[Gojo]

More seems better. IB2s power requirements are suggested to be 300 w at the PMC website. Below is a link to active system James had with IB2s.
James powered each speaker actively with a 7b, half a 4b, and half a 3 b.  Into 8 ohms that's 600 + 300 + 150 watts.  But the IB2s are a 4 ohm speaker. That would much more!!!!  Why would Mr Tanner power each tower with with over 1000 watts if there wasn't merit?


http://www.audiocircle.com/index.php?topic=43966.0

I went from a 4b sst2 to a 7b sst2 powering paradigm 60s and noticed a significant improvement in sound. More bass, more detail.  But not in your face loud.   The speaker suggested power requirements is 150 w at the website.

Several earlier threads have addressed and I believe made the point that speaker performance does improve.  Let your ears decide.  Mine did.

Best of luck

[texaslonghorn]

I would like to go back to the comment about evolutionary versus revolutionary improvements.  This past summer, I bought an old 3B (out of warranty).  As I am not completely inept with a soldering iron, I proceeded to update the amp to Bryston's current 3B design and do a few additional tweaks of my own.  All of these changes were evolutionary as I did not change the circuit design - I simply updated/upgraded components.  The "before and after" was stunningly different - and that was only after maybe 10 hours of playing time after the mods.  Maybe Bryston's designs are just exceptionally well suited to incremental improvements.

So fast forward to last month - November 2009.  I had an opportunity to get a Pass Aleph, so I sold my 3B.  Granted the Aleph has less than 100 hrs on it so far, but I will sum it up this way:  Dang I miss my 3B.  Right now, I am not that pleased with my decision to get the Aleph to replace that old cosmetically beat up 3B.  I am hoping it will improve with more burn in.  But the 3B was awesome from beginning.  My system never sounded that good.  Exact same comment from the guy who bought it from me.  I even offered to buy it back from him for 100% of his cost plus shipping if he was the least bit disappointed.  I was kinda hoping he would take me up on that, but he isn't.

Yes I know my experience is not directly related to the 7B line, but I do think it reflects the brilliance of Bryston's designs and the ability of those designs to make the absolute most out of evolutionary improvements.  If Bryston ever comes up with a true "next generation" design, you will probably have your own personal live orchestra sitting in your house rather than an electronic device.

[James Tanner]

Hi All,

I received this today from a new Bryston 7B SST-2 owner.


New Bryston User  - No More Concerns
 
“Thank you everyone for the kind responses and Mr. Tanner for the timely advice.

With my brother's help, the amplifiers ran all night playing a CD over and over again. This morning, the changes are jaw-dropping. I am happy to say that all our questions have been answered. It is hard to believe that a piece of electronic needs breaking in like a pair of leather boots. These amplifiers are letting us hear instruments and musical lines that we did not know existed. All of them came off very familiar albums we have listened to for years. In other cases, these amplifiers made each instrument sound near "live". We are a family of music lovers with two younger sisters who are musicians so we are all used to live music.

We can now hear instruments in their full "native" glory. We can also easily track complex interplay of instrument lines in a piece of music. It is now possible to hear how each instrument is played as it contributes the overall musical picture. The experience is simply mesmerizing.

My brother insists that these amplifiers need another week of "seasoning" to find their "true voice", his words! So we will keep it running and playing.  When appropriate, I will share our experiences with you all.

Thank you all again!

Anna”

System:
1. Audio Research Inc. CD-2 (vintage 1999)
2. Audio Research Inc. LS-25 (vintage 1999)
3. Audio Research Inc. VT-200 (vintage 1999)
4. Loudspeakers are the Thiel 3.7's (vintage 2009)
5. Bryston 7B SST-squared are to replace the VT200.
6. Room size is a large 20x30x8 room.

[95Dyna]

Hi All,

I received this today from a new Bryston 7B SST-2 owner.


New Bryston User  - No More Concerns
 
“Thank you everyone for the kind responses and Mr. Tanner for the timely advice.

