Musical Fidelity Introduces Flagship Tube Preamp

According to a press release, English hi-fi manufacturer Musical Fidelity is introducing a new flagship pure Class A triode tube preamp called the Primo—a product that has been 12 years in the making. Musical Fidelity claims that a major factor in the Primo’s beautiful sound is “its total system linearity; low distortion, low noise, wide bandwidth whatever the volume control setting.” Musical Fidelity spared no expense, incorporating exotic materials such as a mu metal screen, which acts as a housing for the unit’s power supply and prevents magnetic interaction between the supply and “any of the (Primo’s) delicate signal-handling components.” In designing the Primo, Musical Fidelity invested countless hours in research and development, carefully analyzing both its own past designs and those of worthy competitors with an eye toward setting “a new performance standard for tube preamps.” Check out the full release below for more details.

New!  Primo pure Class A triode fully balanced preamp.Superlative sounding, beautifully built, beautifully designed, extremely reliable.
 

Design background.

The Primo pure Class A triode tube fully balanced preamp has a long history. In 1978, Antony Michaelson’s first company, Michaelson and Austin, went out of business because they could not make a high quality reliable preamp to match their highly regarded power amps. Since then, Antony has wanted to make a superlative, reference standard, tube preamp. In the last 30 years, Musical Fidelity has sold more small signal tube equipment than any other manufacturer. Probably more than all of them put together. The characteristics of Musical Fidelity’s tube equipment are:
 
1.     Very low distortion
2.     Very long tube life.
3.     High reliability.

You see Antony did learn from his bitter experience with Michaelson and Austin.

In the intervening years, the time has never been quite right for Musical Fidelity to make a top quality tube preamp. Despite this, Musical Fidelity’s R&D department has been working on a super tube preamp design since 1997. As the years have gone past, the project has become more sophisticated. With Musical Fidelity’s decision to produce a range of super and pure Class A power amps (Titan, AMS50 and AMS100), it was clear that we needed to make a super performance preamp.

Finally, we had the reason to make the preamp of Antony’s dreams. Although our tube preamp design was well advanced, we increased our commitment. We looked at the best of competitors’ products in depth. The layout, the circuit diagrams, the components even the resistors, capacitors and pcb materials were exhaustively analysed. We were determined to leave no stone unturned in order to make a truly extraordinary preamp. The result of our twelve years of intense research and development is the Primo preamp. 

Technical description.

The Primo pure Class A, triode, fully balanced preamp uses 14 selected ECC81s. Its balanced technical performance is excellent. Distortion, across the band from 10Hz to 50kHz, is hovering around 0.01%. It will deliver this performance regardless of the volume control setting and with a flat frequency response; 10Hz to 50kHz +0.5dB. It is capable of driving any amplifier in existence with any reasonably conceivable length of cable.

The Primo’s special feature is its total system linearity; low distortion, low noise, wide bandwidth whatever the volume control setting. 

When we designed the Primo we examined all the best of the competition. Rather than disparage their no doubt good hearted attempts at making a proper tube preamp, we would like to emphasise why the Primo is different and better.

It is well known that tubes are notoriously bad at driving “loads”. Unless special precautions are taken, distortion and noise are unlinear. For example, if a typical tube is driving a volume control, its performance will alter depending on volume control setting, frequency and voltage level. The performance is continually changing. In a word, non-linear.

The Primo breaks new ground as it is not subject to these non-linearities. The Primo has extremely low interstage coupling impedance. As a result, the Primo’s noise and distortion performance is consistent at any frequency or level or volume control setting.

The output stage is similarly important. As far as we know, all other tube preamps, single ended or balanced, drive the load with a single tube configuration. Not so with the Primo. Both the balanced and single ended output stages have two pairs of output tubes in parallel, to ensure completely linear performance when driving any conceivable amplifier or length of cable. We designed the Primo to be a reference standard tube preamp. Its performance is consistently neutral. Low noise, low distortion, wide bandwidth, huge overload margin and a colossal peak output level.