Technical ? for James on amp input sensitivity

0 Members and 1 Guest are viewing this topic. Read 12858 times.

1oldguy

Re: Technical ? for James on amp input sensitivity
« Reply #40 on: 24 Jul 2010, 07:32 pm »
Interesting.. no mention of speaker sensitivity. IMO a glaring omission. However I use Maggie's (3.6)and at 85 dB the are still not allowing me to use my BP-26 and 4B-SST2 above 8 O'clock volume with a CD input. I use the 1.5 and can get up to the 12 O'clock position. So I have to say the 'theoretical' explanation just does not cut it in the real world for CD.

Interesting you brought this subject up in the first place.I'd like to know more myself about this.I wonder with B&W just how I should have things set up.But of course I need to buy a preamp first.LOL.But given what you've said I wonder which would be the best preamp given the problem(If I can call it that) of volume control.

James Tanner

  • Facilitator
  • Posts: 20861
  • The Demo is Everything!
    • http://www.bryston.com
Re: Technical ? for James on amp input sensitivity
« Reply #41 on: 24 Jul 2010, 09:36 pm »
Interesting.. no mention of speaker sensitivity. IMO a glaring omission. However I use Maggies (3.6)and at 85 dB the are still not allowing me to use my BP-26 and 4B-SST2 above 8 O'Clock volume with a CD input. I use the 1.5 and can get up to the 12 O'Clock position. So I have to say the 'theoretical' explaination just does not cut it in the real world for CD.
Sorry, but it does nothing for my problem, and no reply to my email  to your dude, James.

Not sure I understand - "no reply to my email to your dude, james?"


james

vegasdave

  • Full Member
  • Posts: 4039
    • My online rock magazine-Crypt Magazine
Re: Technical ? for James on amp input sensitivity
« Reply #42 on: 24 Jul 2010, 09:49 pm »
1V sounds better in my system. 2V is too laid-back for my tastes.

Napalm

Re: Technical ? for James on amp input sensitivity
« Reply #43 on: 24 Jul 2010, 09:55 pm »
1V sounds better in my system. 2V is too laid-back for my tastes.

Same settings here. If it's way too loud at 9 o'clock then it's Death Magnetic or something similar that's not worth listening at any volume.

Nap.

BrysTony

Re: Technical ? for James on amp input sensitivity
« Reply #44 on: 24 Jul 2010, 10:27 pm »

For the BP26, your spec sheet calls SNR -103 db at 1V balanced input...so if the average input voltage to the pre is only 0.5V balanced ...how many db SNR are you giving up?

Bryston furnishes test data on each BP-26 unit.  For my BP-26 the balanced result was L -103.01db and R -102.83db.  Unbalanced was L -104.18db and R -103.44.  These measurements were taken with a 0.5V input.

As I said in Reply #21 above there are many variables affecting the volume setting.  IMHO there is learning value in this thread but there is no issue with Bryston hardware and this thread is otherwise much ado about nothing.

Tony

rob80b

Re: Technical ? for James on amp input sensitivity
« Reply #45 on: 24 Jul 2010, 11:23 pm »
Hi Elizabeth,

Just jumping in here but just to quote you from some other threads I can see where your problem lies.

"I play music at low levels only. I am living in an over 55 apt and do NOT intend to disturb my neighbors. So I had to find equipment that would be great without the high SPL. i think I have succeeded."

"I probably will never have clipping. I have Magnepan 3.6's with my Bryston 4B-sst@2 in my apartment and play music softly all the time. The music playing right now is 'A' rated 68dB with Radio Shack meter. I would say my highest dB is mid 80's."

I guess the dilemma is that recommending a smaller amp that may give you more range before it gets too loud defeats using a larger amp that appear to offer better sound at lower volumes.
I'm sure that Bryston can offer a solution by getting service to reduce the gain either at the pre or amp end, but to not degrade the (smaller) signal between the cd, pre and amp which has been optimized on the Bryston end  I'd recommend a small high quality resister on the speaker cable, either at the speaker or amp end to reduce the gain, it'll cost you a buck or two and at low volumes I'm sure the difference in audio quality will be negligible.

Either way it would be nice the get a better usable range on the BP26 without compromising the audio.

Robert

KnowTalent

  • Jr. Member
  • Posts: 296
  • ...stuck in the middle with you
Re: Technical ? for James on amp input sensitivity
« Reply #46 on: 25 Jul 2010, 02:53 am »
Bryston furnishes test data on each BP-26 unit.  For my BP-26 the balanced result was L -103.01db and R -102.83db.  Unbalanced was L -104.18db and R -103.44.  These measurements were taken with a 0.5V input. 

As I said in Reply #21 above there are many variables affecting the volume setting.  IMHO there is learning value in this thread but there is no issue with Bryston hardware and this thread is otherwise much ado about nothing. 
Tony


At what volume setting did you obtain these measurements? 


