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Doug Schroeder gets serious with the $850 Eastern Electric MiniMax BBA preamplifier
September, 2007 |
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Specifications •
Maximum input: 6 V
MANUFACTURER: Eastern Electric URL: www.eeaudio.com Email: alex_eeaudio@yahoo.com
U.S. DISTRIBUTOR: Morningstar Audio Imports 44 East University Drive Arlington Heights, IL 60004
Tel: (847) 255-1150 Email: info@morningstaraudio.com |
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Quick, name a component which:
The component reviewed here, the Eastern Electric BBA, is that very component. It is a most unusual device, both in its development and its function. As we shall see, it’s also an unusually adaptive piece which can influence a wide range of audio systems through the use of an adjustable gain. Intrigued? So was I – that’s why I had to give it a listen. |
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It’s officially known as the Minimax “Booster Buffer Amp” or BBA, made by Eastern Electric. I’ll come right out with it: This is one of the most fun and eyebrow-raising devices I’ve encountered in two-channel audio, with the power to make a sea change in whatever system it’s dropped into. Further, I’ll state that the BBA has the capability to upscale the sound of rigs, from a modest set up to the audiophile’s hard core system. That’s a fairly large build up for a component that I haven’t yet described and which is hardly on the average audiophile’s radar. But I suspect you will know this component in the near future, for it breaks barriers and touches a sector of audiophilia that is woefully lacking – it addresses the impedance mismatches which exist between components. “Impedance mismatches have been well known and almost universally neglected for decades.” Impedance matching seems to be the latest frontier, if not the last (I hesitate to say the last frontier since technology seems to always be peeling off another layer of possibility) in audio. Impedance mismatches have been well known and almost universally neglected for decades. Manufacturers of fine audio equipment by and large have deemed it of lesser importance to other design concerns. Recently, I reviewed the MIT Cables Avt MA line, which includes in its IC a selectable impedance switch. It is an indication that manufacturers are waking up to the impedance mismatch issue. Eastern Electric has addressed it directly and extensively in the BBA. So, what exactly is a BBA? It’s a tiny silver crate of fun, created to support the Playstation One (Dear Audiophile, please do not stop reading at this point! Yes, your tender high-end sensitivities have been offended by the suggestion that anything related to the Playstation One belongs solidly in Low Fi. But do not be deceived, for this is one component which can be considered a hi-fi wolf in low-end sheep’s clothing!) Alex Yeung of Eastern Electric, the designer of the BBA, has friends who are collectors of vintage German studio power amps. Designed for professional use only, these amps have extremely low input impedances and can’t be driven satisfactorily by typical audiophile preamps. |
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Alex explained, “One member of the group suggested the idea of an output pentode in a feedback circuit, which allows for a wide range of voltage settings to match the input impedance and voltage sensitivity of the associated device.” The idea was not novel; it’s been used successfully by German DIY’ers to ameliorate the low voltage output of the Playstation One. Not so unexpectedly, the device produced excellent results with both the German amps and the PS1. The “value added” brainwave was to place the device into the chain of traditional audiophile components, where it proved exceptional. In fact, it was discovered to be outstanding between almost any components (Note: the BBA operates on the analogue signal; one location it will not operate is between DIGITAL OUT of the CD and a DAC)! Members of the group clamored for more than one of them, Eastern Electric was brought in with Alex formally supervising the project, and the name “Booster/Buffer Amp” was coined. The rest is histrionics - wildly fun, outrageously unexpected performance!
