Tube Depot TubeCube 7

I remember a story about a famous rally race in the 1960’s. An unlikely little car called the Mini Cooper entered the scene, and looking like nothing more than a small commuter on its way to the office, it went out and promptly beat the Ferraris. Embarrassing. So race officials disqualified the little Coopers for having headlights that were too bright! I don't think it went over well.

Here we have another unlikely entrant in a field dominated by “Ferraris”, the Tube Cube from Tube Depot. Looking like some kind of imitation of a tube amplifier, perhaps a toy, the little Tube Cube has a few surprises. Namely, its one heck of a good sounding amp and at a price point that simply seems impossible. Currently $180 delivered (including tubes)! That equals a single power tube in many of the amps I’ve owned! After another $100-$150 in well selected NOS EL84 and 12ax7, this little cube delivers WAY more than should be possible.

In the hand (and yes it fits comfortably in one hand!), the Tube Cube feels robust and well made. The transformers, although quite small, are well potted and the whole package is neat, clean and sturdy. The rather unorthodox speaker connection directly into the transformers is odd but makes sense in the space available and is well laid out, with taps for 8, 6, and 4 ohm. The connectors are adequate quality, and a nice touch is a regular fused IEC connector, so an aftermarket power cord can be used here. No wall warts or outboard power packs needed. The volume control makes this a stand alone audio solution.

In practice this is an amp for which I would not want to be on the judging team in a blind demo. Ever hear of the wine critics who all chose the $6 bottle over the big names? I’d be afraid of something like that happening here. Although the amp sounded fine with the stock tubes, vintage EL84 and a 60’s Telefunken smooth plate 12ax7 were an immediate and palpable upgrade. While not the last word on anything, this little amp does the imaging trick pretty well, sounds loud and powerful enough on efficient speakers, in-the-room and fairly revealing. That's saying a lot at this price. Even building your own budget amp would hit this price point in parts alone. Overall, it’s hard to imagine a better value for the dollar than this little jewel. Like the Tiny Sabre DAC, this product hits so far above its price I can’t think of anything to really criticize. If Tube Depot ever buys a room at an audio show it could get interesting. If I were on a tight budget/were a college student/lived in an apartment or tiny space/could only have one amplifier/only had $200 to spend, this is the amp I would pick up and never look back. Upgrading to my beloved Decware does bring real and easily discernable improvements in every category, as well as added functionality and build quality, etc. but the price is 6 times more! The Tube Cube gets 85-90% there. If you are new to tubes or are just curious, this makes a very safe, affordable and rewarding introduction to tubes and tube audio.

The rear hookup is unconventional!

It’s hard to imagine a smaller amp than this. I'm impressed with the build quality of the little amp as well. It definitely perks up to some input tube rolling! As is common, the stock tubes work fine but NOS tubes bring the Tube Cube immediately to another level. Here with a Telefunken smooth plate 12AX7.

The power cable hooked up here retailed for almost 4 times the price of the Tube Cube! Talk about backward.

David and Goliath. Goliath didn’t fall today but David is definitely dangerous.