KeithA

Re: Technical ? for James on amp input sensitivity
« Reply #47 on: 25 Jul 2010, 10:22 am »
Not sure I understand - "no reply to my email to your dude, james?"


james

I think she is referring to the fact that maybe Mike Pickett hasn't contacted her. I think you recommended that she contact him in one of the earlier posts.

Keith

BrysTony

Re: Technical ? for James on amp input sensitivity
« Reply #48 on: 25 Jul 2010, 02:05 pm »

At what volume setting did you obtain these measurements?

These measurements are from the Bryston Test Data Sheet that comes with the BP-26.  I don't know how Bryston did the testing.  I just wanted to show that the spec was met at 0.5V input.
Tony

rob80b

Re: Technical ? for James on amp input sensitivity
« Reply #49 on: 25 Jul 2010, 02:42 pm »
I‘ve been giving this thread a bit more thought and more so in regards to Elizabeth’s situation, who has contributed well thought out and informative posts amongst the various forums proving that she is a seasoned audiophile.
In relation the original OP’s inquiry I think for a lot of us in comes down to reproducing the original signal at the highest SPL level without distortion so when confronted with someone trying to get the most out of their system at the lowest possible volume it throws a bit of a curve into the situation but adheres to Bryston’s “first to the last watt”.

Also, again quoting Elizabeth,

"I play music at low levels only. I am living in an over 55 apt and do NOT intend to disturb my neighbors. So I had to find equipment that would be great without the high SPL. i think I have succeeded."

Having sold the house 2 years ago I took over an apartment for the short term with the intent of purchasing a condo, fortunately it’s connected to my shop and is an extension to the original building so I’ve no tenants to the top or sides so playing at higher SPLs is not a problem.
Now the problem is that I’m unwilling to give up this hobby and I can see foresee that living in a condo will defiantly be problematic as I to do not wish to disturb the tenants.
There’s also the piano and my flute playing so that rules out relegating my music to headphones.
Hopefully I’ll come across something that will serve my needs without resorting to a concrete bunker and being in the same situation as Elizabeth and most likely like many other aging audiophiles who end up in a 55 and over building (although I’ve past that marker).

I guess Bryston will just have to add a 3 way switch 1V, 2V and over “55”V.

Robert

Laundrew

  • Full Member
  • Posts: 7177
  • "Sometimes it rains inside my head..."
Re: Technical ? for James on amp input sensitivity
« Reply #50 on: 25 Jul 2010, 04:48 pm »

In relation the original OP’s inquiry I think for a lot of us in comes down to reproducing the original signal at the highest SPL level without distortion so when confronted with someone trying to get the most out of their system at the lowest possible volume it throws a bit of a curve into the situation but adheres to Bryston’s “first to the last watt”.

Robert

I also consider myself very fortunate that my system provides me with “all” of my music at low volume levels - perhaps full volume at very low power settings would be much more precise as my music fully envelops my room and you can still comfortably talk over it.

This was a quality that I immediately noticed when I auditioned my beasties to be. I think that it is the best of both worlds - awesome detail at very low power and the clear and crsip roar when I get close to the 3 o’clock position.

No requirement to venture into the undiscovered country.

Be well…

KnowTalent

  • Jr. Member
  • Posts: 296
  • ...stuck in the middle with you
Re: Technical ? for James on amp input sensitivity
« Reply #51 on: 25 Jul 2010, 09:08 pm »
These measurements are from the Bryston Test Data Sheet that comes with the BP-26.  I don't know how Bryston did the testing.  I just wanted to show that the spec was met at 0.5V input.
Tony

Tony,

maybe James or Chris would care to chime in but in the meantime I would hazard to guess these measurements are made at either unity gain or max volume...with max volume being the most common reported because it provides the best measurement numbers. 

The problem with this sort of marketing of "best case" technical specification is that hardly any of us listen to music with the volume at settings these measurements are taken at...in fact most common volume settings that correspond with listening levels in the mid-low 80 db spl level can be as much as 20 to 30 db down from what's listed in the specs (probably closer to 30 db for elizabeth based on her previous comments) .. hardly "much a do about nothing" imho when you've just laid down $3-4K for "specs" you aren't getting in typical listening situations  :o

That is why I was orignally asking about amp input sensitivity...because a higher input V sensitivity allows you to achieve the same spl levels though at a higher volume on the pre and thus you get closer to the rated SNRs as if you're forced to run low volume settings you are most likely NOT getting the transparency the measured specs hint at and since that extra 20-30 db can translate to removing the haze (better transparency)...which can lend to better reproduction of three dimensional soundstaging and all the other subtlies that are hallmarks of "high end" audio listening.

I'm not trying to throw stones at Bryston here as I consider their product line, build quality and philosophy to be much in line with the likes of McIntosh...who incidently rates their balanced
input sensitivities at 3.6V up to as high as 5V...Rather, I'm confused as to why they would not simply up their amp input sensitivity to better synergize with the relatively hot output of the BCD/BDA product line...and in doing so remove the preamp volume attenuation issues?

The gain attenutation option on the PRO models "sounds" like it would accomplish this but because I don't know enough about circuit design I can't comment of if it betters or equals the results of a higher input sesitivity.

