WooAudio WA5-LE Class A Desktop Headphone Tube Amplifier / Without Speakers

I've never heard anything close to the amp's visceral punch...Once you experience what an uber headphone amp can do there's no going back. - Steve Guttenberg at Home Entertainment

I am completely blown away by the naturalness of the music, the realness of the sound. I listen to a lot of classical and jazz, especially small classical ensembles, piano, violin, cello, that type of music, and it is simply put, a fantastic sound coming from the W5. My K1000 have never sounded this smooth and enjoyable, with NO ear fatigue, no etched treble, and plenty of good clean bass. Not only do the K1000 sound great, but so do speakers on the W5! - by stax-i-nox at head-fi.org

The bass has more detail, impact, depth than I originally thought. During even complex jazz riffs the notes have a very distinct leading edge, sustain and decay.

Male and female vocals are presented with warmth and wonderful tone, Seal comes to mind with a lot of texture and impact.

The high end has an interesting dual effect going on. Sharp focus and detailed, but at the same time have a wonderful since of air about it. At first this seems like it isn't right... I guess the better thing to say is that each instrument (or notes) have a distinct location in a 3D soundstage, but within in that space the instrument (notes) have room to breath. So it is not edgy, just that balance of detail, and warmth.

All of this provides a quality that allows me to listen at lower levels, because the control, detail, and depth are higher.

I had never heard a SET amp before, but had read a lot about that SET magic and had an idea of what to expect- smooth fluid mid-range, a lot of low level detail, huge and detailed soundstage, and weak in the bass. To my delight I found the WA5 had all of these traits.

The amp sounded very good at the start, but has aged well. As parts and tubes have burned in the amp has changed a great deal. I've never heard these headphones sound better! This amp has so much ease and " you are there" factor.

What I can say is the 274B has a very different character from the GZ34 metal base. It is far from subtle. First there is more bass - both in terms of quantity and depth. Second, the overall sound is richer, or I should say, denser across spectrum. Some people may call it "sweet" but not syrupy. Third, the far end treble is not as detailed as the GZ34 and tends to roll off earlier. Overall, it is a very different presentation from the Metal Base GZ34. - fkclo at head-fi.org