[john1970]

Over the past week I've been listening to a newly purchased Bryston 4B SST.  It is a tremendous improvement relative to my NAD C372 integrated amp (which is now serving as the dedicated preamp). 

Other Equipment:
1) Speakers: VMPS RM40 Signature Series (external crossovers, Bolder Silver wire, MLS HDF cabinets, TRT Dynamicaps, Blackhole 5 treated cabinets)
2) Preamp: NAD C372 (used as an integrated amp until the Bryston arrived)
3) Source: NAD 502 CD Player
4) Speaker Wire: Belden 10 ga. copper
5) Surge protection: ZeroSurge products used through out

Noticeable Improvements:
1) Bass is deeper and faster
2) Dynamics are more effortless
3) Midrange and treble frequencies are clearer
4) At loud volumes (100 dB peaks) the amp does not have any problems driving this 4 ohm (3.5 min, 4.5 max) relatively efficient (90 dB/1w/1m) speaker.

What I like about this amp:
1) Excellent build quality
2) Good looks with the C-series 17" silver faceplate
3) Low distortion and lots of clean power (for effortless headroom)

It will be interesting to see what Stereophile's opinion of the amp is in their upcoming evaluation.  IMO this amp is sonically the same as the 14B SST that received a Class A rating. 

Best,

John

[Bob Reynolds]

Do you see a BP-26 in your future?

-- Bob

[john1970]

Bob,

When I auditioned the VMPS speakers (model RM/X which is very similar to the RM40s) many months ago I switched out the NAD C372 with a Bryston 6B SST & SP1.7 combo.  Switching out the amps made a for a huge improvements in sound.  However, swtiching out the preamps (and using the 6B SST as the amp) made for only very minor improvements.  Because the improvements are very minor I doubt if I will see a Bryston preamp in the near future. 


Best,

John

[Phil A]

IMO this amp is sonically the same as the 14B SST that received a Class A rating. 

Sonically similar, yes. Having owned both, I found the 14B SST to have a clear advantage in overall low-volume performance, with the music sounding alive and full. Also, in my system the 14B SST never ran out of steam, whereas the 4B SST would shut down prematurely driving Aerial 7B loudspeakers. I don't recall the specs on the 7B, but they aren't particularly efficient.

I'd agree in general with the above.  I have a 6BSST (which I know use on the center and rears which is of course a 3 channel 4BSST) and a 14BSST.  When I first got the 14BSST I had a friend over who noted not only is the music more relaxed but there was also a bass response difference.  I have Thiel 7.2s which are also not overly efficient (about 86db per specs) and are also not the easiest load in world.  I had to go with the 15 amp version of the 14BSST (unless I wanted to rip up lots of stuff) and I had kind of the opposite problem.  I have a large room about 16x20 with a 19 ft. ceiling and it opens it other spaces.  When playing movies with big dynamic range or music after about 25 minutes the 14BSST would shut off on one channel.  The 25W of pure class A vs. about 2.5 was the difference.  I built a custom amp stand with fans and when I play certain things I use them.  The 20 amp version or the mono blocks would have probably been better but I bought both amps very lightly used and I did not feel like ripping up tons or stuff.  If I could do it over again, I'd buy the monoblocks.

[john1970]

IMO this amp is sonically the same as the 14B SST that received a Class A rating. 

Sonically similar, yes. Having owned both, I found the 14B SST to have a clear advantage in overall low-volume performance, with the music sounding alive and full. Also, in my system the 14B SST never ran out of steam, whereas the 4B SST would shut down prematurely driving Aerial 7B loudspeakers. I don't recall the specs on the 7B, but they aren't particularly efficient.

I'd agree in general with the above.  I have a 6BSST (which I know use on the center and rears which is of course a 3 channel 4BSST) and a 14BSST.  When I first got the 14BSST I had a friend over who noted not only is the music more relaxed but there was also a bass response difference.  I have Thiel 7.2s which are also not overly efficient (about 86db per specs) and are also not the easiest load in world.  I had to go with the 15 amp version of the 14BSST (unless I wanted to rip up lots of stuff) and I had kind of the opposite problem.  I have a large room about 16x20 with a 19 ft. ceiling and it opens it other spaces.  When playing movies with big dynamic range or music after about 25 minutes the 14BSST would shut off on one channel.  The 25W of pure class A vs. about 2.5 was the difference.  I built a custom amp stand with fans and when I play certain things I use them.  The 20 amp version or the mono blocks would have probably been better but I bought both amps very lightly used and I did not feel like ripping up tons or stuff.  If I could do it over again, I'd buy the monoblocks.

FYI I remember reading a post by James that all Bryston amps are biased the same.  The 25 W bias on the 14 B SST was a misprint in a review that was available on-line.  Perhaps, Bryston can confirm this claim.

Best,

John

[Phil A]

IMO this amp is sonically the same as the 14B SST that received a Class A rating. 

Sonically similar, yes. Having owned both, I found the 14B SST to have a clear advantage in overall low-volume performance, with the music sounding alive and full. Also, in my system the 14B SST never ran out of steam, whereas the 4B SST would shut down prematurely driving Aerial 7B loudspeakers. I don't recall the specs on the 7B, but they aren't particularly efficient.

