[SoundGame]

It was just recently made clear to me that the 7B-SST2 is essentially a 4B-SST2 that has been optimized for bridged operation.  This realization along with requests for a 4B monoblock amplifier product got me thinking about the impact of taking some of what's in the 7B and applying that to the 4B.

The internal configuration of the 4B and 7B are very similar, as can be seen in the following shots:





My question is, what would be the result and the benefits in performance (if any) if you took some of what is in the 7B-SST2 and applied it to the 4B, without the objective of necessarily matching the performance of the 7B (i.e. without trying to get to a 14B-SST2).

In short, if you took a standard 4B, added the 7B transformers, capacitors and output devices - leaving all else the same what would be the results on this upgrade 4B design?  Would there be a performance increase - if so, in what ways i.e. would power output and power stability increase, if so and by how much?  Would the performance increases justify the added cost - or are we simply back to the result the the added cost would not be justified unless you went further and created the 7B?  Maybe I've answered this but it would interesting to confirm if this has been considered?

[spinner]

 Good question. If the 7b has the better transformers why not apply that to the 4b and come up with hopefully another worthwhile tweek? ( 4Bsst cubed){ 3rd power rather than 2nd }.

[SoundGame]

As Chris Russells recent comments bring forth, the bigger amps in the Bryston stable benefit from larger power supplies and the greater power smoothing and filtering that such more robust power supply designs provide - so I'm thinking better transformers, more stable power, better sound.  It's cost that comes into the picture, which makes taking a whole different route the better choice - I believe - but I'm looking to confirm that.

We talk about using Torus devices - if the amps power supply is robust enough - who needs a Torus?

[95Dyna]

My question is, what would be the result and the benefits in performance (if any) if you took some of what is in the 7B-SST2 and applied it to the 4B, without the objective of necessarily matching the performance of the 7B (i.e. without trying to get to a 14B-SST2).

 

The 14B SST2 is not the equivalent of the 7B SST2 X 2.  The pair of 7's has double the power supply capacitance of the 14B.  Even if you re-engineered your 4B to be the equivalent of the 14 B it would not be the equivalent of the 7B. If I'm not mistaken a pair of 4B's is close to half what a pair of 7B's cost and would provide performance in bridged mode that would be inferior to the 7B at minimum due to an impedence handling deficiency.

[95Dyna]

As Chris Russells recent comments bring forth, the bigger amps in the Bryston stable benefit from larger power supplies and the greater power smoothing and filtering that such more robust power supply designs provide - so I'm thinking better transformers, more stable power, better sound.  It's cost that comes into the picture, which makes taking a whole different route the better choice - I believe - but I'm looking to confirm that.

We talk about using Torus devices - if the amps power supply is robust enough - who needs a Torus?

I have a Torus CS15 into which I plug my CD player, MPS2, turntable, tuner and both 7B SST2's.  It makes a more dramatic impact on the sources and pre amp than the 7's however I have listened extensively with the amps in the Torus and in the wall and prefer the sound quality over all with the amps plugged into the Torus.

[Levi]

They look identical inside.  I know that the 4B is not bridge so it will give a tighter bass control vs  the 7b which is a bridge design. To compensate for that, they recommend to use shortest speaker cable you can get.

It was just recently made clear to me that the 7B-SST2 is essentially a 4B-SST2 that has been optimized for bridged operation.  This realization along with requests for a 4B monoblock amplifier product got me thinking about the impact of taking some of what's in the 7B and applying that to the 4B.

The internal configuration of the 4B and 7B are very similar, as can be seen in the following shots:





My question is, what would be the result and the benefits in performance (if any) if you took some of what is in the 7B-SST2 and applied it to the 4B, without the objective of necessarily matching the performance of the 7B (i.e. without trying to get to a 14B-SST2).

In short, if you took a standard 4B, added the 7B transformers, capacitors and output devices - leaving all else the same what would be the results on this upgrade 4B design?  Would there be a performance increase - if so, in what ways i.e. would power output and power stability increase, if so and by how much?  Would the performance increases justify the added cost - or are we simply back to the result the the added cost would not be justified unless you went further and created the 7B?  Maybe I've answered this but it would interesting to confirm if this has been considered?

[redbook]

 O.K.  maybe off this topic but..........Those great pictures show the 4b with what looks like computer chips in that center board and the 7b without. Do this chips allow the 4b to sound more 'tube like" ?

[lanchile]

O.K.  maybe off this topic but..........Those great pictures show the 4b with what looks like computer chips in that center board and the 7b without. Do this chips allow the 4b to sound more 'tube like" ?

Good catch! I also though Bryston do not use ic's in their circuits 

[redbook]

  Here's my 4bst by comparison.

I see some chips there too. This amp was made in 1999-2000. May be this is why it still is surprising me with great sound

[James Tanner]

The IC's are on the power up board for startup, triggers etc.

james

[redbook]

 Thanks ,but why aren't they on the 7b?

[SoundGame]

  Here's my 4bst by comparison.

I see some chips there too. This amp was made in 1999-2000. May be this is why it still is surprising me with great sound

I like the layout of the 4B-ST - it appears a more intuitive dual mono design, with everything clearly separated from left to right.  I'm not arguing the benefits of the SST and SST2 design and layout...which are highly acclaimed but the ST is a beautiful layout in it's own right. 

[vegasdave]

James please clarify and correct regarding these comments.

[Levi]

Here is a picture of my 7BSST.  It looks more like the 4b rather than the 7BSST2

[Levi]

+1

It also uses two power cords and two switches for the left and right channel.  You can literally cut it in half and will function independently. 

I like the layout it appears a more intuitive dual mono design, with everything clearly separated from left to right.  I'm not arguing the benefits of the SST and SST2 design and layout...

[Anonamemouse]

James please clarify and correct regarding these comments.

Since when did you start paying James' salary?
It's sad enough you are on here! A *demanding* vegasdriveler is even worse... When was the last time you accidentally contributed something sensible again?

[rmurray]

  The 4bST looks a bit more like double powerpacks on single chassis.

[James Tanner]

Hi Folks,

The current 7B SST2 and 4B SST2 use the same power soft-start board that have the IC's for some logic control and trigger control and a microcontroller - all to do with power control - there is NO audio circuitry on that board.

And my sincere apology - (I think somewhere I said the 7B had 2 transformers) I was incorrect  - the new 7B SST2 has one large transformer not two (stacked) as in the 4B SST2

james

[SoundGame]

Hi Folks,

The current 7B SST2 and 4B SST2 use the same power soft-start board that have the IC's for some logic control and trigger control and a microcontroller - all to do with power control - there is NO audio circuitry on that board.

And my sincere apology - (I think somewhere I said the 7B had 2 transformers) I was incorrect  - the new 7B SST2 has one large transformer not two (stacked) as in the 4B SST2

james

Hi James,

1. Would you have a high-rez of the inside of the current 7B-SST2 and 4B-SST2 to share?  I'd be interested in seeing the single large transformer vs. the former double stacked version.  All the photos I've seen of the internals have double stacked transformers. 

2. When was the change made from the double to the single transformers in the SST2 models - I assume it wasn't from the start...unless the photos of internals I've seen are incorrect?

3. Will you be getting such high-rez files of the amplifiers on the website at some point?  At present, the photos of the Bryston amps on the Audio Advisor site are much higher quality and size then what's on the Bryston website...

[redbook]

  Good points Soundgame. There seems a bit of mystery here . In the meantime my 4bST is better again due to a mid frequency transducer swap !!  Thanks James for that report on the "chips". I thought they where audio section things........ didn't mean to sweat you so much.