Why are there so many source inputs on pre/integrated amps?
I use only one input on my SN2 and you might argue that only having one might be a bit restrictive but does anyone really need 6 input source selections? I guess over 90% of customers would be happy with one and 99.9% with two. How many really need 6?
Well there had to be one didn’t there? 
Flexibility, you can always not use them but it’s hard to add inputs if there’s not enough. The first amp I bought only had 3 plus a phono section, I ended up making a switch box to add 3 more, OK with an entry level amp but not so good when you want a bit more quality. I could get away with 3 inputs these days as I feed in a couple of signals to my streamer in digital form but having a few in reserve does very little harm. Now if you want to talk superfluous there’s the screen on the streamers, only needed to in order to turn it off.
Actually no… I use the screen all the time. Non-smartphone user here! 
On the Meridian 5.1 Surround:
On the Briks system:
On the Dining Room system:
Need I go on?
Okay… when I said 99.9% happy with two inputs I was obviously wrong. 'nuff said. I’ll shut up now.
ROFL!
But seriously though, all of our systems are from before the “digital download/streaming” era (the Sondek is 35 years old FFS!).
However whatever one’s position or personal preference/likes/dislikes are, the world is going digital fast, content will be delivered over broadband and ultimately that will reduce the need for having more that a couple of inputs.
Neither of our millennial daughters have got Hifi systems “as we know them”, but that’s not to say that they don’t have music. Their “systems” comprise a PC, iThingy and wireless headphones. It also means they don’t need as much storage space as their ageing parents with their 40 years worth of LPs (700), DVDs (1300) and CDs(2400).
TT,
CDP.
Tuner,
DVD.
Why are there so many source inputs on pre/integrated amps?
It very much depends on what you have upstream of the amplifier. If you have something like a Naim DAC with its many inputs, you will probably connect the digital outputs of disk players, TVs, etc. to the DAC. In this case you will use only one or perhaps two of the analogue inputs of the amplifier. If you do not have a dac with multiple inputs, however, things are quite different and you will be glad that your amplifier has more than just two or three inputs.
Once the R&D into the signal path and rekay for 2 inputs has been costed, adding more makes very little impact to the production cost of an amp.
Whether Naim amps had 2 inputs or the current 6, the cost to produce would hardly change. In fact, it could just cause a headache if you cost was relatively unchanged but the percieved value decreased. People expect a preamp with fewer inputs to cost less. When it doesn’t, they start whining about being ripped off.
Simpler to leave it at 6.
To my mind, a streamer is already a multiple input source, having inputs for multiple local and web based streams, iRadio, SPDIF etc. I don’t need more than that, and I think there will be an increasing number of people who find that a preamp with multiple analogue inputs has a great deal of wasted functionality. Others, of course, will want those functions, we are all different. I do wonder if Naim could produce a top flight stripped down pre to cater for this simpler requirement, as well as the full size boxes they now sell.
I’m not so sure. With just one or two inputs, it could probably fit comfortably into a half width box, and the cases themselves are expensive. The labour costs are a big part of the cost, and assembling and wiring up all those inputs and outputs will not be cheap.
There is another one like you…me with a
252 with just a streamer. In the future perhaps we could have options for say 1,2…6 inputs if it’s much cheaper. The conundrum is the resale would be much more limited for a 1 input preamp.
Lord knows how many there are on the 272, I use one, for the MD player. The rest can be disabled in the app so that only the sources that are used show in the list - NAS, Tidal, Bluetooth etc.
EDit: to my list in post #2
So there you go, all 6 inputs on my 82 are in use!
Yes because making 3 types of case and pcb for one model would’t cost a fortune at all
Worth noting that using just 1 source is not a new phenomenon. Even 30 years ago it was common for customers to only use CD or Vinyl. I don’t get any sense that this has dramatically changed in that time. In fact, people use more now, they just happen to be digital quite often and all hub through the streamer/DAC.
Although I just use one input, it doesn’t keep me up at night now, just as it didn’t keep me up at night in 1993 when I also had just 1 source.
Dropping them to less than 4 risks alienating a large chunk of the customer base.
I think that it’s not so much the number of inputs, but how they are displayed. I’d be keen on a modern integrated amp styled like the Nova to go with the NDX2. Select inputs through a simple screen or the app.
On my 552 (or could be on SN2):