[Sasha]

I had a chance to compare performance of Bryston 7B SST amplifiers with an amplifier from a renowned manufacturer, and noticed something interesting.
Will not mention what the other amp was, do not wish to start a war of words and opinions  , it will suffice to say that it was another Canadian manufacturer whose products were at significantly higher price point.
Speakers driven were PMC IB2.
The other amp is rated at 200W/8ohms and according to reviews deals very well with difficult loads.
The other amp had no problems controlling low end, no objections in regard to that aspect of performance.
But the midrange was much laid back, closed in, somewhat lacking in details.
Easily noticeable on music with acoustic instruments and vocals.
With Bryston female voices were extremely life like, open, with great presence.
Considering that other amp did not have problems with low end, was this difference in midrange simply the result of power reserve Bryston had, or it was more due to differences in design?
In other words, can one expect that more power will result in better performance across the board regardless of recommendations from speakers’ manufacturer for power?
Would for example moving from 7B SST to 28B SST result in even greater performance?

[nickelbut10]

If the first watt sucks then so will the rest. Bryston products have a very accurate sound regardless of how much power the amp is capable of producing. The Bryston amp would of probably had better synergy with the PMC speakers. Not saying the Bryston amp just wasn't just plain better, which it probably was. Depending on the speaker, more power is not always needed. It also, doesn't mean it will always sound better. Look how incredible the Bryston B60 sounds. One of the best integrated amps every built IMO, and it is only rated at 60 watts. Put it on a speaker that is easily driven, and you have plenty of power.

[DaveC113]

Taken out of context with the speakers, its impossible to say. My Mirage bipolar floorstanders like very powerful amps and do seem to follow the "more is better" principle, but my single drivers do not require much power and big ss amps usually sound too forward and strident... a simple SET tube amp w/ less than 10 wpc is the way to go with them. Then there is the "synergy" factor, which has to do with components being electrically compatible, as well as subjectively sounding good together. For example, some low impedance speakers would do better with an amp that can source a lot of current and was designed for the task.   

[denjo]

Would for example moving from 7B SST to 28B SST result in even greater performance?

Most definitely! With the 28B SST, the music simply oozes effortlessly!

Best regards
Dennis

[vegasdave]

If you can afford it, go for the 28BSST.

[James Tanner]

If the first watt sucks then so will the rest. Bryston products have a very accurate sound regardless of how much power the amp is capable of producing. The Bryston amp would of probably had better synergy with the PMC speakers. Not saying the Bryston amp just wasn't just plain better, which it probably was. Depending on the speaker, more power is not always needed. It also, doesn't mean it will always sound better. Look how incredible the Bryston B60 sounds. One of the best integrated amps every built IMO, and it is only rated at 60 watts. Put it on a speaker that is easily driven, and you have plenty of power.

Hi Nickelbutt,

I like your comment about the 'first watt'.  One of the major design principles with our 28B SST was to make the 'first' watt as accurate as the 'maximum' watt.

Here is a quote from the 28B brochure:
"A significant part of the design criteria for the 28B SST was to develop a very powerful amplifier that would drive any speaker on the planet but maintain an ideal power curve at 1 watt as well as at 1000 watts and every power level in between. Most amplifiers exhibit a power curve whereby the best noise floor, drive capability and distortion is maintained from about 1/3 power and up."

I think that is one of the reasons why the 28B has had such an incredibly positive response among reviews and customers. They just do not expect a 1000 watt mono amplifier to sound this sophisticated.

james

[nickelbut10]

Awesome James. I have personally never heard the 28b yet. I will have to make a point of it to hear it soon. I am sure it is absolutely amazing, just like everything else you guys make. Just recently I heard a 7B/Bryston CDP/BP26 combo on a pair of B&W 802D's. Now there is a speaker that will not open up unless you have some power, and the 7B made them sound effortlessly amazing. The store I was in was Just Hi Fi here in my home town. I asked the Floor Manager if he had any used Bryston gear and he replied " No, if I did I would have it in my home right now" lol. I think that says a lot.

