I’ve always been curious about Rudi’s amps as there is a small but devoted fan base for his products. Build wise, I’ve also appreciated his sense of sleek industrial styling. But there just isn't really any opportunity to hear one here in the States. I also came very close to buying an NKK-02 at the introductory price a few months ago. The NKK-02 is a handsome little amp, with it’s ¼ aluminum face, black chassis with attractive side heat rails, pair of exposed tubes on top, and large polished chrome volume knob that seems to float on a halo of soft cream colored back lighting. At roughly 8”L x 6”W x 3”H it is a nicely compact size. In terms of sound, as a tube hybrid, it nicely blends the smoothness of tubes with the speed and dynamicism of a SS, where it capably reproduced the complex transient passages with fast electronic percussions on a Faithless track we were playing (which seemed slightly slower on an all tube amp such as the EMP). Overall I thought that it was a very capable unit and should compete well within the price range.
I actually liked the NKK-02 better than the RP-33 Dual Mono. For an SS amp, the RP-33 is extremely tube-like with its warm and lush sound. It is beautifully open in the mids, but seems to somehow taper a bit in the extremes, which reinforces it's tube-like character. But I think the RP-33 can be easily appreciated due it’s a warmth and generally easygoing attitude. Both the RP-33 and NKK-02 I thought were very smooth and liquid, but it comes possibly at a slight expense of higher resolution and conveying subtle and fine harmonic detail.
Here’s where the RP-6DQ separates itself from the other Rudi amps. Similar to the RP-5.1, it manages to extract the delicate detail of instruments and give a better insight into the notes. It also manages to do so while being lush and full. It is also much more linear sounding without the perceived roll-off of the 33 or the forward mids of the RP-5.1. In fact, this amp brings together the best qualities of both of these amps…that being the ease and openness of the 33, the extension and detail of the 5.1. While the RP-6DQ was designed with the Qualia in mind, I thought it worked with everything we plugged into it (HD600 with Blue Dragon, HD650 with Equinox, stock K501, and DT880 with Highflyin9 cable). Compared to the wonderful EMP, the RP-6 was wider, had a tighter bass, and has a slight advantage in upper end extension. This is such a fantastic amp, it should really be produced still and not billed as a Qualia amp at all (which unfairly pigeon-holes this versatile amp).
Nonetheless, the EMP manages to hold its own during this meet. This little jewel is just very lush and dimensional. While it’s a bit narrower than some of the other amps, it manages a better sense of depth than any of them, which produces a more 3D and holographic sound (this being accentuated by the Electro Harmonix tubes I favor) that seem to envelop you in the music. It also seems to have just a slightly better sense of texture and is on par with the PR-6 in conveying the decay and detail of each note. With the DT880, it just has such a musical and spacious pairing, which along with the comfort of the 880s seems to be a rig that’ll allow you to just sit back and enjoy the music for hours.
As for the Hornet, while the approximately 400 hours Peter has put on it had perhaps smoothed things out a little bit compared to the last time, it’s still the same Grado-like experience of forwardness, boldness, and aggressiveness. However, unlike Peter, I didn’t find that it had that much inner or up-front detail, spatiality, separation, and placement…all of which are how I’d describe it’s much more refined big brother the SR-71. To me they represent two different approaches to sound, and people will likely find one or the other to be their cup of tea. It's a good thing Ray Samuels offers these amps with complementary sonic attributes at two different price points. The Hornet is just unabashedly a rock out amp, punchy, dynamic, and impactful. It is a marvel of a small amp and as I’ve said before is a very good portable companion…with a sound that will cut through the ambient noise of the outside world. But for a jazz ensemble or full scale orchestra, the SR-71 would likely convey the nuances and scale to better effect. That being said, I think Peter’s Senn CPX 300 (?) worked very well with the Hornet, in that it actually altered the presentation to expand the soundstage to an appreciable level that I liked and helped create a better feeling of dimensionality…though at a slight expense of an edgier top end and a slightly wonky bottom.
As for the song I played through my speaker rig, it was actually a Roger Waters track from an SACD sampler that came with my very modest Sony DVD player (with my Stello DAC soon to be on its way). Machead had brought an Ultrasone sampler that created about the most out of the head headphone listening experience I’ve heard. So I played a track that showed that a properly recorded/engineered track on a decent 2 channel setup can result in sound that’ll seem like it's coming from a multi-channel system.
