What should i upgrade next?

Hi

My current system is: PC (PlayPCMWin or MusicBee)-->Khadas Tone Board--->Decware Taboo MKIII (Reflektor '75 SWGP 6922 input tube, 2x Tungsram EL84, Svetlana 5u4g blackplates rectifier)--->Fostex THX00 Purple Hearts.

I have a $900 budget and i would like to upgrade my system, but i am not sure which direction might be the best.

I do like how my current system sounds, although the bass could be tighter.

I would like to keep my amplifier so either upgrade the headphones or the DAC. Would a Topping D90 or a Bitfrost 2 be a good upgrade?

I am concerned that the Bitfrost 2 would be a bad match for my headphones and amplifier consider the system has already a warm and smooth tone and i wouldn't want to make it warmer. On the other hand i don't want to make the highs any brighter or sharper. The fostex make the highs already a bit sharp.

It would be nice to bring some clarity into the system tho.

For headphones i considered the Fostex TH900. TH909 or ZMF Auteur.

Do you have some suggestions?

cheers

 

Sorry i didn't see that there is a thread dedicated to ask for advice....i ask the mods to delete this

 

I feel like you are looking at it the wrong way.

I dont say, I have this much money, what should I upgrade.
I say, I want to upgrade this, how much money do I need to do it.

 

I've never had such directionless desire to upgrade my headphones or system before, I've always wanted something in particular, known where a weakness was, etc. I've always wanted to get something new/better because I wanted something in particular or was bothered by something, usually the latter. Just wanting to upgrade in general feels like consumerism. I guess I agree with @spwath