Woo Audio WA234-MONO Headphone/Integrated Amplifier 6.35mm female and the snug fit helps

and the snug fit helps isolate outside noise for uninterrupted listening

and updates:

The 4-pin XLR plug allows fully balanced driver experience

They have earned the trust and respect of music producers

5-mm straight plug

Woo Audio WA234-MONO Headphone/Integrated Amplifier 6.35mm female and the snug fit helpsOverview The WA234 Mono is the ultimate SET (single ended triode) amplifier. The design is unlike any that the world has ever seen. The WA 234 unique design allows for us of legendary tubes like the 300B, 2A3 and 45 triodes. The choice of tubes offers the highest level of transparency and musicality. The WA234 Mono let you experience music like never before. You can now use any headphone and many high efficiency speakers. Whereas a typical tube