Who needs a Preamp??


Seriously, if your cd/dvd player has volume control as my Oppo does.
and you own a phonostage with volume as my PS audio does,  then
you your issues are:
-how to power a sub
-how to listen to tv thru your system

Who believes that a preamp Improves sound??


gadios
Who believes that a preamp Improves sound??
Not me  
It adds coloration that some may like.
It takes away transparency.
It adds it’s own distortions on top of what you already have.
Always better direct if your digital source has a volume control.

If you have one of the higher output (>50-60db of gain), phono stages then all you need is passive preamp

Cheers George
A high-end preamp definitely sounds better than a digital source alone straight in to the amp in my system. I’m sure someone like almarg can explain why from an electrical standpoint this is often the case.
I have never been able to get a passive preamp or a direct connection to sound right. It seems like the drive of a good active preamp always improves the sound of my systems. 

@jaybe thanks for the mention.

This question has been discussed in a number of prior threads, of course. My perception has been that among those who have reported directly performing preamp/no preamp comparisons a significant (but not overwhelming) majority prefer having a preamp in the chain.

I would expect the reasons for that to vary among many possible factors. I don’t doubt that in many cases the reason for preferring a preamp is what George referred to, namely that colorations and inaccuracies in the preamp are subjectively pleasing, and/or are complementary to those of the source component, and/or mask colorations of the source component. But I would expect other factors to be at play in many cases, depending on the specific equipment. Such as better sonics from the source component when its volume control is set at max than when it is attenuating the signal; differences in ground loop effects (which can affect low level high frequency noise and consequently “background blackness,” in addition to potentially causing hum), differences in impedance relationships; differences in sensitivity to cable effects, especially if a long run to the power amp(s) is necessary; and perhaps in some cases what Paul McGowan of PS Audio stated a few years ago in one of his blog posts:

My adamant stance against inserting a preamp between a high quality DAC like DirectStream and the power amplifier should be no surprise to readers of this blog. As well, my subsequent turn around embracing the exact opposite should lift no eyebrows either. But why would inserting an extra piece of gear in the signal path sound better than a more direct approach? How could this make sense?

... For a long time I found that DACs with no-loss digital volume controls sounded better, cleaner, livelier, directly into the power amplifier. Whenever I inserted a preamplifier it sounded different–but not better. That is until I tried a different preamp. My first revelation happened with the stunning Aesthetix Calypso preamplifier. Placed between the DAC and power amplifier, music took on a life and dimensionality that took all of 10 seconds to find it was better–not just different.

... I had written earlier that it’s likely I am asking the wrong question. How could adding more to the signal path make the system sound better, not worse? It turns out the logic is correct: it cannot. So why does sometimes adding a preamp between a DAC and power amp help the system sound better?

Because it’s helping the DAC not sound worse. And that bit of logic is key to answering the question....

... Imagine we have a DAC with an identical output circuit to that of a preamplifier. How would this respond driving a power amplifier directly? Theoretically as well as a preamp and, perhaps, better because we haven’t another component in the mix. But here’s something you may not have thought about.

DACs are significantly more sensitive to power supply changes and noises than preamps. When an output stage struggles to drive a complex load, it is the power supply feeding its output stage that sees these changes. If this occurs in a preamp, it has little effect. But that same situation, when applied to a DAC, has very different results indeed. Small changes in power supplies have big impacts on sound quality–especially jitter.

So this is one reason, and there are more, some preamps can help a DAC.

Generally speaking, IMO the burden of proof should always be on adding anything to the signal path that is not an obvious necessity. But while adding a preamp in the kind of situation the OP describes is not an obvious necessity, due to the variety of factors that may be involved the only way to know for sure in a specific system is to try it both ways.

Regards,

--Al


The reason an active line section can sound better than a passive has a lot to do with interconnect cables. Passive controls have poor output impedance- usually quite high, which allows the interconnect cable to do its worst mathematically speaking- and this is audible as others on this thread have already pointed out.


