I just finished a couple of days of evaluation of the new RubiKon subchassis. For those unfamiliar with it It is a two-piece subchassis (separate subchassis and armboard) precision machined from aluminum made by AudioFlat in the UK. It was designed to give performance approaching the Keel for significantly less money and for a much wider range of tonearms. A model which accommodates ALL Linn arms and one for the Aro are now available with a Rega model soon to follow and an SME mount version planned as well. It just started shipping recently and will initially be avail from a handful of select dealers in the UK and North America. Here are my findings so far.
In order to do a proper comparison I like to eliminate all possible variations between the two units I am comparing. This required borrowing a fully loaded LP12 (including Radikal, Urika and CH plinth) and configuring it to be the same as the store demo table. That meant removing the Urika and CH plinth and installing a Linn Cherry plinth, Trampolin2 and original T.Kable with first version RCAs on the borrowed LP12 and fitting a Radikal, RubiKon and Trampolin2 on the demo LP12 (which already had the Cherry plinth and the same version T.Kable). Once the LP12/Keel had the suspension readjusted and the arm cable properly dressed I then went on to the LP12/RubiKon which, of course, needed to have the suspension completely rebuilt and adjusted, the arm cable dressed, the grounding properly connected and all the new fittings adjusted for the proper torques (a non-trivial task when you have to find all new optimum settings for several fasteners). On the torque front I won't guarantee that I have the absolute best settings for all the fasteners as I didn't have time to check a really wide range of torques on all of them but I am quite sure I at least have very, very good settings for all of them and most likely optimal settings for most.
Both LP12s also feature Ekos SE arms and Akiva cartridges (second generation). In eliminating variables I also optimized the orientation and centering of both platters and transferred the same felt mat along with the record. Then I wanted them placed on the same type of surface so I had to change out Quadraspire Wall shelf from acrylic to Maple to match the Quadraspire Q4 rack next to it. One of the LP12s had to go on the wall shelf and the other on the rack but the top shelf of the rack was isolated to make them as close as possible (switching the LP12s between the two surfaces made little difference and didn't have any effect on the differences heard).
The system used was a Uphorik (pre-Dyanmik due to the difficulty in getting Linn to upgrade it), a KK/1/D, Solos and a pair of Vienna Acoustics Klimt The Music speakers that were in the room at the time. System wired with Linn Silvers and K20 and using Linn AC cords direct into the wall (same version Linn AC cable for the Radikals).
So with that exceedingly long preamble what did I hear? To relieve the tension I will state clearly that I heard the RubiKon sounding really very good. In fact, better than I expected it to be. I had heard from Peter that it had about 85% the performance of the Keel. Peter is a great setup guy and certainly knows his stuff but he is also more of a Naimee and I am more of a Linnie so I have to factor that in. But in the listening I have been able to do here I would have to agree and add possibly even 90%. The RubiKon is first off a product that does nothing to diminish the musical quality of the LP12, in other words it doesn't change the sound of the LP12 it improves it (compared to a Cirkus subchassis). Like the best third party products I've used with an LP12 (CH plinths, Lejonklou phono stages, Archidee and AudioTech stands) it keeps the Linn musical character while letting you hear even more of the music.
In listening to the RubiKon compared to the Keel I found things like the audibility of surface noise and frequency balance to be very similar. Both provided a huge amount more information of how the musicians are playing and of the quality of the instruments than the steel subchassis. They both also have a much better flow to the music and the interplay between musicians is more obvious. The Keel is still superior but it is a close thing with one customer I did the demo for liking the RubiKon on a quick A/B. For myself and the others here we found the Keel had two immediately noticeable advantages: the decay of the notes and harmonics on the instruments was longer, more natural and easier to hear and the low bass had a touch more foundation and a bit more texture. Overall the RubiKon had powerful, rhythmic and tuneful bass, the Keel just let you hear a little more of the string sound and resonance. The musicians seemed to be more real and present with the Keel but not by a large amount. You could tell that the Keel had the more direct, solid connection between the arm, subchassis and main bearing and was thus able to pull out even finer details that give that little bit more realism. But the RubiKon came surprisingly close for a unit composed of three separate pieces bolted together. I would not have believed it could be that close if I hadn't heard it myself. The RubiKon has a very smooth and even frequency balance very much like the Keel, it makes the kind of upgrade over the steel subchassis that has your jaw dropping with the amount of information it pulls out of the groove. If the Keel wasn't here everybody would be going nuts over it. The great thing is that this kind of performance is now available to owners of arms that don't work well or at all on the Keel like the Aro, Akito, Majik ProJect 9CC arm and soon the Regas. So if you really like your Aro or RB1000 you aren't shut out from the highest levels of LP12 performance.
I have to say that it was really difficult to get the setup so that I could really isolate the differences of these two subchassis because of the closeness of them. On Thursday, the first day I had the setups complete, I did the comparisons with a single Radikal so as to eliminate any difference the Radikals themselves might make. We could hear the differences but it was a bit difficult having to wait several minutes for each switch for the Radikal to sync the different motor. So yesterday I brought my Radikal in from home. Mine has the new Akurate case the store's the original case. Since I have found essentially no difference in the different casework I thought this would be fine and it did allow us to do quicker A/Bs with more music. But I didn't have shelf space for both Radikals so they had to be stacked. Now I know Radikals are sensitive to what they sit on but I hoped it wouldn't be too different. Well it wasn't TOO different but whichever Radikal was on the bottom sounded better and the one on top of it was less musical. So plug the RubiKon into the bottom Radikal and the differences were less, plug it into the top one and the differences were greater. Even using an old mat on the Keel and a new one on the RubiKon was almost enough to skew the results - the difference came through but it was definitely harder to hear.
So I really had to average the differences I heard to come up with a real feel for the differences as they could be small or even smaller depending on these factors. The bottom line is that the RubiKon is a very good subchassis, it is excellent value for the money and it brings a top flight performance within the reach of a fair number more people. It is also beautifully finished and very well put together. The work that went onto the design and manufacturing are quite evident. This is about as far from sticking a chunk of acrylic or carbon fiber in there and calling it a subchassis as you will get with a lot of evident work and listening to assure a quality product. Good work AudioFlat!