Are Pre-Amps necessary?

For the vinyl guys, as many of my customers have found.

That even many stand alone phono stages these days, and there are many of them with low output impedance, and enough gain to drive the poweramp via a passive pre directly, that don’t need the extra gain of a mega dollar active preamp in the signal path, with it’s extra distortions, colorations and cost, and their systems sound better for it.

EG: just one is, PS Audio’s Stellar phono stage, it has a 72db!! of gain and lower than 200ohm output impedance, https://www.psaudio.com/products/stellar-phono-preamplifier/ this would be great for direct to poweramp via a $39 2 x switchable input 10kohm passive-pre like the Schiit Sys https://www.schiit.com/products/sys

Or if you want some tube or ss coloration, and still be able to use it passive as well, the $599 Schiit Freya
https://www.schiit.com/products/freya-s

Cheers George

Now if you have a DAC with multiple inputs and a volume control on it, designed to drive an amp directly, the simple fact is you have a line stage with a DAC built in. But like it always works when you integrate things like that, if you want to improve the DAC, you'll be changing the line stage too.

I have owned a DAC with a passive VC, but do not remember seeing one with an active stage.  I am surprised manufacturers of those DACs with VC don’t provide a unity gain buffered output.  Could be a second pair of output jacks, or maybe switched, passive/buffered.  The passive crowd wouldn’t see the need, but some might be surprised with the outcome of a direct comparison.

https://soundcloud.com/johnhdarko/whats-the-deal-with-pre-amplifiers

From Vinnie Rossi  
Podcast

mitch2
I have owned a DAC with a passive VC, but do not remember seeing one with an active stage.

That’s because most dac’s with VC’s do it in the digital domain, yours was a rare one to have a passive VC on it’s output inside the dac, and that would have had to have been after an active buffer anyway, as if not, then it would have had to be after the I/V (current to voltage converter stage) and that would not have been a good idea..

I am surprised manufacturers of those DACs with VC don’t provide a unity gain buffered output.

The ones that have VC’s in the digital domain, all have active output buffers, unity or with gain, as did yours, but it was before the passive VC on the output, what brand model was it??

Cheers George

George, it was the Metrum Acoustics Adagio, which  changes the volume by controlling/changing the reference voltage to adjust the output voltage of the DAC.