Total newbie question here about completing a system

I would skip the equalizer.  At some point, he may want to do that in the digital arena, but first explore room treatments.

What model Yamaha?  Lots of $$ can be spent on analog turntables, etc. which can produce xlnt digital sound instead, so be sure he is into the 'process' of buying vinyl, protecting it, and pulling each one out for a play.

A sand box is a great way to provide acoustic isolation for a turntable (and they all need that) - tho putting it in a room (closet?) sealed off from the listening room is even better...

The LS-2 pre- is the real high end item in the list...

he will need a phono stage to boost and correct the frequency response of the TT before the signal goes to the LS2 line stage. Phono cartridges do not output a strong enough signal to drive the line stage properly and there are also physical challenges inherent in record-making that required the audio signal to be modified before being transferred to vinyl. Those modifications have to be compensated for. Both of those things occur in a phono stage. Some pre-amps have a built-in phono stage, many modern ones do not. Those that do not are often called line stage pre-amps.  Those that do are often called full-function pre-amps.  The LS-2 is a Line Stage pre-amp.  Signals from a CD or SACD or the analog signalk from a computer source can go directly to any input on a line stage.  The signal from a TT needs to go to a phono stage first,  If you want to learn the technical details, google RIAA equalization or phono stage equalization.

Newkphoto ,  Skip the EQ great idea!

 " analog signal from a computer source "....  huh???

You would need to take the signal from the computer using a OPTICAL/TOSLINK  cable connected to a DAC which will have a set of analogue outputs that go to the line stage pre-amp.

Matt M

There are two ways to get a digital signal to your amplifier. The first is to use a computer. Computers have inbuilt Digital to Analogue Converters (DAC) but these are rarely any good. So you need to use their digital output, and that is almost always usb (and not optical or coaxial). Next you need an external DAC (or an amplifier with an inbuilt DAC, as more and more now do). Such external usb DACs exist at many price levels, from the pretty good and dirt cheap Behringer UCA 202 (still a lot better than the DAC in almost any computer), to the very good and very affordable ODAC, to the ultimate in a DAC like the Benchmark DAC3. The ODAC is good enough for an ambitious system.
Another way (instead of using a computer) to get digital input is to use an external streamer like the Apple Airport Express, the Sonus Connect or the Google Chromecast Audio. These all have inbuilt DACs. Even the cheapest of these, the Chromecast Audio has a pretty good inbuilt DAC: http://archimago.blogspot.nl/2016/02/measurements-google-chromecast-audio.html I use it into a pretty revealing system with Quad electrostatic speakers, and the sound quality is fine, as was to be expected from the excellent measurements. So why not start with the analogue output of the Chromecast, and see if you think it is good enough? However, if you want something better, these streamers all have optical digital outputs that can be used with a better external DAC. Since such a streamer is not necessarily the only digital source (think also of an (UHD Bluray) disc player or a television) it is worth using a DAC with multiple inputs and variable output such as the Pioneer U-05, the rather more expensive Benchmark DAC3 or, alternatively, a modern disc player like the Oppo UD 205 with its additional optical input for a streamer like the Chromecast Audio. But all these options are rather more expensive (and double up with the existing pre amp).
If you are considering using the analogue output of the Chromecast Audio (as I would, at least initially - it is just some $35), realize that there is a setting that you have to decide on: high dynamic range, or not. Google says HDR is for ambitious gear, and ordinary is for basic gear such as table radios, but this is misleading. In reality the difference is not in the dynamic range, but in the output level. HDR is at the standard 2.0 Volt that is also used by CD players, and the ordinary setting is simply a lower voltage. If your amplifier's input sensitivity is on the high side (as is often the case) using the lower output level is actually beneficial (HDR would clip/distort the input).

+1 swampwalker regarding need for a phonostage. 

If using a computer for streaming you will want to purchase a  digital to analog converter (DAC). Another option is the Bluesound Node 2, which will serve to replace computer and DAC, or the Bluesound Vault 2 which adds CDs ripping capabilities. 

Do some research on phonostages (ohono preamplifiers), DACs, and music streamers. 

 " analog signal from a computer source ".... huh???

Was trying to keep it simple,,,many computers will output an analog signal using internal digital to analog converter (DAC). 

