AudioCircle

Industry Circles => Bryston Limited => Topic started by: Wim J on 3 Nov 2015, 06:27 pm

Title: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: Wim J on 3 Nov 2015, 06:27 pm
Question: I already have one 3B-SST2 and consider to upgrade amp. What is the best solution? Buy one extra 3B-SST2 and use both 3B-SST2 bridged to mono, or sell my 3B-SST2 and buy 2x 7B-SST2. First option is 50% cheaper, and I don’t need the 600 Watts from the 7B-SST2, the 400 Watts of the 3B-SST2 in mono are plenty!
Price is a factor. Is anyone having experience with the 3B-SST2 in mono?
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: James Tanner on 3 Nov 2015, 06:31 pm
Question: I already have one 3B-SST2 and consider to upgrade amp. What is the best solution? Buy one extra 3B-SST2 and use both 3B-SST2 bridged to mono, or sell my 3B-SST2 and buy 2x 7B-SST2. First option is 50% cheaper, and I don’t need the 600 Watts from the 7B-SST2, the 400 Watts of the 3B-SST2 in mono are plenty!
Price is a factor. Is anyone having experience with the 3B-SST2 in mono?

Hi

What speakers are you using? 

When you bridge an amplifier it "see's" 1/2 the impedance it does in Stereo so you can start current limiting into lower impedances.  We generally do not recommend bridging amplifiers into anything less than a resistive 8 ohm load.

james
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: Wim J on 3 Nov 2015, 06:37 pm
Speakers are easy to drive Link-Audio K100 http://www.link-audio.be/k100twee.htm (http://www.link-audio.be/k100twee.htm). It has an average impedance of 6 ohms and a sensitivity of 86dB/W/m.
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: James Tanner on 3 Nov 2015, 06:44 pm
Speakers are easy to drive Link-Audio K100 http://www.link-audio.be/k100twee.htm (http://www.link-audio.be/k100twee.htm). It has an average impedance of 6 ohms and a sensitivity of 86dB/W/m.

Hi

Looks like you may be OK - 6 ohms is a little low but as long as the phase angles are not excessive you should be OK.

james

Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: srb on 3 Nov 2015, 07:47 pm
Without seeing an impedance curve, who knows how much and where minimum impedance(s) occurs?  A 6 ohm average speaker could certainly have a 3 - 4 ohm impedance dips, seen as 1.5 - 2 ohm impedance by a bridged amplifier.  I think I would personally prefer a 4BSST² over a pair of bridged 3BSST².  YMMV

Steve
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: RDavidson on 3 Nov 2015, 09:25 pm
DEFINITELY heed James' recommendation, even if you believe your speakers are a simple load. Not knowing with 100% certainty what your speakers' impedance characteristics are, you probably shouldn't opt to halve your current. Look at it this way : If you buy another 3B and run the pair of them mono, you'll have no more current on tap than a single 3B. The majority of speakers on earth like current. Current to speakers is somewhat like torque to axels. We like to see that high horsepower (wattage) number on paper and brag to our friends about it, but it is nearly meaningless without torque (current).
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: 95Dyna on 3 Nov 2015, 09:42 pm
DEFINITELY heed James' recommendation, even if you believe your speakers are a simple load. Not knowing with 100% certainty what your speakers' impedance characteristics are, you probably shouldn't opt to halve your current. Look at it this way : If you buy another 3B and run the pair of them mono, you'll have no more current on tap than a single 3B. The majority of speakers on earth like current. Current to speakers is somewhat like torque to axels. We like to see that high horsepower (wattage) number on paper and brag to our friends about it, but it is nearly meaningless without torque (current).

Bridging stereo amps into mono is not a good idea.  I have a collection of popped output stage fuses from a pair of Nelson Pass designed amps to confirm.  If you can only afford a second 3B bi-amp them instead or as Rdavidson has suggested look for a 4B in your price range.
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: RDavidson on 3 Nov 2015, 09:49 pm
Actually srb suggested the 4B as a better step up (than bridged mono 3B's), not me, but we're all on the same page.