If the line section has a low output impedance it can swamp the characteristics of the cable- in other words its output impedance dominates that math I mentioned. So less effect. If you've ever had to audition interconnect cables to pick the one that sounded right then you know exactly what I'm talking about.


Now this problem was identified and dealt with by the recording industry decades ago and resulted in what we know as the balanced line standard (AES48). If you equipment conforms to this standard you'll find very little difference between cables. Most high end audio products do not, but if you have one that does, interceding it between your sources and amps can easily increase transparency if you keep the connections to your sources short. 

Now of course such a line section could be built into a DAC- but then you have the issue of if you ever want to improve the DAC or the line section, you have to replace both (and its often not a good idea to have a DAC and line section run off of the same power supply). DACs are notorious for going out of date; this is a very real issue.
Seriously, if you’ve already set your reference point so low, you are probably seeing the expense of adding a decent preamp, power cord etc. a waste of money, right?

The VC in players or DAC are purpose built. IMHO, they can never equal or replace the SQ upgrade comes from a high quality preamp not to mention the increased functionality.

Buy a cheap pre and it will degrade or yield no improvement in the SQ vs going direct. Buy a high quality preamp and you will never go back to serviceable VC in OPPO or PS Audio.

douglas_schroeder
2,015 posts
10-28-2019 11:02am
Direct without preamp is better, except when it isn't.  :)

Hey, I was about to say that, no fair !!!
Doug said it best. I will say The Truth preamp has been a revelation to me over the last three weeks. It is a zero gain, active input preamp that for the first time in my audio experience, sounds better in many ways, to many big dollar active tube and SS preamps I have owned. It has an output impedance of some 3 ohms and an input impedance in the stratosphere! No caps or resistors or volume control in the signal path.

It seems to deliver all the sonic benefits of a great passive without most of limitations of system synergy. The dynamics are there and is doesn’t suffer from the thinner sound I find with many passives.  
So who makes a passive preamp with balanced ins and outs, two outputs that are active at same time, multiple inputs for various components?
My experience has been with the preamp stage of the PS Audio DSD vs. an Ayre K-5xeMP, PS Audio BHK and Art Audio Conductor.  Hands down, the preamps deliver a better sounding signal with a more dynamic soundstage.  

Could just be the PS Audio, but there is no doubt that connecting the PS Audio to those three units was better than going amplifier direct. Other units may have better preamp stages than the PS Audio.  Additionally, those are all pretty spectacular preamps so with an inferior preamp you may find their is no benefit.  

The idea that preamps are obsolete is definitely something I disagree with.  
In my case direct to amp was not better when I listened at low volumes. It was not even close to the quality as with a good preamp. I listen late at night when family is sleep (when I should be too).
I do both... A tubed DAC w/ VC straight to amp OR either ss or tube DAC to DHT pre. But when it really counts to hear a new live release for the first time, it’s DAC to amp for sure...and that’s with owning a $15k pre—lol. 

almarg
Generally speaking, IMO the burden of proof should always be on adding anything to the signal path that is not an obvious necessity.

This one sentence of almarg’s above and quote from Nelson Pass below, is what going direct or using a passive is all about, so long as they are impedance correct.

A quote from 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."

One step better than this, is going direct, if the source has a volume control. If you don’t like the sound this way, then you don’t like the sound of your source.



aberyclark
So who makes a passive preamp with balanced ins and outs, two outputs that are active at same time, multiple inputs for various components?
Schiit Freya +, it’s all you ask for, has remote one of the best volume controls you can get, and it’s passive, tube active or solid state active all three switchable on the fly.
https://www.schiit.com/products/freya-1

Cheers George

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.


Immediately following the text George quoted above from Nelson Pass is the text above.
I think the most you can expect from a preamp is that it mitigates some limitation in the connected equipment and in all other ways is transparent.
Most of the time a preamp is there for the convenience of switching and having a single control to adjust the volume.
As @atmasphere pointed out an active preamp might act as a buffer and present better impedances than if the components were connected directly to one another. And I agree with @almarg in that a very good attenuator in a preamp allows you to leave all source equipment volume controls at max which will improve the sound.
If your equipment is well matched with top quality attenuators and you don't need the convenience then I don't think you'll get much out of a preamp.
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…
atmasphere Immediately following the text George quoted above from Nelson Pass is the text above.



