[Diamond Dog]

I'm in the process of breaking in a new preamp and was curious about getting a little more usable travel on the volume control and maybe improving the signal-to-noise at the same time. My main source ( BCD-1) seems to have a pretty hot output level and getting the pre's volume knob beyond about 8:30 or so was just producing more volume than I was looking for. I changed the input gain switches on my 7B SST2's to the 23 dB setting from 29 dB and what a difference in the sound...really surprised me how much things changed. I'm still trying to decide on whether or not I prefer it but it's the difference in sound between the two settings that struck me. Has anyone else "made the switch" ( here, I'll save you the trouble: ) at some point and did you find the difference to be as pronounced as it seems to be in my case?

D.D.

[srb]

A small usable volume control range is one of the drawbacks of using a more powerful amplifier than a particular speaker requires.  Dialing a 7BSST down from 29dB to 23dB gain is like dialing it down to a 4BSST.
 
Steve

[Diamond Dog]

Which would sort've fly in the face of the official Bryston position that these amps all sound the same other than amount of power, no?  The change in sonics is not subtle in this case, Steve.

D.D.

[srb]

Which would sort've fly in the face of the official Bryston position that these amps all sound the same other than amount of power, no?  The change in sonics is not subtle in this case, Steve.

I know you said the sound changed and that you're trying to decide which gain setting you prefer, but can you elaborate at all on the type of sound change in general?
 
Steve

[SoundGame]

I know you said the sound changed and that you're trying to decide which gain setting you prefer, but can you elaborate at all on the type of sound change in general?
 
Steve

I'm using single-ended connections between my bp6 and 4b-sst2, using the 23db setting - so lots and lots of sweep on the volume knob available to me.  By James T.'s previous comments, the 23db setting will provide an improved signal-to-noise ratio - from 110db to 113db.  Everything else should be the same apart from the volume level.  If you match the volume level using a db metre, the sound should be the same with the 23db having a lower noise floor.

[Diamond Dog]

When going to the 23dB setting, the thing that comes to mind immediately is that the soundstage compresses both side to side and front to back. Low end seems to tighten up and you lose some of the "air" compared to the 29dB setting as well. Still continuing to form impressions.

D.D.

[Diamond Dog]

I'm using single-ended connections between my bp6 and 4b-sst2, using the 23db setting - so lots and lots of sweep on the volume knob available to me.  By James T.'s previous comments, the 23db setting will provide an improved signal-to-noise ratio - from 110db to 113db.  Everything else should be the same apart from the volume level.  If you match the volume level using a db metre, the sound should be the same with the 23db having a lower noise floor.

So what happens when you change your setting to 29 dB, Soundgame?
The signal-to-noise improvement supposedly comes from being able to take advantage of the ability to run the pre at a higher output level, I believe. Should add that I'm running all single-ended here as well.

D.D.

[Diamond Dog]

  Dialing a 7BSST down from 29dB to 23dB gain is like dialing it down to a 4BSST.
 Steve

James:  Going to the 23dB setting provides for a lower noise floor because it allows you to open the taps a little more on the preamp, no? Further to the quoted statement, would it be correct to assume that at least theoretically, the sound of the amps should not change other than volume when changing the input gain setting? Just want to make sure I'm clear on the concept here.

D.D.

[James Tanner]

James:  Going to the 23dB setting provides for a lower noise floor because it allows you to open the taps a little more on the preamp, no? Further to the quoted statement, would it be correct to assume that at least theoretically, the sound of the amps should not change other than volume when changing the input gain setting? Just want to make sure I'm clear on the concept here.

D.D.

Yes the 23 dB provides about 3dB of additional noise floor.  I prefer the higher gain settings in most of my setups - don't know why

James

[SoundGame]

So what happens when you change your setting to 29 dB, Soundgame?
The signal-to-noise improvement supposedly comes from being able to take advantage of the ability to run the pre at a higher output level, I believe. Should add that I'm running all single-ended here as well.

D.D.

To be honest, I've never done a A/B test of the 23 vs 29db setting.  I assumed the 23db would be better since it provides the lower noise floor (I run single ended as I'm using a bp6 and have no other alternative). 
 
