Preamplifier Fairy Dust

Before you choose a new preamp, here are some things to consider:

1.       Preamps are a profit center for many manufacturers. Take a look behind that pretty faceplate and you'll find that most tube preamps have a lot of empty space in their chassis. So, if it isn't the parts, then where's the money going? Padding the manufacturer's coffers, that's where. We believe a decent tube preamp shouldn't cost an arm and a leg. Compare our modestly priced PrimaLuna tube preamps against those higher-priced designs, you'll be surprised.

2.       There are no new designs in preamps. We keep seeing claims from manufacturers that their entry-level $5,000 tube preamp is “inspired by” or “a trickle-down” version of their $20,000 flagship model. But, are they? Not really. Do a Google search for interior photos and compare for yourself. Also, keep these facts in mind:

A: The best tube preamps use more tubes. If a preamp uses just one or two tubes, it’s usually a hybrid design. That tube (or two) is only used for “amplifying” or voltage gain and is paired with a solid-state device like an FET, which is used to lower the output impedance and “drive” the voltage through. There is only ONE reason to use an FET and that’s because they are cheap. FETs cost pennies while a tube and tube socket costs around $20. Do you think just because you're paying $5,000 for a tube preamp that the manufacturer might spend the twenty bucks? They didn't.

B: The best tube preamps are tube rectified. Look at most manufacturers' flagship models and you will see a rectifier tube or tube regulation. Why? Because tube rectification is quieter than solid-state rectification, which drops the noise floor. Also, tube rectification offers the most natural, textured, and vibrant presentation because the circuit remains pure tube from input to output. Solid-state rectification is a fine choice for a budget tube preamp, understandable and necessary. But for a $5000 preamp? That’s absurd. Implementing a 5AR4 rectifier tube is not cheap, but it is the Gold Standard for sonic performance. PrimaLuna goes even further by using a pair of 5AR4 rectifier tubes in a dual-mono configuration to present your music with a three-dimensionality that will give you goosebumps.

C: The best tube preamps are dual-mono. This means building two completely separate preamps into a single box. Easier said than done, though, because to achieve a true dual-mono design means doubling up on virtually everything; two power transformers, duplicates of all the regulation circuits, more space consumed inside the chassis. Dual mono is a rarity even at the highest price points, yet PrimaLuna preamps are (and have always been) dual-mono.

D: The best tube preamps use analog volume controls. The temptation to use a $2 digital volume control chip to keep costs down is very seductive. Sure, the preamp will sound ok and be relatively quiet, but true to its digital nature, the chip will add an electronic “sheen” to the music. PrimaLuna preamps use the Gold Standard of motorized potentiometers: the iconic Alps Blue Velvet volume control from Japan. Why? Because this attenuator tracks perfectly, stays quiet, and has a gorgeous analog sound!

E: The purest way to transmit a signal inside a tube preamp is by using point-to-point wiring. Look back through history; for instance, the iconic tube preamp of the 1960s, the Marantz 7C. These preamps are still treasured today because of their impressive sonic purity, thanks to point-to-point wiring. Surprisingly, point-to-point wiring has become a true rarity, most manufacturers have switched primarily to circuit boards. There remain only a few companies who still do it (Atma-sphere is one), but this high-purity technique is virtually unheard of today. PrimaLuna proudly features Point-to-Point wiring in ALL of our components.

F:  “Made in USA” doesn't always mean what you might think. Tube preamps are very rarely truly made in the USA. Contract fabricators overseas stuff the circuit boards with parts and ship them to a domestic “manufacturer” where they're bolted into a chassis. You're told it's an American product, but, in fact, it really isn't.

3.       Never buy a tube preamplifier with an internal DAC. Why? There are actually two good reasons not to: The first is that digital circuits generate all kinds of noise, from radio frequency interference (RFI) and high frequency switching noise to digital “backwash” in the power circuit. Because digital changes! History shows that preamplifiers with “old” digital become unwanted and lose virtually all of their resale value.

4.       Never buy a tube preamplifier with an internal phonostage. These are usually a “throw-in", an afterthought. They're rarely of good quality because manufacturers assume the vast majority of buyers will never use them. These internal phono preamps also tend to be quite limited in features and capabilities, which will limit your future cartridge choices. There’s a very vibrant and competitive market for external phono stages. A $200 external phono preamp will sound better and you can easily upgrade down the road.

PrimaLuna doesn’t believe in fairy dust.

We believe in superior engineering and superior parts. This is why we use Swiss-made silver-plated OFC wiring, Mundorf capacitors from Germany, and from Japan, Takman resistors, Nichicon capacitors, Fujitsu relays, and Alps volume controls. Parts well-known for their superior sound quality; quite literally, the best of the best. That’s why you don’t see other manufacturers discussing this topic as we are now. They don’t want you to look behind the faceplate.

Major-brand $5500 Preamp

Just two tubes (mounted directly to circuit board), solid-state rectification, volume control chips, and C-core transformer. Total weight 13 pounds. $423 per pound.

Major-brand $5000 Preamp

Just one tube (mounted directly to circuit board), solid-state rectification, single IE-core transformer. Total weight 13 pounds. $385 per pound.

PrimaLuna EVO 200 Preamp - $2,995

Six tubes in ceramic sockets mounted to steel chassis, tube rectification, Takamisawa relays and Alps Blue Velvet volume control from Japan, point-to-point wiring, dual toroidal transformers, all employed in a dual-mono preamp design. Total weight 39.6 pounds. $86 per pound.

Handy Preamp Shopping Tips

IMPEDANCE

If you are using a tube preamp with a solid-state amplifier, the ONLY compatibility issue you need to think about is the preamp’s output impedance. The input impedance of the amplifier needs to be 10 times or higher than the output impedance of the preamp.

EVO 200 is 2,800 ohms: Amplifier Input Impedance needs to be 28k ohms or higher

EVO 300 is 256 ohms: Amplifier Input Impedance needs to be 2,560 ohms or higher

Very few power amps have an input impedance below 28k ohms, so PrimaLuna’s can be used with confidence in 99% of the systems out there. Consult the owner’s manual for your amplifier.
 

GAIN

When you are using a preamp, you are usually lowering the gain (volume) of your CD player or phono stage by 6dB or even more. For reasons that baffle us, some manufacturers sell preamps with 23, 26, and even 30 dB of gain that you will never use. This practice is nothing short of insane. Not only do you have to deal with the thermal noise and microphony, it causes problems like premature tube failures; with zero upside benefits. PrimaLuna preamps have always had between 10-12dB and are as quiet as solid state. 
 

TUBES

We use 12AU7 gain tubes because of flexibility. There are more types of 12AU7’s than any other tube, either in current production or the world of vintage new old stock (NOS) tubes. A huge variety so you can have all the fun you want, and squeeze out that last 10% of tonal balance. Amperex, GE, Mullard, Brimar, all with a different color. See our Tube Rolling page for more information on fine-tuning your sound.

If you buy a preamp that uses 6H30 tubes, it’s a one-trick pony. There’s only one factory that makes them so there’s no fun to be had and you can’t “season your system to taste”.

WEIGHT

Quality parts and designs simply weigh more. Compare weights when comparing preamps. Then, type the model you are researching into Google and look at “images” until you find an interior photo. What we say is true, but YOU need to see it for yourself. The EVO 200 weighs 39.6 pounds, and the EVO 300 weighs 52.8 pounds.

And remember this:  Magazine critics review many brands.  They buy PrimaLuna.