Bryston 4B ST running too warm ?
JOHN BARR
->I am trying out a new version of Bryston 4B, 4B ST Series. After running
->for an hour, at moderate listening level (without having measured, my
->guess is 85 to 90 dBA, but not louder than that), I found the amp a little
->too warm at the fins.
->I left it ON overnight, idling. In the morning, it feels "a bit too"warm.
[quoted text deleted by RD]
I have an older 4B which runs hot, as I believe most class A amps do.
I notice the difference especially when playing at a loud volume.
It's more than just a "bit" warm. At idle the temp is warm to the
touch but not alarming.
The amp rack is a nice place to be near in the winter, and more than a
little stuffy in the summer. I keep a quiet fan running across the
rack most of the time. Cut my heating bills in half ;)
John Barr
Robert Allen
>I am trying out a new version of Bryston 4B, 4B ST Series. After running
>I left it ON overnight, idling. In the morning, it feels "a bit too"warm.
[quoted text deleted by RD]
When I first got my 8b ST THX (now there's a mouthful), while
playing it on hot days the unit got almost too hot to comfortably
touch on the top and on the fins. Now after using it for a
while I don't have this problem, but then the days are cooler
too.
If you're really concerned about the heat you need to get an
objective measurment with a decent stick on thermomemter tape.
Failing that you could just use the unit for a while and see
if it burns in and runs cooler. Since the unit has a 20 year
guarantee the worse you'll be out is not having the unit for
a couple of weeks should it need to be repaired. I'd also point
out that, as the Bryston rep noted indirectly, running hot isn't
a problem as long as you have sufficient heat sinking, and the
Brystons do. The Bryston is I believe a clas A/B amp, so at lower
power draws the amp will run in class A mode, which is hotter.
Finally, I have my Bryston at the top of my equipment stack, on
an Alon (?) Pyramid stand, which is an open air affair. I recommend
lots of air circulation for such a large power amp.
As long as it sounds good, and nothing is physically melting or
smelling funny much, I'd be confident that the warranty will
take care of everything, and be very, very, happy with the amp.
(Yes, I think Bryston ST amps are a gift from the gods :-)).
---
Robert Allen
r...@sun.com
I hate Frys Electronics. All of them, but particularly the ones
in Fremont, Palo Alto, Campbell, and Sunnyvale.
SSS
writes:
>In article f...@tolstoy.lerc.nasa.gov, David Ta <davi...@canada.cdev.com>
> writes:
>>I am trying out a new version of Bryston 4B, 4B ST Series. After running
>>for an hour, at moderate listening level (without having measured, my
>>guess is 85 to 90 dBA, but not louder than that), I found the amp a little
>>too warm at the fins.
>>I left it ON overnight, idling. In the morning, it feels "a bit to
warm"
Hi there,
The Bryston 4 ST "normally" idles pretty hot. Even after being turned
for only half hour in idle it almost gets too hot to touch. After
playing it pretty loud it gets hotter, but not a lot more. Do not
worry about it, it is normal.
The older 4B used to get warm during idle, and pretty hot when at loud
levels.
I hope this is helpful,
Regards,
--
Ramon E. De la Cruz
rdel...@iastate.edu
D. Agnew
<davi...@canada.cdev.com> says:
>I am trying out a new version of Bryston 4B, 4B ST Series. After
>running for an hour, at moderate listening level (without having
>measured, my guess is 85 to 90 dBA, but not louder than that), I
>found the amp a little too warm at the fins.
>
>I left it ON overnight, idling. In the morning, it feels "a bit
>too"warm.
Well, mine is only a 2B and I don't leave it on all of the time, but
the fins still get too hot to touch comfortably after I've had it on
for a while.
A friend of mine has a 4B that he leaves on all of the time, and (as I
think John Barr says) particularly in winter it's cozy over in front
of the audio equipment.
It sounds pretty normal to me, David.
- D.
Never attribute to malice that which can be
adequately explained by stupidity.
david (d.s.y.) wong
writes:
|> In article f...@tolstoy.lerc.nasa.gov, David Ta <davi...@canada.cdev.com>
|> writes:
|> >I am trying out a new version of Bryston 4B, 4B ST Series. After running
|> >for an hour, at moderate listening level (without having measured, my
|> >guess is 85 to 90 dBA, but not louder than that), I found the amp a little
|> >too warm at the fins.
|>
|> >I left it ON overnight, idling. In the morning, it feels "a bit too"warm.
|>
|> [quoted text deleted by RD]
|>
|> When I first got my 8b ST THX (now there's a mouthful), while
|> playing it on hot days the unit got almost too hot to comfortably
|> touch on the top and on the fins. Now after using it for a
|> while I don't have this problem, but then the days are cooler
|> too.
I've had my Bryston 7B ST (less of a mouthful) monoblocks for a
weekend now. They were brand-new. I did seem to experience that it was
running cooler at the end of the weekend after being on and used for 3
days. However, even at the beginning, the amps were not that hot to
the touch. It is definitely cool enough to leave the hands, or even
the arms (more sensitive), on the top of the amps or heat-sinks
comfortably for extended periods of time. (Why anyone would want to
drape over the amps for any extended period of time is beyond me.)
