The set up:
Two Bryston 7B3 monoblocks (600w @8ohms/900w @4ohms)
McIntosh MAC6700 200w @8/4/2ohms (using autoformers)
McIntosh MAC6700 pre-amp stage (output 1 fed to MAC6700 power amp stage, output 2 fed to Bryston 7B3 monoblocks)
Technics SP10 MkII table & control box (rebuilt by PBN Audio)
PBN GrooveMaster plinth
Sorane ZA-12 12” tonearm
Denon DL103 cartridge ([email protected]
MAC6700’s integrated MC phono stage set at 200ohms)
MAC6700’s integrated DAC 32-bit/192kHz PCM/DSD
Speaker cable physically disconnected/connect from/to the McIntosh/Brystons for back and forth comparison of the same tracks
I love the sound of the Maggies with the Mac but noticed I had to turn the volume up around 53% (avg. ~70dB / peaks ~85dB) before they really sang. Things got better once the Maggies got passed the 6 month mark, but still, the Fletcher Munson curve was more pronounced than with cone speakers. I did a lot of forum reading that suggested, while inherently a characteristic of the Maggies, it could be somewhat remedied by using a high-powered/high-current amp, especially an OTL amp with a high dampening factor. Two amps kept reemerging again and again in the forums: Bryston and Pass Labs. (Mac amps with their autoformers (output transformers) were generally discounted as “not working well” or “would not be a good match” with planar type speakers. However, a few Mac owners would chime in saying they were using Macs with great success paired with their Magnepans.) My local dealer carries neither Bryston nor Pass, but then, I stumbled across a pair of 7 month old Bryston 7B3’s in new condition at a price I couldn’t pass up; even just to own them on a gamble of not liking them and having to re-sell them. So, here we are...
(7B3) = pair of Bryston 7B3 monoblocks
(Mac) = McIntosh MAC6700 integrated receiver's power stage
Music auditions: (WARNING: this is long... if you don't feel like reading song reviews, skip down to "The Final Analysis")
King Crimson::In the Court of the Crimson King::“Epitaph”::Discipline Global Media/Panegyric/Inner Knot KCLP1 (LP) [2010 RE]
(7B3): Lake's vocal strangely recessed into the background as if his voice track was mixed down to the point that it was hard to decipher the words he was actually singing. I have no idea why this anomaly – this isn’t something I would have expected just from switching to a different power amp. This really bothered me because I wondered what other recordings might have their vocals dramatically recessed under the mix of the instruments. Otherwise, I observed a bit wider soundstage and even more noticeable, a taller soundstage. The cymbals on the remix, done by Fripp himself on his own label (much has been written about regarding they finally sounded correct according to Fripp), I noticed they had more air around them, but were not anymore crisp than on the Mac.
(Mac): Lake's vocal magically re-appeared to the forefront and his words were again intelligible.
[Winner]: Mac - while I liked the larger and more defined soundstage of the 7B3's, the oddly recessed vocal made it disturbing to listen to.
The Who::Tommy:: “Overture, It’s a Boy, You Didn't Hear It, Amazing Journey, Sparks”::Decca DXSW 7205 (LP)
(7B3): I was presented with a wider and taller soundstage with instruments well defined and bass you can feel. Beautiful cymbal crash shimmer. French horn arpeggios had great space and perfectly auditable reverb decay with natural acoustics. Acoustic guitar fast strumming and finger picking perfectly well defined, i.e., you could hear the 32nd notes whereas on the Mac they were just a blur sound with mostly just the percussive attack on the strings defined, but not the notes.
(Mac): Presented a smaller soundstage that didn't seem appropriate for a rock opera (or any Who performance for that matter). The natural acoustic and atmosphere of the recording space was missing, i.e., the ambience of the room was missing - it was just presenting recorded voices and instruments.
[Winner]: 7B3 - it's becoming clear the 7B3s are revealing minute detail that recreates the ambience of the recording location contributing to more realism during playback. In addition, being able to hear the naturally occurring reverb and decay of instruments creates more of 3D sound stage.
David Bowie::The Man Who Sold the World::"The Width of a Circle"::Parlophone DB69732 (LP) [RE]
(7B3): Wonderfully articulated acoustic guitar intro and I was greatly anticipating the electric bass guitar when it entered - alas, the punch I was expecting just wasn't there - it seemed to be mixed down. Bowie's voice seemed distant, tinny, and disconnected.
