Oomph or pressure?

Hi Sal,
Thanks for the descriptive comparison of high quality passive and active preamplifiers in your system. Based on your descriptions of sonic characteristics I’d choose the active Epifania (if I could only have one or the other). You found it "more involving " than the passive. Musically and emotionally involvement are critical for my long term enjoyment, this is a must have quality for me.

In my opinion when ever comparing audio components the one that allows/permits more involvement in listening to music is the better component. It seems that the "Emotive Audio" is inappropriately named 😊.
Charles

Charles, I think you got the names confused.  The active preamp is the Emotive Audio Epifania so nothing inappropriate in its name.

I should emphasize that the Emia autofromer is very good by any standard.  I am somewhat splitting hairs by focusing on the differences. 

One final point.  It will take a very good active linestage to surpass the Emia/Intact Audio autoformer.  In my case, the Emotive Epifania started out as an excellent sounding preamp, but I have tweaked it to death over the past 10 years by swapping out different resistors, capacitors, chokes, and wire to find the best sounding combination.  I also eliminated the switching so it is a dedicated single-input linestage.  When I got the autoformer I followed the same approach---no switching, just a single input, and the same wires that I settled on with the Emotive preamp.  So they each have some advantage over your typical commercial products.

52tiger
Emia autoformer as my preamp. It sounds fantastic but one thing I noticed is I have to turn the volume up quite a bit to get any oomph out of it. thanks, Scott

Nothing wrong with having to do that, as Nelson Pass explains below.
Scott, passives rule!!, they are the most transparent/dynamic way of getting the source signal to the amp with control over the volume. Only better is direct source to amp (but you need a level control in the source) 

Nelson Pass,

"We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.

Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.

Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.

What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp."

Cheers George

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.

Precisely the complaint of this thread. Nelson goes on to say:

I suppose if I had to floor the accelerator to drive 55 mph, maybe I’d think the life was being sucked out of my driving. Then again, maybe I like 55. Nice and safe, good gas mileage…

Is impedance matching an issue? Passive volume controls do have to make a trade-off between input impedance and output impedance. If the input impedance is high, making the input to the volume control easy for the source to drive, then the output impedance is also high, possibly creating difficulty with the input impedance of the power amplifier. And vice versa: If your amplifier prefers low source impedance, then your signal source might have to look at low impedance in the volume control.

This suggests the possibility of using a high quality buffer in conjunction with a volume control. A buffer is still an active circuit using tubes or transistors, but it has no voltage gain – it only interposes itself to make a low impedance into a high impedance, or vice versa.

- essentially pointing out the same problems I did earlier in this thread.

Since all digital sources make way too much voltage to clip any amp made, a buffered control is a good idea, as it isolates the volume control from the output, and the buffer circuit helps to control the interconnect cable. Note that Nelson is careful to point out that this is an active circuit. We build similar circuits for customers that don't need the gain (but using tubes with a direct-coupled output).