Hi @Hopsngrains
Welcome to the Sonos Community!
The only preamplification needed in any of the areas you describe is that applied to the signals coming from the styli of the turntables, which you already have.
In area two, the pre-amp between the turntable (or included in the turntable) and Port is taking the signal up to line-level, and the Port will just output at that same level, which is the same level the Power Amps will require as an input (I’m assuming here that the turntable’s preamp is outputting to the Port’s input, and the Port’s output is going to the Power Amp input).
In short, I see no need for you to add further preamplification stages.
If you are unhappy with the current preamplifiers either built into the turntables or fitted to their outputs, you could of course replace them (disabling in-built ones), but the outputs of the turntables are the only signals in need of preamplification. Port outputs do not need it.
In answer to your titular question, no, Port cannot be used as a pre-amplifier as it does not accept the low-level signal that needs pre-amplified.
I hope this helps.
The Port can be used as a preamp, but not as a phono preamp. For example, one could have a Port wired directly to a Power amp to play music streamed to the Port, with the volume levels controlled by the Port.
The advantage of a preamp, even if it does not have a phono socket for turntables, is that it offers more features, especially via more input jacks that the single one that the Port has.
Hi @Kumar
Maybe we’re just getting into semantics here, but is volume adjustment pre-amplification? I’d say no. The only things that need pre-amplification are microphones and turntables - any device that outputs audio made by digital circuitry does not require a pre-amp, nor does it necessarily contain or act as one.
I’ll admit, however, that the type of device that typically connects to a Power Amp is called a Preamp, but it technically only performs as one when a turntable or microphone is connected to it. Really, it’s just an input selector switch. I did not think of this distinction/convention when writing my original reply, however, so thank you for pointing it out!
So, @Hopsngrains, yes - your Port can be connected directly to a Power Amp.
Let’s be careful with our definitions. The signal from a magnetic phono cartridge is very small, too small for most inputs, and also needs special equalization. The special amplification and equalization are provided by a receiver’s special “phono” input or by an external “phono preamp” box. A separate phono preamp has no controls. Unfortunately, there is an audio component that contains a full set of input selector, Volume, and Tone controls. This is also called a “preamp” or “control preamplifier”. This sort of “preamplifier” is designed to be followed by an audio “power amplifier” often referred to as an “amplifier” or simply an “amp”. Conceptually, a SONOS AMP could follow a full preamplifier, however, there will be a war between the Volume controls.
A separate “phono preamplifier” can be connected directly to a SONOS Line-In. Volume will be controlled by the SONOS system. Line-In is available on AMP, FIVE, PORT, MOVE 2, and the ERA units (MOVE 2 and ERA require the USB Line-In accessory).
Really, it’s just an input selector switch.
Many times this is indeed the case, and even this is a useful feature in itself; the Port has just one set of input jacks. But the better pre amps also offer things like being able to set different sensitivities for their different inputs based on different signal voltages from the source, such that the sound levels from the power amp/speakers are about equal regardless of source and volume level setting on the pre amp. Some offer phono jacks that can be switched between MM and MC cartridges The other thing that an audiophile will claim is that keeping the lower level signals in a separate box - the preamp - makes for better final sound quality.
As you have also said: the Port can be used as a preamp into a power amp so long as its one input jack is enough. And if that jack was to be used for a turntable, there would have to be a phono preamp between the TT and the Port to amplify the TT signal to a level that the Port can then take over, and also do the RIAA equalisation thing. A device that is often built into starter TTs these days.
