SKU: 15365347352

Boss SY-300 Guitar Synthesizer

Sale price$445.50 Regular price$495.00
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Description

Boss SY-300 Guitar SynthesizerDESCRIPTION Grab your favorite axe and dive into an extraordinary world of sound creation with the SY 300 Guitar Synthesizer. The SY 300 can be used with all your guitars right away, with no special pickup requiredjust plug into the standard 1 4 inch jack and play! Thanks to revolutionary new BOSS technology, youre able to explore fat, analog style polyphonic synth sounds with zero latency, seamlessly extending the natural expressiveness and familiar

DESCRIPTION 

Grab your favorite axe and dive into an extraordinary world of sound creation with the SY-300 Guitar Synthesizer. The SY-300 can be used with all your guitars right away, with no special pickup required—just plug into the standard 1/4-inch jack and play! Thanks to revolutionary new BOSS technology, you’re able to explore fat, analog-style polyphonic synth sounds with zero latency, seamlessly extending the natural expressiveness and familiar feel of your own instrument. In addition, you can shape your normal guitar with the synth’s filters, amps, and LFOs to create all sorts of cool sounds never heard before. From unique lead textures to rich, evocative soundscapes, the SY-300 brings untapped dimensions of inspiration and creativity to your music.

Access Expressive New Sounds via a Standard 1/4-Inch Input

With the SY-300, tapping into BOSS’ legendary guitar synth technology has never been easier. While our other synth products require a special GK pickup and 13-pin cable to access synth voices, the SY-300 can be used with any guitar via a standard 1/4-inch cable. Powered by ultra-fast DSP and newly developed innovations from the BOSS engineering team, the SY-300 performs its amazing synth magic in real time, with no lag whatsoever. This delivers a latency-free playing experience that’s a natural extension of your normal guitar, letting you to play freely and organically without altering your technique in any way.

A True Analog-Style Synth for Guitar

The SY-300 features a powerful polyphonic synthesis engine with three separate sections, bringing a limitless range of fresh tones to your arsenal. Just like a keyboard player with a classic analog synth, you have complete creative freedom to build sounds with a full palette of synthesis parameters—select different wave shapes, tweak them with filter, amp, and pitch controls, modulate them with LFOs, and layer oscillators for rich, complex tones. There’s even a step sequencer (with tap tempo control) for creating dynamic melodies and arpeggios simply by playing a single note on your guitar! And with the cool Blender function, you can instantly mix and match synth settings from other patches to discover inspiring new sounds with no heavy lifting at all.

Shape Your Normal Guitar Sound with Synth Parameters

Beyond its amazing synth voices, the SY-300’s synth engine can be used to process your normal guitar sound in many compelling ways. Apply filtering to alter the basic tonality, and use the amplifier parameters to alter the attack and decay characteristics. After that, add some sweeping movement to the sound with the LFO section. With these powerful controls, you’re able to extend your regular axe with an endless supply of unique creative textures, from subtle to otherworldly.

Maximize Tones with High-Impact Effects

Effects play a huge role in synthesizer sound design, and the SY-300 is filled with options to take your tones into the stratosphere. 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 even perform two effects at once, such as chorus and delay or delay and reverb. Use the effects to process synth sounds, your straight guitar sound, or both at once—it’s up to you.

Powerful Control Options and Versatile Connectivity

Controlling the SY-300 while performing is simple. Using the four built-in footswitches, you can bypass the synth sound, scroll through patches, and control three different parameters of your choosing per patch. Two external footswitches or an expression pedal can also be connected for even more real-time control if needed. The Thru output lets you to send your dry guitar sound directly to your pedals or amp, or it can be used along with the Return jack as an effects loop. Dual output pairs (Main and Sub) offer assignable signal routing options to integrate with any setup, while MIDI In and Out/Thru jacks are provided for interfacing with switchers, drum machines, and other MIDI gear.

USB Interface for Computers

The SY-300 is equipped a USB audio interface to capture audio tracks directly into music production software on your computer. You can record the SY-300’s synth and effects sounds, or just monitor them while recording a dry signal. Then, feed that signal back into the SY-300 to “re-synth” the sound and create the perfect tone for your mix. You can feed other tracks from your DAW into the SY-300 as well, processing them with the synth engine and effects to create cool new sounds for your productions. The SY-300’s USB connection also allows you to build and organize patches with the dedicated BOSS Tone Studio editor and download new patches from the BOSS Tone Central website.