Granted,before you buy an amp you should know what your speaker sensitivity is and have a rough idea of what power output will be neccesary to generate the spl you desire in your own listening room...if you don't know then a good dealer or manufacturer should be able to give you recommendations that get you close enough.



1oldguy

Re: Technical ? for James on amp input sensitivity
« Reply #52 on: 25 Jul 2010, 11:28 pm »
Tony,

maybe James or Chris would care to chime in but in the meantime I would hazard to guess these measurements are made at either unity gain or max volume...with max volume being the most common reported because it provides the best measurement numbers. 

The problem with this sort of marketing of "best case" technical specification is that hardly any of us listen to music with the volume at settings these measurements are taken at...in fact most common volume settings that correspond with listening levels in the mid-low 80 db spl level can be as much as 20 to 30 db down from what's listed in the specs (probably closer to 30 db for elizabeth based on her previous comments) .. hardly "much a do about nothing" imho when you've just laid down $3-4K for "specs" you aren't getting in typical listening situations  :o

That is why I was orignally asking about amp input sensitivity...because a higher input V sensitivity allows you to achieve the same spl levels though at a higher volume on the pre and thus you get closer to the rated SNRs as if you're forced to run low volume settings you are most likely NOT getting the transparency the measured specs hint at and since that extra 20-30 db can translate to removing the haze (better transparency)...which can lend to better reproduction of three dimensional soundstaging and all the other subtlies that are hallmarks of "high end" audio listening.

I'm not trying to throw stones at Bryston here as I consider their product line, build quality and philosophy to be much in line with the likes of McIntosh...who incidently rates their balanced
input sensitivities at 3.6V up to as high as 5V...Rather, I'm confused as to why they would not simply up their amp input sensitivity to better synergize with the relatively hot output of the BCD/BDA product line...and in doing so remove the preamp volume attenuation issues?

The gain attenutation option on the PRO models "sounds" like it would accomplish this but because I don't know enough about circuit design I can't comment of if it betters or equals the results of a higher input sesitivity.

Granted,before you buy an amp you should know what your speaker sensitivity is and have a rough idea of what power output will be neccesary to generate the spl you desire in your own listening room...if you don't know then a good dealer or manufacturer should be able to give you recommendations that get you close enough.

I believe this is what threw me off as well when I first fired up my system.Now I know what the reason for what felt like poor performance,which looking back wasn't.Using the B&W 802D for speakers and low volumes didn't do much for SPL's for me.But when i did crank it somewhat ....then it was much better,just a little to much for the neighbors.I'll fondly look back at this  as the informational,educational,celebrational,thread. :green:

Napalm

Re: Technical ? for James on amp input sensitivity
« Reply #53 on: 25 Jul 2010, 11:34 pm »
...who incidently rates their balanced input sensitivities at 3.6V up to as high as 5V...

How insensitive....

Nap.  :lol:

vegasdave

  • Full Member
  • Posts: 4039
    • My online rock magazine-Crypt Magazine
Re: Technical ? for James on amp input sensitivity
« Reply #54 on: 26 Jul 2010, 03:04 am »
Same settings here. If it's way too loud at 9 o'clock then it's Death Magnetic or something similar that's not worth listening at any volume.

Nap.

I agree.

Phoenix

  • Jr. Member
  • Posts: 65
Re: Technical ? for James on amp input sensitivity
« Reply #55 on: 26 Jul 2010, 04:17 pm »
A speaker sensitivity of 98dB/Wm and everyone leaves the room voluntarily when my B60 is at twelve.  :wink:

Normal listening levels are at 7 or 8 - never had any problems with that.
Only this one perhaps: to completely silence the system I have to push "MUTE" on the remote!  :lol:

KnowTalent

  • Jr. Member
  • Posts: 296
  • ...stuck in the middle with you
Re: Technical ? for James on amp input sensitivity
« Reply #56 on: 27 Jul 2010, 09:17 pm »
I agree.

If you're typical listening levels correspond with a minimum 12 o'clock volume position then you're probably getting the majority of what the circuit design is capable of  :thumb:

KnowTalent

  • Jr. Member
  • Posts: 296
  • ...stuck in the middle with you
Re: Technical ? for James on amp input sensitivity
« Reply #57 on: 27 Jul 2010, 09:23 pm »
A speaker sensitivity of 98dB/Wm and everyone leaves the room voluntarily when my B60 is at twelve.  :wink:

Normal listening levels are at 7 or 8 - never had any problems with that.
Only this one perhaps: to completely silence the system I have to push "MUTE" on the remote! :lol:

I believe that's called "Klipsching"  :)

vegasdave

  • Full Member
  • Posts: 4039
    • My online rock magazine-Crypt Magazine
Re: Technical ? for James on amp input sensitivity
« Reply #58 on: 27 Jul 2010, 11:11 pm »
If you're typical listening levels correspond with a minimum 12 o'clock volume position then you're probably getting the majority of what the circuit design is capable of  :thumb:


Cool. That's good to know. So, thanks.