The video is set up as a blind test, where you see the same clip twice, but in one you’re hearing the Prophet you see and in the other you’re hearing the Prophet you don’t see.

Now Ball has shared the results of this comparison, and it turns out that – at least in this blind test – people can’t accurately tell the difference between the sounds of the two synths.

People guessed the correct synth 55% of the time, slightly better than what you’d expect from flipping a coin. And nobody had ‘golden ears’ good enough to let them consistently tell the difference between the two synths.

These results were to be expected, because the Rev4 is not intended to be a new synth, but a reintroduction of the classic Prophet-5 design.

What’s probably most interesting about the test, though, is that people did guess a little better than average, and they did better at guessing some sounds than others.

This reflects the fact that there are differences in the two synths’ designs and capabilities. And, on some sounds, these differences are more noticeable than others.

For example, the Rev4 features the ‘Vintage’ knob, which lets you vary the level of per-voice analog variation of individual synth voices, from ‘temperamental’ Rev1 to ‘stable’ Rev4. This is an awesome feature, but it’s not going to make a Rev4 sound exactly like a specific vintage Prophet-5 Rev3, just like some vintage Rev3.

The way these sort of differences show up in the test results is that there are a few sounds where users guessed a lot more accurately than others. For example, on the third sound in the test, there are more audible differences, and people guessed the correct synth about 66% of the time. This suggests that the sonic differences in some patches may make it easier to identify one synth vs the other.

But there are also patches where people did worse than what you’d expect from flipping a coin. People guessed wrong on the third sound test 57% of the time.

Doing 9 simulated coin toss tests shows how there’s a lot of variation from 50% when using small sample sizes.

Unfortunately, the small sample size of this test (148 people) means that some of variation in the accuracy of people’s guesses is indistinguishable from what you’d see if you just flipped a coin.

If you flipped a coin 148 times and guessed heads, you might expect be right 50% of the time. Try it a few times, though, and you’ll find that you may get ‘heads’ 40% of the time on one test, and 55% on the next.

It takes a lot of coin tosses to minimize this random variation. Because of this, small sample sizes make it harder to distinguish the difference between the variation of actual people making binary choices and the variation you’d see from just flipping a coin.

If we had to judge the results of this blind test, the loser would be our ears – the differences between these synths are subtle enough that people can’t accurately distinguish them from hearing their sounds. On the other hand, the winner would be our wallets. If you want a Prophet-5, the Rev4 sounds like a classic, costs a lot less and adds velocity, aftertouch, USB support and other features.

Check out the blind test and results – and then share your thoughts on the results in the comments!

28 thoughts on “In A Blind Sound Comparison, People Can’t Tell The Difference Between A Sequential Prophet-5 Rev 3 & Rev 4

  1. Yeah no, this “test” is BS and flawed. You can clearly hear there is a difference but you don’t know if it’s the synth or the different recording setup/rig/ADC/plugins they used so it’s all useless and concluding with headlines like “people can’t tell the difference!” makes me lose respect for all involved and will piss people off.

    From just about every demo of the rev4 not drenched in effects, but run dry, I can hear that the rev4 has a lot hotter gain staging, is less nuanced and “clangorous” than a rev3.3. In a proper A/B test with both synths in front of you all other things being equal, anyone that doesn’t suffer from compulsive “it’s-all-the-same-you-can’t-tell-the-diffrance-don’t-trust-your-lying-ears/eyes/mouth” syndrome can probably tell they’re different and will at the have likely form a preference for one over the other.

    I’ve owned a rev3.3 for years and have a P10r4 on the way right now, I’ve no interests in dissuading anybody from going in either directions. Just stop trying to BS people and waste their time, it only creates confusion and needles irritation.

    1. Your comment implies that Alex and Marius have an interest in “dissuading anybody from going in either directions [sic]”. Which they don’t, clearly.

      The parameters for the test are laid out in the first video, and Alex finished with “There is no right or wrong […] what we hear is what we hear”. It’s a video on Youtube, interesting and fun. I don’t think anyone’s taking this nearly as seriously as you.

    2. To be honest, this kind of a AB Test are just for fun and any owner, either a Rev3 or Rev4 are just curious, how close they can get. And screw the recording setup, if you compere two Rev 3.3 against each other, they will do sound different too. Then the service factor, are the original chips installed, are broken or dried parts..that had to be changed or any other adjustments to get this beauty running stable again…etc.

      There also differences in the gain stage between the Rev 3s, it depends on the factory calibration and there are huge tolerances back in the days, the same shit is with the Pro Ones…. when you adjust the beatings/tunings of the OSCs or the VCA gain stage on the Prophets and you can sound pretty much clean like a new Synthesizer..or like unstable crap.

