Bryston 7b3 upgrade to 28b3

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CanadianMaestro

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Re: Bryston 7b3 upgrade to 28b3
« Reply #20 on: 21 Jan 2018, 03:48 pm »
clive: Best person to answer this is JT.

But in the end, try to audition if you can, and then decide whether there is any improvement in SQ.

TJ-Sully

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Re: Bryston 7b3 upgrade to 28b3
« Reply #21 on: 21 Jan 2018, 04:18 pm »
hi clive101, i think the basic message in  Paul's video (above) is - if one has a choice in amplification (in terms of watts), go with the larger amp because it provides more headroom and - i believe - deliver lower frequencies with more precision. But that's just me.

In terms of active vs. passive, each of your 7B amps is delivering up to 600watts into each of your PMC passive speakers. The internal crossover network inside of each speaker is directing a unique set of frequency ranges into each driver (one set of frequencies into tweeter, mid-range, and bass driver). In the passive set up,  the incoming signal to the crossover has already received the full amplification from your power amp.

In the active version of your speakers, the incoming signal is split into 3 sets of frequency ranges before amplification. Each unique set of frequency range is delivered to each of the 3 amps (one amp for high, one for mid, one for low)....then each amplified signal is delivered to each driver.

 The power levels you mention (325w, 150w, 150w) correspond to the power of each dedicated amplifier in the active version of your speakers. Each power amplifier in the active setup is dedicated to a single driver. (low, med hi). So in total, the active set up has 6 amplifiers - corresponding to 6 drivers.

Since a 325w amp is used for the low frequency driver in the active setup, a person could interpret that a 7B would be more than enough power in a passive setup. But that 325w is applied to a more narrow range of frequencies for only one driver. A more efficient power delivery system.

Ultimately, to make a decision on a 28B vs. 7B i really think a person would need to A/B test both amps in the same listening conditions.  Or....to be on the safe side....just go with the 28's  :thumb:

Hope this helps.

TJ

G E

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Re: Bryston 7b3 upgrade to 28b3
« Reply #22 on: 22 Jan 2018, 12:12 am »
I have the 28bsst2 and they are sweeter sounding than the 4bsst2 they replaced.

The first 50 watts are Class A and it makers a difference as does the iron grip on bass

srb

Re: Bryston 7b3 upgrade to 28b3
« Reply #23 on: 22 Jan 2018, 01:38 am »
The first 50 watts are Class A and it makers a difference as does the iron grip on bass

According to James Tanner, "Class A for about 1% of the power rating for amps".

That would roughly equate to Class A power of ~ 6W/9W (8Ω/4Ω) for the 7B³ and ~ 10W/15W for the 28B³.
« Last Edit: 22 Jan 2018, 02:59 am by srb »

dznutz

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Re: Bryston 7b3 upgrade to 28b3
« Reply #24 on: 22 Jan 2018, 02:25 am »
I had a very similar dilemma, and I ended up with a pair of 28B3's.   I can almost guarantee you that everyone chiming in has never had a 7B let alone a 28B in their home.  1 watt out of a 7B is not the same watt out of a 28B... you must try

G E

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Re: Bryston 7b3 upgrade to 28b3
« Reply #25 on: 22 Jan 2018, 11:31 am »
The cubed series run class A for 1% of rated power, the squared about 5 %.

clive101

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Re: Bryston 7b3 upgrade to 28b3
« Reply #26 on: 24 Jan 2018, 05:12 pm »
Thank you all for the input....

I am very tempted for the audition of the 28b3 (not so keen on the extra cost) will be making a decision shortly to demo so keep any advice coming.

It's looking likely ...!

G E

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Re: Bryston 7b3 upgrade to 28b3
« Reply #27 on: 24 Jan 2018, 05:52 pm »
The 28 monoblocks are very special. I'm tempted to call them thrill rides instead of amps.

You might consider the used market for the 28bsst2 revision. That's the only way I could swing it. There are two pair on audiogon now.  I have no connection with sellers. Just a very happy and satisfied owner. 

Serial #'s 000180 and higher have the most recent capacitors and transformers

Of course, once you get the greatest amps in the world you will also need to upgrade all your cabling. It makes a big and positive difference.

clive101

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Re: Bryston 7b3 upgrade to 28b3
« Reply #28 on: 24 Jan 2018, 07:15 pm »
Very wise advice but there is also some 28b3 versions at a good price but as I am in the UK not able to take advantage.

I have Chord Sarum T cables as a Loom, so ok for cables apart from the USB cable which is very special ..?

Edit UK Retail £21,000.00 or Canadian $ 36,855.00 for a pair of 28b3
« Last Edit: 24 Jan 2018, 08:44 pm by clive101 »

Ron D

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Re: Bryston 7b3 upgrade to 28b3
« Reply #29 on: 24 Jan 2018, 09:40 pm »
I'll offer up my experience, in brief, and while it involved Bryston amps (been a fan boy since the 80's) it is not the cubed nor 7B to 28B example.

A number of years ago I moved from a 4B-SST to a 14B-SST (both the pre-squared versions) so a 300 w/ch amp moving to a 600 w/ch amp (similar move to what your are considering relative to number of watts). The largest gains I experienced were:

1. much better control over the low end drivers in my speakers, especially at higher volumes (expected outcome)

2. a vast, IMHO, amount of detail retrieval at lower volumes. I was hearing much more content with the 14B than I did with the 4B.

