4B vs 7B Observations

spinner · « **Reply #20 on:** 7 Feb 2012, 11:58 pm »

This topic has been most interesting.

James Tanner · « **Reply #21 on:** 8 Feb 2012, 12:18 am »

Quote from: SoundGame on 7 Feb 2012, 09:44 pm

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...

Yes I will try and take a few pictures on the burn in bench - some of the above pics are of older versions.

James

redbook · « **Reply #22 on:** 8 Feb 2012, 10:03 am »

Thanks James , appreciate your efforts...........

Levi · « **Reply #23 on:** 8 Feb 2012, 04:34 pm »

+1

Thanks James!

Quote from: redbook on 8 Feb 2012, 10:03 am

Thanks James , appreciate your efforts...........

James Tanner · « **Reply #24 on:** 8 Feb 2012, 06:18 pm »

james

spinner · « **Reply #25 on:** 8 Feb 2012, 07:51 pm »

Good stuff James. This should clear things up. Thanks.....

redbook · « **Reply #26 on:** 8 Feb 2012, 07:57 pm »

Nice. James is there a chance the next evolutionary step for the 4b would be a pair of those Plithron trannies?

James Tanner · « **Reply #27 on:** 8 Feb 2012, 08:09 pm »

Quote from: redbook on 8 Feb 2012, 07:57 pm

Nice. James is there a chance the next evolutionary step for the 4b would be a pair of those Plithron trannies?

Then it's a 14B

james

redbook · « **Reply #28 on:** 8 Feb 2012, 08:18 pm »

What I meant was there any improvement to the 4b planned in near future or has it become as good as it gets. I thought there may be a smaller version of those trannies used in the 14b. Sorry for the confusion.

James Tanner · « **Reply #29 on:** 8 Feb 2012, 08:51 pm »

Quote from: redbook on 8 Feb 2012, 08:18 pm

What I meant was there any improvement to the 4b planned in near future or has it become as good as it gets. I thought there may be a smaller version of those trannies used in the 14b. Sorry for the confusion.

Correct - No major changes on the 4B design on the horizon.

james

SoundGame · « **Reply #30 on:** 10 Feb 2012, 12:46 am »

Yes, as a posed in another thread, if you add the larger high output transformers and the larger caps into the 4B-SST, you would need a larger box and what do you have.....essentially, as James said, a 14B-SST.

It would be neat though if you could just custom order the 4B-SST, exactly as it is, with just the 7B or the 14B filter capacitors....I'm quite certain that alone would pull the socks up on the already wonderful 4B-SST2. Hey, I'd pay an extra grand say for just the capacitor swap out - if it was done at manufacture it would only be the difference in the cost of the caps...which couldn't be much I would think...but then again, I'm speaking off the top of my head without the engineering know-how.

Levi · « **Reply #31 on:** 10 Feb 2012, 01:12 am »

Is the 14B bridge design?

larevoj · « **Reply #32 on:** 10 Feb 2012, 01:19 am »

A juiced up 4BSST2!!

I like that idea - in fact it doesn't necessary has to increase its power output but with better quality parts, more refinement, lower noise, higher bias, etc. Externally it can look the same and you can call it Anni, SE, SIG, whatever you like...not sure will the same box will hold or a an inch taller but retain the same floor space.

I do agree and be willing to pay a premium for it either as new or an upgrade to my current model.

Quote from: SoundGame on 10 Feb 2012, 12:46 am

Yes, as a posed in another thread, if you add the larger high output transformers and the larger caps into the 4B-SST, you would need a larger box and what do you have.....essentially, as James said, a 14B-SST.

It would be neat though if you could just custom order the 4B-SST, exactly as it is, with just the 7B or the 14B filter capacitors....I'm quite certain that alone would pull the socks up on the already wonderful 4B-SST2. Hey, I'd pay an extra grand say for just the capacitor swap out - if it was done at manufacture it would only be the difference in the cost of the caps...which couldn't be much I would think...but then again, I'm speaking off the top of my head without the engineering know-how.

larevoj · « **Reply #33 on:** 10 Feb 2012, 01:27 am »

On second thoughts the SQ gained between a juiced up 4BSST2...lets just call it a SE versus a 4BSST2 + Torus??

That would be an interesting A/B

SoundGame · « **Reply #34 on:** 10 Feb 2012, 01:55 am »

Quote from: larevoj on 10 Feb 2012, 01:27 am

On second thoughts the SQ gained between a juiced up 4BSST2...lets just call it a SE versus a 4BSST2 + Torus??

That would be an interesting A/B

Who says you couldn't have both.....if the former was available? ...

SoundGame · « **Reply #35 on:** 10 Feb 2012, 01:57 am »

Quote from: James Tanner on 8 Feb 2012, 06:18 pm

james

I'd swear I can see two transformer coils in the 4B-SST/2, which would be contrary to what was said earlier about the 4B-SST2 having just one large one..I think.

Oh, and yes, there does seem to be much of the same rather than the different between the 4B and 7B - I guess that's why the 7B just cost slightly over double the 4B.

James Tanner · « **Reply #36 on:** 10 Feb 2012, 03:07 am »

Correct 4B has two transformers - one per channel.

James

larevoj · « **Reply #37 on:** 10 Feb 2012, 03:27 am »

SQ/$$ may or may not worth the time.

Quote from: SoundGame on 10 Feb 2012, 01:55 am

Who says you couldn't have both.....if the former was available? ...

SoundGame · « **Reply #38 on:** 14 Feb 2012, 05:13 pm »

With all this information on the relation between the 4B and the 7B, it's raised some additional questions in my mind:

1) Other than the transformers and the filter caps, are there any other signifcant differences in the 7B vs. the 4B? Does the 7B have a different circuit design? Does the 7B have more output devices?

2) Since the 7B is essentially a bridged design of the 4B - why the difference in output i.e. the 4B bridged into 8 ohms is 900 watts, while the 7B is 600 watts into the same load; however, the 7B hits the 900 watts into 4 ohms. Any simple explanation in the approach taken?

mv038856 · « **Reply #39 on:** 14 Feb 2012, 08:03 pm »

Quote from: SoundGame on 14 Feb 2012, 05:13 pm

...Since the 7B is essentially a bridged design of the 4B - why the difference in output i.e. the 4B bridged into 8 ohms is 900 watts, while the 7B is 600 watts into the same load; however, the 7B hits the 900 watts into 4 ohms. Any simple explanation in the approach taken?

I think the "old" 7B ST can give an answer to this question. The 7B ST had a switch where you could bridge it either in parallel or in serial mode. One gave you more power on higher impedances, the other made the amp more powerful in terms of current delivery.

James, correct me if I'm wrong, but I think the 7B SST has been fixed at one of those bridging options and it has been the mode that delivers more current at lower impedances, i.e. difficult loads.

Cheers!

Markus