What I found is that the entire chassis - top, bottom, front, back and
sides - along with the heat-sinks are warm; with other amps, I've
found the chassis to take on less heat.
Bryston tells me that it was a design intent and choice to use the
chassis for additional heat-sinking purpose.
|> If you're really concerned about the heat you need to get an
|> objective measurment with a decent stick on thermomemter tape.
|> Failing that you could just use the unit for a while and see
|> if it burns in and runs cooler. Since the unit has a 20 year
|> guarantee the worse you'll be out is not having the unit for
|> a couple of weeks should it need to be repaired. I'd also point
|> out that, as the Bryston rep noted indirectly, running hot isn't
|> a problem as long as you have sufficient heat sinking, and the
|> Brystons do. The Bryston is I believe a clas A/B amp, so at lower
|> power draws the amp will run in class A mode, which is hotter.
|>
I noticed from the Audio (94) Component Listing magazine that the
Bryston NRB (prior to the current ST series) amps are categorized as
AB2, but found no legend to explain what this stands for. A and A/AB
categories, I know what they stand for. For example, Krells are class
A; McCormack DNA-1 is A/AB.
Bryston tells me that AB2 stands for their Quad Complementary method
of amplification. (It's not that others don't also do Quad
Complementatary, just that Bryston claims and patents theirs as
unique.) In short, the power consumption of class AB2 is on par with
class AB which is much better than class A, and AB2 has much lower
distortion all the way out to 20 khz. Bryston tells me that all their
amps (in the NRB as well as the current ST series) use class AB2
amplification.
|> Finally, I have my Bryston at the top of my equipment stack,
|> on an Alon (?) Pyramid stand, which is an open air affair. I
|> recommend lots of air circulation for such a large power amp.
|>
|> As long as it sounds good, and nothing is physically melting or
|> smelling funny much, I'd be confident that the warranty will
|> take care of everything, and be very, very, happy with the amp.
|> (Yes, I think Bryston ST amps are a gift from the gods :-)).
|>
I don't know that I could be that emphatic, but the 7B ST amps
definitely do sound very good, and brand-new out of the box at
that. OTOH, if Bryston ST amps are a gift from the gods and the Tara
Labs RSC speaker cables are cables from the almighty (something like
that according to their ads), then I must have something along the
lines of a match made in Heaven ...
In actual fact, I wish the Bryston 7B ST amps were a gift, period.
Bryston tells me that the amps are factory burned-in for 100 hours for
Quality Assurance and Robustness testing. Which helps to explain the
excellent performance straight out of the box.
David Ta
> I have an older 4B which runs hot, as I believe most class A amps do.
> I notice the difference especially when playing at a loud volume.
> It's more than just a "bit" warm. At idle the temp is warm to the
> touch but not alarming.
I am supprise to hear the 4B is of Class A. I still have a copy of TAC
review on the 4B, way back in July/August/September of 1977, clearly
states that this amp is of Class AB !
Either way, should I leave it on ALL the time, or just a couple hours
prior to listening ?
David
PSiu89449
sub-woofer duty. Yes they run hot for Class AB2. Measures 50 degrees C at
the heat sink, room temperature dependent. In comparison, my Krells Class
A measures only 57 degrees C. I don't leave my amps on 24 hrs a day. I
feel that most high bias amps reaches a steady operating temperature
within one hour upon switch on. With Bryston's 20 years warrantee, no
fear, I have 19+ years to go.
A friend of mine brought his 4B NRB over for a comparison a few weeks ago.
No contest. I ran both amps full range, one on one. The ST is more
expansive, less grain, slightly more detail but yet sweet. Close to the
Krells but still can't compare on soundstage depth. At double the price
each, they better be!!! Will I recommend upgrade to ST? That's system
dependent. My friend is!!!
Best Regard
Paul
PSiu89449
Best Regard
Paul
[ Post delayed for several days within AOL. -- jwd ]
PSiu89449
dynamic biasing on their Class A amps. I am running the pre-S models,
fix bias Class A.
Best Regard
Paul
Andy Moss
: When I first got my 8b ST THX (now there's a mouthful), while
: playing it on hot days the unit got almost too hot to comfortably
: touch on the top and on the fins. Now after using it for a
: while I don't have this problem, but then the days are cooler
: too.
A local multi-cine-plex uses 4B amplifiers galore. They all run
burning hot after a short time.
However, if it really concerns you a small, quiet fan may be in order.
This will almost certainly prolong component life. However, they do
have a very good warranty anyway. 8-)
Cheers!
Andy
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Walter Clark
I own a vintage 4b (manufactured around 1978 and bought by me about then)
which has been powered on continuously except for moves and extended
vacations. I have experienced NO reliability problems with the
amplifier related to AC power during that time. I have not bothered to
measure idle power consumption but I would guess it is between 100W-200W
based on heat dissipation when the output stages are biased to factory
specs.
Walter