805S with Bryston 3BST

[shades]

I just received the Bryston 3BST and hooked it up ASAP to my 805S. The amp is obviously broke in being it's used. The sound is amazing pushing the 805's with the proper recordings. With bad recordings it will show it to you right away.

My question is the 3BST (rated 120wpc, tested at 157 L&R) has clipping LED's that go from green to red when clipping starts. Now when i turn the volume up to about 72 it starts in with the red LED's, starting to show. Do you think that that's a little low to start clipping on the 805S. I do not want to damage my speakers so i don't go passed this point. At 70 my speakers are clear as a bell with no signs of distortion what's so ever, however the 805S when driven in 2channel with my rotel rsx1056 i can go to 85+ and they are as clear as a bell with no signs of distortion.

Can anyone with experience with bryston or just thoughts from audio heads give me some clear input as to what i can do or is there something wrong with the amp. (if this matters, i'm using cheap interconnects right now, waiting for the new ones from doug)

My system consists of:
Rotel
rsx1056 (5.1 and pro duties)
rcd1072
bryston 3Bst (2channel listening)
B&W
805S fronts
HTM4 center
601s3 surrounds
Paradigm pw2100

Thx,
Peter

[grit]

Different amps operate at different efficiencies. I wouldn't read too much into the volume setting. Is there a difference in how LOUD the Bryston will play the speakers vs the Rotel (overall)?

[shades]

The bryston is much smoother for sure and pushes them very well. I did an A/B on the bryston and rotel at 72 and there's no comparison. The bryston wins hands down but sometimes i like to go to 75-78 or so and i don't want to damage the speakers. ( i did push the bryston to that level and the LED where not glowing red just intermittent, and the sound was smooth and natural)

Peter

[RebelMan]

Can anyone with experience with bryston or just thoughts from audio heads give me some clear input as to what i can do or is there something wrong with the amp. (if this matters, i'm using cheap interconnects right now, waiting for the new ones from doug)

Nothing wrong with what you are doing or the 3B-ST, it's a great amplifier. What you are noticing is the effects of the amplifier's input sensitivity (gain), which I believe is rated at 1 volt and adjustable (caveat) in your case. At lower levels it takes less effort for a pre-amplifier to drive the power amplifier it is connected to. I suspect that the sensitivity of the internal power supply of your RSX-1056 is higher than the 3B-ST. These mismatched levels are harmless but they can be difficult to tame.

[shades]

Thanks guys, much appreciated


Peter

[Karma]

HI,
There is a huge amount of misunderstanding about the meaning of gain and volume, and power. The volume control is a gain control, period. It has no fixed, repeat NO FIXED, relationship to power. The setting of the volume control means one thing and one thing only: how loud the sound is currently with power amp in use, not how loud the sound can potentially get which is the power spec.

For a given room volume, substitute a different power amp and you will have to change the volume setting to obtain the same room volume (assuming the new amp has different gain which it may or may not). Gain is not a significant specification, within limits.

Sparky

[stewfoo]

Sparky, You are right. But, sometimes people are A/B testing the difference in gain and therefore loudness (based on the same volume setting) can be misleading. For example when a/b testing my 1072 through a classe ssp-300 to determine whether I should run it in bypass or digitally and use the DACS of the ssp... there was a volume difference. I followed a suggestion by Andrew Ward and adjusted the input bias to make sure that when switching between analog and digital volume matched.f I think it is kind of the same thing.

[Karma]

HI stewfoo,
Misleading though it may be, the relationships must be understood of one is to avoid conclusions that are not valid. This is not even considering the ability to communicate ideas and facts. I find this is a constant problem for those without at least a minimal technical background. Those folks who fall into this catagory should make at least an effort to gain some understanding.

For everyone, this is a technical hobby. To ignore the technical implications is to do so at your own possible loss. Gain and volume and power and their interrelationship is essential knowledge. I'm not requiring an engineering degree for everyone. No. But there are essentials that should be attacked.

Sparky

[Eliav]

Interestingly, I found that the volume reading-( on the rotel 1068 and the overall loudness was very close comparing rotel 1095 and the Classe CAM400 monoblocks. having both hooked up to the Rotel 1068,I initially expected huge difference and anticipated that whatever sounded loud on "60" with the 1095, will sound the same on"40" with the Classe...apparently this is not the case. anyoune 's explanation ??
Thanks
Eliav

[RebelMan]

"Sensitivity" is not the same as power. It doesn't matter whether you chose the low or high sensitivity option of an amplifier, it will have the same power output. What will change is how loud you set the volume control.

Assuming one wants to play a recording of a singer at a realistic level. With a high-sensitivity amplifier, you might only need to set your volume control to say 6 o' clock to make the singer sound as loud as a real singer would. With a low-sensitivity amplifier, one would need to set the volume control to maybe 8 o' clock to achieve the same loudness.

One caveat to this is that clipping can occur sooner when lower input voltages (higher sensitivities) are selected. To complicate matters further one should take into consideration source and preamplifier output sensitivities and impedences and IC cable capacitances which can also effect signal quality.

It is analogous to speaker sensitivity where more efficient speakers require less power to achieve the same loudness levels as less efficient speakers and conversely.

[grit]

HI stewfoo,
Misleading though it may be, the relationships must be understood of one is to avoid conclusions that are not valid. This is not even considering the ability to communicate ideas and facts. I find this is a constant problem for those without at least a minimal technical background. Those folks who fall into this catagory should make at least an effort to gain some understanding.

For everyone, this is a technical hobby. To ignore the technical implications is to do so at your own possible loss. Gain and volume and power and their interrelationship is essential knowledge. I'm not requiring an engineering degree for everyone. No. But there are essentials that should be attacked.

Sparky

:lol: I know ya didn't MEAN to make a pun outta it, but I just couldn't help but laugh.