Is there a clear definition of what "Integrated" means?

A preamplifier (passive or active) and amplifier in the same box.  All the rest are just options. 

I was always under the impression that all a unit had to have to be integrated was an input stage and an amplification (output) stage and thus would include a volume control pot.  But I could be wrong--I often am. 

Oops--I just cross posted with @soix  .  Yes, that's what I always thought.

@soix but what constitutes the "pre-amp"? Any kind of driver or input stage that increases the signal before the output amplification? And a variable resistor which modulates the grid of the input stage ie volume control pot. ?

but what constitutes the "pre-amp"? 

Who cares???  If you have an amp that has a volume control it’s an integrated amp. It matters not if the preamp section is active or passive, it’s still an integrated amp. 

but what constitutes the "pre-amp"?

my guess is the "pre"?

“A preamplifier, often abbreviated as preamp, is an electronic device that amplifies a weak electrical signal to a level that is strong enough to be processed by another device, such as a power amplifier or a recording equipment. Preamplifiers are commonly used in audio systems, home theaters, and recording studios to boost the low-level signals from various audio sources, such as microphones, turntables, and musical instruments. By amplifying these weak signals, preamplifiers help to ensure that the audio signal remains clear and free from noise and distortion as it is passed through the rest of the audio system. In addition to amplifying the audio signal, preamplifiers often include features such as equalization, tone control, and volume adjustment, which allow users to fine-tune the sound to their liking.”

Conrad Johnson calls their integrated amps Control Amps.  Basically a power amp with volume, balance , and input selector

My first Integrated Amp in a long time, the Cyrus i7XR also has a DAC .   Integrated Amps have come a long way and some are quite good.

My Dad has a McIntosh 8950 and it is a killer one box solution 

To merge both amplifier,and preamplifier.

myself being an ex Audio dealer  know brands components inside and out 

having spent years upgrading Loudspeakers , and Tech friends that do mods parts quality is far more important then a pretty case . One Huge mistakes people make is in the preamp section , a passive preamp or low quality $25 alps volume pot 

which is a Silver round can up behind the volume pot is a NOT !

it robs detail 100% find a resistive ladder to relay they are the best.

Not to confuse the issue, but for most sources (except a phono stage) a preamp is actually *decreasing* the signal to the amp. Sources like streamers, tuners, cassette decks, CD players, and DACs put out up to 2V on single ended RCA jacks, and up to 4V on XLR. These sources are always at "max" putting out from zero to the maximum voltage to the preamp. 

The preamp acts as a volume control by reducing (limiting) that signal going to the amp. i.e. The reason you need a preamplifier (stand alone or integrated) is so you don't blow the hell out of your speakers without having a volume control. 

On the other hand, a phono stage is doing considerable amplification of the weak signal coming from the cartridge. Back in the old days, separate phono stages were correctly called "phono amplifiers", not "phono preamplifiers". But that point seems to have been lost as many manufacturers call their phono stages "preamplifiers" regardless these days. 

It's an evolved meaning. Longer time ago there was just an amp whether it's preamp or poweramp.

I think the definition has been blurred by market changes- in the early '70s, an integrated amp was power amp plus mostly full featured preamp with tape loop, sometimes tone controls, and other features characteristic of preamps at the time-- possibly even a phono stage. With the rise in popularity of digital sources and a range of tube amps (I'm more familiar with those than SS) containing volume controls and often more than one input with selector, such an amp can make a separate preamp stage unnecessary. I'm not sure there is a single definition of "integrated amp" for this reason--I used to think of them as "receivers" without the tuner section. My take, fwiw. 

@whart Well this touches on why I am asking. If I look up most tube amp designs, PP, SE, and a variety of power tubes, the designs usually include the input stage: There is some twin triode doing some initial amplification usually, and discussions of coupling capacitors or transformer coupled etc. This includes guitar amps, too.

So, are these all tube integrated amps? Because nobody really calls them that, just "tube amps". But it kind of makes sense, if so.

Haven’t seen the word resistance yet. Cleaning up the signal so a constant load is presented to the power amp section - allowing it to run in optimal parameters - I thought was the point of a preamp. The input can have varying voltage and resistance, but the power amp doesn’t see any of that. 
 

This is a tricky concept since we always talk about the voltage of the source but rarely the resistance.  

I've always viewed Integrated amps as essentially the predecessors to receivers, because we used to use external tuners.  I think the inclusion of a pre-amplification stage as a qualifier is debatable as a pre-amplifier typically came just before the power amplifier and did not necessarily include more than one input channel, but in the late 70's we started to see many more pre-amplifiers that served as our connectivity as an integrated amplifier would, sans the main amplification stage.

My definition of an Integrated amp is a power amplifier that allows for switchable connectivity to more than one input.

I had no idea such a simple concept (a volume knob and input selector) could be made into something so convoluted. 

@macg19 ....Anytime there's a function added that went beyond a power+volume switch, the complexitie$ begin to toll....

"Integrated"....to self, is what I strive for when I'm or I've a bit more than average looped together.....

...and does what I want to occur without burning Something.... ;)

Integrated as the End Product. 👍

No there isn't.

It needs inputs. If there are more than one, it needs an input selector.

It needs a volume control (not necessarily a physical one, one on a wireless smartphone app is an alternative.)

It needs an amplifier with speaker terminals

All the rest: headphone amp and plug socket, DAC, digital inputs, preamplifier gain section, controls for bass, treble and balance, selectors for different speaker pairs, subwoofer outputs, phono preamp, tape input and output, streamer boards, wireless transmitters to wireslee speakers, Bluetooth are all optional.

There’s a LOT of extremely great performing 1 box solutions, aka integrated amplifiers.