Budget preamp with quality volume control

@pwayland I could not find that gain stage info in the manual for my Parasound amp. The control on the back are the unity gain control whose function, as you know, is to throw away some of the preamp output to get the main volume control in the region one likes best (gain staging process). I am not sure if I could simply get rid of it but I could max it out so there won’t be any variable resistor in the signal path. Then I could use Active preamp without gain in lieu of with gain (like you said) to adjust the volume. At the mean time, I could also bypass the digital attenuator in DAC by switch the volume to the "fixed" mode to avoid sound degradation. By reading the specs, the SPL Volume 2 as you have suggested or several Schiit products such as Freya, Asgard 3, Jot 2, or Magnius on my list will serve that purpose in addition to impedance matching. These Schiit products also come with active w/ gain so is handy when needed. Thank you that really helps me to eliminate a few other choices.

Btw, while reading the tech info. (as shown below) in SPL Volume 2 manual, it really explains what I have experienced with the SYS... It is actually a much better passive preamp compared to the cheap in-line attenutor I purchased for the sub. I therefore decide to retain SYS for my sub. instead.  

Active or Passive?

It is claimed that passive circuits are less signal influencing and more puristic and therefore better. Well, that is not so.

A passive control element such as a potentiometer in the signal path, which is not electronically buffered, influences the frequency response and phase position. Both change continuously as you change the volume.

This is exactly what does not happen with an active control.

Zlone, interested in your comment above.  
I have a Bryston 4B3 (7.5kohm input impedance). The Schiit Freya + has been mentioned several times on this forum as a decent low cost match.  
Freya + has a 75 ohm output impedance.  Not sure why this wouldn’t work?

As many of you know, the basic relationship between the signal transfer (in terms of voltage) ratio to impedance between output (source) and input (load) is

Vi / Vo = Ri / (Ri+Ro+cable impedance), where V = voltage and R = impdenace

For a standard 75 ohms interconnect cable, without loss of generality, if your preamp output imp. is roughly comparable to the cable impedance, Vi / Vo = Ri / (Ri+2Ro). As a rule of thumb, it is desirable to have Ri is at least 10 times higher than Ro. The corresponding Vi / Vo = 83%. There will be 17% signal loss, acceptable (see below for the coveat) but not ideal. If Ri is 100 times Ro, the Vi / Vo ratio will be 98%, only 2% signal loss and will be deemed ideal.

In @jpasko01 case, i.e., Freya -> Bryston 4B3, Ri = 100 Ro and therefore the signal loss is only 2%. The pariing should work like charm. In the case of a passive preamp SYS (Ro = 5000 ohms) into my Parasound A23 (Ri = 33k ohms) where the ratio is merely 6.6, the Vi / Vo = 33000 / (33000+5000+75) = 87%. This 13% signal loss is significant enough to cause noticeable sound degradation that I heard. This demonstrates that the ratio of 10 is just a rule of thumb, the ratio should be as high as possible like 100 to be ideal. Since I have not seen a passive preamp impedance is lower than 5k ohms, practically only the active preamp is possible to achieve an ideal impedance match.

@jpasko01 Two things regarding the impedance matching with the Freya, if you are using unbalanced, you are fine, however output impedance is 600 ohms for balanced. More importantly, read John Atkinson’s analysis in the Stereophile review. Again, regarding balanced connections, but he suggests anything under 10Kohm input impedance may not do well with the Freya. My amp is right at 10K, and seems fine. 

In short, I am looking for a budgetary preamp with quality volume control that either has relay switch stepped control or precise potentiometer for left-right channel match to curb the issue.

@lanx0003, The Wyred 4 Sound mPRE preamp priced at $1100 has both active and passive topology. The volume control is a switched resistor array (based on the $2000 Wyred 4 Sound STP-SE preamp) and it paired with my Clayton Audio M200 stereo amplifier, a full loom of 聖 Hijiri Nagomi interconnects the synergy is there in spades and my modest rig sings. At it’s $1100 price point it also comes with a remote.

Check it out: https://wyred4sound.com/products/mpre Here's a review from sixmoons.com:https://www.6moons.com/audioreviews/wyred8/1.html that will more completely explain the specs of the Wyred 4 Sound mPRE preamp.