[Rod_S]

Hello;

I have had to scale back from my 7.1 setup to a 5.1 setup for an unknown amount of time and that leaves a lonely 4B-SST unused in my rack. I was wondering if I could continue to use it by running it in bridged mode and pair it up with my other 4B-SST (and obviously run that in bridged mode too) but since the other is a C series I'm not sure doing so is a good idea. Would a C-Series and non C-Series work together or not? If necessary I can provide serial numbers.

If this is possible will I notice a difference in the performance of the amps, I am curious if they will run hotter when bridged? When running in bridged mode does it matter which input and speaker terminal are used? And finally, my SSP only has one power trigger, do the amps have a trigger out (I can't remember) so I can slave from one amp to the other?

Thanks,

Rod

[James Tanner]

Hi Rod,

Do you mean running them on the front left and right speakers?

Also what is the impedance of the speakers?

james

[Rod_S]

Yes, basically turning them into mono blocks so to speak. My speakers are Bowers and Wilkins 802 Diamonds and are rated at 8 ohms but they can dip down into the 3 ohm territority apparantely. They are rated for up to 500 watts but I know people drive them with 1000 watt amps with no issues.

[James Tanner]

Yes, basically turning them into mono blocks so to speak. My speakers are Bowers and Wilkins 802 Diamonds and are rated at 8 ohms but they can dip down into the 3 ohm territority apparantely. They are rated for up to 500 watts but I know people drive them with 1000 watt amps with no issues.

I would not recommend different series amps on the front two most important speakers.  For surrounds it might work OK.

james

[srb]

My speakers are Bowers and Wilkins 802 Diamonds and are rated at 8 ohms but they can dip down into the 3 ohm territority apparantely.

Which would be 1.5 ohm territory for a bridged amplifier.  Probably not a good idea for that reason as well.
 
Steve

[Rod_S]

Thanks guys. My C-Series is a non ² version but that's good to know that there were differences between the SST and SST C-Series. My C-Series was purchased 2 or 3 years after my SST.

[Mad Mr H]

In general (not just Bryston) the closest "perfect" match of two channels will be a pair within one stereo amplifier.

Minor changes in production due to component availability or advance in technology lead to slight changes as time goes by.

The second closest "perfect" match will usually be consecutive serial numbers.

In the case of SST and SSTC series I always understood the "C" was a cosmetic change to the facia, as the SST front are still available for the pro versions (TODAY). Changes to the output terminals, cant remember other changes but no "major" change (I don't work for Brsyston).

In your case with B&W 802D series the use of a pair of 4BSST(C) has a very obvious application.

you can Bi Amp in what is often called "horizontal bi amp"

Use one 4B SST amplifier for the bass of both L&R (I would suggest the SST series as it should be older)

Use the other 4B SSTC amplifier for the mid/hi of both L&R - I suggest the "C" series as this should be newer and would include any minor changes or advances.

That option maintains consistent audio quality between L&R and uses your available amplification. Out of choice with those speakers I would use a 7B on each bass and a 4B on the mid/hi L&R (3 amps in a bi amp mode). But your pair of 4B's are well employed in this situation.

The single connector for remote switch on carries an output to the next amp, this allows you to cascade power up numerous amps, the out of the connector carries a slight delay required to reduce current draw in a multi amp setup.

I hope that is of help to you, Enjoy the music.

[Rod_S]

In general (not just Bryston) the closest "perfect" match of two channels will be a pair within one stereo amplifier.

Minor changes in production due to component availability or advance in technology lead to slight changes as time goes by.

The second closest "perfect" match will usually be consecutive serial numbers.

In the case of SST and SSTC series I always understood the "C" was a cosmetic change to the facia, as the SST front are still available for the pro versions (TODAY). Changes to the output terminals, cant remember other changes but no "major" change (I don't work for Brsyston).

In your case with B&W 802D series the use of a pair of 4BSST(C) has a very obvious application.

you can Bi Amp in what is often called "horizontal bi amp"

Use one 4B SST amplifier for the bass of both L&R (I would suggest the SST series as it should be older)

Use the other 4B SSTC amplifier for the mid/hi of both L&R - I suggest the "C" series as this should be newer and would include any minor changes or advances.

That option maintains consistent audio quality between L&R and uses your available amplification. Out of choice with those speakers I would use a 7B on each bass and a 4B on the mid/hi L&R (3 amps in a bi amp mode). But your pair of 4B's are well employed in this situation.

The single connector for remote switch on carries an output to the next amp, this allows you to cascade power up numerous amps, the out of the connector carries a slight delay required to reduce current draw in a multi amp setup.

I hope that is of help to you, Enjoy the music.

Thanks for recommending the above setup. I would like to give this a try. Sorry for the late response as this topic seemed to have gotten lost amongst my e-mail.

Just a quick check in with James on this, this option would seem preferred over running the 2 amps in bridged mode for the reasons Mad Mr H states above? Granted the more ideal arrangement in either setup would be identical amps but with using my two particular amps definitely not recommended for the bridged solution would you argree this would be a nice use of the 2 amps?

