I have a pen-pal friend on SlimDevices forum that upgraded Transporter op-amps to these

http://bursonaudio.com/burson_opamp.htm

he tried few, he told me, but these gave more transparency in highs and more warmth in mid

Transporter analog stage is more or less as pictured on page 35
http://www.asahi-kasei.co.jp/akm/en/pro ... 6_f00e.pdf

Also, same guy advised me to use XLR-RCA adapter, so can hookup the signal directly after first op-amp and by-pass 2nd stage and attenuation mechanisms

What do you think?

נשמע הגיוני, אבל זה לא זול...

Burson costs around 100-150 euro per pair
plus
your work :-)

??