With my brother's help, the amplifiers ran all night playing a CD over and over again. This morning, the changes are jaw-dropping. I am happy to say that all our questions have been answered. It is hard to believe that a piece of electronic needs breaking in like a pair of leather boots. These amplifiers are letting us hear instruments and musical lines that we did not know existed. All of them came off very familiar albums we have listened to for years. In other cases, these amplifiers made each instrument sound near "live". We are a family of music lovers with two younger sisters who are musicians so we are all used to live music.

We can now hear instruments in their full "native" glory. We can also easily track complex interplay of instrument lines in a piece of music. It is now possible to hear how each instrument is played as it contributes the overall musical picture. The experience is simply mesmerizing.

My brother insists that these amplifiers need another week of "seasoning" to find their "true voice", his words! So we will keep it running and playing.  When appropriate, I will share our experiences with you all.

Thank you all again!

Anna”

System:
1. Audio Research Inc. CD-2 (vintage 1999)
2. Audio Research Inc. LS-25 (vintage 1999)
3. Audio Research Inc. VT-200 (vintage 1999)
4. Loudspeakers are the Thiel 3.7's (vintage 2009)
5. Bryston 7B SST-squared are to replace the VT200.
6. Room size is a large 20x30x8 room.

There's that Bryston/Thiel 3.7 matchup again.  There must be something to it!

[Mad Mr H]

More seems better. IB2s power requirements are suggested to be 300 w at the PMC website. Below is a link to active system James had with IB2s.
James powered each speaker actively with a 7b, half a 4b, and half a 3 b.  Into 8 ohms that's 600 + 300 + 150 watts.  But the IB2s are a 4 ohm speaker. That would much more!!!!  Why would Mr Tanner power each tower with with over 1000 watts if there wasn't merit?

You are correct there is merit to the higher power.

BUT you have to think in a different way, Its NOT about the "power" itself........YES there is more total power but that does not mean you are driving the system any louder.........

With the increased power AVAILABLE also comes a better slew rate and damping factor . This leads to better control and detail.

That amp list is also the same used in MB2 and BB5 systems so it could be that the "demo kit" available was the same amp setup used in other larger demos.

IF you drive a speaker driver to hard you distort the voice coil as it heats up and even lights up (like a filament lamp!). that warps the coil & former and causes it to rub on the pole magnet, the process then continues until something gives up - Usually the voice coil goes open circuit.....

Another option of over power is to rip the cone as the excusrion isway past its limits, this can also be related to older age of a driver.

HF units similar issues but the weaker driver so if over driven dont hold out for long !!!

ALL that said - What usually kills the drivers quickest is a distorted (towards square wave from sine wave) signal. What you notice with many amps is that as you near high levels you loose control of the sound, it goes very toppy, no definition and is unpleasant to the hear. Distortion may also have risen to a level that is now audable, this may even be introduced at the preamp.

What I have noticed with Bryston amplifiers in both ST and SST series (Not tried SST2 yet) is the ability to maintain high levels without loss of control, you can drive a system much harder without damage if the signals are pure.

This does not have to be concert loud, there is a comfortable level we enjoy that differs from person to person and room to room. But it is nice to have the ability to turn the wick up a little  from time to time and know the system is still happy  along with its owner........

[Mad Mr H]

For the record........

I prefer the reproduction in the vocal range from my MB2's to my BB5i's......

I run a 7B SST to each mid in the MB2 and one side of a 4B SST on the BB5i

I also run 4 foot long cables to the MB2 and 6 foot to the BB5i

(Same Kimber silver KS3038 cabes)

Lexicon MC12B for the BB5i and Onkyo (Integra) to the MB2 - The Lexicon is the preferred unit.


So all things are not equal in the two systems but I feel close enough that the advantage I hear to be the use of the 7B SST for the mids.