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The BBA is a little box of major potential. My dumbed down description of the BBA is that it’s a tube preamp with variable gain. Alex was more discreet, “We recommend the potential buyer see it as a device to improve the performance of any existing hifi system, similar to use of NOS tubes or after market power cords…except the improvement should generally be much greater.” He’s being modest. There have been very few cdps, pre’s or amps which have brought as much change to my system as the BBA. How’s that for a superlative statement? This gain regulator is capable of making me stop in my tracks and listen well. It’s disarmingly simple looking, with the characteristic Eastern Electric brushed aluminum face and stainless steel body. Two polished knobs, GAIN on the left and VOLUME on the right, flank the power button with it’s trendy blue LED. The top is vented to cool the three Eastern Electric tubes inside, an EZ90/6X4 rectifier and a pair of ECL82/6BM8’s. The unit does get warm after a few hours of operation, but never enough to harm. Still, it should be kept from smaller hands, partly because in using both a gain and volume knob it can very quickly ramp up output. A small twist of the knob can produce a prodigious increase in the listening level. The rear of the unit is as clean as the front, with only one set of input/output jacks for single-ended use. A gain selector switch (230v/115v) makes this a great unit for those relocating internationally. A fuse socket and detachable IEC complete the features. The ever-affable Bill O’Connell from Morningstar Audio, the U.S. distributor for Eastern Electric, first mentioned the BBA as I was working on a review for the M520 tube hybrid integrated amp. He was quite excited about the BBA, so much so that I twisted his arm to hear his pre-production model. After spending several weeks with it I realized it wasn’t enough, for I now have two BBA’s in my possession. Once the production run had begun, Bill (not so accidentally) let slip that BBA’s can be used in multiples to further enhance a system. I couldn’t let that go by without investigation! Bill obliged my curiosity, which allowed me to experiment with twin BBA’s. SINGLE-STAGE I’ll start with the performance of a single BBA and work my way up to the twin setup. I did mention the purpose of the BBA to a high-end store owner who makes his own branded equipment and his initial comment was, “So, it adds distortion.” Though I thought it was a seemingly harsh initial assessment, I kept it in mind as I listened to the unit. There is some truth to his comment: The BBA alters the character of the sound of any component with which it’s associated. Soundstage is typically exploded to a surprising degree. I could not get over how large the rather moderate sized review pair of Wilson Benesch Curve speakers sounded when used with the BBA. (Doug’s Wilson Benesch Curve review was published in July 2007. –Ed) Larger floor standing speakers sounded massive. It may be debated whether this is a positive or negative result. For some individuals an ever enlarging soundstage is good, while others may want to keep a sense of common spatial relationships intact. The BBA enlarges the soundstage while illuminating the entire presentation. Just as a bulb on a dimmer can be set to a lower or higher setting, so also the BBA enlightens the music. The Morningstar Audio website describes it, “The BBA will not alter the overall tonal characteristics of your existing system but it will eliminate dull or dark sounding music reproduction that is missing dynamic contrast and detail.” |
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Frankly, I don’t see how one can eliminate dull or dark sounding music reproduction without altering the overall tonal characteristics of the system. The conundrum is that the BBA is capable of such different sonics when connected to associated equipment that it becomes tricky placing a definitive description on its sound. In general, the BBA has a tendency to shift the system toward more reverberant, expansive and brighter sound while making the soundstage larger overall. Possibly, I can get the point across by comparing the BBA with hair-styling products which add “volume”. These mystery chemicals which add volume to hair styles are called humectants - substances that retain or attract water. The purpose of a volumizer is to make hair follicles plumper from moisture. Consider the BBA as an electronic version of a hair volumizer! It takes the signal, and by adjusting the gain “fattens” or plumps it. In the hair commercials the flat hair, once volumized, looks gloriously full. In the same way, the BBA takes a compact or dense sound (mind you, I’m not saying poor!) and expands it. It makes the sounds as