Tech21 Sansamp Programmable Bass Driver DI

The Sansamp. Ol’ reliable.

This is the programmable version with three foot switches. I have owned the BDDI, the PBDDI, the BDDI Deluxe and the BDDI v2. This one is the only one I kept, because not only was it my first, it was also the best sounding of the bunch – although you needed a quiet room and a good pair of headphones to make out the differences of all the v1 devices. The v2 has a mids knob that allows for different voicings, but the following descriptions can be applied to all the other Sansamps.

This thing simply works. Bring it to a gig, where the FOH person directs you to the DI box on stage, waiting for you to plug in. You say “I brought my own” and start pulling it out. “I’d strongly prefer to use mine because the … oh nevermind, it’s a Sansamp. Of course you can use that” the FOH person replies.
These are built to work well in basically any environment and they will send FOH a useful signal.
But that’s their use as a preamp, or an amp sim for quiet stages. This here is the dirt jounal, so we’re gonna look at what happens when you use the FOH technicians darling as a mere dirt box.

Let’s look at the controls:
Drive is gain.
Bass is bass.
Treble is treble.
Presence is more treble.
Blend is blend.
And Level is volume.
The three buttons are of no relevance here. You can use them to lift the ground, lower the XLR output or raise the 1/4″ output (when you need to drive a power amp from that output).
The EQ is boost and cut, and lives post clipping. While the mids are fixed, the baked in tone feels somewhat scooped. You can actually bring the mids forward a bit by cutting bass and treble and compensating with the level knob – that’s what Tech21 means when they say the mids are fixed.
Presence vs. Treble is a bit difficult to explain. The manual says that presence brings out the upper harmonics. I’ve heard people describe the presence knob as the ‘hiss-knob’. I personally found that both presence and treble affect the upper frequencies and something that worked out well for me was to simply use my ears when setting these knobs. Depending on the bass I play and on the other pedals in the signal chain, I usually play around with those knobs for a bit. Roll down one and compensate with the other. Roll up both just a bit, listen to the differences you get. I can’t really describe how they act because it feels a bit different with different basses. What they do is they influence the higher frequencies.

So how does it sound?
Short answer: It sounds like an amp.
Long answer: It tries to emulate a tube amp with a mic’ed cabinet, and it does a remarkable job of that task. In our modern days, amp sim and cab sim are very common concepts, but the BDDI came out in 1992, when these things were completely unheard of.
The first bit of the drive knob lets your signal stay clean, but as soon as you approach noon, you will get some audible strain. When I say strain, I mean that you’re riding in a car with an exhaust pipe that has a tiny hole somewhere. Not so big that you need to go directly to the shop, but so audible that you know it won’t be long. This car is pulling a trailer that is slightly too heavy for the engine specs, and now you’re hitting a steep uphill road. You drop a gear and floor it, realize that this won’t do and drop another gear.
This is what the Sansamp feels like when you push it. It has that amp like quality that pushes back, especially on note decay, where it cleans up. It has that quality of speaker cardboard brought to the brink of annihilation; Farting out, but hanging on.

It’s an old circuit that has been around for a while and still sees frequent use on stages around the world, because it works so well. You can get better, more sophisticated results, but those usually come with more knobs – and more knobs usually entail more sources for error. The Sansamp is somewhat limited in its use – but the limits are there for a reason – it is close to impossible to set a tone on the Sansamp that does not work.