Trying to add Topping LA90D amp to Topping A9D preamp

As subject, what do y'all carry your gear in for out-and-about/day-to-day and then for travel, if anything other than pockets?

I currently have the the HD 6XX, which sound great but, I'm am looking to upgrade the power of the bass as i really enjoy punchy low end EDM music. Any suggestions in the $200-$300 price range would be awesome.

Any help would be appreciated...I added an amp to my streamer, dac, headphone amp/preamp system and am now not getting any music through the headphone jacks on the preamp - the specifics: Wiim Pro Plus - optical connection to - Topping D50 iii dac - TSR to XLR connection to - Topping A9D headphone amp/preamp (all worked fine as a headphone amp until I tried adding:) - XLR connection to - Topping LA90 D amp. Amp switches are set to bypass, stereo, low gain. In this configuration, I am not getting any music to either my SE or XLR headphone jacks. I made sure I switched the A9D to "preamp" and "xlr" modes. I have no idea what I might be overlooking or missing...any thoughts would be deeply appreciated! Thank you.

I currently am rocking the beyerdynamic DT 990 Pros and have been for a while now, along with a go xlr! I was trying to see what other headset you guys recommend along with something to replace the xlr? Thank you!

I just got my pc38x in the mail today and the out put is quiet but fine and I'm happy. But the mic will not work when on my Xbox series and I was wondering if this issue can be resolved or if the head set is not compatible with Xbox.

Any good long lasting ones? I have a massdrop Stride, but i want wired earbuds that can be charged with usb-c