I'd agree in general with the above.  I have a 6BSST (which I know use on the center and rears which is of course a 3 channel 4BSST) and a 14BSST.  When I first got the 14BSST I had a friend over who noted not only is the music more relaxed but there was also a bass response difference.  I have Thiel 7.2s which are also not overly efficient (about 86db per specs) and are also not the easiest load in world.  I had to go with the 15 amp version of the 14BSST (unless I wanted to rip up lots of stuff) and I had kind of the opposite problem.  I have a large room about 16x20 with a 19 ft. ceiling and it opens it other spaces.  When playing movies with big dynamic range or music after about 25 minutes the 14BSST would shut off on one channel.  The 25W of pure class A vs. about 2.5 was the difference.  I built a custom amp stand with fans and when I play certain things I use them.  The 20 amp version or the mono blocks would have probably been better but I bought both amps very lightly used and I did not feel like ripping up tons or stuff.  If I could do it over again, I'd buy the monoblocks.

FYI I remember reading a post by James that all Bryston amps are biased the same.  The 25 W bias on the 14 B SST was a misprint in a review that was available on-line.  Perhaps, Bryston can confirm this claim.

Best,

John

The specs I quoted were from memory of what James Tanner posted on this forum.  From memory the 3BSST is about 1.5W pure class A, the 4BSST is about 2.5 and the 14BSST is 25.  James has tons of posts but if you go through them I'm sure you'll find it.

[Phil A]

FYI, here's a post by Chris Russell for James Tanner on the 3BSST vs. the 4BSST:

http://www.audiocircle.com/index.php?topic=5750.0

[perose]

Sebastiaan de Vries
Registered

Posts: 55


   Typing Error, Hoax or Truth? "Bryston 28B Mono Amplifie
« Reply #21 on: January 13, 2006, 09:33:29 am » 

--------------------------------------------------------------------------------
Quote from: jethro
Quote from: perose
Any idea as to how many Class A watts this bad boy puts out?


James or the amp ?


hwwhhwa. That would mean James have a high blood pressure al the time, even when he don't move at all...

With Bryston I think the class A power is not that important to know. Bryston's Quad complementair principe works great with a relative low bias. See the technotes on the Bryston website. They want to avoid the disadvantage of class a power (high temperature, big power comsumption etc.) but reamain the low crossover distortion and low THD of a good class A design.

Best regards,
Bas
 
  Logged 

--------------------------------------------------------------------------------
Bryston 7BSST, the best amplifier ever exist!!
 
 
James Tanner
Moderator

Posts: 1181


   Typing Error, Hoax or Truth? "Bryston 28B Mono Amplifie
« Reply #22 on: January 14, 2006, 12:05:44 am » 

--------------------------------------------------------------------------------
Well said sir.

james

Now don't you guys go asking about Class A power output!!!!
 
 
 
 

[Phil A]

We'll get over it - just a temporary flare-up of audiophile neurosis aa

[john1970]

I am interested to know.  What about the 9B SST amps?

All the Bryston amps run Class A for the first few watts.

james

[jakeman]

I need some enlightment.  Why is it beneficial to have as much Class A wattage up front before it turns to Class AB?   I understand lower distortion in A but that would argue for staying in A and putting up with the heat? 

[perose]

I need some enlightment.  Why is it beneficial to have as much Class A wattage up front before it turns to Class AB?   I understand lower distortion in A but that would argue for staying in A and putting up with the heat? 

The reason for wanting to have Class A watts is that for "normal" listening levels the amp isn't really putting out all that much power say 1 - 5 Watts. If the amp remains in Class A at this power level, the distortion would be lower.

[James Tanner]

I need some enlightment.  Why is it beneficial to have as much Class A wattage up front before it turns to Class AB?   I understand lower distortion in A but that would argue for staying in A and putting up with the heat? 

The reason for wanting to have Class A watts is that for "normal" listening levels the amp isn't really putting out all that much power say 1 - 5 Watts. If the amp remains in Class A at this power level, the distortion would be lower.

Actually the distortion is not lower in Class A. Here is a white paper we wrote on the subject.
http://www.bryston.ca/BrystonSite05/pdfs/MiscDocuments/Class-A-versus-B.pdf

james

[jakeman]

Thanks good read.  If "Class A is passe "  why is the fact that several  the SSTs run in class A for the first few watts considered an attribute?  I am taking a hard look at a 14BSST and would like understand the nuance. 

[john1970]

I am by no means an expert, but I believe that the Bryston amps are ran for the first few watts in class A so the transitors are at their optimal operational temperature for low distortion.  Please excuse my mistake if I am wrong...I am sure James or Chris can clarrify this point.

When the comment "class A is passe" was made I believe that the reference was to amps that operate in full class A upto their rated output.

Best,

John

[James Tanner]

Thanks good read.  If "Class A is passe "  why is the fact that several  the SSTs run in class A for the first few watts considered an attribute?  I am taking a hard look at a 14BSST and would like understand the nuance. 

Hi,

It is just the nature of the Bryston quad complimentary circuit to run in Class A for the first few watts.
http://www.bryston.ca/BrystonSite05/pdfs/MiscDocuments/OUTPUT-STAGES.pdf

'Class A is Passe' was referring to Class A amplifiers running in Class A throughout their entire power range and the concerns thereof.



James