Bryston Cubed amp owners please check in ...

[joeinid]

Please show me some Bryston love. What amp, preamp and speakers are you are using.

I'm also especially curious to hear from those of you that have the new 28B Cubed amps.

[Mr Peabody]

I noticed the Cubed amps recently and wondered how they sound. Prices seem pretty good for a name brand muscle amp. Also, they have two models within $200 of each other I was wondering what the difference was. The sight I was looking at was giving me issues, I need to try again.

[Jack]

They carry them at AA so you can try them for the cost of return shipping if you have to give up on the ML. Do the JBL's need that much juice? Another amp you might want to try out is the BHK 250.

[Mr Peabody]

I wouldn't need 300x2 necessarily but I like to have reserve. The 4367's are 94dB but do seem to like current.

The Cubed amps don't double down, the design with the convection cooling etc. sounds a bit similar to my 532h or Crown. Cubed are dual mono though with separate power supplies. Bottomline is how the ears like it when it's playing though.

[Jack]

I haven't heard one in years so don't really know how they sound. Joe liked the last version and now they have the new 2.5 which might be enough power if those are your endgame speakers. The BHK does double down and mine is staying put for a while. You can fine tune it a bit with the input tubes so might be worth a listen.

[joeinid]

Yes, I absolutely loved the 28BSST2 amps and only sold them to get the 28 Cubed. Shipping dates were unknown at the time and I kinda got sidetracked. I still think about them but am curious what others think about them after living with them for a while. Having a little extra headroom is always welcome. My 28 squared were smooth and slightly sweet with no grain. I expect no less and actually more of the good stuff from the new Cubed amps. IMO, a great SS pre or a nice tube preamp could be a killer combo. Certainly not your typical solid state amps.

I haven't heard one in years so don't really know how they sound. Joe liked the last version and now they have the new 2.5 which might be enough power if those are your endgame speakers. The BHK does double down and mine is staying put for a while. You can fine tune it a bit with the input tubes so might be worth a listen.

[Mike]

Joe - I had the little 3BSST3 in the store on the Magico M3's last month. WOW!! I honestly wasn't expecting what I heard. Tight bass. Sweet top end. I kept standing over it saying "where the hell is all that power coming from?"

Not the new SST3, but I've owned the 9BSST2 FOREVER. No wonder there is a 20 year warranty. It's built like a tank.






Sent from my iPhone using Tapatalk

[joeinid]

I am loving the new look. It took a while to grow on me but now I think it's great. I did love my 28 squared amps.

[James Tanner - Bryston]

Thanks Mike - coming from you this is high praise indeed - will pass it along - thanks.

james

[Mike]

James - does Bryston have a new SSP coming out?

[James Tanner - Bryston]

Hi Mike

No plans on that front currently - the SP3 is still selling well.

james

[Mr Peabody]

The Bryston website has some basic info on the Cubed amps, some design features but really don't tell much about them. Anyone know if a white paper or more indepth description is available? Example, are they differentially balanced or XLR inputs just that, type of output devices and amount, etc.

[James Tanner - Bryston]

Hi Mr Peabody

Will post some for you.

BRYSTON

Bryston has used Class AB output stage architecture for many years because it provides an excellent platform for one of the things we find most important in music reproduction: Linearity. There are numerous ways to implement a high-current output stage for an amplifier meant to drive speakers. There is Class A where all output devices carry signal current at all times; Class B where the individual output devices carry signal current 50% of the time, each on one polarity of the signal; class AB where each polarity of output device carries signal current more than 50%, but less than 100% of the waveform cycle.

There is also Class D, where the signal is converted to a varying pulse-width square-wave on a supersonic carrier, but that is beyond the scope of these comments. Suffice it to say that this can be a good, accurate way to amplify a signal, but the overall linearity is dependent on the accuracy of the conversion to an HF carrier, modulated square-wave. It also presents challenges with excluding the carrier itself from the final, delivered signal to the speakers. It can represent many hundreds of watts of RF energy, and the necessary filtering has a tendency to affect audio frequencies to some extent.