[Sasha]

If the first watt sucks then so will the rest. Bryston products have a very accurate sound regardless of how much power the amp is capable of producing. The Bryston amp would of probably had better synergy with the PMC speakers. Not saying the Bryston amp just wasn't just plain better, which it probably was. Depending on the speaker, more power is not always needed. It also, doesn't mean it will always sound better. Look how incredible the Bryston B60 sounds. One of the best integrated amps every built IMO, and it is only rated at 60 watts. Put it on a speaker that is easily driven, and you have plenty of power.

Hi Nickelbutt,

I like your comment about the 'first watt'.  One of the major design principles with our 28B SST was to make the 'first' watt as accurate as the 'maximum' watt.

Here is a quote from the 28B brochure:
"A significant part of the design criteria for the 28B SST was to develop a very powerful amplifier that would drive any speaker on the planet but maintain an ideal power curve at 1 watt as well as at 1000 watts and every power level in between. Most amplifiers exhibit a power curve whereby the best noise floor, drive capability and distortion is maintained from about 1/3 power and up."

I think that is one of the reasons why the 28B has had such an incredibly positive response among reviews and customers. They just do not expect a 1000 watt mono amplifier to sound this sophisticated.

james

James,

How does one know the power level at which an amp operates?
For example, with BP26 and 7B SST, if volume control on BP26 is just below 12 o’clock, would that mean that 7B SST is close to ½ of its power?

[niels]

Its actually close to full power I assume......music is not a steady sinus tone, its dynamics, and in peaks it will use 5-10 times the power it uses on average. Try watching an older Pioneer 50 watt amp with VU meters if you get the chance and see the red lights for clipping light up even when you average 5 watts....
Combined with speaker sensitivity you can get really bizarre results, I used to own IMF RSPM MK IV transmisjonlines, and the need 40 watts for 96 db/ 1 meter !!!  With an Accuphase 200 watt power amp going at full throttle I could stand 3 feet from the speaker and actually have a conversation with a buddy....

[Burke]

I like your comment about the 'first watt'.  One of the major design principles with our 28B SST was to make the 'first' watt as accurate as the 'maximum' watt.

Here is a quote from the 28B brochure:
"A significant part of the design criteria for the 28B SST was to develop a very powerful amplifier that would drive any speaker on the planet but maintain an ideal power curve at 1 watt as well as at 1000 watts and every power level in between. Most amplifiers exhibit a power curve whereby the best noise floor, drive capability and distortion is maintained from about 1/3 power and up."

James,

Out of curiosity as an owner of some 7B SSTs, how accurate is the 'first' watt of the 7B SST compared to the 'maximum' watt? Is the 7B one of those designs that exhibits "a power curve whereby the best noise floor, drive capability and distortion is maintained from about 1/3 power and up." ? (If so, that seems to be awfully difficult to detect in normal listening.)

Thanks,
Burke

[nickelbut10]

I am no Engineer for Bryston. But my guess would be that the 7bsst was designed with the same mind set as the 28 just with less power. Meaning, the first watt is as good as the rest. I doubt anything they design would have this issue. Cheers.

[rabpaul]

The 14 and 28 are bridged designs (plus a lot more new stuff) so they are not the 7 plus more power. Yes/No?

[James Tanner]

The 14 and 28 are bridged designs (plus a lot more new stuff) so they are not the 7 plus more power. Yes/No?

Hi,

The 7B,14B and 28B are all fully balanced bridged designs. So you can think of the 14B as two 7B's on one chassis and the 28B as a 7Bx2. However we have used some new circuit design ideas in the 28B SST.

james

[James Tanner]

I am no Engineer for Bryston. But my guess would be that the 7bsst was designed with the same mind set as the 28 just with less power. Meaning, the first watt is as good as the rest. I doubt anything they design would have this issue. Cheers.

