Getting It Up
Most moving coil (MC) cartridges have very low output levels compared to a standard moving magnet (MM) cartridge. Levels of about 1/10th of MM (4.7mV) level are common. Some MC cartridges have higher levels, and some lower, but most are in the 0.3mV to 0.5mV range.
Such output levels are so low that the first stage of a phono preamp must be carefully designed so that the noise of the phono stage will not interefere with the music. Ordinarily, this would not be difficult using standard low-noise design techniques and parts . . . unless high-quality sound is desired. Tubes, which provide excellent sound, are just not up to the task: though they are quiet enough for MM use, they are just too noisy to work with the weaker MC levels.
The only way to get a good signal-to-noise ratio from a tube phono stage with MC cartridges is to make the signal louder before it enters the phono stage. Except in the case where the output level of the MC cartridge is lower than usual, a 10 times (20dB) increase will bring typical MC levels up to MM level. Once raised to this level the signal will be so "loud" that tube noise will be unobtrusive by comparison.
So how do we get that signal up? The ideal step-up technology would be super-quiet, sound great, and inexpensive. Which is pretty much not possible. We are limited by the choice of amplifying devices.
There are four types we can use: tubes, two types of transistors (bipolar junction transistors and junction field-effect transistors, or "BJT" and "JFET" transistors), and transformers. Each type of device has its own typical noise level, its own sonic signature, and associated cost. (Please note that under the category of "transistors" I am considering discrete as well as integrated circuit solutions where either BJTs or JFETs are used in the front-end.)
Ranking these parts in terms of noise level, from quietest to noisiest:
As mentioned, tubes are just too noisy to be used with MC cartridges. Transformers and transistors are quiet enough for good results. The early SA preamps (SA-7/7.1; SA-3/3.1; SA-5/5.1) do not have MC stages: their phono stage front end is tubed. They are well-matched with MM cartridge level. The SA-3000, SA-5000, and SA-9 all use JFETs as the MC step-up stage.
Ranking the part types in terms of sound quality (my own personal ranking), from best to worst:
Generally speaking, a good transformer is very neutral-sounding. Tubes sound like tubes, and we all know I like tubes (when used as voltage amplifiers). JFETs are pretty benign, but thin the sound a tiny bit and add some fine grain or mist to the top end. BJTs are the devices famous for that disagreeable "transistor sound": they are fast-sounding, but at the expense of considerable thinning of the sound. They can be quite edgy when used as voltage amplifiers. Some may argue with this ranking order, but this is my page and if they don't like this ranking, they can make their own web page.
Ranking these devices in terms of cost, from least expensive to most expensive:
In commerce there is an old saying: "You can get it fast, good, or cheap. Pick two, but you can't get all three."
In the case of MC step-up options it's, "You can get it quiet, good-sounding, or inexpensive. Pick two, but you can't get all three."
This is especially true when you consider that every dollar spent on parts by the manufacturer raises the retail price by 5 to 6 dollars. That's why you'll rarely see products on the dealer's shelf with MC transformers. Upgrading, however, helps reduce the cost because the markups are far lower. (For more about how your retail dollar gets parceled out, see "Why Upgrade" by clicking here.)
In summary, upgrading your Counterpoint phono preamp to use MC step-up transformers is the best choice when sound quality matters because