I've raised this thread as Lampi valve / tube reviews are scattered all over the place.
From now on it'd be great if everyone can use this thread for valve / tube reviews. I'm not sure they will, but it is worth a try.
So basically I have been comparing Emission Labs AD1 valve with the RK 300B. The DAC is an extensively modified B7 - one of the very first hardwired Lampizator BIg 7 DACs which originally used 6X5 rectifiers and had a clever noise reducing 'preamp' section that really reduced valve microphony over later produced DACs.
It now uses 5U4G, active triode loading (6N6P) and has dual capacitor outputs (Dueland 0.47uF copper foil and Jupiter 2.2uF copper foil), Audio Note silver tantalum film resistors (seriously expensive for resistors), Audio Note silver UX4 sockets, silver WBT Topline RCA sockets (two pairs, one for each capacitor type) etc etc. So it doesn't really match up with any currently prcduced Lampizator DAC anymore. It is currently sounding very, very good indeed, by my own personal estimates, which is all that counts in my book
So here are the review notes I promised a week or so back. From a 4 hour session comparing KR RK 300B to Emission Labs AD1 fitted with UX4 sockets (custom order).
Speakers are Apogee Duettas - a hot rodded custom version thereof. Amps are some huge 211 monoblocks in this case.
Cornelius - For The Love Of You (TIDAL)
RK 300B - Good control, tight bass, average imaging, architecturally strong. The control aspect is slightly weird, it feels like the valve is trying too hard to achieve it.
In this sense it is slightly unnatural.
AD1 - More dynamic, unchoked, natural, brighter, more exciting, more 3D, more engaging, better air/space in top end, feeling of "that's awesome". Bass feels like it isn't being controlled (rather it is just really fast and seems like it is tracking the source, not imposing its own character on it).
Orbital - Tiny Foldable Cities
RK 300B - Imaging very 2D, tight, controlled, dry.
AD1 - Same traits again. There's just no contest. AD1 is obviously superior. Even the bass, an RK strong point when compared to other valves, is more extended. Switching between Dueland and Jupiter caps seems to remove the lowest bass but the Duelands are clearer overall. This valve definitely likes Dueland output caps. It is marginal, but it is definitely there and noticeable.
B52s - Planet Claire
RK 300B - RK wins here. It just presents the track more calmly. Welcome on this particular track.
AD1 - just overwhelmingly energetic. Awesome, but a bit hard to handle. A bit "too much".
Trentemoller - Rykettid
RK 300B - Clean, clear, boring? This is a very dynamic track it should be more exciting. Still a feeling it is being "clamped down" or overly controlled. Overall it is very good, just too calm on this one.
Some sign of 3D dimensionality appearing at the end of the track, where the soundstage shot past the left and right ears.
AD1 - Deeper and stronger bass than RK, or possibly just more of it. A bit more raucous. Is this the reason for the excitement? Bass is massive. Panel filling. Worthy of an Apogee. Soundscape fleshed out to the full. Superb sense of vertical bass i.e. really even output from the top to the bottom of the bass panel. Excellent 3D imaging from the speaker plane to well behind my ears.
Trentemoller - Physical Fraction
RK 300B - Sense of filtering out excitement in favour of control. But the again this track sounds awesome in a way that makes sense.
AD1 - F^&k. Massive dynamics. Crazy sense of all the signal getting through. Unfiltered. Free. Huge imaging. Wrapped in sound. Who made these things? Respect.
Stevie Ray - Little Wing
RK 300B - Filtered, less real sounding.
AD! - Raucous, fantastic amp distortion. Brilliant.
A few other selections were from Nirvana, Santana. Nancy Sinatra (bang Bang), Anita Ward (Ring My Bell), Daft Punk (RAM - really not as good via RK).
The comparisons end as I just give up with RK and get into a load of Barry Gray with AD1 - Joe 90, Captain Scarlet, UFO, Thnderbirds, Space 1999, Esso, Fireball XL5 etc