[sdiy] tonal tilt

[JH.]

>>http://www.headwize.com/projects/equal_prj.htm
>Nice find. Thanks, JH. I have a feeling that I read this about 5
>years ago, but I remembered the tilt feature from reading my brother
>Terry's Stereo Review mags back in the '70s (which certainly helped
>spark my interest in electronics).

Looking at it more closely, the headwize version might be more simplified 
than the Quad circuit.
The Quad has two RC combinations in parallel - might be some staggered time 
constants stuff to create a more widespread rolloff than the headwize 
version. But I've _not_ really looked at it in detail - I still have to go 
slow.

Last week I wrecked my turntable, because I'm still clumsy and walk around 
as if drunk. :(
Ok, it was old, and I wanted a new one anyway. Ordered a Pro-Ject Xpression 
III.
And had my interest in HiFi / home stereo stuff rekindled, so that "tilt" 
topic just comes right for me.
I must say it looks like a remarkable feature.
If I ever build my own tube stereo preamp / headphone amp, I'll include this 
feature.
The philosophy behind that unusual bass control of the same amp looks 
promising, too.
Did they use stepped attenuators, or pots with reduced angle?

And look at these treble filters. They start with an ever so slight rolloff 
at the highest frequencies, and then they straighten it out with positive 
(!) feedback. (Or not, depending on the "Slope" setting.)

JH.