Updated May. 3, 2022

TWA SH9

New Jersey’s TWA is mostly known for their filter and synth pedals, but their new stompbox, the SH9, is actually an evolution of a classic distortion pedal, the Maxon SD9 – an acronym for “Sonic Destruction.”

Designed in collaboration with Tube Screamer creator Susumi Tamura, the SH-9 boasts a circuit that was designed to meet the ear of fusion legend Scott Henderson, who lent his signature for the occasion.

Henderson is a long time SD-9 user but took the opportunity to suggest a few fixes that were addressed in the TWA’s model:

a loss of low-end on high notes and a Tone control that was basically unusable past the 9 o’clock setting.

The circuit’s output was also raised, and its headroom (optionally) improved when powered with 18v, something the original didn’t support.

The SH9 is available with two different faceplate screens, one with the SH-9 logo in the same trademark lime-green color as the original SD-9, the other one with the all-white fonts and Scott’s signature.

Have a listen to it in the video below. The SH9 will start shipping in June and the first batch will be limited to 100 pedals.

TWA SH9 Distortion, Builder’s Notes

For the past 20 years, Jazz Fusion guitar great Scott Henderson has had a Maxon SD-9 Sonic Distortion parked on his pedalboard. He’s even gone so far as to call it “…the best distortion pedal ever made.”

Yet for all his praises, there were several shortcomings to the SD-9 that many players –Scott included– had discovered. Chief among these were a loss of low-end on high notes and a Tone control that was basically unusable past the 9 o’clock setting.

Over the years, many boutique pedal builders have modified the SD-9 in hopes of improving its performance, but they have all missed the mark—Until now.

TWA is very excited to announce our first signature model, as well as our first collaboration with Tube Screamer creator Susumu Tamura – the Scott Henderson SH9 Signature Distortion.

With the SH9, Mr. Tamura has taken the basic SD-9 circuit architecture that he invented in 1981 and re-worked it to meet Scott Henderson’s exacting performance standards.

Mr. Tamura has shifted the center frequency of the SH9’s Tone control and focused it in the lows and lower-mids. Even as the Tone control is turned up, there is no loss of the bass frequencies that Scott considers essential for allowing notes to speak properly in the higher registers on the guitar.

This increased note girth combined with the SH9’s inherently compressed sound allows Scott to effortlessly articulate the fluid, horn-like lead tones that he is known for.

Another useful improvement to the SH9 circuit is an increased output level that helps the pedal to be heard clearly in a full band context.

Mr. Tamura also designed the SH9 to operate with 9-or 18-volt power. Although Scott only uses the pedal with 9-volts, powering it with 18 VDC will allow for increased headroom with less compression and a slightly different character to the distortion.

The SH9 is housed in a die-cast zinc chassis and coated with a beautiful and durable metallic purple powder coating that was chosen by Scott (we love it too!).

Only the highest quality components such as ALPS potentiometers, Marushin Jacks, KOA/Speer resistors and WIMA, Nichicon & Kemet capacitors are used in the SH9 circuit in order to maintain the highest standards of tonal reproduction.

The SH9 is available with two different faceplate screens: The first version highlights the SH9 logo in the same trademark lime-green color as the original SD-9, while the second, all-white screen features a replication of Scott’s signature.

We would like to offer our heartfelt thanks to both Scott Henderson and Susumu Tamura for their involvement in this project and their willingness to go above and beyond the norm. We have learned many invaluable lessons during our interactions with these two Masters of their crafts.

We are deeply honored to have been a part of the SH9 development. We had been knocking this one about for the better part of three years, and there were several times that we didn’t think it would get off the ground – we’re very pleased that the SH9 has finally taken flight.

• Signature distortion pedal inspired by classic SD-9 circuit
• Thick, compressed, amp-like tone
• Improved Bass and lower Midrange response
• Increased “girth” on high-register notes
• Allows notes to “speak” properly
• Increased output level
• JRC4558 OpAmp
• Optional 18vdc operation for increased headroom, less compression and alternate drive signature
• True Bypass switching
• Die cast zinc enclosure with custom powder coat
• Made in USA