You definitely need a phono amp to use the turntable. Just to get him up and running, you don’t have to spend much, but if you’re looking for the best possible sound quality, you should find out the model of turntable and the cartridge/needle (if it’s functional) and ask for more feedback with a post on the analog page. Include in your question a budget range and you’ll probably get several great suggestions that fit your needs. You’ll get suggestions here but more people with that expertise will see it if you post in that section too.

If the current turntable doesn’t have a working cartridge, the same can be said for that component as the phono amp.

Since digital is likely to be his most used source, a DAC or streaming device with built-in DAC would also be a good investment. A chromecast audio gets him playing cheaply and easily, but there are better sounding options if you/he wants to spend more. Bluetooth receivers are an option but usually have worse sound quality than things that utilize your wireless network.

Lastly, you need cables to connect everything. You might have these already and just not bothered mentioning them. Interconnects from turntable to phono amp, phono amp to preamp, each other source to the preamp, a set from the preamp to the power amp, and speaker cables between the amp and speakers. Just starting out, there’s no need to go crazy here, but don’t forget about them when picking other items or you’ll end up over budget...even budget friendly options add up when buying several sets. Monoprice has good quality, inexpensive cables if you need them. Used cables are also a great option.

I agree with skipping the equalizer...especially for now.

Do you have a budget in mind for the full system?

Much thanks for all...this has given me a good next step in my understanding. I'll circle back with more info on the TT, but in the meantime I'm intrigued by Willemj's suggestion of "the very good and very affordable ODAC"... I'm a little unclear about the model.. Is this it? https://www.amazon.com/FiiO-E10K-Headphone-Amplifier-Black/dp/B00LP3AMC2/ref=sr_1_1?ie=UTF8&qid=1514410871&sr=8-1&keywords=ODAC
And can I assume you simply connect this to a USB port on your computer, then attach cables from line out on this unit to line in on the preamp?

https://www.amazon.com/JDSLABS-ODAC-Digital-Analog-Converter/dp/B00EJ9N8U2/ref=cm_cr_arp_d_product_top?ie=UTF8

The one you linked to looks fine to start with. You'll need a 2.5mm to RCA cable to connect these DACs to the LS2.

The one the OP linked to is not the ODAC but a FIIO. The ODAC is a now legendary design by an anonymous experienced engineer called NWavguy (you can google him and his description of the design process, plus measurement data) who was fed up by expensive snake oil products and designed an affordable usb dac that really is about as good as the best. It is available from different sources and with different cases.See e.g. here: https://www.jdslabs.com/products/46/standalone-odac-rev-b/
The one I bought is from Mayflower and sells for $119: https://mayflowerelectronics.com/odac-rev-b-stand-alone/
It is a basic usb DAC: you connect it to the usb port of the computer, and you connect the output to the line input of the amplifier. You normally do not need any specific drivers on the computer. Output is 2.0 Volt, just like a standard CD player. It takes its electrical power from the usb port, so no further cables are required. And it is a tiny and discreet box, smaller than a cigarette case.

thanks for this...we'll pick up the ODAC as a start.

The turntable/cartridge combo is from an old kit and is nothing special -- Yamaha Stereo Turntable TT-300U3, cardridge -- Audio Tecnica VS245LP

Would love recommendations on a phono amp.

As for cables, can I assume the normal Monoprice cables are good enough?

A Pro-Ject Phono Box would be a good place to start: ($100)
https://www.amazon.com/Pro-Ject-Audio-Phono-preamp-output/dp/B007DB5I60/ref=sr_1_8?ie=UTF8&qid=1...

...or I have a friend with a cambridge cp-1 he's been happy with as a budget phono amp: ($150)
https://www.cambridgeaudio.com/usa/en/products/hifi/phono-stages/cp1

...or if you or he likes puns, people tend to love Schiit Audio equipment and they make a phono preamp. I haven't heard it myself, but their stuff is usually very good for the money and includes decent warranty and return policies: ($130)
https://www.amazon.com/Pro-Ject-Audio-Phono-preamp-output/dp/B007DB5I60/ref=sr_1_8?ie=UTF8&qid=1...


Cables are a huge debate on these forums, but I'm of the opinion that so long as your cables aren't broken or damaged, they're almost never the weakest link in the chain. I'd get these interconnects:
https://www.monoprice.com/product?p_id=5346
and I'd spring for speaker wire with banana plugs already attached just to make your life easier. Something like these:
https://www.monoprice.com/product?p_id=13913

Best of luck and enjoy the music!