Blue Microphones' first foray into studio hardware comes in the form of the Robbie, a Class A, discrete single-channel mic and instrument tube preamplifier.

Blue Microphones' first foray into studio hardware comes in the form of the Robbie, a Class A, discrete single-channel mic and instrument tube preamplifier. Like all of Blue's products, the Robbie is a fusion of high-class engineering and quirky styling. Both the unit's design aesthetic and name were inspired by Robby the Robot from the classic 1950s sci-fi movie Forbidden Planet. The Robbie's look will likely appeal to some and not to others, but it is definitely guaranteed to stand out in any studio.


The chassis and controls of the Robbie are simple and flamboyantly oversize, sporting a sleek, bulbous appearance. The brushed-silver front face is occupied only by a ¼-inch hi-Z instrument input; a single conspicuous chrome gain knob with 11 blue rear-glowing, unmarked gain-position notches; and an even more noticeable transparent plastic dome, inside of which lives a single ECC88 twin triode tube that can be replaced by users to fit their specific needs. The large gain knob has a single blue circle on its front perimeter as a gain marker. When the unit is powered up, the entire front panel is separated from the black body by a ring of more blue glowing light. That's all that occupies the front — no limiter controls, EQ, level or clipping LEDs or any other potentiometers.

The rear panel is just as simple. It contains a Speakon-style power-cable connector; a single balanced XLR microphone input; a single balanced XLR line-level output; a power switch; and a bank of four small buttons that includes a polarity switch, a -20 dB pad, an input-selector switch and a phantom-power-engage switch. A chrome model-number plate boasts the unit's logo, a caricature of Robby the Robot. The oval body sits atop a spherical chrome stand that has screw points underneath for rackmounting purposes; Blue also sells an optional custom rack-shelf adapter. Although the power supply is external, the transformer is positioned between two cables, and the outlet plug is a standard two-prong, thus happily avoiding a space-hogging wall wart.

But the Robbie isn't all visual pizzazz: Blue packed the electronic goods inside, including audiophile-grade metal film resistors and polystyrene capacitors. The unit's completely balanced signal path begins with a fully discrete input stage, passes through the tube-gain stage and exits via an electronically balanced solid-state output. The circuitry has no ICs and includes discrete components throughout, with no switching crossover distortion. The Robbie's tech specs are impressive: The unit boasts a low self-noise rating of -131 dB EIN at 60 dB gain from 10 Hz to 30 kHz with a 50-ohm source and -129 dB EIN with a 150-ohm source. The total harmonic distortion rating comes in at a mere 0.006 percent, and the unit's headroom reaches a healthy 34 dB before clipping. This all looks good on paper, but how does the Robbie actually sound?


My tests with the Robbie included monitoring male vocals, a semihollowbody vintage Kay steel-string guitar, and various hand drums and percussion instruments through a variety of condenser and dynamic microphones from Audio-Technica, Shure, MXL, AKG and M-Audio. I also put the juice through the Robbie, monitoring the Kay played through a Fender Vibro Champ amp miked by a vintage Shure SM57. Finally, I checked out an Ibanez TR electric bass plugged in directly to the Robbie's instrument DI. To add the least amount of corruption possible to the signal chain, I connected the Robbie's XLR output directly to the balanced XLR input of one of my studio's Tannoy active monitors and listened in mono.

Before performing all of the instrument tests, however, I decided to check out the unit's output, gain and controls with nothing connected. I tried slowly pushing the gain back and forth from its lowest to highest setting and punched each of the four buttons on the back in and out several times. The gain knob possessed a smooth, quiet sweep all the way through, and although the output was silent to about 9 o'clock (approximately 85 percent gain), from there to the top position (68 dB), the sound of air steadily grew. I found a threshold just shy of full gain in which the hiss jumped up in volume noticeably; granted, it was at the very top, past where you're ever likely to need to push the unit. It should also be mentioned that this was not the case upon initially firing up the Robbie; it consistently happened only after being powered up for 20 to 25 seconds — enough time for the tube to heat up. Because this can be common with tube gear, I believe this noise was a byproduct of the vacuum tube. To be safe, I also tried moving the Robbie and the Tannoy to different outlets and even different circuits but got the same results. You should never leave the volume up of whatever the Robbie is connected to while switching any of the four switches on the rear or while connecting or disconnecting anything. The switches definitely pop, as do the jacks when touched. The Robbie is sensitive; I could even hear my hand rubbing on the chassis through the loudspeaker. With this preamp, I think the best practice is to find a suitable setting and then keep your hands off while recording or playing.


Next, I monitored several takes of each instrument with the different microphones, and despite my initial reservations, I was impressed. The first noticeable aspect of the Robbie is that the gain control never drops the volume into silence. Because there are no markings on the front panel, it pays to read the manual to know exactly what is going on. The unit provides an amazing 60 dB of total gain, and the sweepable range is from 8 to 68 dB. This is somewhat common for quality amps, but it also requires extra care when plugging things in and out to protect your speakers. Both with microphones attached and bass or guitar plugged into the DI, the Robbie provided more than adequate gain and headroom, just as the specs would have you believe. With vocals and percussion miked up, I was able to get a strong, noise-free signal without pushing the preamp near the noisy zone at the top.

At moderate gain, the Robbie showcased each mic's unique color, and when pushed, the unit displayed its own characteristic tube sound. When putting an Audio-Technica condenser to the task of capturing some very soft percussion and whispered vocals, I gave the unit an extra boost, which produced a subtle, warm tube distortion that became more audible from approximately two-thirds gain and beyond. It wouldn't be an unpleasant effect if that is what you are going for, yet there is abundant headroom before any distortion or clipping occurs (34 dB according to the specs). There was certainly sufficient headroom for all of my test applications. On the other hand, when dealing with a high-SPL source (such as the synthetic-skinned pandeiro that I tested), the -20dB pad does just what you expect it to, and it comes in handy.

I found the tube distortion favorable when playing electric guitar and bass through the DI jack, especially on bass. The Ibanez that I tested with has a full and warm funky tone, not unlike a Fender P-Bass. When I kept the Ibanez' volume up and raised the gain on the Robbie to achieve distortion, the Ibanez really growled. This may not be its intended use, but the Robbie would make one heck of a portable DI and effects unit for bass players. While playing the guitar and bass directly through, I switched the polarity back and forth, and the difference in the two tones was, again, subtle yet noticeable, just demonstrating that Blue implemented things properly.

My lasting impression of the Robbie is that excellent sound has been delivered in a quirky-looking, sensitive little box. The combination of Class A, solid-state electronics and a healthy tube-gain stage boasts a sound that is crisp, clear, warm and never harsh in the lower decibel ranges while being hot and gnarly at higher levels. Beauty is in the eye of the beholder, so you will have to judge for yourself if you like Robbie's retro-futuristic outfit; I really dig the look but don't love that Robbie could take up a total of five spaces if placed in a rack with adequate room left for proper ventilation. And even though the build feels totally solid, the fact that my hands rubbing on the chassis produced audible noise in my speakers means that the Robbie needs to be handled with kid gloves. Because most in the studio business like strange-looking toys that glow in the dark and virtually everyone likes those that sound great without requiring a large trust fund to afford, many Robbies should find happy homes in dimly lit rooms around the world.


ROBBIE > $1,299

Pros: Unique, simple design. Excellent headroom. Warm and clear-sounding. Can achieve tube distortion. Class A, discrete electronics. Strong construction. Portable and affordable.

Cons: Occupies a lot of space if rackmounted. Chassis sensitive to touch.