Firstoff, I'd like to thank Bill for allowing me to audition the Bella. I thoroughly enjoyed the 9 days I spent with it. Over that period it was completely trouble free. I did not look inside, but build quality appears to be fine. Just one small comment......I think the R phono input is just a bit fatter than the rest. It was a very tight fit attaching the 2 phono cables that I own.
SystemI played both my vinyl setups through the Bella:
(1) Townshend Rock mk3 table + SME V arm + Zu Xaus phono cable
(2) Kuzma Stabi "s" table + Kuzma Stogi "s" arm + captive Cardas phono cable
I used three high output cartridges: Benz H20, Clearaudio Virtuoso Wood mk2, Dynavector 20X-H
Rest of my system can be seen in my post above, and also in my photo Gallery.
Self NoiseWith the Bella in place there was an audible hum emanating from the speakers. It got louder as I turned the volume up, but I can't say it was intrusive or bothersome at my normal listening levels (typically 80-85 db). It was present with all the tubes I tried, and all the interconnects I placed between Bella and my line section. During its stay here, the Bella was always plugged into my original Shunyata Hydra power center. I did not try it direct into the mains, nor did I try floating any grounds. I don't know if the hum is a feature of the unit, or some kindof interaction with my system.
While my JuicyMusic Blueberry Xtreme full function preamp produces no hum, the tube rush with its volume fully 100% open is much greater than the Bella. Fortunately, at my normal listening levels, it is not so obviously apparent to the point that it is an issue or objectionable. Nonetheless, the noise is present and this higher noise floor, particularly at higher listening levels, is no doubt obscuring low-level detail when listening with the BB. So kudos to Bella for a lower noise floor.
GainCompared to my Blueberry (BB) MM section, the Bella has noticeably less gain. I don't know the specs on each unit, but with the volume pot at a fixed setting the Bella measures 4 db less (RatShack SPL meter) at my listening seat. My Benz H20 (2.0 mV output) in my BlueBerried system is just barely adequate in terms of drive and headroom, so I found it weak and soft sounding with the Bella. The Bella did better with the slightly greater output of my Dynavector 20X-H (2.5 mV), but it wasn't until my Clearaudio Virtuoso Wood mk2 (3.5mV) was inserted that the Bella had the kindof drive, ease and overall balance that sounded right.
With the overall gain and sensitivity profile of my system, I would consider a 2.5mV cartridge absolute minimum when using the Bella. Just something to be aware of if your system is a bit on the inefficient side. I consider my system to be fairly efficient with decent gain: speakers are 91db; amps are 1.4 volts sensitive on the input; line section has 15 db of gain.
TubesWith stock current production tubes the sound was just decent. A bit dry, wiry, grainy and kindof uninteresting. Nothing that would rivet my ass to the listening chair. But I could certainly hear potential in the Bella, and I knew that it had more to offer. Time to roll some tubes!
I emailed Bill and he suggested concentrating on the 12au7. Since it was the output tube, it would yield more sonic improvements than the 12ax7 (input tube). So I spent most of my time doing just that, with the stock 12ax7 in place. While sonic changes were certainly apparent with different 12au7's, I could never really get it to be "just right". It was either always too lean, or too veiled, or too dark, or too bright, or too flat, or too dry, etc.
It was not until I started inserting some decent 12ax7 that things began to get interesting. I first tried a Sovtek 12ax7 LPS....a decent tube. With it in place, I rolled in all the same 12au7's that I had previously. Once again, they each had their own distinct flavor and personality, but now they all sounded better than they did before. It was as if the stock 12ax7 was inhibiting, or putting a choke on things and not allowing the NOS 12au7 to sound as good as they could. A "better" 12ax7 tube seemed to allow the quality and unique characteristics of each 12au7 to shine through in a more interesting and musical way.
My conclusion is....
Don't ignore the 12ax7. Unfortunately I discovered this on my last day with the Bella, so I was not able to try all my NOS 12ax7. Nor was I able to try all the different combinations of NOS 12au7 and 12ax7 that I have. I did move from the Sovtex 12ax7-LPS to a Baldwin "organ pull" 12ax7 (made by Raytheon, I think). This really elevated performance. This is a great tube that I have used and always loved in the past, regardless of the circuit in which it is placed. Warm, rich, palpable and smooth, it sounds quite refined and musical.
I only tried these two 12ax7. I wish I had more time to play with some other nice ones I have. One must live with a piece of gear for a good while before its nuances, intricacies and charms can truly be revealed. And that takes time.
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Post size limit reached: more on tube comparisons in my following post)
CablingI would also recommend that you try different interconnects to link the Bella to your line section. I love the look, build and ergonomics of the one Bill included. It appears well made with nice connectors, and is flexible. So it is a joy to work with and route through your system. But in my setup and to my ears, I kept getting the nagging feeling that it was holding things back. Since both it and the Bella were new to me, I tried the Bella i/c on my cdp to assess what it was doing. In that location it impressed me with its nice clean, clear and open view on the music, but it also sounded a bit flat and mechanical to me. I got better performance with some other cables I have on hand. As with most cabling situations, this may be system dependent and others may find differently.
ComparisonsI don't have lots of experience with outboard phono stages. I have only owned two in the past, and that was many years ago, in completely different systems. Since then I have owned two full function tubed preamps, with internal phono sections. So I don't feel qualified to comment on how the Bella stacks up to comparably priced competition, or if it is priced fairly or offers good value.
What I can comment on is its sound, and give general comparisons to my BlueBerry Xtreme (BB). I think the Bella is a fine sounding phono section. It produces a sonic landscape that is clean, open, and balanced. It is quite detailed in a natural way, never fatiguing. It is fast and lithe performer. No part of the frequency range sticks out relative to another. The soundstage it throws is large, and the images are solid, non-wavering and believable.
Comparatively, my BB sounds a bit darker, and not quite as open or transparent sounding. Bella has greater detail and openness in the HF, making the BB sound slightly shelved in that area. I suspect the Bella's superiority in transparency is due in large part to the BB's higher noise floor. My BB has a "fatter" sounding bottom and midrange. The bass never seems lacking or lightweight when listening to the Bella, but it has greater presence, weight and thump with the BB. This is particularly noticeable with jazz where the bass lines are just that much more "there" and present with the BB. The Bella is not dry by any stretch of the imagination but comparatively the BB sounds a bit more bloomy and liquid. The Bella also sound a bit faster and more propulsive. The BB has just a bit of a vintage tube sound to it, while the Bella sounds more modern. The Bella is a bright clear crisp sunny day, while the BB is late afternoon with sun low in sky and all the golden hues and long shadows that accompany that "gloaming" time of day.
I also get the sense of slightly greater coherency with the BB...that the music just seems to hang together better as an integral whole. What I might be hearing here is simply the advantage of an integrated phono + line unit with its shorter and more direct signal path and one less interconnect, and not necessarily any inherent flaw with the Bella.
Personally, I think I could live with either of these units, and I am not able to conclude which is "better". That is for the individual to decide. Personal tastes and system balance will be determinative. My limited time with the Bella tells be that bloom, liquidity, detail, space and musicality can all be significantly improved with the right tube combo, and i/c selection. With careful selection, I'm
sure the Bella can be nudged in whatever sonic direction one desires.
Apart from great sound, one of the beautiful things about the Bella is how insanely simple and convenient it is to tube roll. And with only two tubes of the 12a_7 family, nice NOS ones can be had at reasonable prices. This unit responds so beautifully to tube swapping, that in my view not doing so is a serious mistake. So much is to be gained, and nothing lost.
Bravo Bill! I think you have done a really nice job with the Bella. I wish you continued success!
John
