Cheap Balanced great sounding headphone amp

Available from Apos Audio and Penon, the MT-604 has it all if you are a balanced audiophile. It only has two three pronged XLR inputs and one 4.4 all balanced. It has one 4.4 and one 4 pronged XLR balanced outputs. The amp is class A SS and the preamp is all tube using( 4 ) 5654 tubes. $169.00 and is very dynamic and only a tiny touch warm sounding. In fact it well take you a while to realize that there is some Warmth. Tubes go for around $24 per matched, tested and balanced pair. I did not use the fancy tubes, just 1952 JHS Sylvania from random Ebay vendors.
Amp has plenty of power and slam for my HD 600s and Utopias.

 

The original Chinese tubes are crap. I first tried 1952 and 53 Sylvania JHS 6AK5s and they were a good improvement. I next installed WE 403Bs and am going to leave the amp on for a week to burn in.

 

This doesn't burn the amp in FWIW. You need to be playing music through it with a load attached. ie with a headphone plugged into it, playing music through the headphone.

 

Using 20 plus hour play lists I created on Tidal. That Tara Labs break in file worked good breaking in my M9 and VE EXT.