(Mac): The punch and deep bass that I was used to hearing with this track was thankfully restored and Bowie's voice was more connected, fuller, and a shade warmer.
Deee-Lite::Dewdrops In the Garden::"Say Ahhh..."::Get On Down/Elektra GET 52728-LP, 61526-1 (LP) [RE]
(7B3): How about saying, "Ohhh... something in my room is vibrating" The incredible bass here, besides thumping through my chest, is also is making something in my listening room actually rattle intermittently - this has never happened before. What can I say - I can now charge admission and a drink minimum as I have an official disco - just need to rip out the carpeting. Seriously, this is so much fun with the B3's 900 watts I actually had to stand up and boogie!
Heart::Dreamboat Annie::"Crazy On You" & "Soul of the Sea"::Mushroom MRS-5005::(LP)
(7B3): Alas, the anomaly of the recessed vocal appeared again - not as dramatic as on the King Crimson track, but still mixed down. It'a a shame because the 7B3s created their great strong bass and gave vocals their effortless authority such as when Ann belts out "Let me go crazy on you...". The soundstage was reproduced so large that it spread the instruments way too far apart with each feeling rather isolated.
(Mac): Vocals brought back to expected level in the mix and more cohesive soundstage for the five piece.
Barbara Streisand::People::"Absent Minded Me"::Columbia CS-9015 (LP)
Eydie Gorme::Softly As I Leave You::"You've Changed"::Columbia CS-9394 (LP)
(7B3): These two gals can belt it out and both recorded during the mid-sixties on Columbia. The Columbia "female vocal-orchestra backed-house sound" never sounded so good - when these ladies are belting it out, it can tend to sound “shouty” on lesser amps. These ladies' loudest most powerful passages sounded effortless and smooth. The other thing I noticed was the orchestra‘s upright pizzicato bass sounded realistic - enough bloom, bounce, and depth you could feel.
(Mac): Vocals come across thin and shouty, and the upright bass was very anemic.
Art Blakey & The Jazz Messengers::Gypsy Folk Tales:: "Jodi"::Roulette SR-5008 (LP)
(7B3s): There's a lot going on here, a big sound almost big band like, the brass finally had room to spread out and be uncongested - with so many instruments playing loudly and up tempo, the spatial power offered by the 7B3s was greatly appreciated. Then, when the solo sax entered, wow, a hologram of the player aurally appeared in my room. Sax timber was spot on with enough crisp reediness and alto body hoot that put the sax out in front of the speaker. The high-hat short opening sizzles leapt out from the speaker in a startling way of also being physically present in the room.
[Winner]: 7B3 - the Mac just couldn't spread out each family of instruments enough to give them the room they needed to breathe and sound uncongested.
John Coltrane::Giant Steps::"Giant Steps"::Atlantic 1311 (LP) [RE - mono]
(7B3): Even though this is a mono recording, it strangely sounded more spread out and thinner overall. The upright bass was more scooped, i.e., just a percussive high-end and low-end feel without the rounded sound of the middle bass.
[Winner]: Mac - delivered a more cohesive, warmer, and rounder sound to this ensemble.
Diana Krall::Turn Up the Quiet::"Like Someone In Love"::Verve B0026480-01 (LP)
(7B3): On this track, due to either recording technique or Diana's enunciation, her very breathy and half spoken vocal intro sounds like she has a lisp, e.g., when she says, "...someone in love", it sounds like, "...sthomeone hen luff" - the 7B3s were able to open this up so that there's less "th" following the "s" in "someone". Although a digitally sourced LP, it is very warm sounding and the 7B3s were able to maintain that warmth while giving the piano and bass more authority without spreading the instruments too far apart - cohesiveness maintained and the added authority contributed to more "live ambiance".
Chic Correa::Now He Sings, Now He Sobs::"Steps - What Was"::Solid State/Blue Note B0029363-01 (LP) [RE]
Bill Evans::At the Montreaux Jazz Festival::"One For Helen"::Verve V6-8762 (LP) [RE]
(7B3): Lumping these two recordings together because both exhibited the same anomaly regarding the pizzicato upright bass on where you get all the bass but the finger sibilance and fretboard tap come out separately in the quasi-ribbon tweeter sounding as if it’s another percussion instrument playing along with the double bass instead of being one coherent sound of the bass notes being played. Admittedly, I believe part of this is contributed to an inherent flaw/fluke of the Magnepan’s crossover from the midrange panel to the quasi-ribbon tweeter that I've read about. On a positive note, there was more of the vibrance and acoustical space of the room where each recording took place, one a studio; the other a casino club.