Once we have chosen maximum linearity as one of the most important parameters of an output stage, we can look at the characteristics of the power devices to see where they perform best, and where they may have problems. Power transistors have a rather broad linear region in their transfer function, from just above their 'on' threshold, up to the higher current region closer to saturation, or fully 'on'. At very low current near threshold, and at very high current near saturation, the transfer function bends toward an overall 'S' shape. Thus, it becomes obvious that for the best linearity we want to keep the output devices operating within the optimal linear region of their transfer function. We can do that by operating the output transistors as opposite polarity pairs, switching from one polarity to the other at the zero-crossing region. Class B will inevitably show a discontinuity in the zero-crossing region, since as we saw above, the transistors are not linear at those low-Voltage, low current parts of the signal. Placing a known continuous biasing current on the transistors prevents them from entering that nonlinear part of their curve, and smoothes the zero-crossing region. There may still be a small discontinuity in the zero-crossing region if the upper and lower output devices do not have exactly equal and opposite characteristics at the crossover point. Unfortunately, opposite polarity devices have similar, but not exactly equal, characteristics.

Attempting to overcome the small remaining zero-crossing discontinuity by increasing the bias current to a level that it keeps the output devices 'on' for 100% of the waveform cycle does nothing but push the devices into the nonlinear region at the high-current end of their transfer function. Distortion actually goes up, not down, all else being equivalent.

Thus, Bryston began exploring the possibility of giving the two polarities of output transistor exactly 'equal and opposite' characteristics. In that way the zero-crossing region can remain linear. The way we found was to incorporate our 'Quad Complementary' output section, discussed in the white paper sent to you by James Tanner earlier. That output configuration goes a long way toward virtually eliminating zero-crossing artifacts from the signal, and sound quality is very improved.

In the future, it remains to be seen whether Class D can achieve the overall musicality that a correctly designed Class AB amplifier can achieve. It is not there yet, but we feel it holds promise.

In today's noisy world, there are challenges remaining in terms of an amplifier's immunity to RF and other noise signals coming in on the power-supplies and input cables. Our latest 'Cubed' models have demonstrated that it is quite important to take that into account as well as overall linearity of a test signal. That's also outside of this discussion, of course, but it matters.

I hope this above is helpful, but please let me know if you have questions or comments.

Best regards,
Chris Russell
Bryston Ltd.

[James Tanner - Bryston]

Cubed Amps Advantages


The improvements in each 'Cubed' amplifier model starts at the input buffers. That stage now consists of a new patented super-linear, low noise circuit developed by a partnership between Bryston and Ph.D. engineer Dr. Alexandru Salomie. It reduces noise and distortion in the overall amplifier by a substantial margin. Audible improvements consist of expanded spaciousness and depth of focus, better 3-dimensional presentation, improved midbass clarity, and more top-end 'air'.

In addition, the Cubed Series has much-improved RF and audio-frequency noise filtering before the power supplies to prevent 'hash' on the power line from interfering even minutely with the power supplies or the signal. The audible effect is immunity from power-line spikes and fluctuations, quieter silent passages in the music, 'blacker blacks'.

[James Tanner - Bryston]

28B Cubed Amplifier Philosophy

FIRST TO LAST WATT PHILOSOPHY:

A significant part of the design criteria for the new Cubed amplifiers was to develop amplifiers that would maintain an ideal power curve through the 'first and last watt'. Most amplifiers exhibit a power curve whereby the best noise floor, drive capability and distortion are maintained from about 1/3 power and up. The new Bryston Cubed series maintain their ideal power curve right from the first watt to the last watt. Think of it like a torque curve in a car. The sweet spot or the torque curve has been expanded.

Achieving this 'First-to-last-Watt' fidelity and clarity has to do with a number of design approaches:


• First is complete freedom from low-level crossover, or zero-crossing, artifacts. This is not as easy as it sounds. Most class-AB amplifiers have sufficient bias to prevent primary crossover distortion, but there is another type of crossover artifact called 'secondary crossover distortion', caused by insufficient speed in the driver transistors. We use very fast drivers to prevent this, but more important is Bryston's proprietary Quad Complementary Output design vastly reduces the capacitance 'seen' by the driver transistors, virtually eliminating storage delay in the output stage that could contribute to nonlinearities in the zero-crossing region.

