Boss Intros SY-300 Guitar Synthesizer

At Musikmesse 2015, Boss introduced the SY-300 Guitar Synthesizer – a polyphonic synth designed to work with all your guitars, with no special pickup required.

Here’s the official video intro:


  • Plug into the standard 1/4-inch jack
  • Play rich and expressive polyphonic synth tones with any guitar
  • Latency-free playing
  • Three simultaneous synth sections and four effects processors
  • Shape your normal guitar tone with synth filters, amplifiers, and LFOs
  • Graphic LCD display, three assignable footswitches, and dedicated on/off footswitch
  • 70 ready-to-play preset patches
  • 99 user patches for storing custom sounds
  • Create and archive sounds on your computer with the BOSS Tone Studio editor/librarian and download new sounds at BOSS Tone Central
  • Works with bass and other electronic instruments as well


The Boss SY-300 Guitar Synthesizer

Unlike other products that require a special GK pickup and 13-pin cable to access synth voices, the SY-300 can be used with any guitar or bass via a standard 1/4-inch cable. It also integrates with stomps and pedalboard setups.

According to Boss, the SY-300 performs its synthesis in real time, with no lag whatsoever.

The SY-300 is equipped with a polyphonic synthesis engine with three separate sections. Users have complete freedom to build sounds, with a full palette of synthesis parameters, including different wave shapes, filter/amp controls, and LFOs.

There’s also a step sequencer (with tap tempo control) for creating dynamic melodies and arpeggios by playing a single note.

Beyond its synth voices, the SY-300’s synth engine can also be used to process a normal guitar sound to create unique textures. Users can apply synth filters, change attack and decay characteristics, and create dynamic movement with the LFOs and step sequencer.

The SY-300 also includes powerful multi-effects to enhance both synth and straight tones. Four simultaneous effects engines are available, each packing a number of effects types including overdrives and distortions, Slow Gear, Isolator, Slicer, and many others. Some types can perform two effects at once, such as chorus and delay or delay and reverb.

The SY-300 includes a USB audio interface to capture audio tracks directly into music production software on a computer. Via USB, users can also route existing tracks into the SY-300 to “re-synth” sounds using the synth engine and effects to create new sounds for music productions.

The SY-300’s USB connection also enables players to build and organize patches with the dedicated BOSS Tone Studio editor and download new patches from the BOSS Tone Central website.

See the Boss site for details.

45 thoughts on “Boss Intros SY-300 Guitar Synthesizer

  1. Still trying to figure out if it’s just affecting the sound with various fx to attain that “guitar synth” sound, or if it’s a true guitar synth, e.g. does it send midi notes out of the unit?

    1. There does appear to be a MIDI Out/Thru jack on the device, which would be a lot of fun if it works well. I bet they’d sell a bunch of these if they took out the synth engine and just sold it as a guitar to MIDI box, especially with a corresponding price drop ($99-199 maybe). I suspect there’s plenty of synth players who wouldn’t mind using a guitar as a controller if it worked as well a keyboard. But from the video, there doesn’t seem to be anything likable about the sound of the box itself.

      1. Matthew,

        Are you saying it is possible to convert your guitar notes to midi in this device and send it to a midi keyboard to play the note off the keyboard?

        …That’s rad!

        I might be late to this concept, so if there’s a cheaper alternative… Let me know?

        1. I had an older Roland guitar synth that sent notes out by MIDI. It worked, but was a bit less responsive than using the onboard synth. Of course with all those other boxes, you need to install the Roland pickup on your guitar.
          With this one, seems like you are stuck with their synth, so if you don’t like how that sounds, you aren’t going to like this…

          1. to answer the question, “is there something cheaper?”
            single note solutions (you can’t play chords): Sonuus i2m and G2M2, or B2M for bassists.

            Plus there are a few Mac, PC, and iPad apps out there. Even one that might be polyphonic, I believe, but the tracking is questionable.

      2. The sounds in the video are rather 80ies trash, absolutely right. I saw this guy playing at Musikmesse Frankfurt and unfortunately I can not say something better about the sounds I heard there, it sounded either cheesy or trashy. But on the website they say “The SY-300 features a powerful polyphonic synthesis engine with three separate sections, bringing a limitless range of fresh tones to your arsenal.” And there is an editor too. So I think you should be able to program some cool sounds yourself. Even if this thing sends out Midi, I think the response from the internal synth engine will always be a bit faster. And controlling sounds will be much better because this guy is already optimized for being played via guitar. But yeah, nevertheless a guitar to Midi box with this new technology would be absolutely great too

    2. “e.g. does it send midi notes out of the unit?”
      No, it is NOT a sampler. Read the article VERY carefully, it states that you plug your guitar’s 1/4″ output jack directly into the box. It does NOT convert your guitar signal to midi, rather, the guitar is used, directly, to trigger the oscillators. So yes, unlike machines mistakenly called “guitar synthesizers”, which are really just samplers, this is a TRUE synthesizer.

