Switchable versus always-on: why it is the whole decision
Every deck above has a small switch on the back marked something like PHONO / LINE. In the LINE position the internal preamp is doing the RIAA correction and the amplification. In the PHONO position the signal leaves the deck raw, exactly as the cartridge produced it, and something downstream has to handle it.
That switch is worth more than any spec on the box, for three reasons:
- It future-proofs the deck.The preamp is the single cheapest component to upgrade in a vinyl system — a $100 external stage beats what fits inside a plinth for free. A switchable deck lets you make that upgrade without replacing the turntable.
- It stops the double-preamp mistake.Plug a LINE-mode deck into a receiver’s PHONO input and the signal is amplified and RIAA-corrected twice. It sounds distorted, bass-heavy and wrong, and the usual conclusion is that the turntable is broken. It is not.
- It shortens the signal path when you want it short. With the internal stage bypassed, the cartridge feeds one preamp instead of passing through a spare one.
An always-on preamp is not automatically disqualifying — the all-in-ones in our all-in-one roundup all have one, and it never matters there because nothing downstream expects a phono signal. It matters the moment you own separates.
What a built-in preamp lets you plug into
This is the practical reason people search for one. With the internal stage switched on, a turntable will drive:
- Powered speakers— the Edifier and Fluance pairs in our powered speaker roundup take a line input and nothing else, so a built-in preamp is what makes that pairing work at all.
- Any AUX, CD, TAPE or TUNER input on an amplifier or receiver, including modern ones that dropped the phono socket.
- A Bluetooth transmitter or a soundbar with a 3.5 mm input, via an RCA-to-3.5 mm cable.
- A computer interface for digitizing — see how to record vinyl to a computer.
What it does notdo is drive headphones or passive speakers. Both need power amplification, which is a separate stage again — see do you need an amp.
How to check the deck you already own
Three checks, in order, and they take under a minute:
- Look at the back panel. A PHONO/LINE switch beside the RCA outputs means yes, and it is switchable. This is the common case on anything from Audio-Technica, Fluance, Sony or Denon in the last decade.
- Look for a 3.5 mm output or a captive cable ending in a headphone plug.That is nearly always an always-on internal preamp — the connector implies a line-level signal.
- Plug it into an AUX input and press play. If it is loud enough to be normal, there is a preamp in circuit. If it is faint and tinny at full volume, there is not.
The full version of that test, with the failure modes, is in what is a built-in phono preamp.
When to buy a deck without one instead
Two situations. First, if your amplifier already has a PHONO input — then the internal stage is redundant and you are better off spending the money on the platter and arm, which is what the decks over $500 do. Second, if you already own or intend to buy a standalone preamp, in which case a preamp-free deck like the Fluance RT82 puts every dollar into mechanics.
For everyone else — and that is most first-time buyers — a switchable built-in stage costs almost nothing, works today, and gets out of the way later. It is the right default.
