[JLM]

Start by educating your sense of hearing.  Music appreciation classes are a good place to begin.  Listen to unamplified music in places with good acoustics.  Get your hearing checked.  No point in spending gobs of money if you can't hear.

Set a budget.  Good systems that serve medium sized rooms can be had for $1000 retail, but won't go super loud or deep.  Avoid DIY that leads to proud papa bias which all audiophiles are guilty of anyway. 

Setup your listening space.  As I mentioned above the room shouldn't be squarish, small, or uninsulated.  Ideally it will be dedicated to listening.  My room is 8ft x 13ft x 21ft and well insulated.  It has a fiberglass exterior door with weather seal and flexible ductwork (can't hear the furnace).  It is treated with ten GIK 244 2ft x 4ft absorption panels plus three side wall tall bookcases (diffusors) that I can vary the "design" to suit.

Spend considerable time auditioning (months/years).  In many cases this would involve traveling, make a vacation out of it.  Bring 10 or more varied selections of what you love, including an audiophile guilty pleasure (poor recording) as the system needs to serve your desires.  Take written notes.  Only audition in a space that's similar to your room, not an open/noisy space.  Audition complete systems.  Insist on in-home trials. 

[JohnR]

It would probably be helpful to begin by defining what a purist audio system is.

I can think of two definitions which lead to completely opposite approaches:
1. Focus on the hardware. This is FRM's approach. No crossover, simple circuits (except for the later comment about Class D, which surprised me), no boxes.
2. Focus on the result. This means measurements and (in my opinion and experience) active+DSP. But it's a longer road. Still, if I were starting again, that's where I'd start.

[FullRangeMan]

The summer is too hot for a tube amp, I forgot to consider that.

[artur9]

Start by educating your sense of hearing.  ... Listen to unamplified music in places with good acoustics. ...

This, a thousand times this.  Otherwise, it's akin to making a space travel movie in the forties, when no one knew what the Earth looked like from orbit. 
https://www.thespacereview.com/article/3470/1

HST, electronica runs afoul of the "unamplified music" touchstone.

[MC275V]

As a longtime audiophile and music enthusiast, I feel that a “purist” system can be quite different for each person.  I also believe that your audio listening preferences can and will change over time.  If you listen to your system (or systems) often and enjoy it, you shouldn’t worry about it being purist.  I started my audio journey in the late 1960s with a Fisher tube receiver, ElectroVoice speakers and a Garrard record changer (which I only used manually for 33s).  By the mid 1970s I had moved to a solid state Sherwood receiver, Technics direct drive turntable and Sansui speakers.  By the early 1980s I had moved to Stereophile approved equipment, including HarmanKardon Citation power and preamp, Rega turntable, and Fried speakers.  By the 1990s I had B&K power amp, Musical Design tube preamp and Energy Pro22 Connoisseur speakers.  Today it’s McIntosh 275 amp, McIntosh C2200 pre, Clearaudio table, Harbeth speakers etc.  I’ve enjoyed each system throughout the years.  It’s been a fun experience for the last 50 plus years and I still listen every day. So, how to start a purist audio system; listen to live music, listen to as much equipment as you can, then purchase what you enjoy can afford.

[sircrashalot]

Hi to all,

I'm new to this forum and chose this circle to introduce myself because I'm always looking to improve my system's sound. I have been in the audio hobby for about one year, and as you might guess, already have a small collection of integrated amps, receivers, and of course, assorted speakers... most are second-hand and picked up locally. Every time I think I have an excellent sounding system, I find something that increases the SQ, although usually in small increments. Sometimes there are trade-offs: sometimes more clarity and detail at the cost of a little perceived bottom end, for example. I hope to learn more from you all. Thanks.

[AllanS]

Every time I think I have an excellent sounding system, I find something that increases the SQ, although usually in small increments.

This could get to be an expensive hobby for you.  Welcome aboard!

[Jon L]

Sometimes there are trade-offs: sometimes more clarity and detail at the cost of a little perceived bottom end, for example. I hope to learn more from you all. Thanks.

Careful shopping locally is a great way to build a nice system without spending audiofool money (and STILL not happy ). 
If I were starting out today, I would go modular and separate bass from treble/mid.  For example, start with bass module using a vintage Alnico 12"/15" bass/mid driver with separate enclosure for treble/mid.  Reasonable Altec/JBL, etc horns with good compression drivers..

[JimBobWay44]

This is a very true statement; I have found my best bargains for some excellent gear on Facebook Marketplace and Craigslist.  But buyer beware, be sure to audition the equipment in person before plunking down a dime.

[marcos overload brazil]

good tips

[I.Greyhound Fan]

I would start by going to stores and audio friends if you have them and listen to as much gear as possible.  Write down or make a mental note of what you like and do not like.  Bring along music when you go listen.  Also consider your tastes in general tone like neutral, slight warmth of even slight brightness.  Pick out speakers first and then match electronics.  Also, as others said, consider the room and where the speakers are going to go.  This is probably the most important thing.

I would also see if there are any local audio societies or clubs that have meetings as many audition gear at the meetings, plus you may meet some nice audio people and be invited to listen to their gear.  See if there are any local audio people on audio forums like this one.  There are several forums as you may know.

Then keep things as simple as possible.  I am not a fan of using separate amps to drive woofers and tweeters.  I do like separate components but I will eventually be selling my amp and preamp and move to a high end integrated for simplicity.  Something like an Ayon tube integrated.

[danvillesignal]

Welcome to the journey! There is no one path - you will need to find your own.

In addition to some of the previous tips, I would try to attend one of the high end regional shows. You will see a lot of gear, meet a lot of like minded folks, and probably have a great time.
The Tampa show is coming up very soon and Axpona (near Chicago) is in April.
In the EU, there is the Munich high end show in May.

As a manufacturer of gear, I am going to avoid the info commercial, but I do hope to see you and other newcomers at Axpona. The circles on the site are great examples of things you might see at the aforementioned shows and certainly not the typical Best Buy stuff.

Al Clark
Danville Signal