PrimaLuna loves tubes. The Dutch-based company uses them in its whole range of products, from preamps, to power amps, to integrated amps. Even a tube-equipped CD player has graced its lineup. Kevin Deal of Upscale Audio distributes PrimaLuna in the U.S., and also stocks and sells a wide variety of vacuum tubes (he’s my favorite supplier). PrimaLuna recently replaced its Prologue and Dialogue series equipment with a new series, called the EvoLution line. Although EvoLution includes Evo 400, Evo 300, Evo 200, and Evo 100 integrated amps, power amps, and preamps, there is only one DAC, the Evo 100 Tube DAC, which for brevity, I’ll just call the Evo 100. Like most PrimaLuna products, the Evo 100 draws heavily and innovatively on vacuum tubes, although all digital products require chips these days.
The Evo 100 looks like other PrimaLuna components, although at 11" x 7.5" x 15.9", it’s smaller than most. At $2999, the Evo 100 falls into the midrange of DAC pricing. It’s reasonable considering its construction and the parts used. You can buy cheaper DACs and you can buy much more expensive ones—the real issue is value. Is the Evo 100 a good value for the money? Let’s find out.
The Evo 100’s tube cage looks like those used in other PrimaLuna components, which is a good thing. Most amplifier tube cages I’ve seen are awkward, even ugly, appendages that degrade the appearance of the amplifier. Yet PrimaLuna designed a tube cage that’s quite attractive, and had, fortunately, used it in the design of the Evo 100. It covers the tube complement, which comprises two (each) 12AX7, 12AU7, and 5AR4 rectifiers—one of each type of tube per channel. The use of a separate 5AR4 rectifier tube indicates a very stout power supply. (My fairly expensive tube amplifier uses a single 5AR4 tube for both channels of its power supply!) All of these tubes are very popular, in current production, and available for prices that aren’t extravagant. In a pinch, you could probably find replacement tubes at your local guitar or professional music store. Since the tubes are easy to find, you can also indulge in tube rolling—the practice of switching tube brands and types to get the sound that pleases you. The stock PrimaLuna-branded tubes will sound fine, but maybe there’s a tube from another manufacturer that will satisfy your desire for, oh, more treble sparkle. Naturally, being a vendor of vacuum tubes, both new and new old stock, Upscale Audio doesn’t discourage tube rolling. However, I didn’t try any alternate tubes; that’s beyond the scope of a review.
One additional tube is used in the Evo 100, and it’s in the clock. That’s right, a tube is used in the clock. And it’s not just an ordinary tube, but “a very rugged, long-life Russian military triode specifically designed for oscillation purposes . . . which is its function here. It is running very conservatively, so life expectancy is roughly 5 to 10 years of operating time.” You should never have to change it, which is good, since it’s hard-wired onto the circuit board. PrimaLuna makes a strong case for using a tube-based clock, which they call the SuperTubeClock, claiming “this boldly conceived design provides vastly superior resolution, detail retrieval, clarity, definition and detail from top to bottom.” Normally, a DAC’s clock is a solid-state oscillator designed to produce a timing signal at a precise frequency. PrimaLuna justifies the SuperTubeClock by claiming that “by using a tube, we have significantly lowered the amount of jitter and noise, resulting in superior detail retrieval. This in turn yields superior detail and dynamics from top to bottom, and improved overall musicality.”
Although PrimaLuna is justly proud of its point-to-point circuit wiring, any DAC is a digital product using chips mounted on circuit boards, and that’s how it is with the Evo 100. On one such board, you’ll find a venerable and respected Burr-Brown PCM 1792A DAC chip.
The Evo 100 takes the unusual step of converting USB input to the SPDIF format, with PrimaLuna claiming that this improves the sound. That claim is not new; several other manufacturers will tell you the same thing. SPDIF connections are designed to play music, while USB connections are designed for accurate file transfer. If converting USB to SPDIF sounds better, why doesn’t everyone do it? Converting USB to SPDIF imposes certain limits on a DAC’s ability to play the highest-sampling-rate digital music files, since the SPDIF circuit is limited to 192kHz. If you want your DAC to play the highest-sample-rate files, you’ll use an unconverted USB connection. In addition to playing 192kHz PCM files, the Evo 100 will play (via DoP encoding) DSD files up to DSD128. The Evo 100 is unable to play DXD, DSD256, and higher-rate files. Do you really care? There really aren’t many of those files available, and they are premium priced. MQA files? Sorry, Charley—you’ll have to look elsewhere. If streaming is your bag just subscribe to Qobuz instead of Tidal. Since Qobuz uses standard FLAC format files to stream hi-res instead of Tidal’s MQA-encoded files, the Evo 100 will play all your streamed hi-res files just fine. Of course, the Evo 100 plays encoded MQA files just fine, too, as do all DACs; it just doesn’t decode them.
In addition to a USB input, the Evo 100 has AES/EBU, coax, and optical inputs, all with the same limits. Why would you need inputs other than USB? Perhaps you have a CD player with a coax SPDIF output or even an AES/EBU output; you could connect it to the Evo 100 to bypass the player’s internal DAC. A few companies (NuPrime and Cambridge Audio come to mind) still make CD transports designed strictly to play through an external DAC. The Evo 100’s analog outputs are on RCA jacks—no XLR. Another “feature” omitted from the Evo 100 is selectable digital filters. Some DACs offer up to eight different filter settings from which the poor audiophile is supposed to choose based on sonic preference. Talk about audiophilia nervosa! The Evo 100 offers a single, unswitchable filter for PCM and one for DSD. I kind of like that—the designer picks the filter that sounds best and makes it standard.
The Evo 100 uses a circuit feature called AC Offset Killer to lower transformer noise. The Evo 100’s circuit is a dual mono design, which means there are no shared components, including power transformers, between channels. The only shared part is the power cord.
There are two windows in the center of the faceplate, each with a vacuum-fluorescent display; the top window shows the input selected, while the bottom, upon turn-on, shows a counter that counts down from one minute as the Evo 100 warms up. After the DAC starts to play, the bottom window shows the sampling rate of the music file being decoded. The text in both windows was a bit small and difficult to see from my listening chair about ten feet from the unit. Faceplates can be either black or silver.
Evo 100’s controls are very simple. Each of the four buttons on the half-height faceplate selects one of the four digital inputs. That’s all. A slim, black metal remote also selects one of the four inputs, and mutes the DAC. It does not control volume, so you’ll need a system volume control (preamp or linestage). The remote’s single column of silver buttons includes one labeled Display, which adjusts the brightness of the text in the front panel windows. The only control missing is the one I would use most, a remote on/off switch—hardly a show-stopper. I didn’t use the remote at all.
On the rear panel are the four inputs, an IEC power connector, and the RCA output jacks. The output impedance is 2700 ohms, which could be a problem driving very-low-impedance preamp inputs. I suggest using it with a preamp that has a minimum 30k-ohm input impedance.