FEATURES 

  • Plug into the standard 1/4-inch jack and play rich and expressive polyphonic synth tones with any guitar
  • Completely latency-free playing feel directly connects your hands with the sound
  • Three simultaneous synth sections and four effects processors enable rich, dynamic, and diverse sound creation
  • Shape your normal guitar tone with synth filters, amplifiers, and LFOs to create all-new sounds
  • Graphic LCD display, three assignable footswitches, and dedicated on/off footswitch
  • 70 ready-to-play preset patches and 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
SPECIFICATIONS 
  • Oscillators: Three OSCILLATOR (wave: SIN, SAW, TRI, SQR, PWM, DETUNE SAW, NOISE, INPUT)
  • Effects: 
    • Effect (FX) x 4
      Type:
      TOUCH WAH, COMPRESSOR, LIMITER, OD/DS, EQ, SLOW GEAR, DELAY, CHORUS, REVERB, PHASER, FLANGER, TREMOLO, ROTARY, UNI-V, PAN, SLICER, ISOLATOR, LO-FI, DELAY+REVERB, CHORUS+DELAY, CHORUS+REVERB
  • Patch Memories: User: 99, Preset: 70
  • AD Conversion: 24 bits + AF method
  • DA Conversion: 24 bits
  • Sampling Rate: 44.1 kHz
  • Nominal Input Level: INPUT: -10 dBu, RETURN: -10 dBu
  • Input Impedance: INPUT: 2.2 M ohms, RETURN: 220 k ohms
  • Nominal Output Level: MAIN OUTPUT: -10 dBu, SUB OUTPUT: -10 dBu
  • Output Impedance: MAIN OUTPUT: 2 k ohms, SUB OUTPUT: 2 k ohms
  • Recommended Load Impedance:
    • MAIN OUTPUT L/R: 20 k ohms or greater
    • SUB OUTPUT L/R: 20 k ohms or greater
    • PHONES: 16 ohms or greater
  • LCD: Graphic LCD (132 x 64 dots, backlit LCD )
  • Connectors: 
    • INPUT jack: 1/4-inch phone type
    • THRU jack: 1/4-inch phone type
    • RETURN jack: 1/4-inch phone type
    • MAIN OUTPUT R (MONO) jack: 1/4-inch phone type
    • MAIN OUTPUT L (PHONES) jack: 1/4-inch phone type
    • SUB OUTPUT R (MONO) jack: 1/4-inch phone type
    • SUB OUTPUT L jack: 1/4-inch phone type
    • MIDI (IN, OUT/THRU) connectors
    • EXP/CTL4, 5 jack: 1/4-inch TRS phone type
    • USB port: USB type B
    • DC IN jack
  • Power Supply: AC adaptor
  • Current Draw: 400 mA
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 15365347352

