How much do I need to spend to get a preamp that sounds better than no preamp?

@georgehifi 
I'm pretty sure you got taken to task on that jazz already. No matter how you cut the cake, a buffer is going to provide more ideal impedance matching. You seem to love banging on about Nelson Pass. Maybe you should go watch his BAF lectures where he demonstrates the differences between a 25 ohm source and a 600 ohm source. It's not an insignificant difference. And you're talking about putting upwords of a few thousand ohm on the amp's input. It makes a difference. That's why Nelson has never once produced a purely passive pre-amp. 

Your really just not worth the effort, you live in denial kosst, and question everything Nelson Pass tells you. I’ll post it up again just in case you missed it.

Nelson Pass:
"This preamplifier flows from a commitment to create the best sounding product: a simple circuit with the most natural characteristic.

Unique to this preamp, patent pending, is a volume level control which combines the best qualities of a passive attenuator and active gain circuitry:
At the 3 o’clock volume control position, the Aleph L offers a direct path from input to output.
The only component in the signal path is wire and switch contacts.

At positions below 3 o’clock, the volume control functions as a precision passive attenuator using discrete resistor ladders.

Above 3 o’clock, active gain is added to the output signal in 2 decibel increments, for a maximum of 10 dB.
As a result, you suffer the effects of active circuitry only when additional gain is necessary."

And this as well from him just for good measure.

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."

Hello @georgehifi

We've had a similar discussion about preamps:
https://forum.audiogon.com/discussions/bypassing-a-preamp-with-volume-pot-in-amp
I knew I've seen that Nelson Pass quote before.

I have had great success "bypassing" a preamp with a Khozmo stepped attenuator using Z-Foil TX2575 resistors inside an amp.

I ditched the volume attenuator completely in my current setup and only control the volume from the computer. I prefer to lose a few 1s and 0s from the computer volume than to add a preamp that brings so much favorable and unfavorable distortion/coloration from tubes, resistors, capacitors, regulators, diodes, interconnects, power cords, etc.

Who needs an preamp when you have a Pass XA25? (jk) This amp is amazing.

@georgehifi 
You're such a tool. You really are. All you can do is keep barfing up the same quotes to bolter the same poor understanding. I crunched the numbers the other night on the Aleph L. No matter how you figure, the gain stage contributes to the output signal and is NEVER fully attenuated. In fact, the "typical distortion" coorelates with the residual gain trickling all the way down the ladder. 

Again, and again, and again you keep trying to make Pass sound like some big believer in the virtues of purely passive attenuator. Yet the man has never once designed or sold one! If you're OPINION of how the Aleph L worked were the reality, the distortion would be below .001% in the passive region. Resistors don't make jack for distortion. 10 to 20 times that distortion tells you something is going on. Any fool can see that. Practically everything you claim is the case is refuted in the B1 article. And the B1 does it's job with a tiny fraction of the distortion the Aleph L does. At it's worst, pushing 2 volts out the outputs, it's still doing less than a quarter the distortion of the Aleph L. Don't sit there and tell me there's no audible different between between .003% distortion and .015%. The Aleph L is coloring the signal vastly more than the B1. 

c_avila1
Who needs an preamp when you have a Pass XA25

Hi again Ciro.
Your XA25 (very nice poweramp btw) is 47kohm input impedance and I believe you used a 50kohm Khozmo stepped attenuator as a passive pre?
You really should of used a 10kohm Khozmo passive pre, it would have been a much better better impedance match to the XA25’s 47kohm.

But your now going direct from source to XA25, even better again, so long as you don’t lower the digital domain volume control of your source below 75%, as you will start to "bit strip", 14bit resolution instead of 16bit ect ect.

Cheers George