That is why one of Nelsons favorite preamps he says is the Aleph L, passive up till 3o’clock then turns active above that if you need the extra gain, but he says at sound a penalty of having active components in the signal path. (They are like unobatinium to find as no one gets rid of them.)

Nelson Pass
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.

I know many love the Freya, I’m just doubting the unit would be an improvement over a $4000 preamp like my BHK pre. 
Now those responses were exactly what I hoped for. Thank you all for adding your thoughts to a question no doubt addressed many times before. It is a question I asked in earnest.

There are several schools of thought going on this subject.
Active, Passive or Nothing.
Some contributors seem to be trying to justify the money spent on a preamp.Not ready to admit that perhaps they have only degraded their system.

Many feel Nelson Pass walks on water. I am becoming a disciple
myself after both reading the above quote George passed on
and seeing Steven Guttenberg's interview, Part 4, in Pass's home where he said his very customized 1960's Tannoy 15 Dual concentrics reveal more about his amplifier than any other speaker he has tried.https://www.youtube.com/watch?v=msE14...  

I was advised to buy an Audible Illusions amp by my audio mentor Blake Hovecar. Recently I did. Retail was around $4,500. Mid-Fi I suppose. My reference point may be well below where some high brows posting here are but my mind is open to learn and this I have done, thank you all.

The whole question came to me when I sent the AI back to the factory
for a repair. I had a good 5 weeks of listening direct and though I am not 100% sure it sounded better but I am fairly certain it did not sound any worse.

Our group met with local genius Dan D'Agostino for an evening
in his new digs last April. We had an audition of his latest creation in Amplifiers. Dan made a point of telling us that if you set the volume too low on a source controlled by a preamp you will lose SQ. I believe
someone mentioned this above.

Thanks Again to All


Assuming all impedance and voltages are matched, passive is superior in sq, to me, at least. However, I feel it might come down to the recordings, themselves. My highest quality recordings, shine, and the extra gain stage, those I have heard, obscured details and nuances in the recordings. With tubes, added colorations ( again, to me ). But, if I put on a mediocre recording, of which I have many, some sound thread bare, however, detailed, I prefer hearing it this way, as it is from the prospective of what the musicians and the producers were striving for. But, having some excellent preamps and listening to some excellent preamps, I can see why some people prefer them. However, I feel these preamps are " sugar coating " what is being heard, adding some things of their own. Listen, I do not know why, after all this time, people are still debating, better or worse, tube or ss, passive or active, horns vs. box vs panels, etc. The important thing, is to hear everything you can, and, determine what it is " you, the listener ", wants. I will tell you this, and I posted this on another thread, but this will be shorter.....The tone of a violin, as an example, will have changed, to a large degree, once it has been recorded, in it’s final " laydown ", due to the microphones, their placement, and the recorders, and everything else the signal has to see and go through. Unless I was there where the mic was placed, during the recording, I am clueless as to what the result should be. So, I listen to the musicianship, as I try to connect, with the emotional content of the composers, and the players. Tone, harmonics, dynamics, imaging, soundstaging, detail, and other attributes, are all things we expect, and strive to recreate, but, we can only accomplish a fascimile of the real thing. However, when you listen specifically to the " prat ", the start and stop of the music, this is, a given, as the musicians and producers were satisfied, to lay down the final cut. Everything else will fall into place, but when I went passive with my Luminous piece, this, is the area, that truly shows itself, with every recording. So, if the tone of an instrument is off, because of the recording, it is all about what is happening with the " playing " of the instrument. I am not as interested in the instrument itself, as I am listening to the instrument, " being played ", and this, is somewhat lost, or fuzzed over, with a lot of systems. Some of you might know what I am speaking of, but I suspect some of you think I am a wacko....It’s ok....I listen differently than most, and I enjoy, every recording, I play.....Enjoy ! MrD.
One more thing....imagine your favorite artist  ( piano player, sax player, vocalist, it does not matter ), and you had the ability to have him / her, play for you, solo. These are your choices. ( 1 ) you could hear him / her, perform, at his / her best, but....., in a poor sounding environment, similar to an airport bathroom, or, ( 2 ) you can hear, a high school student, of the same instrument, play, at Carnegie Hall, with you in the front row, the same piece of music. Mind you, the student is not bad, but lacks the " expertise " and years of " experience and polish ", of the instrument, your favorite musician possesses,........you cannot have both, in this situation. What scenario would you opt for........if you selected # 1, you know of what I speak. If you select # 2, well, you figure it out.....Again, thanks for indulging. 
For sure an active preamp is better then 
a passive gain stage on a dac or Cd player with a volume control.andanother point the oppo has a few hundred dollars in parts speaking of the 205 .you get what you pay for.a active preamp has much bigger power supplies and much better 
dynamics,also much more $$. I have owned all types and owned a Audio store for years ,any good active  preamp will give you a bigger more stable performance.
vacuum tube preamps enhance the performance further still.
I have always said and experienced that there is nothing like a good preamp in a system. YMMV but my systems have always sounded best with an active preamp.
I will remind folks that The Truth preamp is a wonderful option with an input impedance of 6 trillion ohms and and output impedance of 3 ohms.  If your source puts out 1.5v or more of output, then you are good to go.  They all do today. No impedance issues to deal with.  In terms of the amp you pair with it, ideally it should be relatively sensitive with full volume attained with under 2 or so volts.  

