Bryston 7B3 compared with McIntosh MAC6700 Integrated

[JimmyEL34]

The set up:

Power:
Two Bryston 7B3 monoblocks (600w @8ohms/900w @4ohms)
McIntosh MAC6700 200w @8/4/2ohms (using autoformers)

Pre-amp:
McIntosh MAC6700 pre-amp stage (output 1 fed to MAC6700 power amp stage, output 2 fed to Bryston 7B3 monoblocks)

Speakers:
Magnepan 3.7i

Turntable ensemble:
Technics SP10 MkII table & control box (rebuilt by PBN Audio)
PBN GrooveMaster plinth
Sorane ZA-12 12” tonearm
Denon DL103 cartridge (VTF@2.65g)

Phono stage:
MAC6700’s integrated MC phono stage set at 200ohms)

CD transport:
Tascam CD240

DAC:
MAC6700’s integrated DAC 32-bit/192kHz PCM/DSD

Method:
Speaker cable physically disconnected/connect from/to the McIntosh/Brystons for back and forth comparison of the same tracks

Why?
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...

Key:
(7B3) = pair of Bryston 7B3 monoblocks
(Mac) = McIntosh MAC6700 integrated receiver's power stage

Music auditions: (This section was too long to post here - if you want to see the song reviews using these two amps, please read the music auditions)

<<< The Final Analysis >>>

Overall winner:
7B3

Most surprising:
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).

Most impressive:
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.

Observed generalizations:
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).

Most perplexing:
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.

Biggest disappointment:
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.)

Biggest question:
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?

Next steps:
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.

...And beyond:
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.

Stay tuned:
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!)

 

[crouse]

 

[xero-D-hero]

Most impressive:
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.

This all has to do with the way the gain is staged between the preamp and the amp.
If the preamp is sending the same "loudness" signal & both amps input levels are set to account for such.
Then that was to be expected.

You could change that realtionship by upping the input level controls on the 7B3's.
That would allow the preamp's volume control to seemingly pass along a "louder" signal at a lower setting.
Thus it would play "louder" at a lower setting on the preamp's volume control.

But pretty much it's often just a game of give & take that really is'nt changing all that much.

What it boils down to is this:
Those speakers need what they need to play @ the level you are listening at regardless of which amp is driving them.

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.

One word > Overhead.
The 7B3's have a bunch more vs. the Mc.
That additional overhead allows more effortless reproduction of the sort of material you're talking about here.

Biggest disappointment:
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.)

See my first reply above and study up on gain staging and how that whole preamp gain and amp gain relationship works...

Biggest question:
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?

Again,see comments above on the whole "overhead" thing...

I predict that you'll like the bigger Mc amps and the 7B3's will be bested by those.

As for the digital side,that's a whole other can-O-worms...

Food for thought.

Bret P.

 

[JimmyEL34]

This all has to do with the way the gain is staged between the preamp and the amp.
If the preamp is sending the same "loudness" signal & both amps input levels are set to account for such.
Then that was to be expected. You could change that realtionship by upping the input level controls on the 7B3's.

That would only be doable on the 7B3 Professional model which has an adjustable gain pot on the back; I have the "regular" 7B3s which just have a 26dB/29dB switch on the back. Bryston recommends using 26 for balanced input and 29 for unbalanced, and since my Mac's pre-out only has unbalanced, I used the 29dB setting. But to your point about both amps receiving the same loudness signal, I get that, but then I'll have to ponder some more on the fact that since a power amp is always running wide open and one is 200 watts and the other 900 watts, I guess I don't get how the same loudness signal comes out to the same listening dB whether it's 200 or 900 watts. I guess I have a lot to learn. So, now I'm thinking more watts just means you can play louder with less distortion and have more overhead. All this time I was thinking, wrongly, along the lines of a 100 watt light bulb burns brighter than a 40 watt light bulb, etc...

One word > Overhead.
The 7B3's have a bunch more vs. the Mc. That additional overhead allows more effortless reproduction of the sort of material you're talking about here.

So true! That I totally understand and was expecting exactly that and the 7B3's excelled beautifully in this category - I listened to gobs more music than I listed in the review and nothing I threw at them could trip them up - the more complex the music, the more they shone. Overhead 'tis a wonderful thing!

As for the digital side,that's a whole other can-O-worms... Food for thought.
Bret P.

Yeah, I'm a little behind in my digital realm, but I'll get there eventually - after I get my amp situation sorted out. Thanks for the food for thought - all good points

 

[mozcho]

Stay tuned:
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!)

Very eager to read the Part II......

 

[KentTeffeteller]

My favorite modern brighter voiced equipment is Bryston. And for me, an equally superb company in audio. And the best warranty and support in audio today. One of the best systems I ever heard was a pair of B&W 801 loudspeakers, powered by Bryston.

 

[audiofun_21]

I realize this is an old thread, but uniquely with AK, I find the most engagement with it looking for threads relative to my current interest then dropping in my thoughts. I’ve come back to some of these threads a decade later and found useful discussion off and on (not on this account of course I couldn’t recover my other one) as a result. And hope that it helps others in the future doing late night random searches.

