Do I want my every day stereo, all out performance

[Kingrex]

I know someone driving their Dartzeel with your Atmasphere preamp. He absolutely loves the combination. Its nice to have some tube in the mix somewhere.

Last night I had an interesting discovery. My tube amps have a stepped ladder attenuator built in. I was told by my tech run it wide open. Yesterday I was working out. My wife was working. I dialed the attenuator to 1. Very quiet. Later that night I tried to turn up the music but my preamp had no impact. So I had to start adjusting the attenuator on the amp. I moved it up to 5 (It has 40 steps) and the sound was smooth and clean. A tad loss of normal dynamics and extension. And my normal preamp only impacted the volume up to about half open. So I turned the Amp attenuator up a little more. Now the extension and dynamics started to come back. And my preamp would attenuate to about 3/4 open. Eventually I found this sweet spot of 19 clicks on the amps. At 19, my system just sings. The slight bit of forwardness and edge I was getting with the tubes when the amp was wide open was gone. But all the tube magic is there. I'm very happy with how its playing now.

 

[Solypsa]

In the pro audio world finding the right 'gain' for input and then output for each preamp ( there are often many in a row as eq compression etc ) is a matter of course. In the hifi world we became so 'minimalist' that this sort of experiment faded away...

I'm sure wide open is the technical best solution but real world can be a different story.

 

[Kingrex]

I'm sure wide open is the technical best solution but real world can be a different story.

Why? I believe what I am doing is adjusting the voltage on the amp signal. That amp signal wire is connected to my preamp output. Changing voltage would impact impedance, right? The current flowing through the resistance is directly proportional to the voltage across it with this linear relationship in an AC circuit being called Impedance. So are I not impedance matching my preamp to amp.

Maybe part of the reason matched amps and preamps by a manufacturer perform at such a high level as the manufacture has taken the time to dial them in. The same as I am doing with my amp having a restive ladder altering the voltage/impedance relationship between the 2.

I hope Ralph doesn't tear me apart on that one. I am not an engineer.

 

[Atmasphere]

Later that night I tried to turn up the music but my preamp had no impact. So I had to start adjusting the attenuator on the amp. I moved it up to 5 (It has 40 steps) and the sound was smooth and clean. A tad loss of normal dynamics and extension. And my normal preamp only impacted the volume up to about half open. So I turned the Amp attenuator up a little more. Now the extension and dynamics started to come back. And my preamp would attenuate to about 3/4 open. Eventually I found this sweet spot of 19 clicks on the amps. At 19, my system just sings. The slight bit of forwardness and edge I was getting with the tubes when the amp was wide open was gone. But all the tube magic is there. I'm very happy with how its playing now.

A volume control interacts with the input capacitance of the tube its driving. Often in the middle of the control this issue (Miller Effect) can cause phase shift due to high frequency roll off. You are also dealing with the distortion created by the preamp to achieve a certain level of output. Some amps are overly sensitive so as to minimize the distortion of the preamp. I would certainly try running the amplifier control wide open as that will get you the best bandwidth and the lowest distortion from the preamp. The only reason I can think of to run the control on the amp lower is to do 'gain riding' which might be helpful to reduce background noise. But if the noise floor is acceptable with the amplifier gain all the way up this isn't a concern.

People often tell me that they can't imagine it getting any better. And then it gets better anyway! Never turn down an opportunity

 

[LampiNA]

This is a fantastic question and one I've tormented on myself. For me the solution was an engineered space in my basement (more 'all out) and a second system in my family room which is also excellent but not quite the electron microscope of the ref room.

I find that most of my listening has ended up taking place in my family room, but it isn't an entirely fair fight. My kitchen and bar are closer and it's a large space rather than a relatively small (11x16) room which can feel a bit isolating...

That said, when the ref room is shinning it's lovely to be able to crank the tunes (I'm a loud listener) 2 floors below while the family sleeps.