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Pass Labs X-1, X2.5 preamp volume increments.

I have a xa30.5  and have been contemplating picking up a used X generation  preamp.   I think likely that particular generation  because the next is generally more than I would like to spend.   XP-10 etc.    And interestingly  the XP-10 does not have tape  in/output--- you have to go to the XP-20 to have that which will cost even more. 
  My question is quite simple and were I able to hear the pre in my system I would immediately know my answer.    I have read the manual and notice that  volume graduation is around 2 -3 db and this possibly may be inadequate when trying to volume down to a barely audible volume---such as I would need for my bedroom system.   I often keep music on into the night and turn it off at some point in the early am.   It would not be an issue in the main system because essentially just dont play at barely audible levels so I may still go for one if there are reports of a less than ideal volume range.    Do those who have used the X-1 or X-2.5 find the volume  control lacking in incremental  attenuation?      I do notice that many preamps in the $4 to $6k range often have  volume increments of   .5db..   Some ,  I forget which,  possibly BAT actually will have .5db at the lower end of the spectrum and when going up to higher volume will increase  1-2 db .  
Appreciate any experience others have had regarding this.
   Skip
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georgehifi's avatar
georgehifi
10,312 posts
 
skiroeThanks much for the info.. (George) re/source output, amp gain, speaker sensitivity---I hear where you are coming from---but--- just off the top of my head .. would not a preamp that is able to do volume increments of .5db or even 1db have more capability of volume range then a pre that does it in 2 or even 3 db steps?


Depends on the sources output, I’ve seen some cdp that have 6v output at 0dbf and some the only have 1v output at 0dbf. This then would be the deciding factor on which one will be quiet enough at minimum. Then there are the amp gain and speaker efficiency which will come into it as well after that.

This is why Nelson Pass also quoted this little gem. (Even though he designs and sells preamp with gain, he needs an income as well as anyone.)

" 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


watercourse
23 posts
 
Sorry, "Ono" is the Pass Aleph Ono, their first phono stage. I stepped down the output voltage to about 2V, and that gave me a workable volume adjustment range, while still being above the unit's noise floor.
watercourse
23 posts
 
Re: passive preamps. I have used TVCs and resistor-based, and indeed, with digital sources, there was a noticeable flatness to the sound. With all of my phono stages however, this was not the case - analog had intact dynamics with either passive or active preamp stages.
The passive preamp stage in the INT-30A does not suffer from any loss of liveliness, so I would not assume that passive preamps will generally sound less lively.
georgehifi's avatar
georgehifi
10,312 posts
 
watercourse

Re: passive preamps. I have used TVCs and resistor-based, and indeed, with digital sources, there was a noticeable flatness to the sound. With all of my phono stages


Very simple explanation for this, this is why I never recommend a passive for a preamp just with a TT/phono stage setup, unless the phono stage has a well known strong low impedance output buffer with enough gain.

If this was the case then your phono stages output stage was not up to the task. As many are hardly ever as strong as other non phono stage line sources, such as cdp, dacs, tuners ect


Cheers George

watercourse
23 posts
 
George, I think you misunderstood my post.
It was the digital sources that lacked drive with certain passives; these same digital sources do have plenty of drive with the INT-30A. All of my phono stages worked fine with passives, Pass Labs Ono or otherwise.
But again, the moral of the story is you can't generalize about passive vs. active preamps, you just have to try.
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