I stumble down a fcking rabbit hole right now. And if it were the 2010s I just wouldn't have to, and it sucks.
It started innocent. Bought a cable for my headphone, one I could just yank into my computer. Thought I might go for a usb-c cable with integrated converter dac and amp. Because I wouldn't need that much output. How hard could it be?
Got that, it sounded like shit, no problem I sent it back.
So I ordered some of one of those usb-c to 3,5mm jack dongles with a little case and a piggie tail. Those have 2 to 3 chips in there and enough space to get a decent implementation in there. How hard could it be, my Nokia 5800 sounded terriffic, right?
Long story short: Most had the same problem (absolutely no dynamics, like it was compressed, no bass, and they were nasty... you know, that 5k nasty cheap condensers have).

Oh, I forgot, disclaimer: We are talking driving a 32ohm headphone. Something a handcrank should handle.

I remembered I had one of those dongles somewhere, one I liked. Went digging. Found it in an drawer.
Surprisingly: That one DOES sound decent. None of the problems the modern ones have. Bought it about 8 years ago, and no, that one is not available any more. The chipset is EOL (some Realtek stuff).

Then I paniked a little. I don't use headphones that often. When I do its on a Yamaha Amp from 2007 or a store brand headphone amp from 2017. So.. is it possible any off the shelf solutions a manufacturer can choose today are bad sounding dac/preamp sets that are optimized for using as little power as possible while compromising quality?
I started checken my outboard interfaces. The most modern ones were a steinberg (yamaha) usb-c interface with 2 mic inputs and a Presonus one, that 'go' thingie. Yes, these sound like shit to over headphone.
Checked back with a fcking behringer u-phoria 204 from 10 years ago (60 bucks and still available): That one sounds terriffc!

After opening everything and spotting the chipsets I found something interesting:
The ones I like most (the behringer thingy for 60 bucks and the store brand headphone preamp) amplify oldschool. The Behringer seems to use some opamp and the store brand cranks old school to 11: it's got four of those 3 legged descrete transistors we had in our walkmen.

But there were decent digital amps as well. Like the usb-c dongle form 8 years ago or the pioneer amp my girlfriend uses. But these are from 2010 to ?? (lockdown?). And Stuff since covid seems to be trash.
Sure there might be good but expensive solutions (I guess?), it's just like: I am happy with 4 transistors that are worth cents. Do I really have to buy something for several hundreds of bucks to get measly 10 to 20000hz up to some hundreds milliwatts?
What am I gonna do when the tech I use now dies?
Soldering opamps to a brassboard?

 

Soldering is indeed the answer you are looking for. If you have any experience with soldering, I would find a DIY kit. I can't recommend any, but I know that I have seen them for sale over the years. You could also even likely design your own with the help of AI. Either using protoboard, or getting a small run of pcb's made.

What i would do, is find a DIY kit thats not too expensive and has good reviews. Then chat with AI and give it the specs of your kit, and see if there are any components you can swap out or add to make the kit even better. Either higher quality components (that are available for purchase on mouser etc, not some unicorn fairy dust component thats impossible to find), or different value components depending on your needs.

This sort of thing is extremely rewarding. Not only do you save money, but you get a great piece of gear, customized to your needs, that you built. Its a fun project, and gives you a one-of-a-kind piece of gear.