[listenermark]

It lets you travel 5 years back in time so you can tell your audio-self 3 things.  What would those 3 things be?  I'll go first:

-Dual subs
-Near-field listening can be good
-Tidal's "My Daily Discovery"

[artur9]

The Cary Cinema 11 is not broken so don't go down a rabbit hole trying to find its equivalent at multiple times its price.

Save yourself some serious aggravation and just buy Linn Sneaky DS for everywhere you want music.

Measure 10x before ordering any cables.

[JLM]

Active monitors are superior to passive speakers.

The room is the second most important component in your system, after speakers.

Digital is the way to go.

[Tyson]

Buy stock in Nvidea and use the money to buy the ultimate system.

[Letitroll98]

Don't sell off all that equipment.

[mresseguie]

Buy stock in Nvidea and use the money to buy the ultimate system.

~Seven weeks ago, I must have dreamt that you would say this, so I went ahead and bought a bunch of NVDA. I look forward to tonight's quarterly report. Even more exciting has been my purchase of CRWV @ $47.74/sh. My unrealized cap gain on CRWV is 4 times greater than the gain on my NVDA shares. Exciting times....oh, my.

Three things:

Buy NVDA, and soon after its IPO, buy CRWV.
Buy that expensive piece of audio gear now because it's going to be a helluva lot more expensive in 5 years.
Don't sell that KT88 amp that you like so much.

[AllanS]

So much of what I’ve learned over the last 3 years is informed by the expensive misdirections I’ve taken but in hindsight:
- take the time to define what I wanted that my modest but good sounding then current system wasn’t delivering
- after deciding on speakers, invest time with REW to understand how the speakers interact with the room before throwing treatments at a problem I didn’t understand
- trust that my ears were telling me there was no discernible difference between the $1500 integrated I’d been enjoying and the $5K mono blocks I should have returned.

[vrao81]

- stick with headphones, don't bother with speakers.
- don't waste money on cables until the electronics/speakers/headphones are at a high level
- don't get suckered into glowing reviews or online hype.

[FullRangeMan]

- stick with headphones, don't bother with speakers.
- don't waste money on cables until the electronics/speakers/headphones are at a high level
- don't get suckered into glowing reviews or online hype.

I will second it, I was afraid to say it 
And speakers yet need a large room to sound decent, not mention a tolerant wife.

[RonN5]

For me:

1.  Stop waiting, start streaming
2.  Dual subs
3.  Little speakers can sound great in a big room

and a bonus suggestion:

4.  Room Perfect...maybe not perfect but oh so good