SGT-DI - Frequently Asked Questions (FAQs)

Q1) What is SGT-DI?
SGT-DI is The All-In-One Bass Box. It’s our new preamp and DI that features an onboard compressor, an enhanced Super Grit Technology overdrive circuit with SVT® and B15 voices, a 3-band EQ with a sweepable Mid control, and an IR Loader/Cab Simulator.

Q2) How was the Super Grit Technology overdrive circuit enhanced?
We took the beloved SGT circuit from the Rocket Bass combo amps and added a Voicing switch that lets you choose between the sound of the studio stalwart B-15 or the monster grind of the legendary SVT. The Grit and Level controls, in tandem the Voice switch, make for a super-versatile overdrive. SGT-DI lets you go from mild tube fatness to all-out mayhem.

Q3) How does the SGT overdrive differ from the Scrambler overdrive?
We built the SGT overdrive circuit from the ground up to give you what we believe is the most accurate and comprehensive representation of Ampeg overdrive available. The Scrambler produces the specific grind of an SVT, whereas the SGT covers the complete range of warm tube-driven sounds from both the SVT and the B15, including a bit of low-end boost.

Q4) What’s the advantage of having an EQ with sweepable mids?
Lots of legacy Ampeg products have both a Midrange boost/cut control and a 5-way Frequency control that selects the frequency to be boosted or cut. We replaced them with a single concentric control that combines both functions, but instead of being limited to five fixed frequencies, you can sweep the entire range including the “in between” frequencies. You can still dial in the same familiar sounds as before—but you can also get a little more nuanced or even surgical with your midrange tailoring if you choose.

Q5) What’s the IR Loader/Cab Simulator all about?
SGT-DI boasts the first IR Loader/Cab Simulator ever incorporated into an Ampeg product. It has two sections, one of which contains three onboard classic Ampeg cabs, and the other three user slots that you can load your own IRs into using the free Ampeg IR Loader application (downloadable at

Q6) What are the three onboard classic Ampeg cabs?
The cream of the crop: a Heritage Reissue B-15, a Heritage SVT-410HLF, and the highly-coveted original Squareback 810.

Q7) And the three user slots are empty until I upload my own IRs?
We’ve actually preloaded those three slots with Ampeg SVT-112, SVT-210, and SVT-212 cabs—but you can replace them with up to three of your own IRs.

Q8) Can I use premium third-party IRs purchased from the Line 6® Helix® Marketplace?
Yes. These will be denoted in the Ampeg IR Loader application with a diamond icon.

Q9) What else can I customize using the Ampeg IR Loader?
Our free Ampeg IR Loader application allows you to edit and save things like the Hi Cut, Lo Cut, and Level settings for each IR, and you can also rename and reorder the IRs.

Q10) What is the IR format used in SGT-DI?
SGT-DI supports the use of IR .wav files of practically any sample depth and bit rate available from third-party vendors (IR .wav files are automatically converted to mono 32-bit float/48kHz at 2048 resolution upon import).

Q11) Can I use the SGT-DI as a rehearsal tool?
SGT-DI works perfectly as a rehearsal tool. It includes a stereo 1/8" Aux input with Level control, allowing you to connect an audio player and play along with any music (and as a bonus you can also feed your in-ear monitor mix through it for a better live performance experience).

Q12) What other EQ controls are there besides the 3-band EQ?
SGT-DI also includes our treasured Ultra Hi and 3-way Ultra Lo switches.

Q13) Where is the one-knob compressor placed in the signal chain?
SGT-DI’s variable one-knob compressor comes after the tone controls and SGT circuit. The Comp knob acts as a threshold control and at max is a 10:1 ratio.

Q14) Where are all of the gain controls located on SGT-DI?
There are three primary gain stages that can affect your clipping LED (when Cab LED turns red). The first is the Vol control located on the leftmost top/inner concentric knob, which adjusts the Preamp level. SGT Level, located on the outer rightmost knob, controls the overall level of the SGT overdrive circuit. The Cab Level control, located on the left panel, adjusts the overall IR level.

Q15) How do the Preamp, DI, and Line outputs differ?
We wanted to give you as many routing options as possible in a compact DI pedal. The Preamp output signal includes the compressor, preamp, and SGT circuits—but not the Cab/User IR and Aux input signals. The Line Out/Phones output includes the compressor, preamp, SGT, Cab/User IR (when active), and Aux Input signals. The DI balanced output includes the compressor, preamp, SGT signals, and Cab/User IR signals—but not the Aux input signal.

Q16) Are there any accessories for the SGT-DI?
Because SGT-DI is The All-In-One Bass Box and therefore the perfect fly rig, we wanted to make sure you had a small carry bag for those throw-and-go situations. It can be found here -

Q17) IR Loader System Requirements

Supported Operating Systems

  • 64-bit Mac and Windows®
  • macOS v10.15 and later (Intel and Silicon)
  • Windows 10 and 11

Please refer to the IR Loader installer’s Release Notes or Ampeg Customer Support for specific details regarding support for the very latest Mac and Windows operating systems.

Minimum Hardware Requirements

  • Dual-Core 2.0 GHz processor
  • 4GB of RAM
  • 100MB free disk space
  • Internet connection required for updating firmware and for Line 6 Marketplace asset license authorization

Additional product specifications can be found in the Online Owner’s Manual, available at

Heritage, SGT, Super Grit Technology, SGT-DI, SVT, Line 6, and Helix are trademarks or registered trademarks of Yamaha Guitar Group, Inc. in the U.S. and/or other jurisdictions.
Mac and macOS are trademarks of Apple Inc., registered in the U.S. and other countries and regions.
Windows is a registered trademark of Microsoft Corporation in the U.S. and/or other countries.