[Winner]: Mac - didn't exaggerate the upright bass fretboard tapping as much and brought more cohesiveness to these small ensembles.
Bach::Mass in B minor::Eugen Jochum - Bayerischen Rundfunks::"Kyrie", "Credo"::EMI 5-68640-2 (CD)
(7B3s): This large ensemble sounded fantastic from the larger soundstage and power that it requires. Yet, the delicateness of the basso continuo was never lost in the mix and it's own defined place in the soundstage as did the clarion trumpet. Choir enunciation was articulate and well defined. (However, I have to point out a small but bothersome grievance - the 2nd track of disc 2, the female silibants on both “s” and “t” was almost unbearable - it was there also on the Mac, but not as pronounced or bothersome as. In all honesty, I will chalk some of this up to the dry and analytical EMI recording, and perhaps, yet another example of the previously alluded to inherent flaw of the Magnepan’s crossover from the midrange panel to the quasi-ribbon tweeter.)
[Winner]: 7B3 - it's becoming clear that the larger the ensemble and the more complex the music is, the 7B3s have more of what it takes to unpack all of that density and reproduce its "bigness".
Mahler::Symphony #8::Rafael Kubelik - Bayerischen Rundfunks::Deutsche Grammophon 429-051-2 (CD)
(7B3): I could hear the spatial layout of the choir - tenor’s standing on the rafter upper-right, soprano’s upper left. No “s” sibilants here and a warmer recording from DG vs. the Bach Mass on EMI. Nothing new here - the same beautifully uncongested and expanded sound stage from the 7B3s vs the more compressed sound from the Mac. Better definition from genre of instruments and voice timbers. This is a big production instrument wise and choir wise - the 7B3s are definitely up to recreating the “bigness” that the Mac just can’t handle. (Nic pic: I was expecting more separation between the tympani and the double basses towards the end of the 1st movement during the ffff sections - it came across on the muddy side of low tympani and double bass notes running together.)
Verdi::Otello::Tullio Serafin - Rome Opera::RCA 1969-2-RG (CD)
(7B3): Wow! The crashing symbols of the thunder and lighting storm as the ship comes into port starts this opera with a ffff and I’m so overwhelmed and mesmerized with what I’m hearing, I’m putting down my iPad and retiring from writing as I can only listen while being totally drawn into a live performance - (pouring my 2nd glass of cognac and settling down for a night at the opera...). [Next day]: This my friends, is a great example of why you need to have amps like the 7B3s with Magnepan 3.7i's - big productions require the wattage and power reserves to properly reproduce the dynamics as well as the sound stage: the cymbal CRASHES, piccolo chromatic runs, drones of the bowed double bass and tympani rolls, stuttering out bursts from the brass, noble trombone regal decrees, the trumpets upward chromatic staccato, and the swelling dynamics of the large chorus milling around the harbor in the beginning of Act I. I've seen this opera live at the Kennedy Center's Opera House and this is as close to live acoustics that you can get. The wonderful interplay of Iago with the chorus of Cypriots in "Inaffia l'ugola" getting everyone to drink in an attempt to get Cassio drunk with chromatic runs of "Beva, beva!" and the chorus resounding with him. I wanted to stand up and raise my glass of cognac and salute with them - I mean, I was in the middle of it! The love duet between Otello and Desdemona presented a very realistic sound stage and intimacy - both female and male vocals had just the right timber and very realistic in that they were neither rolled off (too smooth) nor shrill or harsh - just as they should be. One tidbit of eerie detail was the single plucked bass notes on the harp at the very end of the duet - it reminded me of sitting just a few rows away from the orchestra pit. At the beginning of Act II during Iago's credo, "Credo in un Dio crudel", things for the first time got shouty with the forte passages of the upper baritone range - some glare there that quickly fatigue my ears, but this was the only negative noted.
(Mac): Just didn't have the power required to recreate the large and immense soundstage of an opera. Overall sounded small, thin, and anemic.
[Winner]: 7B3 hands down!