      Fact is, they can sound pretty much similar (if you program it right and make some production adjustments) and that’s marvelous.

      As an Owner of a P10 Rev4, I can say at least you get that ” Vintage” Prophet Sound as desired and both Filter do their jobs on different purposes, without the headache of the next service bill.

    3. “In a proper A/B test with both synths in front of you”

      What you’re describing is the opposite of an actual scientific a/b test. What you’re talking about is deciding which synth you think sounds better, biased by all the things that you know about the two synths.

      Lots of people have biases that make them think that vintage synths sounds better than modern ones, analog better than virtual analog, through-hole better than surface mount, etc.

      The fact that you try to discredit an actual blind comparison test makes me think that you fear the idea that you might not be able to tell the difference between your expensive vintage Prophet and the modern version using just your ears.

      What this test demonstrates is that most synthesists are unlikely to be able to accurately distinguish between a Rev3 and a Rev4 in a blind test. It doesn’t demonstrate that there are not differences – there are – nor does it demonstrate that one synth sounds ‘better’ than the other. Just that people can’t accurately identify the difference between the two.

      That’s very useful info to me, because it makes getting a Rev4 very interesting to me. I’d be interested in hearing what you think of your Prophet-10 when you get it, that’s the one I’m interested in.

    4. Jazm, the FACT is that even with vintage analog synths, two examples of the same model will sound slightly different from each other. It’s true of many vintage keyboard instruments. I can’t count the number of times I’ve heard people say two Hammond B-3s sound different from each other. The same is true for Fender Rhodes models. So your comments really don’t amount to much.

    1. That is the best approach. No one cares if you use analog, digital or VST. Even better and although this A/B attempt: Scientific blind tests on university level have proven that people simply can not hear difference between analog, digital and are not able to tell the difference, let alone point out what synth they here. People who claim they can as a matter of fact totally deny science and therefor talk complete nonsense. There has been a scientific blind test with stradivari violins (sonic differences are even bigger in comparison with electronics !!) The outcome of this test was didn’t leave no doubts at all as the majority of experts (85%!) could not tell the difference between cheap violins and multi million dollar Stradivari. So please, don’t fool people around with pure guesses and it’s outcome.

  2. “People Can’t Tell The Difference Between A Sequential Prophet-5 Rev 3 & Rev 4” Normal people do not distinguish virtual instruments from hardware so what is this for?

  3. I really can’t tell the difference between these but I appreciate that they did it. Anyone would be lucky to have one of these synths! They are magic!

  4. It doesn’t really matter if the instrument you’re playing sounds exactly like the 40-year old design it’s based upon. All that matters is that it sounds good to you.

    1. Sure, Re-Pro 5 is damn close too in a well mixed Song u couldnt tell any differnces! Using some analoge outboard would kill any comparison! 😉

    2. It would be interesting to hear a comparison between a new Prophet Rev 4 and a free VST like Prophanity. The vast majority of music listeners probably couldn’t tell and wouldn’t care about any differences.

    3. Not once recorded, no. But if you’re playing the instrument live, and the analog synth has a good headphone amp, the difference in dynamic range is huge. Model D, Microbute, etc… It’s all about the dynamic range across the spectrum that inspires you while you’re playing it.
      I was skeptical as well until this stuff became cheap enough for enthusiasts.

  5. The inevitable post-test hissy fits are just free advertising. You can get the same reaction by going to a sci-fi convention and yelling “Star Wars sucks! Baby Yoda tastes like chicken!” I’ve had a few Prophets. I always loved the poly-mod, distinct resonance and colossal pads. Each type of synth has some notable strong points. That’s why you need at least 30.

    1. > That’s why you need at least 30.


      I’m waiting for the return of the Prophet T8’s excellent polyphonic aftertouch keyboard, which was also used in the Synclavier.

  6. Should have had some comparisons where both sounds were coming from the same synth. This is measuring the ability to identify each synth rather than whether there’s an audible difference between them.

    1. i was right only once out of the 9 times so i maybe i can hear audible differences but the opposite of what i expected 🙂

  7. > In A Blind Sound Comparison, People Can’t Tell
    > The Difference Between A Sequential Prophet-5
    > Rev 3 & Rev 4

    In related news: In a blind comparison, people can’t tell the difference between Benito Mussolini and Donald Trump

  8. it’s mostly the same for me in these comparison videos, i prefer certain patches on one and certain on the other, be cause if for instance the new version has more bite, it may be more suited for certain patches and if the old is mellower, perhaps i’ll prefer it for a pad or something. every synth is different, which is why we’re all here and convinced we need them all! lol.

  9. I remember a similar comparison of a Prophet 5 vs U-HE Repro VST plugin. Its still on Youtube. Of course, the plugin also sounds exactly like the orginal P5 hardware …of course…;)

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