The 6700 is a phenomenal value, likely one of the best value products Mcintosh has ever produced… but that it couldn’t quite keep up with 900w of separates amplification is no shocker. likely even just as much down to architecture differences between the McIntosh’s amp section versus the Bryston. Like you said, I think it’s more revealing how little difference there was (more on that below).

Now that being said, the “volume percentage” issue is no different even with McIntosh’s own XR100 towers. Which aren’t super efficient, and the volume needs to be around 50 percent or so to really make those “sing” as well. So this likely didn’t have much to do with your speakers as much as how Mcintosh has set up the operating range on the preamp section, I guess?

Furthermore, this will probably piss off some folks… but I love experimenting with everything from 5.00 to 50k and mixing and matching all kinds of combos. High end front end gear with pawn shop find speakers… high end speakers with dumpster grade gear etc…

I may not have “golden ears”… I may not be using the latest DSD123456 sources with 97000khz resolution. But I feel I have a pretty decent grasp on what sounds good *to me*. And my trusty old 1997 beat to pieces Pioneer VSX406 Pro Logic receiver has absolutely NO trouble with the XR100s. No… i dont just mean “it makes noise”, I mean as in its completely usable. In fact, things come alive far lower on the 406’s motorized volume knob than the equal percentage representation on the Mac. And I’d be lying to myself if I didn’t say it sounds well… just about as good. But it’s an ugly old black box with a dim orange tinted VFD I can barely see from across a room. The Mcintosh has so many other wonderful aspects beyond just how it sounds. And that’s why I love it. Much as I may respect Bryston gear, it just doesn’t capture me the same way as the all in one Mac does. But your example also illustrates on the other end why I have no desire anymore to stack up a 30,000.00 rack of *anyone’s* components just to convince myself it must be better because it’s more watts and boxes.

I consider myself an evangelist for the 6700 more so than Mcintosh itself. It gives the *average* audiophile everything they could ever need and flexibility for a long time to come at a fair price considering all you get. This of course somewhat extends to the 7200 with the important caveat that it’s tuner section can never be replaced, and thus you can never enjoy the benefits of HD Radio via the superb TM2 tuner module with it.

 

[damacman]

@JimmyEL34 - ooc, which taps on the 6700?

As the Maggies are 4 Ohm rated and the Brystons OTL designs, the 8 Ohm taps would be the correct choice for a level playing field. Either way, I enjoyed the read.

 

[markd51]

I realize this is an old thread, but uniquely with AK, I find the most engagement with it looking for threads relative to my current interest then dropping in my thoughts. I’ve come back to some of these threads a decade later and found useful discussion off and on (not on this account of course I couldn’t recover my other one) as a result. And hope that it helps others in the future doing late night random searches.

The 6700 is a phenomenal value, likely one of the best value products Mcintosh has ever produced… but that it couldn’t quite keep up with 900w of separates amplification is no shocker. likely even just as much down to architecture differences between the McIntosh’s amp section versus the Bryston. Like you said, I think it’s more revealing how little difference there was (more on that below).

Now that being said, the “volume percentage” issue is no different even with McIntosh’s own XR100 towers. Which aren’t super efficient, and the volume needs to be around 50 percent or so to really make those “sing” as well. So this likely didn’t have much to do with your speakers as much as how Mcintosh has set up the operating range on the preamp section, I guess?

Furthermore, this will probably piss off some folks… but I love experimenting with everything from 5.00 to 50k and mixing and matching all kinds of combos. High end front end gear with pawn shop find speakers… high end speakers with dumpster grade gear etc…

I may not have “golden ears”… I may not be using the latest DSD123456 sources with 97000khz resolution. But I feel I have a pretty decent grasp on what sounds good *to me*. And my trusty old 1997 beat to pieces Pioneer VSX406 Pro Logic receiver has absolutely NO trouble with the XR100s. No… i dont just mean “it makes noise”, I mean as in its completely usable. In fact, things come alive far lower on the 406’s motorized volume knob than the equal percentage representation on the Mac. And I’d be lying to myself if I didn’t say it sounds well… just about as good. But it’s an ugly old black box with a dim orange tinted VFD I can barely see from across a room. The Mcintosh has so many other wonderful aspects beyond just how it sounds. And that’s why I love it. Much as I may respect Bryston gear, it just doesn’t capture me the same way as the all in one Mac does. But your example also illustrates on the other end why I have no desire anymore to stack up a 30,000.00 rack of *anyone’s* components just to convince myself it must be better because it’s more watts and boxes.

I consider myself an evangelist for the 6700 more so than Mcintosh itself. It gives the *average* audiophile everything they could ever need and flexibility for a long time to come at a fair price considering all you get. This of course somewhat extends to the 7200 with the important caveat that it’s tuner section can never be replaced, and thus you can never enjoy the benefits of HD Radio via the superb TM2 tuner module with it.

I think I see what you are saying, and I'll agree to not discount an Integrated Amp. That these truths go back about 50 years or so. Countless super examples of such. Both yesteryear, and today.

Who would be shamed with a Luxman, Accuphase, Gryphon, Audio Research, etc sweetie pie in house?