Beethoven::Sonata #14 "Moonlight"::John O'Conor::Telarc CD-80118 (CD)
(7B3): This one is hard to describe, but this solo recording, in St. Barnabas Church, London, always sounded murky, soft, and too warm lacking definition. The 7B3s were able to open it up and add the missing articulation. I believe this was accomplished because the 7B3 has the uncanny ability to reproduce recording venue acoustics and room vibe. Every room has its own sound of silence... if you know what I mean? It's the ambient room acoustics even when nothing is producing sound, a vibe, if you will. The 7B3s reproduce this as well as the smallest details of room reverberation/decay which combined, render a live sound no matter where the recording. (True, small studio recordings have less of this than large-hall studios, on-location, or live recordings.)
[Winner]: 7B3 - because of all of the above.
<<< The Final Analysis >>>
How similar the 7B3 and Mac sound. While I've never heard a Bryston amp before, I had read that with the "3 cubed" series, it was designed to have a smoother overall sound profile compared to previous series. Except in very dense and complex recordings, to my ears, both amps had virtually the same sonic signature (or lack there of).
How the 200 watt Mac was able to hold it's own against the 7B3's 900 watts - the 7B3 never "sounded louder". Depending on the recording, the 7B3's bass was stronger (you could feel it), dynamics, articulation, and soundstage were better and larger, but no perceived difference in loudness. In fact, I kept the pre-amp's volume control set at 53% for both amps and the perceived loudness was the same regardless of which power amp was being used.
1) Pop/rock LP's pressed from a digital source, sounded warmer and more cohesive on the Mac.
2) Large ensembles, albums recorded in large venues, and complex/dense/fast music sounded better on the 7B3s - in fact, the more complex and dense the music, the more the 7B3s stepped up to the plate and really showed their magic...
3) Likewise, smaller ensembles and less complex music sounded better and more cohesive on the Mac.
4) All of my CD's sounded better with the 7B3 - most of my CD's sound fuller and warmer I assume because of the extra watts. I never liked how thin and flat my CD's sounded as amplified through the Mac - the 7B3 really brought them back to life, closer to an analog sound.
5) Most of time, the 7B3s produced more bass that was well articulated, fast, and great "chest feel". However, on certain recordings, it's almost like the 7B3s produced a "scooped" bass sound where the fundamental mid tone was recessed so that you were "feeling" the very low end and just hearing the high-end articulation of the note. Whereas, in these cases, the bass seemed louder and punchier on the Mac, but sans the "chest feel" and better articulation.
6) 7B3s have the uncanny ability to resolve the minute details of room acoustics - reverberation, decay, ambiance, vibe, etc. (see "Moonlight" review above).
I was expecting to hear huge differences in these two amps - especially regarding all the threads out there discussing how OTL amps are the best to use with Magnepan's and how the Mac's autoformers roll off the high-end and suppress detail, etc., not to mention the difference of 700 watts between the two.
After reading so many forum threads regarding the Bryston/Magnepan match being made in heaven and how the Bryston amps would really make the Magnepans "sing", I still had to keep the volume up at the same level I use as when they "sing" with the Mac. (Yes, the Magnepan's did "sing" better at the same volume with the 7B3's, but I guess I was expecting something more dramatic going from 200wpc to 900wpc, as well as the Fletcher Munson curve effect being reduced; alas, it wasn't.)
For all the things that the 7B3s did better than the Mac (bass you could feel, better dynamics, more transient details, larger/taller soundstage, uncongested and accurate reproduction of large ensemble performances, impressive reproduction of recording venue ambiance, etc.) was I simply hearing the benefits of stepping up from 200 wpc to 900 wpc? Or, was there, in addition, something inherent to the Bryston that was contributing to these sonic improvements?
Now that I know what the 7B3s are cable of in my system, and to answer the above question, I will now be scheduling an audition at my local dealer to listen to the Mac MC462 and MC611's hooked up to the Magnepan 3.7i's. I will be grabbing the music I listed here and will be listening to hear if the higher powered Mac's can reproduce all the goodness I heard from the 7B3s.
If the above audition reveals that the higher powered Macs can reproduce most of the goodness heard with the 7B3s, and at the same time, not reproduce the "shoutyness" or "glare", nor the anomaly of recessed vocals, on the same songs as tested with the 7B3s where those negatives appeared, then I will sell the 7B3s and look to upgrade within the Mac family. If not, then I'll keep the 7B3s and upgrade to a Mac tube-based pre-amp.
I'll update this review after I audition the higher powered Macs with my findings. (And if you made it through this too long review, thanks and cheers!)