    1. In that case, it seems they might be limping soon. Their website doesn’t mention anything about guitar to midi out, just interfacing with other midi controllers and drum machines, and audio and patch editing over usb. Which is especially odd given that the much cheaper GT-001 has mono guitar to midi over usb.

  2. It’s not guitar to midi, even with a hex pickup (individual conversion per string) this only works some over the time with clean right hand playing and a well set up guitar. If you want to play a synth or vst with your guitar go fisherman tripleplay (wireless midi guitar via usb to computer – about 300 gbp)

    This looks to work more like those electroharmonix pedals that conver the guitar sound to organ sound, cool enough, but very dependent on the built in synthasis.

  3. Ugh what a rotten, stinky demo. Almost nothing but standard guitar sounds and wankery, and the lack of info available about its actual synth capabilities and connectivity don’t bode well. I’m a guitarist who only casually dabbles in synths and I felt embarrassed watching this

  4. Common, sounds bad, as a all gr products (a have gr-33 and play other).

    If you want play true synth (hardware or vst) from your guitar, go with “Fishman Triplay” or soft based (vst or ios) solution from JamOrigin Midi Guitar (soft polyphony with great tracking, so audio2midi nothing new for 2015 from boss). Just plug in guitar cable to Triplay and usb-adapter to any usb2midi device, than to any true hardware synth (for example some analog rack). Or usb-adapter to computer and play with any good vst sound what you have. Same with JamOrigin, plug in guitar cable to your audio interface, open your DAW, drop JamOrigin and than any vst instrument. And of course, you may midi out from audio interface to hardware. At the end, with Ipad & app JamOrigin + example some app synth like Thor or Iprophet, you’ll be the king of the mobile synth guitar. And of course, you may connect ipad to usb2midi device and play with hardware. So, a lot of options for the right guitar synth sound -)

    PS. On this video from Messe, guitarist said that did’nt work wtih synthesizers and therefore studied synth when he made presets for SY-300. LOL.

  5. I have the Roland VG99 with FC300 floor controller. That includes windows patch creation tool and the unit is capable of amazing sounds so I expect this new box to be just as good if not better. Liked the demo song.

  6. Having owned the boss Slider pedal and stuff like the Addrenalinn and the eventide stuff, I see nothing that would indicate this is a “synth” … more of an effects pedal tailored to beat sync filters octave followers and resonant effects. no bad thing…but not a synth per se.

    1. Not synth per se? It’s not supposed to be a synth. It’s supposed to be a guitar synth. There’s not much guitar left if you take the entire signal and convert it to something else. I think this is clearly some sort of signal processing type of synthesis. And I think signal processing qualifies as synthesis genuine synthesis. Given all the different types of synthesis there are in the out in the world, I don’t think there’s any definition of synthesis that would exclude signal processing techniques. In fact, the HOG2 and POG2 are based principally on additive synthesis, which is the original method that was used prior to the Moogs. If one wants to get real particular about the definition of ‘guitar synth’, then the Vo Guitar is probably the only true one out there. I plan to buy the SY-300 because the no latency and 1/4 inch cable outweigh most other things to me. Like most others, I do feel that there is a 80s sounding cheesiness to a lot of the sounds. Boss calls it an analog style synth, but it really has more of an 80s digital sound generally. However, it’s apparently very tweakable, so I think I’ll have a good time seeing what I can do with it whenever I can actually buy one.

  7. It has 3 oscillators with various waveforms, envelope generator, LFO’s- what is it lacking that would make it “a synth” by your defintion?

  8. 3 osc (9 waves types ) , 6 notes poly , 4 fx , midi + usb + exp pedal !
    a synth killer most features than just some new hype “full analog” things …

  9. It sounds to me like this box is doing something using an envelope follower from the guitar signal to trigger on board synth sounds that bubble along in some kind of way, but it’s not really translating the guitar into synth tones. We clearly hear the guitar as a guitar tone throughout the whole thing, while the “synth” parts are running more like a looping pedal.

    1. Xtopher,
      I’m guessing due to faster and more powerful DSPs, that the SY-300 is analyzing the fundamental tones and converting that to resynthesize it using the internal synth engine.
      If you listen to the video again, you will hear that you can use only the guitar tone, only the synth or combine them both.

    1. I was thinking it reminded me of Al di Meola’s stuff, which brings me to my opinion here- I liked the video!

      I am not trying to get angry responses or anything…I legitimately am not understanding all of the hate here? I thought it was a really cool sound that track had going. I was reading the replies while the video loaded and expecting a gameboy chiptune or something and then I was like WHOA it reminds me of Meola!

      Are my tastes outdated? What are the sounds you guys like instead that modern guitarists are using?