well as the spaces between the sounds seem larger, or as the hair ads declare, “…adds body and bounce!” In absolute terms is there some distortion as a result? Yes, but the effect is so pleasant that the ear protests very little. The beauty is that the voltage regulation knob without detents allows for infinite settings, so that one can always find the point where distortion is minimized and the “volumization” is maximized. “As long as it was kept within acceptable parameters, the expansiveness in many cases more than offset the slight diminishment in precision.” As a general rule, to my ear as the gain was decreased by turning the voltage control counter-clockwise, the sound acquired the tighter, denser nature that would result without the BBA’s presence. As gain increased, the “volumizing” ramped up, until at maximum the sound was noticeably getting exploded too much. As long as it was kept within acceptable parameters, the expansiveness in many cases more than offset the slight diminishment in precision. People who love listening to audio in surround mode will probably be ecstatic about the effect, since it easily pushes the soundstage out almost to envelop the listener. Add to this the fact that even more subtle changes can occur by contouring the BBA’s volume control off of the associated component’s level control. Like a fine tuning knob on an older receiver, the infinite volume adjustment can be set to either low or high levels. Conversely, the associated level control on the pre or DAC can take up the slack or be backed down. Between the gain settings and the volume control, a myriad of possibilities for shaping the sound emerge. This also makes the BBA suitable for using direct outputs from DAC’s, like the Monarchy M24. The M24’s attenuation can be bypassed in favor of the volume control of the BBA (i.e. setup as follows: cdp to M24 DAC to BBA to amps). I have said that this unit can bring a sea change to the system, always pleasing, but not always better in absolute terms. My reference amplification is the bridged pair of Pathos Classic One MkII tube hybrid integrated’s. The BBA inserted between the Rega Saturn cdp and the Pathos amps did not create an absolute improvement. There was a loss of clarity, the bass a hair less defined; however vocals were tremendously engaging and the sense of a live presentation increased substantially. The “live” sound is so elusive in many rigs, but the BBA imported it in spades to almost every configuration I put together. Vinyl is not an absolutely pure medium, yet audiophiles flock to it for its warmth and “real” feel. The same could be said of the BBA’s effect – it’s presence in a system means the signal by necessity is less perfect, yet the gain regulation allows components to pull a shocking amount of vibrancy out of the signal! It’s fantastic at making other components sound fantastic.
DOUBLE BBA |
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The BBA showed its prowess as a mate to the clean and simple sounding Channel Islands PLC-1 passive line stage. As a stand alone preamp, I found the PLC-1 to lean toward a cool, analytical sound. However, when paired with a BBA, the PLC-1’s sonic nature was transfigured to become a full bodied tube preamp. Some of the most amazing moments with the BBA came from the addition of the second BBA unit in conjunction with the PLC-1. Having been informed of the multi-unit capabilities of the BBA’s, I set up a wildcard system: Saturn cdp, BBA “A”, Channel Islands PLC-1 passive pre, BBA “B”, and finally Monarchy Audio SM70 mono blocks (in for review). I was stunned at the result. In several respects, I preferred this sound to the bridged Pathos amps. The Classic One’s put out 270wpc into 4 ohms, but the twin BBA’s had the effect of making the reserved 70Wpc Monarchy sound like 200Wpc! I have never had such an extreme shift of sound with an amplifier, and it was difficult to comprehend just how radically the sense of power had changed! The strength and palpability of the bass was superb, the clarity of the treble outstanding, along with the aforementioned vast soundstage. Further, there was a seemingly limitless range of nuances which could be achieved by deftly blending the two BBA’s. Varying amounts of edge could be placed on the treble by increasing gain from BBA “A” to BBA “B”. I could make “designer bass”, tailoring it from taut to loose by lowering gain on both BBA “A” and BBA “B”. One can hardly find two more different speakers than the Wilson Benesch Curves and the Eminent Technologies LFT-8A’s. One is a 2.5 way, aluminum cabinet dynamic speaker, the other a hybrid planar magnetic design. Yet, in using each with the PLC-1/BBA/Monarchy setup, I was able to adjust both BBA’s to bring out stunning sound from each speaker. I have never been able to do so with any other amplification scheme. There had always been elements of disappointment in the final resultant sound – the bass too unrestrained with the Curves and not strong enough with the LFT-8A’s. The treble was recessed with the curves and the LFT-8A’s at times a bit too strident. The use of the twin BBA’s dialed in both of the speakers as optimally as I have heard them. I have never had one amplification system handle both of these radically different speakers with aplomb, and I give the credit to the BBA’s for their ability to adjust impedance. |