Hi,

Yes we have always attempted to design the amplifiers with the same attention to low power performance as high power performance. It just gets more difficult as the power range gets larger due to the complexity of the circuitry.

james

[James Tanner]

I like your comment about the 'first watt'.  One of the major design principles with our 28B SST was to make the 'first' watt as accurate as the 'maximum' watt.

Here is a quote from the 28B brochure:
"A significant part of the design criteria for the 28B SST was to develop a very powerful amplifier that would drive any speaker on the planet but maintain an ideal power curve at 1 watt as well as at 1000 watts and every power level in between. Most amplifiers exhibit a power curve whereby the best noise floor, drive capability and distortion is maintained from about 1/3 power and up."

James,

Out of curiosity as an owner of some 7B SSTs, how accurate is the 'first' watt of the 7B SST compared to the 'maximum' watt? Is the 7B one of those designs that exhibits "a power curve whereby the best noise floor, drive capability and distortion is maintained from about 1/3 power and up." ? (If so, that seems to be awfully difficult to detect in normal listening.)

Thanks,
Burke

Hi Burke,

I will get a more technical answer for you from engineering on exactly how the design parameters change when looking at low power performance in large power amplifiers but think of it like designing a car engine to have as wide a 'power (torque) curve' as possible rather than having to attain a high revving condition before the engine power is applied to the car wheels.

james

[James Tanner]

I like your comment about the 'first watt'.  One of the major design principles with our 28B SST was to make the 'first' watt as accurate as the 'maximum' watt.

Here is a quote from the 28B brochure:
"A significant part of the design criteria for the 28B SST was to develop a very powerful amplifier that would drive any speaker on the planet but maintain an ideal power curve at 1 watt as well as at 1000 watts and every power level in between. Most amplifiers exhibit a power curve whereby the best noise floor, drive capability and distortion is maintained from about 1/3 power and up."

James,

Out of curiosity as an owner of some 7B SSTs, how accurate is the 'first' watt of the 7B SST compared to the 'maximum' watt? Is the 7B one of those designs that exhibits "a power curve whereby the best noise floor, drive capability and distortion is maintained from about 1/3 power and up." ? (If so, that seems to be awfully difficult to detect in normal listening.)

Thanks,
Burke

Hi Burke,

I will get a more technical answer for you from engineering on exactly how the design parameters change when looking at low power performance in large power amplifiers but think of it like designing a car engine to have as wide a 'power (torque) curve' as possible rather than having to attain a high revving condition before the engine power is applied to the car wheels.

james

Hi Burke,

Here is a more technical explaination for you on your first watt question.

I have been asked a few times what Bryston means by 'super-low distortion from the first Watt'.  Simply stated, this means Bryston amplifiers, (and the new 28B SST is the prime example), do not have annoying high-order harmonics that get worse with descending power levels.  Class-AB amplifiers have often been found to have high-frequency artifacts that become a larger percentage of the overall distortion picture at lower power levels.  Bryston's proprietary circuitry, however, eliminates this possible problem, and results in amplifiers that sound smooth and sweet from the very lowest power levels all the way to thunderous outputs that threaten to 'raise the roof'. 

Over the years, tube circuitry has often enjoyed a reputation for sounding deliciously smooth, especially at low levels.  This is because tube circuits typically show their lowest distortion at the lowest output levels. Bryston's new amplifiers have acquired a reputation all over the world for being 'tube-beaters' in that respect, albeit with much higher potential power levels and lower overall distortion in any power range.

First, Bryston's proprietary Quad-Complementary output circuit responds faster and more accurately to high audio frequencies than any other type of output circuit.  As a result, even at higher output levels, THD at 20KHz is well under 0.005%, and vanishes into the unmeasurable, below the low noise levels, at 1 Watt.

Second, Bryston's super low-noise input circuitry removes the final veil from low outut levels and faithfully reproduces the dynamic range of the original performance.  The 28B SST, for instance, measures typically more than -115dB from 20-20KHZ, Unweighted.

