Welcome,
@bananacat67
I have been using my JT7 with Fosi SK02 connected to Wiim Mini via optical. There seems to be plenty of headroom with only Low Gain engaged on the Fosi using either the balanced or unbalanced cables included with the JT7 (I'm not sure I could pick the difference via blind testing, but of course the balanced cable feels more 'spacious'... ):
This is a review, listening tests, and detailed measurements of Fosi Audio SK02 USB powered DAC and balanced headphone amplifier. It was sent to me by the company and costs US $99.99 (€99.00). The SK02 is excellently designed. Having it horizontal gives comfortable access to the rotary volume...
www.audiosciencereview.com
Listed price is US$100, but I picked mine up for much cheaper via a voucher on Fosi's ebay store.