Now that James and you suggest the 29db (higher amp. gain) might sound better, I'm gonna have to try it against the 23db.  Tells you that experience may trump the specs.  Odd.
 
So James - to get it correct - you used the 29db setting then - though I assume you're running XLR balanced from your bp26 and/or SP3?  Thanks.

[Diamond Dog]

You gents should A-B the two settings in your set-ups and report back on what you hear - I'd love to hear what you have to say after you try it.

D.D.

[James Tanner]

To be honest, I've never done a A/B test of the 23 vs 29db setting.  I assumed the 23db would be better since it provides the lower noise floor (I run single ended as I'm using a bp6 and have no other alternative). 
 
Now that James and you suggest the 29db (higher amp. gain) might sound better, I'm gonna have to try it against the 23db.  Tells you that experience may trump the specs.  Odd.
 
So James - to get it correct - you used the 29db setting then - though I assume you're running XLR balanced from your bp26 and/or SP3?  Thanks.

Correct - I use the 29 unless the speakers are really efficient. I find at least in my setups the higher setting provides a better sense of dynamics.

James

[PRELUDE]

Correct - I use the 29 unless the speakers are really efficient. I find at least in my setups the higher setting provides a better sense of dynamics.

James

Hi James
I did A/B between this two settings long time ago and find out in the active system the 23 works the best and has the least noise.How did you set up in your new active speakers.

[James Tanner]

Hi James
I did A/B between this two settings long time ago and find out in the active system the 23 works the best and has the least noise.How did you set up in your new active speakers.

Yes Active systems tend to be more efficient so that would make sense. I have my active system at home now on 29 for now.

James

[Asimov]

I'm using 23 db with balanced XLR IC from the very inception and after reading this thread I've tried 29 db. But I failed to appreciate higher gain setting, the sound was overwhelming for me, noise floor increased ......... so I get back to my previous 23 db setting.
I tried it with 26 BP and 7B SST2 with BDP-1 and BDA-1.

[Diamond Dog]

Yes the 23 dB provides about 3dB of additional noise floor.  I prefer the higher gain settings in most of my setups - don't know why

James

So James, am I correct in the assumption that in theory , the lowered noise floor provided by the 23 dB setting would offer better low-level detail but not alter the sound much in other aspects ?
If that is indeed the case, to what would you attribute the other changes that one hears when switching between the two settings? I thought my preamp might be the wild card here but it looks as though others who are using different pre's from mine are also experiencing the phenomenon...or have we just entered the Audio Twilight Zone? 

Also, does using the lower setting actually restrict the available power or does it simply require the pre to goose the amps harder to access all those ponies?

D.D.   

[SoundGame]

With the lower 23db setting - the preamp would be on the hook for supply more gain, accordingly BUT Bryston preamps have lots of gain vs. the competition out there.
 

[Diamond Dog]

With the lower 23db setting - the preamp would be on the hook for supply more gain, accordingly BUT Bryston preamps have lots of gain vs. the competition out there.

My thought as well, G-man, which is why I found this post intriguing:

"Dialing a 7BSST down from 29dB to 23dB gain is like dialing it down to a 4BSST."

 Have you tried A-B'ing the two settings and if so how would you describe the differences you hear? I'm curious as to your impressions, SoundGame.

D.D.

[SoundGame]

My thought as well, G-man, which is why I found this post intriguing:

"Dialing a 7BSST down from 29dB to 23dB gain is like dialing it down to a 4BSST."

 Have you tried A-B'ing the two settings and if so how would you describe the differences you hear? I'm curious as to your impressions, SoundGame.

D.D.

Buddy, I'd love to try but my kit has been mothballed for the moment.  We had a third child 2 months ago and I got evicted from my upstairs mancave.  I need to setup a new room in the basement but in the meantime am working on a temp setup in my mainfloor office - not done yet.
 
I've only got my HT right now for music - no Bryston amps in that one....yet.

[redbook]

 So how would things be if using balanced connections. I do between my cd and pre and there is a better overall effect........  IMO.