I need a loudness switch


I am by no means what I would consider a Audiophile, or a Engineer. 
 But I am fortunate enough to own some semi decent equipment.  I love music that gives me goosebumps. 
My CD playback is fine , as I don't really use it anyway. 
 But as with many others I lose substance at low volume with vinyl playback.
Dial set between 55 and 60 things come alive. But that is too loud for most sessions. 
 System is.
 VPI Classic table with a Soundsmith Carmen mkii cart.
Decware zp3 phono stage. 
Conrad Johnson et3 preamp
Conrad Johnson premier 140 amp.
 Proac Response D38 speakers.
 I would love to run the system around 35 to 45 setting , but to have a little authority. 
Does anyone have any suggestions?
 I was considering a Decware zbox that boosts the voltage. 
But with not being a Engineer.  I do not know what effects the 4 volt input will have on the cj gear.
Any input would be appreciated.  
Thank you,  Scott 
 
scottht

     Yes, the old loudness controls boosted both the bass and treble to compensate for the Fletcher-Munson curve reality of human hearing.

    Strange, but this is also one of the 1st qualities I noticed with all the high quality class D amps I've owned.  The bass, midrange and treble balance seemed to be properly balanced to me no matter the volume.  YMMV?  Not sure.

Tim
I had tried a Loki. It does what it says it does. If you can flip the bypass on/off and settle on a loudness profile, you'll be overjoyed.

I kept fiddling and it drove me crazy :-)

Also, in bypass mode, its pretty hard to discern its actually there.... which is a good thing

mijostyn: Yes, I’m aware that old loudness controls boosted both bass & treble, and that the F-M curves justify that.

I read many years ago that the treble boost is questionable. I can’t remember where I read that, so I can’t cite a source. I will say, my subjective experience is that boosting the bass provides most of the benefit. My preamp has a treble control, & I’ve never felt the need to boost treble as volume decreases.
Mike, if you look at the Fletcher Munson curves the boost in treble is pretty high up and is less noticeable than the bass boost which is in a part of the range that is very obvious. So you are right in that the obvious part of loudness correction is in the bass but if you could AB curves you would note that the curve with the treble boosted correctly sounded more natural.