• Second is Bryston's continuing efforts to reduce low-level noise. The clarity of Bryston's designs is enhanced at low listening levels by pushing the noise floor far below the signal level, improving the 'silence between the notes' and enhancing the clarity of the music at low power levels.

• Third is Bryston's concentration on reducing distortion at all levels, and most especially at high frequencies. Bryston amplifiers are perhaps the only designs to concentrate as much effort at reducing HF distortion artifacts as we do, and the results are remarkably 'flat' THD-with-frequency curves, showing almost no tendency to increase distortion as frequency rises. This has the effect of reducing overall 'haze', helping to pull the quietest passages out of the background.

There are other small contributors to this low-level clarity, some having to do with power-supply design for extreme stability, (and in Stereo or multi-channel amps, separated for each channel), which very notably improves the placement-in-space and focus of the sonic 'image'. We think the overall result is an unprecedented degree of clarity and freedom from artificiality, especially noticeable at lower levels in comparison with other designs, but continuing to even the highest outputs.

[Mr Peabody]

James appreciate the additional information. One other thing, maybe I should have deduced from what you gave, are the Cubed amps differentially balanced?

[James Tanner - Bryston]

James appreciate the additional information. One other thing, maybe I should have deduced from what you gave, are the Cubed amps differentially balanced?

Hi

Yes all the balanced inputs are deferentially balanced.

james

[Paul]

Hi James. I'm doing some home audition with your 4B3 amp for last couple of days. Let me tell you I never been a fan of Solid State at all. I owned/tried so many SS amp and gave up few years ago and been only own the tube amplification since. However this 4B3 amp just open up the whole new world to me. I just can't believe the depth , 3D presentation and how smooth it is without losing any details and high without being harsh. I'm so impressed with it and wondering about the 28B3 amps. Now quick question for you I understand you have a gain control on this 4B3 amp and early production of 28B3 with choice of 23 db and 29 db. I just checked the 28B3 you deleted the gain control option. Is there any reason for it ? Also , if I order one is it possible to you can make one with it ?

Thanks in advance.


Sent from my iPhone using Tapatalk

[James Tanner - Bryston]

Hi Paul

Well thank you for your kind comments and of course I agree that the new Cubed amplifiers really do bridge the gap between the best of solid state and tubes.

The switch is not there on the 28B's as we found with that much power we got better measured performance with the switch out of the circuit. I believe it has to do with the amount of current the 28B can deliver.

I could ask engineering if we could do a special version at 23 if it was needed.

james

[Paul]

Joe . Here you go

[joeinid]

Looks awesome Paul! Tell me more

[bthomas9]

Joe . Here you go

Sadly it only lets me like this once...Paul with SS. I'm screenshotting this incase you delete it later


Sent from my iPhone using Tapatalk

[Paul]

Looks awesome Paul! Tell me more

I will soon, let me enjoy them first !

[bthomas9]

Demo or bought and paid for. I'm with Joe. I want to know more...


Sent from my iPhone using Tapatalk

[Paul]

Sadly it only lets me like this once...Paul with SS. I'm screenshotting this incase you delete it later


Sent from my iPhone using Tapatalk

Ha! So true ! I never thought I would buy the SS amp ever ! But let me tell ya, this one is different breed compare to any other

[Paul]

Demo or bought and paid for. I'm with Joe. I want to know more...


Sent from my iPhone using Tapatalk

Bought and paid in full !

[Mike]

Congrats Paul!


Sent from my iPhone using Tapatalk

[joeinid]

So what convinced you to try SS again and specifically Bryston? I personally think Bryston does not get enough respect. Since the squared line and now the Cubed series, Bryston can certainly go up against the big boys, and now, win. With their excellent service, 20 year warranty and superb fidelity, there's no way you can dismiss Bryston. I only sold my squared amps to get the Cubed. Looks like I've found another excuse

Ha! So true ! I never thought I would buy the SS amp ever ! But let me tell ya, this one is different breed compare to any other

[Paul]

So what convinced you to try SS again and specifically Bryston? I personally think Bryston does not get enough respect. Since the squared line and now the Cubed series, Bryston can certainly go up against the big boys, and now, win. With their excellent service, 20 year warranty and superb fidelity, there's no way you can dismiss Bryston. I only sold my squared amps to get the Cubed. Looks like I've found another excuse

Hmmm very good question Joe. Let me think .... I owned several SS amps and heard thousands and I always found something was missing regardless of price. If you are tube fanboy you will know exactly what I mean please don't get me wrong my tube amps won't go anywhere. I love both of them for different reasons.