If you cannot get the 7B's, the 4B is the logical choice and the least expensive upgrade route with Bryston from where you are today.
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: Rod_S on 4 Nov 2015, 12:24 pm
Don't forget about the 14. It'll be a bit cheaper than two 7's and takes up less space than the 2 amps would. But seeing as you say you don't need the 600 watts the suggestion of getting a 4 makes the most sense.
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: Wim J on 4 Nov 2015, 01:18 pm
I bought the 3B-SST² some years ago after comparing it to the 4B-SST². I preferred the 3B-SST². It is slightly more musical and has better timing than a 4B-SST².
I'm considering a monoblock setup because of the long cable runs I need in my current situation (over 7 metres for each speaker). So this gives me 3 options : 2X 3B-SST² (bridged), 2x 7B-SST², 2x 28B-SST². The last option being too expensive, the first option not really recommended,... I'll start saving for 2x 7B-SST².  :roll:
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: RDavidson on 4 Nov 2015, 02:45 pm
Nice. That'll allow you to put the amps closer to the speakers too.
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: 95Dyna on 4 Nov 2015, 06:45 pm
I bought the 3B-SST² some years ago after comparing it to the 4B-SST². I preferred the 3B-SST². It is slightly more musical and has better timing than a 4B-SST².
I'm considering a monoblock setup because of the long cable runs I need in my current situation (over 7 metres for each speaker). So this gives me 3 options : 2X 3B-SST² (bridged), 2x 7B-SST², 2x 28B-SST². The last option being too expensive, the first option not really recommended,... I'll start saving for 2x 7B-SST².  :roll:

I have a pair of 6 year old 7BSST2's and they are stellar amps in all regards.  My only concern is I only have 14 years left on my warranty  :lol:
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: Rod_S on 4 Nov 2015, 07:33 pm
Would the PowerPac's be an option for you? Certainly an inexpensive way of getting 300 watts out by your speakers.
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: turnovertherecord on 12 Nov 2015, 05:37 pm
Question: I already have one 3B-SST2 and consider to upgrade amp. What is the best solution? Buy one extra 3B-SST2 and use both 3B-SST2 bridged to mono, or sell my 3B-SST2 and buy 2x 7B-SST2. First option is 50% cheaper, and I don’t need the 600 Watts from the 7B-SST2, the 400 Watts of the 3B-SST2 in mono are plenty!
Price is a factor. Is anyone having experience with the 3B-SST2 in mono?

I bi amp 2 3bsst with focus audio fs-788 ,10 ohm speakers,no problem

Did bridge for a while also no problem


(http://www.audiocircle.com/image.php?id=131669)
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: rollo on 12 Nov 2015, 08:36 pm
I bought the 3B-SST² some years ago after comparing it to the 4B-SST². I preferred the 3B-SST². It is slightly more musical and has better timing than a 4B-SST².
I'm considering a monoblock setup because of the long cable runs I need in my current situation (over 7 metres for each speaker). So this gives me 3 options : 2X 3B-SST² (bridged), 2x 7B-SST², 2x 28B-SST². The last option being too expensive, the first option not really recommended,... I'll start saving for 2x 7B-SST².  :roll:


   Bingo !!! t 7 mtrs what Ga. wiring are you using ? Hopefully balanced and shielded.


charles
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: mkaiser on 12 Nov 2015, 09:25 pm
Would the PowerPac's be an option for you? Certainly an inexpensive way of getting 300 watts out by your speakers.

+1
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: Wim J on 13 Nov 2015, 02:43 pm

   Bingo !!! t 7 mtrs what Ga. wiring are you using ? Hopefully balanced and shielded.


charles
Speakercables are Kimber 8PR's (2x7meters (2x5.27mm²)). Cables between pre-amp PB26 and 3BSST² are balanced and shielded.
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: sfraser on 20 Nov 2015, 09:06 pm
Bridge your  single amp, and listen to some music in mono mode for and evening with one speaker. See how it sounds , how hot your amp gets etc. Things to consider is your  typical SPL/dynamic range you like to experience with  2 speakers  VS  the single speaker SPL / dynamic range test  . But it might answer some questions for you.

I have run a 2B LP in mono bridged mode for yrs powering my center channel. Works ok but can get hot.
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: redbook on 24 Nov 2015, 06:19 pm
I bought the 3B-SST² some years ago after comparing it to the 4B-SST². I preferred the 3B-SST². It is slightly more musical and has better timing than a 4B-SST².
I'm considering a monoblock setup because of the long cable runs I need in my current situation (over 7 metres for each speaker). So this gives me 3 options : 2X 3B-SST² (bridged), 2x 7B-SST², 2x 28B-SST². The last option being too expensive, the first option not really recommended,... I'll start saving for 2x 7B-SST².  :roll:
   How is the 3b more more "musical" with better timing than the 4B. I find this an interesting observation since this has not been pointed out before (to my knowledge at least )  Perhaps it's doe to less circitry ? Thanks for any comments on this....... :thumb:
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: Grit on 24 Nov 2015, 11:17 pm
I know this is worthless without the link,  but I distinctly remember a forum post of someone who preferred the 3B SST2 over the 4B SST2, citing a very slight difference in detail.
Title: Re: 2x 3B-SST2 bridged mono or 2x 7B-SST2?
Post by: RDavidson on 24 Nov 2015, 11:32 pm
Yes. I think the same was said about the 3B-ST (vs the 4B-ST) as well. Not a night and day difference whatsoever. But if you really don't need the 4B's power, you could come out ahead with a 3B. Same could probably be said of the 2B. It all goes back to amp & speaker matching.