Bryston 7B ST - Sounds anaemic. Any help?


I bought a new Bryston 7B ST recently to replace a 94 model 4B THX to drive my bass and I was hugely dissapointed. I wonder if there is a possibility that it may not be pumping 500w as it supposed to do. I have Alon Circe speakers.

I just don't get the oomph factor and I feel the 4B THX kicks better.

Would appreciate suggestions
hafeez
Pbb: thats probably why Bryston did not bother putting an extra resistor or relay in the amps. They expect (or are accustomed) to users who leave it on all the time (studio's etc.). I leave my Brystons on for most of the time. The occasional holiday or weekend when I switch them off is really only a luxioury problem....

Happy trials!
Hafeez: Bryston is the real deal. I'm glad people like them are in business. In the quest for perfection, we sometimes lose perspective. I hope you enjoy the music and forget the hardware for a while. Regards. BTW, leave them on and the issue of the noise on exit is solved.
Hi Everyone,

I guess the amp just needed warming up and yes, the bass is more controlled and of course the legendary Bryston support and response within 24 hours did help. Whatever, Bryston is about the best co there is out there, hi end stuff at real world prices and they are over zealous in customer satisfaction which is always a nice feeling. The oomph is perhaps due to over extended expectations but the tonal balance is there. The FM Acoustics gave me more slam though.

Problem solved and happy listener and always a Bryston fan. Glad I bought the Bryston instead of the Pass Labs or Krell.
You can wire a resistor from the caps to gound to discharge the caps more quickly if you like. It is my less than humble opinion that you end up with two choices:

1) Discharge the caps, which produces heat the whole time the amp is on.
2) Add a relay which can (if done correctly with gold contacts doesn't) degrade the sound.

Last I don't believe that any transient signal has any place near my less than robust tweeters. In my opinion this is a design oversight, and is unacceptable.
Ok, thank you for putting my audiophiles' mind to rest. I guess at Bryston less is litterally more (sounds...)

;-)
Dear Nanning,
I have observed the same noises with my 7Bs. I agree with PBB that it is probably from capacitors discharging. It is disturbing but not damaging. There are ways to prevent these sounds, but obviously this was not done for our 7Bs. I am happy not to pay for extra circuitry. I left my 7Bs on virtually all the time anyhow.
All power amps that I have owned did something similar. Ask Sean, but I believe it's the storage caps that are discharging.
Since there are quite some 7B users on this topic, I have a question about these amps that I'd like other 7B users to answer. When I turn off the amps (7B ST) I hear terrible squeeky sounds through the loudspeaker which then slowly fade away... First I was afraid that my speakers where being slaughtered but now I know that they don't and keep working normally. Do all Bryston amps have this strange behaviour or could there be something wrong with my Brystons?

I'd really appreciate 7B owners experience with there amps in this regard.

Thanks you!
1) I have worked on enough gear to know that sometimes what measures fine is still not operating "correctly". As such, i do not doubt that a component is acting "squirrely" for a customer even though i may not be able to duplicate the problem on my bench.

2) I have run into TONS of situations where a component was "screwed up" or "not running right" simply because it was responding to a problem elsewhere in the system. In many of these cases, the customer blamed what they thought was convenient rather than doing any of the simple yet effective steps to troubleshoot the problem themselves. If i was an unscrupulous person, i could charge them for repairs that were never done or sell them something else that would do nothing for them while nodding and smiling while i say "this will fix your problem".

3) Our testing methods are very lacking. There are things that we just can't explain even if we have all of the data directly in front of us. I could go into details but it would be a moot point. Once one realizes that, "crazy explanations" sometimes seem to make more sense than "what should work but doesn't" or vice-versa.