You can use 30 foot long ICs with no issue.  Worth looking into for $1000. 
Technically, seldom needed, but a lot of music played through my Modwright 36.5 in the chain produces an emotional response in me that is kinda like the first bite of a hot fudge sunday...an "ahhh."  The 36.5 replaced the output attenuuator in a high-end DAC.
George says:
It adds coloration that some may like. 
Bingo. Every single component in the world is subtractive. The very, very best subtract (distort) very little. Some distort a lot but with euphonic distortion (ok the world champ in that regard is the sounding board of a boesendorfer piano, but I digress).
The real issue is that most digital volume controls are truly awful. A couple of weeks back i posted a great PPT deck (from ESS tech) on the whys and the measurements.  want to make your 16/44 digital into 10 bit sound? use many digital volume controls. And we aorry about 192/24?  LOL!!!!!!! or am i crying?

That said, the Oppo may in fact use the ESS chip. If they apply digital control in the 32 bit core, it can be almost transparent. But you must check very carefully, and polls on Audiogon don't change the facts. Check how they go about it.
G
Post removed 
 A preamp sets the stage. My SFL1 Sig++ throws a stage with right and left, up and down and near and far. Its quite amazing with the right stuff. The Chesky Test CD is just frightening. ;)

I did quite a few tests using the ps audio DS sr dac straight into the PS Audio BHK amp or going thru a McIntosh C47 preamp, both using soundstring balanced ic’s.

There are some tuning steps  you can apply to the dac. Best sound directly into amp is with attenuation on. Best sound going thru the McIntosh preamp is with attenuation off and volume is set to 85.

Overall, the best sound is when going thru the dac
To pre or not to pre, such is a query...

I don't have one.  Two matrix; one for source selection, the other for where and what I want to direct the signal to or through to the amps.

I can loop through eq...or not.

I can eq @ the source if it's from the 'puter...or not.

I can mix or crossover to whatever as desired.

I got over a 'stand alone' preamp.

It's just a form of signal control, after all.