Luckily I have one super dealer call " Audio by Mark Jones " and he was kind enough for me to do home demo of 4B3 Cubed amp and I had a zero hope until I plugged in .. ( comparing $5,600 amp vs my $23 k amp I know I know the price is not everything but usually what you pay is what you get )

I played few albums that I familiar with over the years and I was shaking my head and saying " What the heck! This can't be right. It's a SS amp ! how come sounds so beautiful so neutral and not missing anything? "

It just blew me away with its performance with super tight bass ( my 15" driver finally found a nice partner who can control her completely) and dead quiet. Also, the vocal was very close to tube. ( but it's still not a tube ) and wondering what 28B3 can do and I was done. I had to get them. So far I played last 10 hours and just couldn't be happier. I had a very high-end amp ($60k amp ) and I'm much more satisfied with Bryston 28B3. It's also a big step up from 4B3. Much more defined details and vocal have more weigh into it ( well I will review them more when break in is done ) thanks to James make this wonderful amp that can compete with double or triple price amps out there. It's keeper and since I have the 96db speakers I'm listening as Class A part most of the time too. Way to go Bryston and thanks to Joe bring up this thread. I'm a very happy camper.


P.S : Do not judge by the name of Bryston will be bright sounds. Not a hint of bright at all

Sent from my iPhone using Tapatalk

[Mike]

Congrats Paul! I bet classical music is insane.

28 Cubed and 4B Cubed and BDA3 on it's way to Suncoast Audio! Can't wait to hear these babies on the big Magico's. 1800 watts and sweet sounds.

The little 3B Cubed was excellent on the M3's, I can't imagine what the 28's will sound like.

[Paul]

Wow. Congrats Mike. That's wonderful news. I'm sure you will love them like I do.


Sent from my iPhone using Tapatalk

[joeinid]

Thank you Paul for your explanation. If we (meaning me) didn't have crazy upgraditis, my 28 squared would have been fine. But like you, wondering what their new gear sounds like, I get the itch.

[James Tanner - Bryston]

Hmmm very good question Joe. Let me think .... I owned several SS amps and heard thousands and I always found something was missing regardless of price. If you are tube fan boy you will know exactly what I mean please don't get me wrong my tube amps won't go anywhere. I love both of them for different reasons.

Luckily I have one super dealer call " Audio by Mark Jones " and he was kind enough for me to do home demo of 4B3 Cubed amp and I had a zero hope until I plug in .. ( comparing $5,600 amp vs my $23 k amp I know I know the price is not everything but usually what you pay is what you get )

I played few albums that I familiar with over the years and I was shaking my head and saying " What the heck ! This can't be right. It's a SS amp ! how come sounds so beautiful so neutral and not missing anything? "

It just blew me away with its performance with super tight bass ( my 15" driver finally found nice partner who can control her completely) and dead quiet. Also the vocal was very close to tube. ( but it's still not a tube ) and wondering what 28B3 can do and I was done. I had to get them. So far I played last 10 hours and just couldn't be happier. I had a very high end amp ($60k amp ) and I'm much more satisfied with Bryston 28B3. It's also big step up from 4B3. Much more defined details and vocal has more weigh in to it ( well I will review them more when break in is done ) thanks to James make this wonderful amp that can compete with double or triple price amps out there. It's keeper and since I have the 96db speakers I'm listening as Class A part most of time too. Way to go Bryston and thanks to Joe bring up this thread. I'm a very happy camper.


P.S : Do not judge by the name of Bryston will be bright sounds. Not a hint of bright at all

Sent from my iPhone using Tapatalk

Hi Paul,

Thanks for this great explanation - much appreciated - will pass it along - ENJOY!

[Mike]

Paul.pdf

[joeinid]

Very cool Mike/Paul, that's great.

[bobwah]

I've never heard Bryston gear but any company offering a 20year warranty has my respect!


Sent from my iPad using Tapatalk