As to your comments about listening to music, i am lucky in the fact that i get to listen to music at least 6 to 8 hours every day. I typically listen to my HT system via the mains ( large 4 ways with 5 drivers per cabinet with very high powered digital amps ) for appr 2 to 2 1/2 hours before leaving for work in the morning. When i get home from work, i listen to my computer room / home office system ( omnidirectional full-ranges with monoblocks ) for what usually turns out to be about 4-6 hours a night. On occassion, i will fire up my basement system ( tubes with horns ) for a couple of hours before heading into the computer room. On weekends, i make use of my main system ( tri-amped with mono-blocks and a line array of e-stat tweeters, double stacked e-stat panels for mids and multiple dynamic woofers ) for several hours on end. When it's time to "keel over", i can doze off in the bedroom with a bi-amped pair of monitors on stands and two downloaded subs. If i'm not listening to music, it is because we are watching a movie, etc... When all is said and done, i probably need a little more "peace and quiet" : ) Sean
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Sean, don't take my comments too personally. I think that there might be some merit in the fact that if someone is not used to tight bass, of the type to be heard with a 7B ST, but is rather used to a fat, floppy sort of bass, the conclusion could be that (assuming the only change in the system was the power amp) the power amp is not hefty enough. Unless a Bryston is not working properly or is being asked the impossible in source material being reproduced, SPL and load, it, like any other amp, will clip. The point at which it does is, for all practical purposes short of torture testing, so high as to be irrelevant. I stick to my point that manufacturers are at the whim of people who invent problems where they don't exist and would rather believe gibberish than rational explanation. No, it's not good enough in my opinion to say, nay to insist adamantly, that one's ears are the only and final arbiter and that anything goes in high-end audio. Like I said before, some people out there are laughing as I write this thinking how gullible their customers are. On the other hand, some honest, hard-working, intelligent people are not so prone to hilarity when nonsense about their wares has put them, if not in bankruptcy, on the edge of it. On the topic of measurements: what is being measured and how is very important, the correlation between the numbers generated and the sound is another kettle of fish. A sane and rational approach to evaluating components individually and systems as a whole in the one and final important criteria, that is listening to music in a real world situation, is sorely lacking. The placebo effect is all to real. So many audiophiles cannot tell the difference between a malfunction and some artefact in the reproduced sound, that another problem has crept up: audio-psychosomatic disorders. As a technician you surely must have come across such instances. One and all, stop fretting and listen to music is my advice. You will still enjoy the "hobby", not to worry.
1) Have the unit checked, even the best lets a little quality issue slip out from time to time.

2) However, a bigger, higher current amp gets a lot tighter grip on the woofs, and may have just corrected the looser boom sound your used to. As such it will sound less bassy.

3) Does the bass sound tight, tighter than before? Then see #2 again.

jeff
Pbb, you forget that i make my living working on electronic gear taking hundreds of measurements on a daily basis. As such, i'm not just talking as an "avid audiophile" discussing "fantasy situations" and associated explanations. There are PLENTY of times that one component will perform measurably better on a bench but just won't cut the mustard under real world conditions.

I've seen an RF transmitter showing more than twice the power output on a lab grade wattmeter and scope get its ass kicked by another transmitter showing slightly less than half that same amount of power. Before you ask, this testing was done using the same loads ( same dummy load on the bench and then both transmitters feeding the same antenna on a switchbox ). We are not even talking about how each deals with different types of loads and why but in effect how they work apples to apples. As far as i know, Hafeez did that same "apples to apples" type of comparison.

Try explaining to a customer why his "antique" radio that he thought would be a "spare" works better than his latest / greatest / far more expensive "high tech" piece of gear that he just bought and shows more than twice the power. Then you'd know how i feel at times. There are some things that we just don't know how to explain and are not "quantifiable" at this point in time.

The above RF situation is no different than what i've experienced with AF ( audio frequency ) amps. My old 250 wpc 4B that was factory serviced could not drive speakers as well as the 75 wpc Classe' 70 that i had. While i have NO doubt believing that the 4B would measure quite noticeably more powerful on the bench, i also have NO doubt that it sounded anemic and kept going into clipping. At the same time within the same system, the "baby sized" Classe' just kept pumping out the tunes with nary a problem and at higher listening levels. Neither amp really sounded "good" to me, but i had a HELLUVA lot more respect for that little Classe' for obvious reasons. Once again, this was an "apples to apples" type of situation with the same equipment being used. The only variables introduced were the two different amps.

As i mentioned, i was simply commenting on the information that was presented in that article. LG's comments fell "close to home" as i had been in a similar situation with the older Bryston. As to my "reading between the lines" about the amp going into clipping on more than one occassion, would that be "illogical" given the statements that were published ??? Personally, i think not. Then again, i have no agenda ( i don't sell or service ANY brand of hi-fi gear ) nor do i feel the need to stick up for a product that i felt performed in a sub-standard manner. How much "weight" or "value" someone puts on my comments as an end user is strictly up to them. As anyone that has read more than a few of my posts knows, i always try to stress that one needs to buy / use / work with their system and not worry about brand names, what someone else likes or what is currently "fashionable".