Rod

[James Tanner]

Thanks for recommending the above setup. I would like to give this a try. Sorry for the late response as this topic seemed to have gotten lost amongst my e-mail.

Just a quick check in with James on this, this option would seem preferred over running the 2 amps in bridged mode for the reasons Mad Mr H states above? Granted the more ideal arrangement in either setup would be identical amps but with using my two particular amps definitely not recommended for the bridged solution would you argree this would be a nice use of the 2 amps?

Rod

Hi Rod,

Yes looks OK to me.

james

[Rod_S]

Which would be 1.5 ohm territory for a bridged amplifer.  Probably not a good idea for that reason as well.
 
Steve

So are you suggesting that if the speakers do dip into 3 ohm territory which would be 1.5 in bridged mode you are saying that could damage the speakers? The reason I am curious because on another forum this morning I just read a post of a 802D owner running 2 4B-SST² Series in bridged mode and he has just blown his tweeters. He said he turned the system up really loud and noticed the Bryston LED turning red which indicates clipping and he turned the system down immediately but it was too late aparantely.

Thanks,

Rod

[Rod_S]

Hi Rod,

Yes looks OK to me.

james

Very good Sir, thank you! Now I can't wait until I get back home from my vacation next week to wake up my sleeping 4B-SST and get that beauty singing again 

[vegasdave]

There ya go. Get that 4B rockin!

[Rod_S]

... and the reality hits 

I just realized in order to do this type of bi-amping I would need to use a Y splitter from the L/R outputs of my SSP in order to get the signal to both amps. I use XLR connectors on all of my SSP to amp interconnects and I have never seen a XLR splitter before, does such a thing exist?

The other issue, and maybe it's not really an issue is that I will have to use the speaker cables from my surround speakers (which in an of itself is not a problem because those speakers aren't being used right now hence the downgrade from 7.1 to 5.1) but the lengths are much longer than the pair used for my mains. My mains are 15' and I think the surounds are either 30' or 35'. The cable is the same cable, so same manufacturer, same guage and model. Is this much of an issue? Will it make a difference where the short/long cables connect, should the mid/high use the shorter run while the long run connects to the low or vice versa?

Rod

[Rod_S]

I just Googled XLR Y splitters and they would seem to be a very common item so that's good to see.

[Rod_S]

I picked up a pair of splitters yesterday and got everything hooked up. I didn't have much time with the system last night but I will get some critical listening in throughout the week. I'm looking forward to it, not only to get my amp put back into use but to finally get a chance to hear the affects of bi-amping.

[sfraser]

So are you suggesting that if the speakers do dip into 3 ohm territory which would be 1.5 in bridged mode you are saying that could damage the speakers? The reason I am curious because on another forum this morning I just read a post of a 802D owner running 2 4B-SST² Series in bridged mode and he has just blown his tweeters. He said he turned the system up really loud and noticed the Bryston LED turning red which indicates clipping and he turned the system down immediately but it was too late aparantely.

Thanks,

Rod

If your speakers impedance dip that low, it is most likely only at a certain lower frequency range, and perhaps multiples of that frequency. I ran into the same issues with a couple of sets of speakers (Old Cerwin Vega's and PSB Stratus Goldi's) and a pair of older Bryston 4B's run in bridge mono mode. My amps ran hot in this mode when used with the above speakers and the protection would trip (I assume heat) when pushed extremely hard. Never seemed to hurt anything, all the equipment mentioned is still in use today.

Perhaps James or some one else could discuss if the newer 4B amps would behave differently?

Cheers,

Scott

[Rod_S]

So far so good. I have only spent about 30 minutes so far doing critical listening but I immediately noticed a difference in the bass. It is much tighter with a bit more authority. I'll get more time over the next few days and will report back.

[vegasdave]

So far so good. I have only spent about 30 minutes so far doing critical listening but I immediately noticed a difference in the bass. It is much tighter with a bit more authority. I'll get more time over the next few days and will report back.

Cool. Keep up the good work. As someone who's interested in biamping too, I look forward to your comments.

[Mad Mr H]

Very glad you like my suggestion - its from experience 

Dave - Do it already!

[Rod_S]

I got some more listening in over the past couple of nights, just movies off the PVR. I plan to do more listening with CDs and probably some SACD's and DVD-A's this weekend along with Rio on Blu-Ray. I'm still noticing that the bass has more punch but it's not as obvious when watching movies. That may be because the sound was in legacy Dolby Diigital or simply because all of the speakers in the surround system were active and not just the 802 Diamonds. I'll probably be able to answer that by the end of the weekend.

As for the mids and highs, there is no real stand out difference like with the bass, if I heard any change it would be that the speakers appear to breathe better and seem more open as if in a larger room and separated further than they actually are. I definitely didn't have any moments like OMG the highs are now so clear and the mids so smooth, etc., etc. I find the 802 Diamonsd incredibly clear and articulate anyways so there probably wasn't a lot to gain here. I'm sure for most normal listening the tweeter gets used the least with the mids and bass drivers seeing the most activity and it would stand to reason that the bass drivers, in my case 2 8" drivers would benefit more from having 300 watts to their own than the single 6.5" mid driver would.