preamps with multiple ways to control volume/output

[Ilusndweller]

Im messing around with my B&K AVP-1030 5.1 pre and was reminded there are 3 ways I can adjust overall output. 1. Volume 2. Each input has a setting in 0.5 dB increments from -6.0 to + 6.0 dB. 3. Left channel and right channel same thing as 2, but from -12.0 to +12.0.

Ive played around with both settings (and the volume of course) It all sounds the same whether at 0, +6, -6, -18, or +18 and everything in between. You just have turn the “official” volume knob up more or less depending on the other settings. And the volume automatically stops at the same loudness (crazy loud and clear) no matter what any of the other settings are set at?!?

Are multiple variable output controls common on higher end preamps? This is my only example of one that has it. The rest have a single volume control.

Do you use these (or just the volume control) in combo with amps that have volume control to get more or less “preamp sound” and/or more or less “amp sound”. Are you confident you are hearing these differences? In this preamp a total possible range of 36 dB in overall output is quite significant so I dont see why not.

Could be a way to fine tune (or more) your music by adjusting the pre:amp ratio.

thanks (it probably only has all this “junk” bc its home theatre?)

 

[fiddlefye]

Im messing around with my B&K AVP-1030 5.1 pre and was reminded there are 3 ways I can adjust overall output. 1. Volume 2. Each input has a setting in 0.5 dB increments from -6.0 to + 6.0 dB. 3. Left channel and right channel same thing as 2, but from -12.0 to +12.0.

Ive played around with both settings (and the volume of course) It all sounds the same whether at 0, +6, -6, -18, or +18 and everything in between. You just have turn the “official” volume knob up more or less depending on the other settings. And the volume automatically stops at the same loudness (crazy loud and clear) no matter what any of the other settings are set at?!?

Are multiple variable output controls common on higher end preamps? This is my only example of one that has it. The rest have a single volume control.

Do you use these (or just the volume control) in combo with amps that have volume control to get more or less “preamp sound” and/or more or less “amp sound”. Are you confident you are hearing these differences? In this preamp a total possible range of 36 dB in overall output is quite significant so I dont see why not.

Could be a way to fine tune (or more) your music by adjusting the pre:amp ratio.

thanks (it probably only has all this “junk” bc its home theatre?)

I've not done this at the preamp end, but have had a number of power amps with their own volume controls (usually separate ones per channel). Ditto with the output from CDPs or DACs. The end result would be somewhat similar, no? The differences have sometimes quite audible in terms of the sound character.

 

[MikeyFresh]

Im messing around with my B&K AVP-1030 5.1 pre and was reminded there are 3 ways I can adjust overall output. 1. Volume 2. Each input has a setting in 0.5 dB increments from -6.0 to + 6.0 dB. 3. Left channel and right channel same thing as 2, but from -12.0 to +12.0.

The Input trim pots are for level matching among sources with disparate output characteristics, so that one source isn't screaming loud while another quiet given the same Volume setting. So a DAC with as much as 4 VRMS output could be trimmed to effectively match a CD player with a 2 or even 1 VRMS output.

The L/R channel trimmers are simply a dual mono balance control.

If those trim pots have a center detent in their travel that typically means it is the point in which the pot is actually out of the circuit. They should be used that way for best sound quality unless it's otherwise necessary not to do so, as every trim pot will degrade the sound at least a little, typically best to leave them out of the signal path if possible. That assumes they are actually analog pots and not IC based controls.

it probably only has all this “junk” bc its home theatre?

Yes, most high-end stereo preamps don't have those controls, other than some will have a balance control. In an AVP they were probably intended for dialing in surround sound.

 

[Ilusndweller]

Thanks, makes sense. I had no idea that dacs (other sources as well Id guess) could output as much as 4v. In addition, there is balance, and center, rear, and sub levels. So Im still not quite sure what the +/-12dB on the L and R channels are for. Maybe my pre:amp ratio theory? And Im sure this theory has never been discussed in the past.

// I just broke the spring in the volume knob of the B&K (the knob would return to a central position). It still works, but I wish it was a traditional potentiometer knob. Though maybe that it is not contributes to its very clean and clear sound.

Also, I was doing a lot of stereo web surfing today. The Pioneer 9100 (2?) integrated and a few of the Heathkits had additional variable level controls for the inputs.