Third, Bryston's power-supply design prevents interchannel crosstalk, and preserves the exceedingly subtle directional-cues, image placement and 3-dimensionality of the original performance better than any other amplifiers we have heard, akin to a 'sonic hologram'.

Sincerely,
Chris Russell
CEO, Bryston Ltd.

[vegasdave]

Thank you for the info, James. That was very interesting!

[Freo-1]

OK, so what about this:


http://www.spectrum.ieee.org/archive/1640/distortion

Seems the noise and distortion characteristics are not as clear cut as first blush would appear.

[Sasha]

OK, so what about this:


http://www.spectrum.ieee.org/archive/1640/distortion

Seems the noise and distortion characteristics are not as clear cut as first blush would appear.

Interesting reading.
On the subject, I have one problem with claims related to triode based amp performance from the aspect of entire system performance.
I do not find tube amps objectionable and had them in the past, but my experience was that power plays a significant role with them as well. Triodes being in general low power require very efficient speakers, and my listening impressions were that such speakers trade other aspects of performance for high efficiency, resulting in the entire system performance being unsatisfactory. So what is the point of having such an amp with low distortion if the overall performance is not that great?
Maybe I never heard proper combination and setup, cannot say, but that was my experience.
In addition, the paper talks about MOSFET being the worst, but I never heard a system driven by big Halcro amps, such as DM68, sound bad.
At present time I can think only of a couple of amps that I would consider to be a good replacement for 7B SST, both being in megabuck range, and it would have to be a proper my system / my home audition.
To add to the story, I heard a bigger brother of the amp mentioned in the post, not in my system, but it was interesting nonetheless. Bigger brother was significantly more open, yet still had a trace of such a character.
So I am still not sure what is at play here.
Seems only your ears should be the judge.

[Freo-1]

OK, so what about this:


http://www.spectrum.ieee.org/archive/1640/distortion

Seems the noise and distortion characteristics are not as clear cut as first blush would appear.

Interesting reading.
On the subject, I have one problem with claims related to triode based amp performance from the aspect of entire system performance.
I do not find tube amps objectionable and had them in the past, but my experience was that power plays a significant role with them as well. Triodes being in general low power require very efficient speakers, and my listening impressions were that such speakers trade other aspects of performance for high efficiency, resulting in the entire system performance being unsatisfactory. So what is the point of having such an amp with low distortion if the overall performance is not that great?
Maybe I never heard proper combination and setup, cannot say, but that was my experience.
In addition, the paper talks about MOSFET being the worst, but I never heard a system driven by big Halcro amps, such as DM68, sound bad.
At present time I can think only of a couple of amps that I would consider to be a good replacement for 7B SST, both being in megabuck range, and it would have to be a proper my system / my home audition.
To add to the story, I heard a bigger brother of the amp mentioned in the post, not in my system, but it was interesting nonetheless. Bigger brother was significantly more open, yet still had a trace of such a character.
So I am still not sure what is at play here.
Seems only your ears should be the judge.

Well, I'm not so sure.

If one takes a Harmon Kardon Citation II, converts the out to triode, the result is 35 WPC that will drive most speakers to realistic SPL levels.

For example, I've used this setup with a pair of Polk LSI 15's, and I can assure you my audiophile and non audiophile friends alike love the sound from the setup. (I also changed the front end from pentode to 5687 triode). I've owned a lot of high end gear over the years, including some very respected solid state products, and at the end of the day, I find tubes are more pleasing (and realistic sounding) than solid state (in general-too many variables overall).

MOSFET amps can sound quite nasty (the MOSFET mist is REAL). As stated earlier, depends on the overall topology. One of the best solid state MOSFET amps I've heard is a Sony DA9000ES with a Fire Wire input (SACD bitstream) as an input. Unbelievable detail and clarity for a solid state setup.   

The other point I found interesting in the piece is what happens with noise regarding the JFET and 6AU6 when a signal is applied. 

It's definitely "Horses for Courses"

PS: Bryston makes great stuff! I recommended their amps be used at the local YMCA for exercise classes. They are long lasting, and sound excellent.