The road to hell is paved with good inventions: clever ideas that appear, in hindsight, motivated more by a desire to sell clever ideas than to make musically superior products.

The DiaLogue tube amplifiers from PrimaLuna have, at their heart, a clever idea of their own: an output circuit that is user-switchable between triode operation, in which the screen grid of a tetrode or pentode power tube is defeated by means of connection to the tube's anode; and Ultralinear operation, in which the screen grid of a tetrode or pentode carries a portion of the AC music signal, supplied by a tap on the output-transformer primary, in a feedback-like effort to reduce distortion and increase power. Fans of the former often report a sweeter, more tubey sound, while fans of the latter report a tighter, more detailed, more timbrally neutral sound. Audio enthusiasts are given to reporting any number of things.

Last month, I wrote about Light Harmonic's use of Kickstarter to fund the final production and packaging of their Geek Out portable USB DAC–headphone amplifier. The campaign raised $303,061 from 2146 backers. That success led Light Harmonic to create a new division dedicated to mass-market products: LH Labs. The Geek Out would be its first product. (Pre-orders are still being accepted.) LHL's second product would be the Geek Pulse, a "pure class-A" desktop integrated amplifier–DAC capable of handling 32-bit/384kHz PCM files, as well as decoding native DSD64 and DSD128 files.