Upgrading caps on this DAC and OTL amp worth it (pics)?

Hi,

I recently acquired a DAC and amp for Stax headphones built by a local amp/dac builder. The sound is a quantum leap over everything I have ever owned before with Stax L700 headphones :).

However, when I opened them up i noticed that the caps used are no-name and I wonder if there are sonic gains to be made by upgrading them?

The DAC uses a dual mono AKM AK4497EQ chip and Russian tubes 6Н16Б for buffer.

https://lh3.googleusercontent.com/7CPjWgkVbd2ORmDA78EkhSi-ihOC0kFNWfhYGRNUYFkq6eqtG2QwltmDpUOzuEuPaPyRuI-BqReo-XoXY5fC2QjJ-wM2AgAae9TsxtvBWU-ut09tUTMzZ6fN475WOnbZNarvUH8sObpkHnqfiiSsaZO3VNAD5Jl1wgAKkS-a5XNJx-NLmAVoP-pKzvdMhWqkNpaRr3e0LQTVI99TZ_4RC4ahnCNZS-b05V2tPeMINHs7DD9omso2IADprT4qcKoJ38ux8Uj01yBLVYJ3RCcx5YeIYnm-rTyCFWev2TzM55ySIhC5xVJliWI04GWP3H3Ua-guUmFe34WixnPy3vZmEIKTGP2PeoCbY8bA3-WdZX341FWZRHq3FlMpfkQ2dfd1vd4gOVtQV0qX7VR-IWs-hmBEF2AYMbE69OhegON5OeJNNT_B61zscVucR4QrfbEg-isDQ8HFmpZojVT86eijcEhMboQYG85v5r0xnPr3lXIagHgxPKtPQjR9BKOH3tpahVmisntrRBDoF5oLN6GLtWUGm5QmOuUbCcU3OgsIlOBp6bEuXE8psW_LOjBRQ-_a4KRTc7eEqKbh2dadjKhoUm-PZ7dt8OFMB6Mz3oCoVKHqeS873KyEPpW3pPO-sbrIX7yZUxHQpnxY_xBn9rlNSMRHJKp_idGh=w1252-h939-no

Here is the output stage

https://lh3.googleusercontent.com/YBIZvXtEFcX8KQfGdXNcaBmWytTySYmltK6Kj-2YgQcjRvf0mWHgLYYu0CExp5885U...

The amp is a OTL with 6Н17Б and 6S4A tubes.

https://lh3.googleusercontent.com/ALvttCbWKv5Z34F7OSjP2gAT4qdIxpr-vJzlJNqfjJ5w5crJ2j2Tlg7MTTZCiKUcBN...

These seem to be the interstage coupling caps

https://lh3.googleusercontent.com/nOo8rMZkyQQSgFyDleUeqJSamdTRN6YnP_FCrvJbBTavQjMVXWgXEhp9cIN9mmOZHL...

And these the final coupling caps

https://lh3.googleusercontent.com/ceXc6aSv9oNr_5DrMtkkGotaJ4X6vbFYyb-etHinnsPrskaPJxigmpHDLR3Fzr2Hfz...

Any recommendations, where to start? :)