Seymour Duncan SFX-11 Twin Tube Blue Distortion Guitar Effects Pedal  

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The Seymour Duncan SFX-11 Twin Tube Blue is the stompbox for the no-compromise blues player seeking a range of bluesy tones from classic Chicago raunch to modern high-gain sounds.

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The Seymour Duncan SFX-11 Twin Tube Blue is the stompbox for the no-compromise blues player seeking a range of bluesy tones from classic Chicago raunch to modern high-gain sounds.

The Twin Tube Blue is a high-quality, 2-channel guitar preamp voiced especially for the blues”modern blues, Chicago blues, Texas blues, and classic rock. Unlike its Twin Tube brethren, the guitar pedal features a duet of premium, mil-spec, subminiature, USA-made Philips-Sylvania 6111 dual-triode tubes. These tubes are voiced similar to a familiar 12AU7.

And the Twin Tube Blue distortion pedal will never degrade into "starved plate mode," where the tubes function like clipping diodes and do not actually amplify. The Twin Tube Blue's high-plate voltage and 100% vacuum tube signal path allows the tubes to operate at their fullest potential and provide maximum dynamic range. The means you get the most gain and all the smooth, bluesy tone you expect from a high-quality tube preamp.

The SFX-11 Twin Tube Blue's 2 channels provide versatility. The Rhythm channel offers up sparkly chords and bright, punchy leads. The Lead channel starts with familiar Texas blues and goes all the way to the heaviest blues tones you'll ever need. The Twin Tube Blue is true-bypass and features a heavy-duty chassis and a fully encapsulated toroidal transformer for quiet operation.

  • 2-channel guitar preamp voiced especially for the blues
  • 2 premium mil-spec, subminiature, USA-made Philips-Sylvania 6111 dual-triode tubes
One year replacement warranty on all pickups.

  • Customer Reviews

Review Snapshot

by PowerReviews

(based on 8 reviews)

Ratings Distribution

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Reviewed by 8 customers

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(1 of 1 customers found this review helpful)



By The Fan-oimf6

from PA

This box is great! I am very picky about tone (almost everyone thinks they are) and I can say that if this pedal was ever lost, stolen, broken, or fried then I would hurt several people as I pushed them out of the way to get another one. Don't let the "blue" phrase fool you, as you can get anything from blues, rock from the 60's, 70's, 80's, 90's, and even modern tones. This thing makes my home recordings (direct to computer through a Tech 21 Blonde) sound like I have a full on tube stack mic'd.It rocks!!!!!

(0 of 1 customers found this review helpful)


Still have the blue!

By Stratman-7XPDx

from Currently playing in Asia

Seymour Duncan has done it again with the SFX-11 Twin Tube Blue.This pedal is great for blues and rock & roll, including 60's ~ 70's rock from Cream, Led Zeppelin, ZZ top, Jimi Hendrix, and even SRV.Plugged into a good tube amp with a good guitar - you will make heads turn, follow guitarist green with envy.Easy to set up for different tonal quality and diversity.I love this pedal and use it with Seymour Duncan SFX-10 Deja Vu Tap Delay with Les Paul, Stratocaster, PRS, and a Telecaster all plugged into a Celtic Edana and a Fender Deluxe Reverb (Two amps = Twice the fun)

(5 of 6 customers found this review helpful)


exactly what I wanted

By Gman

from orange ca

Like most guitar players I prefer the tone and dynamics of a tube amp.I have the G-Dec 30 amp, and while it is very cool and sounds great for a solid state amp I still go for my tube amps.That is why I got the Blues twin tube pedal.Now I can dial in that clean to dirty tone just by picking harder. It sounds full and warm and I can get just about any distortion setting easily!The channel switch gives my amp 2 channel capibility.


Good Clean Boost

By Grandpa's Revenge

from Cow Country USA

This is a good clean boost pedal. Two channels which can be set separately as far as gain and volume control go. The tone settings are global but the rhythm channel is definitely darker/deeper than the lead channel. I'm using mine through the effects loop on my Zoom 9.2tt and it is pretty quiet when used with a clean setting. I have mine set to give just enough boost during solos to cut through the mix. To say this is a distortion pedal is kind of misleading though. The distortion is more of a crunch/overdrive sound that you would expect from a boost pedal in front of a tube amp. I give it 5's across the board. If I had a complaint, it would be that the chicken head knobs/pots could have a little more resistance to them. However, having said that, I marked my settings with small pieces of tape so when the knobs move, I can easily set them back where I want them. Once you get this baby dialed in, it'll definitely give you a bluesy crunch sound regardless of whether you are using single coils or humbuckers. A little pricey as boost pedals go but well worth the investment if you are looking for that tube overdrive sound. Go to Seymour Duncan's website and watch the demo video, it's a good accurate presentation of what you can expect from this pedal.


Twin tube blue

By Docsisk

from South Bend, IN

Just got this new distortion petal and played my Ric, retro-fitted with p-rails, through it connected to a Vox Valvetronix. The base and treble controls really give you a great deal of tonal flexibilty. Having both a rhythm and lead volume and gain controls lets you set each channel and switch between them, especially when you need a boost for playing lead. The pedal is well-built and solid and the sounds it generates from my amp are really great! I found the effects from this pedal very blendable with my amp's effects and when reverb, delay and some compression are added, it blew me away. Very much a blues effects pedal, well worth the investment.

(12 of 12 customers found this review helpful)


Awesome natural tube overdrive

By Derek

from Atlanta, GA

This unit sounds amazing. It really picks up where other overdrive units leave off. Both channels are extremely versatile and sound great. Channel 1 is capable of producing a nice boost to a light breakup, like a tube amp being pushed to the edge. Channel two has a lot of gain on tap capable of producing edgy, Austin-like blues tones to all out blues crunch. Both channels are very transparent and have a minimal, if any, effect on your overall tone. The two tone controls have a wide sonic range and will help round out your tone. A huge plus is that this unit does not reduce your bass response when engaged like most overdrive units. It really does sound like it is pushing your amp's natural sound into overdrive. Two internal tubes add to the warm, natural sound of this pedal. This thing is LOUD! Most of my settings at gig level do not have the volume controls on the unit above 9 0'clock. Simply a fantastic unit.

(10 of 10 customers found this review helpful)


Smooth tube tone!!! Excellent pedal...

By Robert C.

from Sacramento CA

I just purchased this pedal about three weeks ago and I couldn't be happier with it. It gets a very warm & smooth sounding tube tone with crystal clear cleans with just a tinge of blues distortion all the way through the blues/rock spectrum to all out high gain lead. With the two channels on the pedal, plus the the true bypass you effectively get three custom channels set to your liking. The SFX-11 Twin Tube Blue also sounds exceptional alongside existing pedals.

(10 of 12 customers found this review helpful)


Great Product!

By dfarrisca

from Santa Barbara, CA

I demo'd the Seymour Duncan SFX-11 today, and was very impressed. The tone of the rhythm channel was smooth and clear, and with one click of the foot, I was into the rich, edgy crunchy solo channel. Of course, I dug the gain and tone controls on both channels and set my personal settings accordingly. I had fantasies of getting rid of my 4 other stompboxes and just using this one. I find Seymour Duncan products to consistently be extraordinary, well thought out, and engineered to meet the needs of a growing market.

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