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Listening to Joss Stone on the PLC-1/BBA/Monarchy rig was a dream. I could hone her voice to a knife-like edge or soften it and bring in more bottom-end to make it relaxing, all by tweaking the gain. You know you’re getting to a point of sonic nirvana when you can obtain detail such as hearing the singer’s lips part nearly every time she opens her mouth, yet not cringe when she hits a high note. The BBA can be used independently as a preamp, at which it excels. However, as demonstrated above, I would not assume that the most pleasing sound which can be extracted from it will come merely by using it alone. Even though the signal was not as absolutely clean with the addition of the BBA into several setups, the vibrancy it generates more than compensated. As a stand alone preamp, the BBA is as clean and engaging as any active or passive design I have used. I would not recommend piggy-backing two BBA’s, literally placing one before the next. I asked Bill if they could be used in tandem – after all, if the purpose of the unit is to adjust voltage, why not |
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adjust the voltage for the voltage-adjusting component? Bill didn’t know the answer as no one had ever hooked up two of them in such a fashion. I determined if anyone was going to blow up a BBA, it would be me! Recognizing that it was unlikely to cause a major meltdown, I proceeded. The net result was Hearts in Space music. Hearts in Space was a late night ambient music show I listened to in college. The tandem BBA’s turned all music into “notes in space,” as the expanded soundstage was too much, too disconnected. It was obvious that I had created a guitar amp with the gain on max. Interestingly, the reinsertion of the Channel Islands passive line stage between them returned me to the superb results stated above.
ROLLING BBA’S Tube rolling brought yet another level of intimacy from this design. It is well worth exchanging the listenable stock tubes for quality replacements. Bill graciously supplied me with NOS tubes for each of the BBA’s. In BBA “A” was the Haltron CV 493 rectifier with the pair of Matsushita 6BM8/ECL82’s. Unit “B” was outfitted with a Tungsol 6X4WA and a set of Telefunken ECL82’s. I preferred the sound of both of these to the stock version. That should come as no surprise, since Eastern Electric is known for their affinity to tube rolling. |
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The “A” unit was rich, warm and glossy sounding, while the “B” unit held more crispness and a pinch more bite. I found myself listening to the “B” unit more since I was usually pairing the BBA with darker amps or preamps and was trying to increase the size of the soundstage and add a bit more brightness to the presentation. It is very economical to outfit the BBA with aftermarket tubes and I would suggest that every purchaser pursue a combination which pleases their ears. In addition, the BBA is sensitive enough to merit experimentation with aftermarket power cords and interconnects. I found that the Magnan Cable Type Vi interconnect was a revealing but forgiving match with the BBA, and the Tara Labs RSC Air power cords gave me some of the most detailed listening with the unit. |
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To describe the
BBA’s effects on music, I will detail how three tracks from the
Midnight Groove: Windham Hill Jazz Collection disc differed with
and without the BBA. Two configurations will be seen; the Monarchy
M24 DAC (it has volume control built-in) and SM 70 amps alone, then
the same setup with the BBA between the DAC and amps. I hasten to
add that my notes transcribed below should not be construed to
indicate poor performance by Monarchy equipment! At its price point
I find the Monarchy equipment superb, which is one reason I chose to
use them for this test. I am going “super-critical” below to