Whatever boats your float. ;)
 generally a shorter signal path is better as long as you have the essentials for proper sound reproduction and a good preamp is one of them .it's critical for depth imaging and soundstage and helps you adjust the sound to your taste. the wrong preamp will degrade the sound and take you away from the sound you like.
a preamp can soften a digital source and make it listenable
tube preamps are the best for that . adding a gain stage with volume control allows you to keep all the volumes on other components like dacs at their sweet spot so it improves sound quality.on some recordings i keep the dacs volume high and the preamp low some sound better the other way around it's more flexible vs having no choice about the dacs volume.you just have to pick a high quality preamp that you like what it adds to your system.if you like your dac's output stage that much try a preamp from the same brand it will give you more of what you like.  
If your source has a high quality volume control (as with a few DACs that change volume by adjusting the reference voltage), you can achieve the impedance and power supply benefits mentioned earlier using a high quality, unity gain, buffer, which I believe is similar to what @grannyring‘s well-regarded The Truth preamp is doing, although The Truth provides the volume control too using photo cells.  Pass is correct about having sufficient gain in our sources but he also recognized the sonic benefits of an active stage, which is why he designed his B1 buffer.  SMc’s VRE-1 is another excellent unity gain line stage (with volume control).  Tortuga Audio’s tube preamp buffer is another buffer option (no volume control) at a lower price.
I've tried powering a Jolida JD100 tube CD and a Meridian 506 CD, both of which are respectable CD players, directly to my solid state amp that had volume controls for each channel. They both sounded flat to me. Uninvolving. After placing my Conrad Johnson PV5 preamp between the CD player and solid state amp, it made a world of difference IMHO, not just to my ears, but for every single person who listened to my system. It was just MUCH more musical and involving. I guess it depends on the equipment and maybe the music you listen to, since I've hooked both CD players up to a Conrad Johnson CAV-50 integrated and though that too sounds much better than the solid state without the CJ preamp, it doesn't quite have the same sound I prefer compared to the solid state mated to the CJ PV5. Definitely more slam and low end power with the latter. I've never had a truly high end solid state preamp, so I can not comment how that would influence the sound from the solid state amp connected to the CD player.    
a preamp can soften a digital source and make it listenable
This then is the fault of the source, and not the fault of going direct.

Better to fix the problem (get better source) and not just put a band-aid fix over it, by softening the problem with adding an expensive preamp.

Ivor Tiefenbrun, inventor of the Linn Sondek LP12, had a very good saying.
"It all starts with the source, get that right and your part the way there.
Don't get source right and it'll be a never ending struggle"

Cheers George
1. try tubes?

2. loudness compensation (progressive low volume boost of lows and highs) usually an on/off switch. When 'on' it automatically, and progressively, engages boost as you lower the volume below ...

Typically misunderstood because it is 'oppositely' named, it should have been called 'low vol compensation'.

https://en.wikipedia.org/wiki/Loudness_compensation

Note: the amp volume/preamp volume/low vol boost circuit work interactively, you need to find the combo that only engages it when the preamp vol is turned below ... Another reason it is either misunderstood, or, disliked because it gets engaged too soon at mid to high volume.

When you get it right, t is a wonderful thing to listen to Jazz at low volume and still hear/enjoy the bass player and brush work on cymbals at proper 'relative' levels.

3. balance/tone controls. remote volume from listening position, oh yeah!

some recordings benefit greatly by a very slight balance adjustment, and some recordings benefit from a bit of tone control

Add the fact that we lose our ability to hear high frequencies as we age. Of course you don't.

carpet is a tone control, acoustic treatments are tone controls, why the heck not use tone controls for certain recordings? bypass of controls is nice.
................................................

give yourself a flexible/optional setup (I change my path often)

Three optional paths

1. direct into my tube integrated amp, Cayin A88t, which has remote volume and 4 inputs (one preamp in)

For sources that I know I will listen to fully attentively, at moderate to high volume, i.e. reel to reel, single cd player, never low volume when I would want low volume boost.

2. tube preamp/tuner via integrated amp's 'preamp in',

McIntosh mx110z for it's amazing tube FM and it's tube Phono EQ. When listening to FM at low volume, it automatically and progressively applies 'low volume boost'.

My TT has switch to bypass or use it's optional built-in phono preamp eq. I prefer the McIntosh tube phone eq. However, my prior McIntosh SS C28 preamp, I preferred the TT's preamp. Then, the TT goes to line, or direct to an amp or integrated amp. Sometimes I go straight to tube monoblocks.