As to the subject at hand, Hafeez MAY be in a similar position. As such, i simply referred him to what was already a discussion in progess on another forum. I then asked questions so that we may be able to get to the bottom of his problem. Obviously, something IS wrong or being misinterpreted. Unless all of the variables can be explored, we'll never know what is taking place. The more that he knows and can familiarize himself with that piece of gear, the better off he'll be. Even then, since we can't "quantify" everything, we still may never know what is taking place. Sean
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If you are unable to correct the problem you're having with the 7B-ST's, I suggest you contact James Tanner at Bryston for advice/suggestions. The easiest way to contact James is to go to Bryston's home page (www.bryston.ca), and at the bottom of the page you will send a hyperlink for technical questions. James (or one of his minions) always responds very quickly, and will probably have the solution to your problem.
When I first received my 14b-st I used balanced
from my vk-30 bat to the amp and had no bottom.
then I saw the switch on the back that said balance
+ 6db . flipped the switch and problem solved. this
made a huge difference not only the bottom end but also
a much smoother tonal quality.A friend of mine borrowed my
amp and just used the unbalanced innerconnects and had no
problems with bottom end either.With my system there is
no lack of bass.
Sean,
I have looked briefly at the Asylum thread you referred to. I think you prove my point that when subjective listening by an avid audiophile such as you does not jibe with any rational measurement, some sort of explanation is drummed up to support the golden eared. Two of the favourite ones being some incompatibility (less virulent a position) to questioning the reputation of the manufacturer (example: Bryston may have found a loophole in the mandated measurement method). Reading too much into what the insane press says is also a good way to shore up one's subjective defences (well this "critic" said that he heard clipping and saw the indicators and it sure sounded that it happened on more that one occasion). Reading between the lines is a hazardous propostion. Oh yes figures lie and liars figure. Where does that leave pure subjectivity though? I'm just happy I am not a high end manufacturer having to survive with the whims of audiophiles, with the flavour-of-the-week syndrome and where conjecture, if not out and out fabrication, passed off as "discussion" or "opinion", can force me into bankruptcy. In this search for every perceived fault in any piece of gear, it's a wonder you guys find any time to enjoy music.
After having said the above, is the 4B higher gain than the 7B ? If so, you would be experiencing less bass output for the same amount of drive that the 4B used to give you. This could come across as less "oomph" or a slightly lean tonal balance. There would still be bass output, but just not as much as what you were used to. Do you find the bass lower in quantity or is it also poorer in quality ?

Keep in mind that many larger amps also offer better control over the drivers, so you might actually be hearing "less slop" and more accurate output. Sean
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Take a look at the thread below.

As to Pbb's comments, how is sharing experience and commenting on the experience of others ( even in published glossies ) "undermining" a company ? If what you say is true, devotees of Bose can lay claim to the same "mistreatment" on a X10 basis.

Personally, i would rather hear both the "good" and "bad" surrounding a product. This allows me to have a more informed idea of what i might end up dealing with. Like anything else though, i would form my own opinions of the product based on my own experience with it. Like anything else, that experience could be good or bad or a combination of the two. Sean
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http://www.audioasylum.com/audio/general/messages/200490.html
Perhaps the Circes' woofers are wired for hi-impedance (suitable for tube amps)... if so change them to the 4-ohm setting (done by dealer or mfg?)
Also the bass on these speakers is very well damped so you won't get great gobs of bass.
If you had better performance with your 4B, this is a puzzle.
I assume you have two 7Bs in mono config, not one as your post suggests.
A 7B ST anaemic? I have a pair and they could drive the proverbial brick. Two possibilities come to mind: the amp is sick and needs professional care; your level of anticipation was such that the amp can never be equal to the task. This second possibility happens more often than subjective audiophiles care to admit. After all, no matter how good an amp is, it's just an amp. The same goes for any other component: too much hype equals disappointment. Most level-headed audiophiles come to that realisation sooner or later. Those highly touted HUGE differences are, as likely as the sun is to rise in the East, in the ear of the behearer (did I write that?). Get the amp checked. If it's ok you have two outs: claim that there is some sort of mismatch between amp and speaker or, as a lot of audiophiles are wont to do, undermine the reputation of one of the most honest companies in high-end audio by repeating in every forum and to all concerned (heck throw in some not so concerned for good measure) that this amp is "thin", "lightweight" or any other purely subjective epithet. Oh, by the way, make sure that the switch at the back is properly set for series or parallel operation: it could make an appreciable difference. Good luck and good listening and don't give up on Bryston they are great amps.
Are you driving the Bryston directly from the wall? They do not require power line conditioners and if you are using one don't plug the Bryston into it...Maybe the Bryston doesn't like the speaker matching? Are the speakers a difficult load?
Sounds like a faulty unit. Check with Bryston; they'll probably suggest you send it in. Bummer to be without it for a while, but at least you've got the 20 year warranty.

Other possibilities: some kind of impedance mismatch with your preamp or whatever is in the signal path immediately in front (unlikely). Suboptimal setting of the current/voltage switch in the back -- try flicking it the other way and see if the sound improves. Also, it may not be sufficiently broken in (unlikely). Gook luck.