The phono pre-amp can be a bit of a mystical black box... What does it do? Why are some better than others? Why are some much more expensive than others? Hopefully, this article can help a little.
A Phono Pre Amp has two jobs:
Job One - Amplify the turntable's signal to "Line Level"
Most turntables have a tiny electrical output, which is from the stylus vibrating a little magnet or coil, and many amplifiers are not designed for such a low level signal. If you plug your turntable straight into a regular input on your amp, it will be very quiet and muffled and generally sound horrible. The pre-amp massively boosts this sound, so that it is the same volume as from a component CD player or similar device.
Job Two - Re-balance the sound from the record
In order to fit all of a song's information onto the record groove when the record is mastered the low frequencies are massively reduced and the high frequencies boosted. If you played back a record "as is" it would generally sound awfully tinny. This EQ has been standardised as the "RIAA Curve" Since the 1950's.
The phono pre-amp has to reconstruct the original sound waves from this EQ'd signal. The way this is done can vary dramatically and has an impact on the sound you hear through your speakers.
What are the differences between different models?
Key things that make a good Phono Pre-Amp
At the end of the day, for most people the only way to tell is to physically inspect the Pre-Amp and have a good listen with any cartridge you may be using.
A solid pick for most Moving Magnet Cartridges - decent enough to be an improvement from the built in Phono stages of many amplifiers.
A huge step up from the phono box e, the Phono Box DS is a far nicer design which also allows for perfect adjustment to suit whatever cartridge you throw at it. The far lower noise floor means you are hearing more of the detail and nuance of your records.
The Arcam rPhono is built to an exacting standard. The design and casework alone make this a lovely product, but when you plug it in, it really shines. Capable of getting stunning musical details from a wide range of cartridges and using a fastidiously precise RIAA curve, to improve on the rPhono, you have to be spending serious money. Incredible musical value for the dollar.
Watch Crighton unbox the rPhono on our Youtube channel.