The Ditto Box ($399) is a tube DI with a new wrinkle: a variable gain control that provides a whopping 30 dB of gain. Capable of dishing out robust line-level signals from passive electric guitar or electric bass input, the Ditto Box is the only DI box (line-level preamps aside) that does not typically require a downstream microphone preamplifier to attain adequate record levels.
The Ditto Box is built like a humvee, encased in a heavy, well-ventilated steel chassis with large rubber feet. Its front-panel controls are straightforward. The high-impedance instrument input and unbuffered loop output are both on unbalanced phone jacks and wired in parallel: what goes into the input comes out the loop output unchanged. Just patch the loop output to your guitar, bass, or keyboard amp if you want to mic up your cabinet in addition to going direct.
The Ditto Box's transformer-balanced XLR output gets the benefit of the all-tube, transformer-coupled audio path. You can connect the XLR output directly to an outboard A/D, DAW input, or console insert-receive jack when the Ditto Box's rotary gain control is cranked fully clockwise, and, in most cases, you'll have adequate gain. A ground-lift switch (to reduce hum) and neon-blue power-status LED complete the front panel's feature set.
The Ditto Box's spartan rear panel provides a power switch, fuse holder, and IEC receptacle for the detachable AC cord. The front- and rear-panel controls are protected on the top and both sides by the extruded chassis, making the Ditto Box ready for the road.
The Ditto Box features two triode tubes in its audio path. A 12AX7 buffers the input signal and provides the gain. The unit's gain control adjusts the amount of negative feedback returning to this input stage, thus varying the amount of gain output by the 12AX7. Following the gain-control circuit is a 12AU7 tube that drives the unit's custom-wound output transformer.
Tech titans will be pleased by the Ditto Box's professional specs. The unit's frequency response is stated to be 6 Hz to 200 kHz (±3 dB) at unity gain. Its dynamic range is cited as 118 dB, and the equivalent input noise spec is -90 dB. The Ditto Box's input impedance is 1 Mž.
To its credit, the Ditto Box is quiet even when its onboard gain is maxed. But even with its gain control adjusted to its lowest setting of 0 dB, the Ditto Box's output level is competitive with that offered by other DIs.
I got great results using the Ditto Box to record electric bass guitar tracks. The sound was very round and lush, with the bass frequency response nicely extended. In an A/B test with my more expensive Demeter Tube Direct box, the Demeter offered a little more top end, but the two boxes sounded quite similar otherwise.
When I recorded my '62 Strat first through the Ditto Box and then through my Demeter Tube Direct, the sonic differences between the two DIs were more audible. The guitar track recorded through the Demeter DI sounded a little more sparkly and clear than the one I recorded with the Ditto Box. The Ditto Box's guitar track, on the other hand, offered a tad more body. The differences were no doubt due in part to the Ditto Box's much lower input impedance (1 Mž, compared to the Tube Direct's 27 Mž input impedance). Synth tracks recorded with the Ditto Box also sounded plenty round but a hair wanting for top end. Keep in mind that we're talking subtleties here.
Overall, the Ditto Box sounds great and is built to last. At $399, it's less expensive than other tube DIs offering this level of quality (beating the Editors' Choice award — winning Valvotronics Tube Amplified Direct Box by only $1 on this front).
When you consider that the Ditto Box's variable gain control gives you the equivalent of an instrument preamp at no additional cost, you can come to only one conclusion: the Ditto Box is a winner.
Overall EM Rating (1 through 5): 4.5