Hi @grannyring ,
Duelund 600volt 20 avg can be used for headphones cables. Cotton isolation is not as durable as plastic one.
I'm also thinking about to upgrade 50 cm long run of cables from RCA inputs to input selector in my 300B integrated SET. Now I use a twisted pair cable made from Neotech Wire 22awg LEGENBURG Rectangular wire.
1. I think the Duelund 16AVG will be difficult to install to input selector switch because width of this wire. (I need to solder 16 wires to this thin switch).
2. And Duelund 20AVG can be sound too lean and hollow.
3. So, I think that 600 volt version of 20AVG can sound more like Belden 8402, not as open and detailed like the cotton version of Duelund 20AVG but more balanced.
4. I also can leave Legenburg Rectangular as is. It is very good sounding wire. It has smooth, bloom and clean sound. But it is not as detailed and good in instrument separation and sound-stage like Duelund cables.
Regards,
Alex.