      1. I think some of Dimeola’s synth stuff is cool. But Roland for some bizarre reason as some have
        pointed out, throws in the entirely antiseptic clean delays and cliched generic chorus sounds of
        the 80’s in the video along with the tasteless shredding. The sequencer stuff is cool, but the irony
        here is that properly tweaked, my VG-99 and this Boss box have potential for some radical stuff.
        The video will lose many customers as players want USABLE and VIBEY freak out effects, and
        good tone as well, which Boss products have but some idiot chose a completely non-tube like
        amp sound.

      2. My impression is people want guitar synths for different reasons. Most people who gravitate to the Roland or MIDI style synthesis are looking to be able to model other instruments. If you want a realistic piano sound from the SY-300, you’re not going to get it. I, on the other hand, want a synth that sounds like a synth – an instrument unto itself. The SY-300 will clearly do that, but that doesn’t mean that I want it to sound corny or cheesy. I’ll just have to see. The factory presets are questionable. Most of the demos are shallow. I would like a demo that shows what the SY-300 oscillators sound like without all the bells and whistles; a pure square wave, sawtooth, sine and triangle wave, please. I think the quality of those sounds heard in an isolated fashion would tell a lot.

        By the way, I plan on buying one, yes. But I don’t know why just yet it costs more than the HOG2.

  10. They give the impression that it does polyphonic pitch sensing. And as a synth, it is going to generate tones based on that conversion. The guitar tones we’re hearing are layered via a mix control.

    If they are able to get to all this with low latency, that is a big step. If the synth is tweakable enough, it won’t matter whether or not you like the above examples, you could make tones you like. If the MIDI out port does output the MIDI notes that the converter is producing (the webpage doesn’t really specify), that would be useful– especially if the velocity values are both scaled to volume and adjustable. If the price point is decent, this will be hard to pass on.

    That’s a lot of IF’s. I’m looking forward to some good ole’ honest (and critical) reviews.

  11. i want to know if it can follow rapid pitch bends, slides and whammy technique (like jeff beck)
    better than the GK pickup synths, which tend to glitch on large, rapid pitch glides (even with their internal sounds)


  12. Ray Wilsons MFOS sells a Guitar Synth for DIY enthusiasts. I am just about to start building mine. $45 for the PCB plus the cost of components self sourced, so about £60 in English.

  13. “Zero Latency Feel” whatever that means… Well, if it tracks worth a damn (mono or poly) and is quick, it could be really cool.

  14. It is a pretty stupid way to say it. It can’t be zero latency, because it has to hear something before it can tell what note it is. But it can’t be “low latency” because that has become a meaningless claim to describe “some latency”. A “zero latency feel”– they wager– will tell you what you want to hear.

    1. Stub,
      Zero latency can probably be taken pretty literally. This is what a lot of the discussion about signal processing is about. It is probably using some sound manipulation that does not need to know what the note is any more than a distortion pedal needs to know what note is being played. There’s already a guitar synthesizer out there that has zero latency, it’s the HOG2. It does this by shifting the pitch polyphonically with an advanced digital algorithm and using shifted pitches for harmonics. The SY-300 is doing it a bit differently, apparently somehow modeling virtual oscillators. This still does not mean that it needs to detect the pitch. There are very simple non-digital DIY circuits that will modify a guitar signal to create sawtooth, triangle, sine and pulse-width modulated waves through filtering of distorted square waves (distortion synthesis). No pitch to voltage conversion necessary. Consider also that Boss has had a wave shaper function for quite some time on its SYB-5 that used a digital version of waveshaping/distortion synthesis incorporating lots of trigonomic algorithms to multiply and then subsequently subtract (filter out) harmonics. The wave shaping function of the SYB-5 also has no latency and is fully polyphonic. I’m really curious as to whether Boss used what it learned from producing that wave shaping function, and if not then why not.

  15. For guitar players who were looking for that Pat Metheny lead sound, this is really exciting.
    I think people here also forget that you can use this synth for other instruments as well.

  16. I have a VG-99 and with the pickup and gtr setup right it tracks really well. The problem(or advantage) is
    that it can be overwhelming for computer/synth beginners. But used you can get it usually for $800-900
    including a stand from EBay. That’s including the pickup, as well. But it is very complicated. The new Boss
    “Synth” has some things that the 99 doesn’t have, like the step sequencer, the waveform and LFO things
    which can radically alter the attack and decay of notes, among other things I cannot explain verbally.
    But, because the Boss doesn’t utilize a special pickup, it cannot do unique custom turnings , have hand
    controlled(theremin like) effects, or most importantly, the ability to interface with a midi keyboard.
    I also must mention that the post that mentioned using iPads for synth purposes should recognize
    that iPad 4’s and Air’s use lightning connectors which have a built in microchip which causes all kinds
    of compatibility problems. Using the camera connection kit to convert to USB tanks all the software.

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