Based on your anticipated usage I think #2 may relate more to your situation.

As is always the case YMMV and an audition is the only sure way to know for sure...

Good luck

TJ-Sully

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Re: Bryston 7b3 upgrade to 28b3
« Reply #30 on: 24 Jan 2018, 10:50 pm »
Great feedback and advice RonD. Goes to show, you don't necessarily need to own the products in question to provide meaningful input....right dznutz?

dznutz

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Re: Bryston 7b3 upgrade to 28b3
« Reply #31 on: 25 Jan 2018, 03:37 am »
Great feedback and advice RonD. Goes to show, you don't necessarily need to own the products in question to provide meaningful input....right dznutz?

Correct, that's assuming you have relate-able experience.  Too many people talk out of their butts and dont have a clue, internet experts.  Going from a 4B to a 14B will yield similar results as going from 7B to 28B.  for me its the sheer effortlessness and scale that comes with the jump in peak power.  Its not a matter of simply saying you have efficient speakers so you dont need the power.

adol290

Re: Bryston 7b3 upgrade to 28b3
« Reply #32 on: 26 Jan 2018, 05:38 am »
I had a pair of PMC MB2i's. I originally ran them with a pair of 7bsst2's. I then upgraded to 28b sst2's, and was extremely happy with the results.

Each 28b has 2 sets of speaker outputs on them. So i ran a one speaker cable from one output to the bass, and the other cable from the other output to the midrange on the MB2i from each 28b. I then ran a jumper
 from the mid to highs. I found the bass to be very well controlled and could(when turned up a bit) give a good kick in the chest. The mids were so detailed on smooth.

I would not recommend the 28b sst2's though, i would definitely go the the 28b cubes. Why, i found the sst2's a bit hot on the high end of my Mb2i's.

BTW now i am running a pair of bryston model T actives with the cube amps. I currently have a pair of 7b/4b cubes and find the top end is much more tamed.
Now wish i had a chance to pair the cube amps with a pair of MB2i's. 

So if you can afford the 28b cubed, or can audition one go for it, you will not be disappointed. 

TJ-Sully

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Re: Bryston 7b3 upgrade to 28b3
« Reply #33 on: 27 Jan 2018, 12:10 am »
wow. cool story adol290. you are a lucky person to own, and have owned such wonderful gear. My dream speakers are the MB2's. I am currently running the Bryston Mini T's and love them - driving them with my 4BSST2. I am trying to develop a plan to move to the new Active Mini T's over the next few years. It will be a journey.

Although I have not owned the 28's, i have heard them in several different listening environments.

Overall, I totally agree with your advice - if a person can afford the move to 28 cubes (especially with such lovely speakers) then definitely go for it. No brainer.

peace out.
TJ

gtaphile

Re: Bryston 7b3 upgrade to 28b3
« Reply #34 on: 31 Jan 2018, 05:04 pm »
Clive,

In order to chime in please tell us what preamp you are using. 

clive101

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Re: Bryston 7b3 upgrade to 28b3
« Reply #35 on: 5 Feb 2018, 06:28 pm »
Clive,

In order to chime in please tell us what preamp you are using.

I am using the Bryston BP26 as a preamp.


Long story short. I have found that using Dave direct suits me better now, before I preferred the preamp.


jtinto

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Re: Bryston 7b3 upgrade to 28b3
« Reply #36 on: 6 Feb 2018, 09:51 pm »
BTW now i am running a pair of bryston model T actives with the cube amps. I currently have a pair of 7b/4b cubes and find the top end is much more tamed.

Nice system adol290. I'd enjoy reading more about your impressions.

That's exactly where I hope to get to ... just have to add a pair of 4b cubes and a BAX-1  :lol:

G E

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Re: Bryston 7b3 upgrade to 28b3
« Reply #37 on: 11 Feb 2018, 02:39 am »
Listening session tonight is pure joy. The amps have been on for 27 hours and the tubed phono preamp is fully warmed up. I turn it off overnight.

Been burning in new speaker cables on my FryKleener Pro and after 240 hours things are starting to sound very good in man cave #1.

These 28's have made all the difference in my system. It is the best decision i have made regarding my soundsystem.

Bel Canto Pre 6 solid state and Hagerman Cornet 2 phono pre with Amperex mid 1950's Vintage tubes. Morrow signal cables everywhere. Cardas M power cables on the pre and phono positions. Stock Power cables on the 28's!


Zoophaugus

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Re: Bryston 7b3 upgrade to 28b3
« Reply #38 on: 11 Mar 2018, 12:17 am »
I as well own a pair of 7B3's  and although they have plenty of watts and volume I am  considering a jump to the 28's. My intention is not to blow the roof off of my house but as other posters mentioned I am looking for more control or better command of the speakers particularly on the lower end ....

I am feeding an Yggdrasil DAC to an ARC LS26 pre amp and then the Brystons . Makes for a good combination. ..

tie_breaker

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Re: Bryston 7b3 upgrade to 28b3
« Reply #39 on: 11 Mar 2018, 02:36 am »
We have similar systems zoophaugus.  I have the yggy dac as well feeding an arc Ref 5se, feeding 7b3 amps... I use a bdp2 as the player.  The sound is great.  I just made the jump to the 28b3 amps and should receive them soon.  I hope to hear the improvement others mentioned on the thread.