Before you choose a new preamp, you need to understand two things:
1. Preamps are a profit center for many manufacturers. While tube amps are expensive to build, a decent tube preamp can be built and sold for $1500; at a profit. Shocked? People see a pretty faceplate and never look under the hood. But if you did look, you might be bummed out to see a lot of empty space. If it isn’t the parts inside, what exactly are you paying so much for? Manufacturers have steadily increased the price of preamps over the last 20 years at a pace that far exceeds inflation. They are also utilizing fewer parts in their designs
2. There are no new designs in preamps. Manufacturers make lofty claims about their “entry level” $5,000 preamp being “inspired by” or “trickle down” versions of their $20,000 flagship models. But are they? Not really. All you need to do is search Google for interior photos and remember these facts:
A: The best tube preamps use more tubes. If a preamp uses one or two tubes, it’s usually a hybrid. The tube is used for “amplifying” or voltage gain, and a solid-state device like an FET is used to lower output impedance and “drive” the voltage through. There is only ONE reason to use an FET. It’s cheap. FET’s cost pennies while a tube and tube-socket costs around $20. Since you are paying $5,000 for the preamp, you would think they might be nice and spend the twenty bucks. But they don’t.
B: The best tube preamps are tube rectified. Look at their flagship model and you will see a rectifier tube or tube regulation so the circuit is pure tube. Solid state rectification is fine choice for a $1200 preamp. That is understandable. But a $5000 preamp? That’s absurd. Using a 5AR4 rectifier tube is not cheap, but it is the Gold Standard. All PrimaLuna preamps utilize two 5AR4 rectifier tubes, one for each channel.
C: The best tube preamps are dual-mono. Easier said than done because to achieve a true dual-mono design means two power transformers and all the regulation circuits. In effect, dual-mono means building two discrete and separate preamps into one box. This is a rarity even at the highest price points. All PrimaLuna preamps have been dual-mono from the beginning.
D: 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!
E: If you could have it all. Everything. You would want point to point wiring in the signal path. This is a true rarity. There are a couple of companies that do it (Atma-sphere is one), but it’s almost unheard of today. You need to look at history: The iconic preamps of the 1960’s like the Marantz 7C are desirable today because of point to point wiring. Products with printed circuit boards (PCB’s) go down in value and end up forgotten at pawn shops.
F: Made in USA preamps are rarely made in USA. Contract factories overseas stuff circuit boards with parts and those circuit boards are then bolted into a box in the USA; and you are told it's an American product.
PrimaLuna doesn’t believe in fairy dust.
We believe in superior engineering and superior parts. That 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.
Compare For Yourself
Major Brand 'A'
Major Brand 'B'
|Rectification||Solid-state||Solid-state||(2) 5AR4 Tubes||(2) 5AR4 Tubes|
|Construction||Printed circuit board||Printed circuit board||Point to point wiring||Swiss-made OFC
Point to point wiring
|Volume Control||Electronic||$4 Chip||Motorized Alps Blue Velvet||Motorized Alps Blue Velvet|
|Transformer||Single IE-core||Single C-core||Potted toroidal x2||Potted toroidal x2|
|Design||Shared parts between channels||Shared parts between channels||Dual mono||Dual mono|
|Weight||13 lbs||15.9 lbs||37.5 lbs||52.9 lbs|
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 $4000 Preamp
Just one tube (mounted directly to circuit board), solid-state rectification, single IE-core transformer. Total weight 13 pounds. $308 per pound.
PrimaLuna DiaLogue Premium Preamp - $3199
Eight tubes in ceramic sockets mounted to steel chassis, tube rectification, Takman audiophile-grade resistors, Takamisawa relays, and Alps Blue Velvet volume control all from Japan, Mundorf EVO SilverGold capacitors from Germany, point to point wiring with Swiss-made silver-plated OFC cable, dual toroidal transformers utilizing an exclusive AC noise filter, all employed in a dual-mono preamp design. Total weight 53 pounds. $60 per pound.
PrimaLuna ProLogue Premium Preamp - $2199
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 37.5 pounds. $59 per pound.
Handy Preamp Shopping Tips
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.
ProLogue Premium is 2800 ohms: Amplifier Input Impedance needs to be 28k ohms or higher
DiaLogue Premium is 256 ohms: Amplifier Input Impedance needs to be 2560 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.
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.
We use 12AU7 gain tubes because of flexibility. There are more types of 12AU7 tubes being made today than any other tube, and in the world of vintage new old stock (NOS) tubes, there is such a huge supply and variety you can have all the fun you want. And dirt cheap. Amperex, Cifte, Mullard, Brimar. Tons of choices. If you buy a preamp that uses 6H30 tubes, it’s a one-trick pony (besides the fact that 6H30’s sound thin). 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”. You better like what you get, because you are stuck. And, what happens if 6H30 tubes go out of production?
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 PrimaLuna ProLogue Premium weighs 37.5 lbs., and the DiaLogue Premium, 52.9 lbs.
And remember this: Magazine critics review many brands. They buy PrimaLuna.