Drive Your Speakers with Authority with the PrimaLuna EVO 100 Tube Power Amplifier: 40Wpc Unit Plays with Convincing Slam and Airiness, Helps Expose Inner Detail and Extended Responsiveness

The creators of the PrimaLuna EVO 100 tube power amplifier know you’ve got plenty of options for driving your loudspeakers. Which is why nearly everything about this extremely well-constructed and smartly engineered component is different — and subscribes to an audiophile mentality.  

Let’s begin with the hefty toroidal transformers enclosed in metal housing and potted in a non-microphonic resin to future reduce noise and protect the windings from deterioration, a solution that far out-performs C- and EI-core types in outboard power supply boxes. Then continue with the custom-made super-wide-bandwidth output transformers, the most important (and expensive) part of any tube amp. Wound in-house and beefy in size, they ensure long tube life and contribute the desired “slam” any high-end system needs to reproduce music with authority and presence. Point-to-point wiring throughout the entire signal path, ultra-quiet sealed relay inputs, bad-tube indicator LED lights, and the absence of any internal DAC or phonostage to prevent unnecessary complexity pile on the benefits you’ll hear every time you fire up this puppy.

Outfitted with eight tubes and outputting a robust 40Wpc (into eight ohms, stereo) and available in stereo or mono configuration (read more about the latter below), the 37.4-pound EVO 100 goes to further lengths with Adaptive AutoBias — a smart, completely passive technology that employs sensors to monitor your tubes and makes adjustments in real time. Since it addresses “tube pinch off” at high volumes, it reduces distortion by a figure of more than 50 percent. Just as importantly, EVO 100 runs its output tubes at a minimum dissipation without veering into crossover distortion. 

Hold the phone, you might be thinking. That means the amp provides less power from each tube. Right. But then again, big power numbers never automatically correlate with stellar sonics. By leveraging the strength of big transformers as well as high-grade sockets, wiring, resistors, and capacitors, EVO 100 supplies power that is pure and clean, and which leads to gorgeous midranges, controlled low-end passages, and airy, extended highs. 

Yet another advantage of EVO 100? Roll tubes as much as you please. Go ahead. Fine-tune for days and days. EVO 100 is compatible with 6L6G, 6L6GC, 7581A, EL34, EL37, 6550, KT66, KT77, KT88, KT90, and KT120 tubes. And since EVO 100 runs tubes at about 417 volts for plates and screens, you can rest assured your tubes will last a long time — far longer than in competing designs. And no matter what type of speakers you own, now or in the future, the presence of two-, four-, eight-, and 16-ohm outputs has you covered. 

Sold with a three-year manufacturer warranty, the 7.5 x 11 x 15.9-inch (HWD) EVO 100 invites you to experience the warmth, musicality, and fullness of tube sound like you may never have imagined accessible at this cost. To learn more about EVO 100 or any of PrimaLuna’s amplifiers, speak with a Music Direct audio consultant at 312-433-0200. 

Buildign a Better Monoblock
In creating its monoblock amps, the design team at PrimaLuna faced a formidable challenge: How to match (or exceed) the sonic signature of its integrated and stereo amps in a set of monoblock amplifiers with twice the power. As many designers will attest, it’s quite easy to take a step backwards when creating a more powerful amplifier.

While many designers opt for larger transformers to double the output power, PrimaLuna team decided against that approach knowing that big output transformers sometimes don’t behave as well or sound as good as their smaller brethren. Instead, the company elected to use two discrete audio channels in one chassis and paralleled them at the loudspeaker terminals. Building an amp with two output transformers per monoblock amp is almost unheard of due to one simple reason. cost. 

Yet the sonic benefits are significant. This design adds a 16-ohm tap to each transformer which, when paralleled in this circuit design, resulted in an eight-ohm output. So, you now have three sets of speaker taps: two, four, and eight ohm to get a perfect "handshake" from the amps to your speakers. The ability to drive planer and ribbon speakers is unmatched. 

Of course, with this approach, you risk a percentage of power from one free-running transformer pushing into the other due to output-voltage differences caused by circuit tolerances and tube aging. To counter this problem, designers developed a specific cross-coupled positive/negative feedback scheme to balance out both channels — and lower distortion in the slipstream. In addition, newly designed pre-stages improved the drive capacity to the power tubes, resulting in lower distortion levels without the need for extra negative feedback. The circuit is now inherently more stable and virtually immune to drive imbalance and the distortions that accompany tube aging.

In sum: This innovative twin-channel-summing approach with cross-coupled positive/negative feedback results in surprisingly low harmonic distortion, further pushing the performance of all PrimaLuna mono amps.