[Daniel Datchev]

Hi Andy,
the difference between 4B-SST and 7B-SST is not only the power, but the basic principles impliment in these amplifiers.
3B,4B are using qard complimentary scheme and 7B,14B and 28B fully balanced for parallel connected transistors. As there is a virtual refference to zero the slew rate is combined sum of positive and negative which in lower amplifiers is 60V per micro second here becomes 120V per microsecond. At some piont of this topic I answered the question which bacmsl stated about the sufficient power for PMC OB1. Many would suggest going upper than 4B-SST whether I would suggest to change the speakers.
Daniel

[Gojo]

Hi Daniel

This is a more FYI (below).  I'm certainly not wanting to play devils advocate.  There seems to be enough of that.  I am however a convert when it comes to overpowering speakers.  No one would dispute the numbers comparison between the 4b and 7b.  Before I upgraded to the 7b on the paradigms (which have now been replaced with Ib2s) i was intrigued by some of the earlier threads on power and speaker/amp connections.
1) A smaller PMC speaker LB1s were powered by 7bs at a demo not long ago by James.  (sorry James for dragging you in!)  The outcome convinced me to go bigger.  The link is


http://www.audiocircle.com/index.php?topic=56757.0

2)  The power requirements of BB5 seems to go over the top as you alluded to earlier.  As you mentioned earlier or inquired, per channel with the sub, PMC suggests about 2000 w into 4 ohms.  The link to the PMC brochure is below (the amps set up is towards the end of the brochure).  As I recall 2 x 7bs, half a 4b and half a 3b per side. The wattage is based on earlier Bryston amps.

http://www.neotec.com.au/pdf/new/BB5-A%20&%20MB2-A%20Brochure.pdf

Somewhere in an earlier thread (would have to look) the cost to set up with amps a pair of BB5 both with subs ran around $85, 000 US.

My only regret is not to be able to comment on how the IB2s would have sounded with the 4bsq first.  That was not the in order of the purchases.  In speaking to Maurice of PMC USA, he did indicate that studios using IB2s in about 60% of the cases where using 4Bs only. I guess funds do become limited at some point!

Finally, in my own comparisons, the amps have always been plugged into a torus 20 (unbalanced).  Given many of the testaments of sound improvement, listening with a torus in my experience is a force to be considered.

I apologize in advance if I sound like I'm trying to twist arms re: which up grade next.

Sincerely,

Joe

[Mad Mr H]

Hi Joe,

From personal experience I agree............

My 5ch MB2 system is run Passive Bi Amp front L C R with 6 x 7B SST.

My 2ch BB5i system is run (currently) Passive Tri amp 2x7,4,3.

I would like to change the BB5i mid amp to a 7B - That is based on the results in my 5ch system.


Following that logic I can hear the question "Why not 28B's all round?"

Well for me I can't afford them, an have deliberatly NOT heard them, in fact some members know I question theor existance! just so I am not tempted.....

DrummerMitchell has a pair of 28's and wants another - I would love to hear that system...............

JOE - Could I just pick up on a point you mentioned......

" In speaking to Maurice of PMC USA, he did indicate that studios using IB2s in about 60% of the cases where using 4Bs only. I guess funds do become limited at some point!"
 

What are the other 40% using 7b's ???




In larger studios the active systems are sold so the market is there.....

[Gojo]

hi Mr H

Yes, the other 40% were using 7bs.  As I recall (it was over the phone in the spring), when I mentioned that I had the 7bs on order back in April, he responded by saying if you can afford that would be the way to go.  He is a former studio engineer with MB2s driven by 7bs in a home studio.   I believe 5 of them.

Just on the point of studios and what I've read at Mixonline, and these may be smaller studios, I was surprised to read many of them using smaller 2 way active powered nearfields such as Genelec and JBL.  In fact, I was surprised to read that the creation of the Beatles love by Gilles Martin were on smaller Adams near fields.  Having said that, I believe the final mastering was done on BB5s with 7bs etc (link at PMC).

I realize, I've strayed from the initial direction of the thread.  I will exercise more self control on the next reply.

All the best in the new year!

Joe

[werd]

Hello folks

As a big believer in overpower speakers i have to say  that my Torus rm-20 has made me re-engineer the idea. The Torus presents my 4B with so much more new found jam that i have to be careful now with my volume (especially in the 1volt setting). Where before the 4B seemed to not put my AZ's in any danger as it does now with dynamic swings.

Its important to mention though i used a Blue Circle mr1200 balanced conditioner that no doubt held back current.