The EVO 400 is not only PrimaLuna’s best line preamp offering ever, but it also holds its own against ultra-high-end competition . . . If purity of expression and tonal realism are two of your sonic priorities, get ready to embrace the EVO 400. I certainly did. In a nutshell, it’s an insane audio bargain that delivers pure tube magic.
The Absolute Sound
PrimaLuna EVO 400 Preamplifier
Swiss Made Wiring
DuRoch Tinfoil Capacitors
AC Offset Killer
Dual Mono Topology
Vacuum Tube Rectified
Dual Toroidal Power Transformers
ALPS Blue Velvet Potentiometer
Home Theater Pass-Through
AC OFFSET KILLER - A PRIMALUNA EXCLUSIVE
AC Offset Killer is about goose bumps. The ones you get when music comes out of a background so quiet, you may say to yourself “Just how is this possible?” PrimaLuna custom-winds our own massive toroidal power transformers that are low in hum and EMI. But we wanted more. Our engineers designed the AC Offset Killer to lower transformer noise to a place no other manufacturer dreams of going, regardless of how bad your electricity is. The result? Sense of space. Texture. The resonance of an acoustic guitar or violin string that seems to trail on forever. The AC Offset Killer will amaze you.
If you bought a lesser amplifier, you would pay hundreds to make this upgrade. Easy to identify through their pink color, these premium resistors from Japan are popular with those who rebuild and upgrade their gear. "Modders" love TAKMAN for their low noise, linearity, and musicality.
DUAL TOROIDAL POWER TRANSFORMERS
Power transformers generate two types of noise, magnetic and acoustic. That's why toroidal power transformers are used in the very best audio products. Compared to standard transformers, toroids radiate about 1/10 the magnetic field that pollutes music and obscures detail. Additionally, the absence of an air gap typically means toroids have an 8:1 reduction of acoustic noise. As transformers are the most expensive components in any audio product, manufacturers will even house cheaper C-core and EI-core transformers in an outboard power supply box with an umbilical cable rather than upgrade to an expensive toroid. The increased cost is significant, but PrimaLuna doesn’t cut corners. All PrimaLuna products use massive, potted toroidal transformers. PrimaLuna transformers are enclosed in a metal housing and then potted in a non-microphonic resin to further reduce noise and to protect the windings from moisture and deterioration forever. They are massive, resulting in a preamp weighing a substantial 53 pounds.
In the world of preamps, experts agree that tube rectification is the gold standard. It’s quieter than solid state rectification, dropping the noise floor. And it offers the most natural, textured, and vibrant presentation because the circuit is now pure tube. But because it is expensive to implement, you’ll only find it in the top of the line models typically costing $10,000 or more. Finding a preamp using one rectifier tube is sweet. PrimaLuna goes even further using two 5AR4 rectifier tubes in a dual-mono design to present your music with a three-dimensionality that will give you goosebumps.
JAPANESE ALPS BLUE VELVET POTENTIOMETER
The best tube preamps use analogue volume controls. Not volume control chips. Look inside the most well-known brand of tube preamps and you will see a chip called a DS1666-10 Digital Resistor IC. At Primaluna, we understand the temptation to use this chip as they cost $4 each (half that in quantity!). The preamp will sound fine and be quiet, but true to “chips” it will add an electronic “sheen” to the sound. PrimaLuna prefers analogue. And we use the Gold Standard in motorized potentiometers: The iconic Alps Blue Velvet. Why? Because they track perfectly, stay quiet, and don’t sound like chips!
SUPERQUIET LINE INPUTS
Input selector switches leak noise and signals from other sources, as they never turn off the other inputs completely. And, they deteriorate with age, requiring the use of cleaners. Many are mounted on the front panel requiring long runs of wires to the back panel inputs. These wires pick up stray noise from RF and EMI.
PrimaLuna has a better way. Instead of a switch, input selection is done using premium quality sealed relays mounted in the rear where you plug in your components. When an input is selected, that relay closes giving you the best connection possible. All the other relays are left open, so noise and signals from other sources can’t leak in. The signal path is now almost non-existent, so there are no wires to pick up noise.
POINT TO POINT WIRING
You spend a lot of money on interconnects. So why have the signal go right from the RCA jacks or speaker terminals into circuit boards with copper traces so thin you can hardly see them? What’s high-end about that?
PrimaLuna employs Point to Point Wiring on all products. EVO 300 and EVO 400 models even use Swiss-made silver-plated OFC wire. The entire signal path, including resistors and capacitors, is painstakingly hand wired with heavy-gauge cable by craftsman.
NO INTERNAL DAC / NO INTERNAL PHONOSTAGE
Never buy a preamplifier with an internal DAC. Why? Because digital changes, and history shows that preamplifiers with “old” digital become unwanted and have almost no resale value.
Built in phonostages are “throw in” and are rarely good quality because manufacturers assume 90% of buyers won’t use them. The external phonostage market is very competitive. You can get something much better for as little as $200, and buy one that actually meets your cartridges needs and YOUR budget.
Expensive and exotic preamps always use a dual-mono design to achieve a level of imaging not possible otherwise. Most manufacturers don’t employ dual-mono because of expense. It requires two power transformers, double regulation circuits, and in fact….everything is double. In effect, dual-mono means building two discrete and separate preamps into one box. It is so expensive to build, it’s a rarity even at the highest price points. All PrimaLuna preamps are dual-mono for the ultimate in stereo imaging and a sense of space that goes on forever.
A preamplifier is typically not required to add any gain to your system when you are using it. It is usually lowering gain from the source you are listening to. The number one complaint from audiophiles about preamp performance is noise. So why is it that so many manufacturers design preamps with 20 to 27dB of gain? And you wonder why there is "hiss", and why tubes go noisy or microphonic? PrimaLuna preamps use SmartGain. With a gain specification of only 10dB, you will find your PrimaLuna preamp is as quiet as a church mouse. If tubes are less than perfect, you may never know it because they are not amplifying as "loud". High efficiency speaker owner's rejoice!
Another exclusive PrimaLuna feature is PerfectMatch, a circuit designed to present a perfect 100K ohm impedance to your source components. This is vitally important especially for tube source components, such as phonostages and DACs to sound their very best.
DIALOGUE FRONT-END CIRCUITRY
The DiaLogue Premium uses three 12AU7 tubes per channel. The result is even lower distortion and increased bandwidth over ProLogue. The change in dynamic range is stunning! Distortion levels in the first stage have dropped by a factor of five at low levels, and at least 20 at higher levels, above one volt. The four 12AU7’s on the outside are driver tubes. By using four instead of two, we can swing more voltage. The two tubes in the center are the input tubes, and that’s where you want to have fun later if you wish by experimenting with different tube brands.