3. Chase RLC Remote Line Controller. Primarily for it's remote balance control from listening position.

It's a remote controlled switch/volume/balance/tone control, and,



Primarily it is for CDs I know need a balance tweak, perhaps a single favorite track, or compilation CDs with many different engineers choices.

Also for a batch of CD's during a picnic/party ... 

And for memory lane a dual cassette deck and an 8 track thru it.

It has two sets of outputs if I want to easily compare amps, SS/Tube/....

.....................

IOW, give yourself options that are practical: direct when best, preamp for it's advantages, low vol boost when desired ....


My amps sit by my speakers allowing for short speaker cables. I find with shorter speaker cables the system has greater resolution.

But I also find that having the front end of the system in an adjacent room also helps as there is less vibration (despite a custom stand and platforms)- which makes a difference to things like CD transports (less errors) and turntables (less coloration).


So my interconnect cables are 30 feet long. Obviously a passive can't do the job. I have tried them (in fact we used to make one 30 years ago) because it would be nice if things were simpler; more compact (although I'd have to have the system sitting between the speakers, which I don't like). But I find that there are colorations that don't exist when using the preamp. Particularly disturbing for me is the reduction in bass impact and dynamic contrast, a bit like a tone control. I don't get this effect with my preamp. I've played bass since the 7th grade so this bit has to be right for me or I'm unconvinced. People that don't like bass may find a passive to their liking.
  atmasphere
I'm unconvinced. People that don't like bass may find a passive to their liking.
What a crock of ****. You've really surpassed yourself with that one.
To the OP: Please save us and yourself the aggravation and do a search as this topic has been discussed ad nauseam. The discussion doesn’t usually end well as you can see. Thanks in advance.
@ atmasphere,
I have to agree with you on the bass. After using a passive for 9 years, I can say with experience, that bass is pretty light with a passive. My current preamp has a bass that the passive simply could not match. Dynamics is something that the current preamp has in spades. I loved the sound of my passive, but my current preamp is something else. 
Post removed 
I am a bass fanatic, in both substance, and detail. I hear nothing that suggests compression, lack of weight or heft, or any negatives, spoken about here. This subject will never go anywhere, as I have mentioned many times before....there is no right or wrong...it is up to the individual to what he / she, likes. I will never use a preamp ( an additional gain stage ) again. It is agreed, that a preamp does add " something ", as " additional " punch, warmth, and certainly, ime, colorations ( that some might find to be euphonically enjoyable, whatever ), but I have enjoyed my recordings, more, currently, than in the past, and " this ", is what it is all about. This will be my last post on this thread, as I agree with kalali........So, to everyone....Enjoy ! MrD.
I used to think no preamp is better, until I heard a Backert rhumba 1.2., this preamp will tell you, you need one, this preamp has a huge soundstage, with amazing 3D, I tried to buy their discontinued rhumba model or demo? All gone.
I think you have to look at the evolution of the home music reproduction system to understand the Pre-amp's role.  It is the result of the need for a single point of control and access. It was about control as in signal path switching, balance and 'tone' alterations, level setting,  It also provided a cost effective and systemically benign location for an RIAA equalizer and some additional gain for it.  In those days the production of music sources and the recording technology combined with early component left a lot to be desired. The need to 'balance' the early stereo effect was present along with the need for the classic Base and Treble personalization of the listening experience - It all resided in the Pre-amp.

Times have changed a bit.

Ralph (Atma-Sphere) i got great sound with a Townshend Allegri+ with a pair of your mono's, one of the best sounds i have heard.
The Townsend is a Transformer Volume Control rather than a simple passive (potentiometer)- a bit different in principle than what has been discussed here so far.

If the output of the source is direct coupled then passive controls have a better chance of working. This is one of the reasons you see so much variation in user experiences.
Passive or Active I believe that the volume control is the componet 
that one should be evaluating .
I have noticed that many passive pre tend to use stepped resistor VC
and many active pre tend to use either Alps or Burr Brown electronic stepped VC . 

I have experienced an Active pre with an Alps VC 
and that same pre with a stepped resistor VC , Stepped won !

I am currently using a Goldpoint passive pre  .