highlight the effect of the BBA on the sound. First the Monarchy Equipment: Earl Klugh’s “No Regrets” from the Windham Hill track has clean guitar, not exceptional reverberation of strings. Bass was tight but not “setting the pace”. The lowest notes were popping from lack of power to resolve them adequately. Lani Hall’s “Waters of March” is sung/spoken. The piano had average “weight” to its sound. Strings were somewhat indistinct, almost like they were synthesized. Lani’s cadence was punctuated but the words themselves did not carry through with intensity. “I’ll Always be with You” by Paul Horn is a piece with lead flute. The extremely low bass is almost indiscernible, and the rushing sound of the breath through the flute is not pronounced. Now, my notes with the Addition of the BBA between the M24 DAC and the SM70 Mono amps: Earl Klugh’s “No Regrets” has bombastic bass with much more oomph at low notes; treble more distinct and guitar body resonances can be heard at each note. Beads can be heard inside Maracas in background and triangle is distinct. On the “Waters of March”, the piano sounds closer to a Steinway Grand with strong low note emanation. Hall’s vocals have a sharper enunciation with every consonant detailed. The strings sound like an orchestra, not synthesized, and they “float” in background. On “I’ll Always be with You”, the flute is quite a bit more chesty and the duet with the flute an octave higher is more easily discerned. The breath in the flute’s cavity is more pronounced. Again, do not misconstrue my comments to read anything negative about the Monarchy equipment. I believe I could have produced similar notes on the distinction between “BBA sound” and “non-BBA sound” with any setup. I did not have to strain to hear these distinctions between the Monarchy and the “enhanced” Monarchy and BBA systems. As has been indicated before, there was more absolute cleanness without the BBA, but the experience was more “open” and the nuances of the pieces were more readily discerned with the BBA. In comparison, the sound without the BBA was tilted slighty toward a treble-diminished sound, and with it a slightly treble-enhanced sound. “It is a device which can turn a “Ho-hum” experience into an “Oh, Yeah!” event. With multiple placement options, one is virtually assured that there will be a pleasing configuration where the BBA produces striking results.” My casual observation is that audiophiles fall into two camps – either the camp which seeks tight, focused soundstage with ultimate clarity, even if it comes at the expense of comfort, or the camp which seeks warm, larger sound with enveloping soundstage and the acceptance of some imperfections in the sound if it makes the listening experience feel more live. The BBA is a device to produce a shift in a system toward the second camp’s objectives. It allows one to literally experience both of these sounds for under $1,000. In addition, it can take a lower end, sterile sound and inject body and life like no other component I have used. It is a device which can turn a “Ho-hum” experience into an “Oh, Yeah!” event. With multiple placement options, one is virtually assured that there will be a pleasing configuration where the BBA produces striking results. |
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Lately, I have noticed following use of the BBA that I have been humming the music, instinctively re-creating in my mind what I found so pleasurable. I don’t do that very often even though I immensely enjoy listening sessions. It signals to me that the BBA is making my system sound good enough that I want to re-live the experience in my mind. What the BBA offers is not one chance at a system alteration but several. Even the most rudimentary source, pre and amp setup yields two options for BBA placement, and the difference in presentation between placing the BBA after the source or after the pre is surprisingly significant. Throw in a DAC with RCA OUT’s and there are three potential configurations. Add a subwoofer with line level inputs and it increases to four (Bill says the effect of the BBA on subwoofers is outstanding, and I believe him.) The BBA is only $850. Peanuts, for the potential it can unleash. Consider that it put a brand new spin on vocals, helped technical sounding components mellow, made lower powered amps sound impressive, accommodated well both planar and dynamic speakers, and offered a minimum of two placement options – It has easily found a place among my components. |
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Also read Doug Schroeder’s article on: Thou shalt not listen to any solid-state integrated with stock jumpers!
Thou shalt not skimp on power cords!
Solid-state DAC
Solid-state preamplifier & monoblock amplifiers
Solid-state Integrated amplifier
tube hybrid integrated amplifier
with Dussun V8i
Jena Labs "Jazz" & "Java" cables
tube amplification system
MIT AVt MA cable system & Z-Stabilizer
CD player
loudspeaker system |
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Comments: editor@dagogo.com ©Dagogo 2007 |
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