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4.1 ★★★★★
Based on 18 reviews
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Product Reviews
D
Verified Purchase
David Spencer
Port Orchard, US
★★★★★ 5
Good stuff
Material Type: 157mil Closed Cell Foam, Style: 157 mil 36 SqFt
Good stuff, easy to use, self adhesive backing contours around curves easily and works great.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 29, 2026
S
Verified Purchase
stookie778
Lowell, US
★★★★★ 5
Works amazingly, but only if you install it correctly.
Material Type: 157mil Closed Cell Foam, Style: 157 mil 36 SqFt
If you purchasing Siless Liner 157 mil (4 mm) Sound Deadening mat, to block unwanted sounds in your car, this is what you need to buy. But wait! It's not the only thing you need to buy if you want to "actually" deaden sound. By itself, it will definitely block a noticeable amount of sound, and, most likely, that's all you realistically need. But... But... If you want the Siless Liner Sound Deadening Mat to really help you take it up a few notches, to get the best sound almost bordering on soundproofing, listen up. You will have to install traditional butyl rubber first. Doesn't have to be the Siless brand, but I'm sure they would love to sell both to you, I used both Killmat (80mil) and Noico (50mil). I have a Honda S2000. It's a two-seater convertible sports car if you don't know what this car is, and it's loud when I'm driving above 60mph. I also happen to have a sound system installed as well. Other than that, the car is stock. I first installed the butyl rubber on the car's interior sheet metal. I went all out and covered everything I could. I didn't need to but I wanted to. I was extremely impressed with the results. But I wanted to go further. Not because I needed to but because just wanted to see what it would be like. So I bought Siless Liner 157 mil (4 mm) 36sqft Sound Deadening mat to go on top of the butyl rubber mats. I put this over every area I installed the butyl rubber. I had to be careful of clearance issues since I added a significant amount of underlayment, and you should too. If you put butyl rubber sound-deadening materials in 50% of the total interior area, you'll hear a noticeable improvement. If you put butyl in about 80% of the total area, you'll be even more amazed at the improvement, compared to before. I originally did all the above myself, so that's my experience and so your mileage may vary. I then installed the Siless Liner Sound Deadening mat over every place I could even going further than I could with the butyl rubber. I used the Siles Liner in areas where butyl rubber would not have been effective, such as the roll bar hoop area and large empty cavities or holes. I covered everything I could, firewall, doors, floor pan, transmission tunnel, trunk, trunk lid, fuel tank area, rear quarter panels, and rear-wheel tunnels, in Siless Liner Sound Deadening Mat. WOW!! The Siless Liner Sound Deadening Mat was the icing on the cake! Let's not forget, this car is a convertible sports car so it will never be a quiet ride, ever. But I can now actually have a conversation with a passenger at a normal-ish volume! This also means I can now have a normal hands-free phone call without having to plug one ear to block out the noise! My sound system sounds so much better! Just by going through the install process, I looked for any vibration, rattle, squeak, and noise-prone areas to either eliminate or reduce unwanted noise production. If you forget this step, the inside and outside of your car will rattle and buzz. I skipped this step the first time around. But did it right before I installed more butyl rubber and the improvement was impressive, especially inside the car. Outside the car, I didn't notice a difference until I put the last layer of Siless Liner Sound Deadening Mat. The sound deadening mat works both ways from what I can tell. If I turned up my music, as loud as I occasionally do, parked in the attached garage to the house, with the garage door closed, I would be barely able to tell the car was playing music in the garage. It sounds like it is another car, just a little bit down the street, with a very loud base. If you stand 20 feet away outside the car, the sound system is noticeable, but not obnoxious by a long shot. Get a 3 piece wood/metal roller set as well, which makes quick work of large areas.
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Reviewed in the United States on December 23, 2021
L
Verified Purchase
Ligia
Port Orchard, US
★★★★★ 5
Better than Kilmat
Material Type: 157mil Closed Cell Foam, Style: 157 mil 36 SqFt
Great adhesion, and you can immediately see the sound difference when you rap the area and compared it to another area without it. Also, very easy to cut and apply. Once on, you may not be able to peel it and reposition it, so be sure where you want it.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 2, 2026
J
Verified Purchase
J M.
Los Angeles, US
★★★★★ 3
Not much noise reduction…
Material Type: 157mil Closed Cell Foam, Style: 157 mil 36 SqFt
Easy to install but did not provide much sound dampening…
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Reviewed in the United States on April 28, 2026
M
Verified Purchase
Mike
New York, US
★★★★★ 5
Great sound mat for the price!
Style: 50 mil 50 SqFt, Style: 50 mil 50 SqFt
This is a good product. Many people go with KILMAT because of the value to price point. I did as well. When you clean the surface (in my case it was all painted metal) this stuff sticks very well. I do recommend you use a seam roller of some type, I used Lumiteco 3 piece roller set. This will help with adhesion and mostly flatten the overlapped edges. It also helps you see where you have rolled as it leaves little grooves. The difference when we had no sound mats and after was very impressive. We haven't finished our install yet and it is quieter than when we had an interior in the van. There are thicker mats available in other brands, but this will work great for our van build, but this helps keep the weight down. It is quality material, just be careful when you are removing the backing, the edge of the foil face can cut you. I suggest you layout where you are installing the mat and cut to fit. From what I have read, you don't need to cover every inch in the vehicle, just spot install for a big difference. I chose to cover most surfaces to help keep sound out when we are sleeping in the van. We haven't finished putting the van yet, but we have driven it around and been very satisfied with this product.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 3, 2025

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