Why Do I Need A Phono Preamp?

Why Do I Need A Phono Preamp?

Phono stage preamplifiers are standalone analog devices which boost the electromagnetic signals received by the record player’s cartridge to a line level output signal, as necessary for reaching a power amplifier’s input stage.

Phono stage preamps require their circuitry to be highly versatile, as they are often tasked with amplifying ultra-low signal levels delivered by cartridges of different design type (MM/MC, which we’ll explain below). These cartridges in turn deliver vastly varying signal gain and impedance results.

High-end phono stage units offer extensive control over parameters such as capacitance, impedance and gain, which can prove especially beneficial in setups dealing with large music catalogs covering different eras, vinyl specifications and requiring different cartridges. The more control you have, the better things will sound!

It is important to remember not to connect the output of a turntable with a built-in phono preamp (i.e. newer generation record players featuring line outs) to the input of an external phono stage. Similarly the output of a phono stage preamp is raised to a line level, so when connecting it to the next device in your system chain (i.e. A/V receiver, hi-fi preamp or amplification) the type of input it’s connected to must be line level as well - normally labelled either as Aux or Line In just don’t connect it to the Phono In of your A/V receiver!

Once a vinyl ‘rig’ is fine-tuned, simply no CD or any other digital media playback can even come close, on account of audio depth, width, warmth, punch, transient detail and just the sheer musicality emanating from vinyl records. Vinyl enthusiasts trying to improve their audio first reach out for a real good cartridge - the easiest ‘mod’ which delivers an immediate and often tremendous difference in sound quality. Getting the silent-as-a-whisper signal of the cartridge optimised to a healthy level needed by an amp’s input stage is one of the biggest challenges for achieving that coveted sublime vinyl playback. and this is why you need a great phono stage.

As with any A/V related technology, there’s always something else out there that does it better. It is a fact that your regular A/V receiver or hifi preamp probably has a phono input, which means that there is an integrated phono stage present already. It is super rare that these are any good though - they surely will do the job in most cases, but they will sound generic.

This of course won’t be evident until you’ve compared them to something really good. The SPL Phonos ProFi MM/MC, for example, will sound leagues away from a stock phono input. As explained already, in the instances of putting together a proper vinyl setup, getting a dedicated phono stage with control over the cartridge signal impedance, capacitance and gain is as vital to record playback quality as the choice of your cartridge.

To deal with the challenge of boosting ultra-low signals, phono preamps often feature advanced features, such as isolated dual-mono inputs (meaning each side of the stereo feed has its own dedicated discreet circuit), input stages with variable impedance and capacitance (via pots or switches), balanced connections and even switchable passive EQ modes (explained below).

Many high-end models feature truly esoteric circuit components (precision film capacitors and resistors, and low-noise Class A gain stages)  which translate into staggeringly high price-tags, but the sonic results can be often astonishing - with super-low noise/distortion floor, increased resolution and transient response with super natural, life-like portrayal of any frequency spectrum.

Read the full article written by TheMasterSwitch.com