Is my preamp useless?


I enjoy my current system, which is built around a BAT VK-52SE preamp. I listen mostly to digital, via a Bryston BDP-2 player into a PS Audio DSD. I also enjoy vinyl on my VPI Classic/Dynavector/Sutherland 20-20 combo. Like most of us, I’m usually on the upgrade path. For me, the next component to upgrade would be the BAT preamp from a 52SE to a 53SE. But something occurred to me. I don’t listen loud. The gain on my PSA DSD is set to less than 100 and the BAT preamp is usually set between -20 and -10. So if my volume control is never set in the + range, is my preamp doing ANYTHING other than attenuating the volume and serving as a multi-input switch? Is all that Super Tube, single gain stage, zero feedback, high energy storage circuitry a waste of money?

Don’t get me wrong. I am very pleased with the sounds I hear. But if my pre isn’t doing anything, then I’d be better off to sell it and get a very simple passive attenuator, wouldn’t I? If that’s the case, what brands and models should I listen to?
Thanks for any advice.
slanski62
Hi. Original poster here. I’ve been following this discussion with interest, and I didn’t know it would become so controversial!

A couple of thoughts:

Trying my DAC direct into my amps is certainly a good idea. I need to re-arrange my equipment so that my interconnects will reach both amps. I’ll try to do that some time this week.

Is the Luminous Audio Axiom a decent passive? It uses a conventional resistive ladder network for attenuation. It’s not a lot of money, so I won’t be risking much.

Finally, there doesn’t seem to be a lot of love for BAT in this group. I expect their next to top-of-the-line (at the time) would be pretty decent. If you disagree, please tell me why. Thanks!

"03-23-15: Slanski62
Hi. Trying my DAC direct into my amps is certainly a good idea. I need to re-arrange my equipment so that my interconnects will reach both amps. I’ll try to do that some time this week."

This is the most sane comment in this thread so far, as it will cost nothing, and the gains could be massive.

Cheers George
"Mr. Hansen of Ayre has stated that passives will outperform actives in suitable systems until one gets pretty high up in price for the active unit. There might be some truth in that.
Larryi (System | Threads | Answers | This Thread)"

I think you're right about Pass and the Ayre AX-7 has a passive line stage. His reason for not using an active is that he can't make something active that sounds as good for what the AX-7 sells for.
"Is the Luminous Audio Axiom a decent passive? It uses a conventional resistive ladder network for attenuation. It’s not a lot of money, so I won’t be risking much."

I haven't heard one myself, but the comments are generally very positive. If you can get one at a price that wouldn't involve too much risk, I say try it.

"Finally, there doesn’t seem to be a lot of love for BAT in this group. I expect their next to top-of-the-line (at the time) would be pretty decent. If you disagree, please tell me why. Thanks!"

There's one thing you need to understand when reading our comments. If you sat every single one of us down and had us listen to the same exact system, we would all hear something different. We all have different taste's, level of experience and beliefs in how we judge things. For example, I will immediately focus on the high frequencies. That's what's most important to me. I may miss a flaw in the bass, but one of the others may not. Some listeners will focus on bass and not so much the highs, like me. Some people like a lot of detail, some do not. Some are very picky about dynamic contrast, and others like coherency. At this point, you probably understand why I asked you if you had a technical background. That's another obstacle to deal with.

All of this means that you should use our comments as just that. Get some ideas from them. But under no circumstances, should you let us make decisions for you. That is something you must do on your own. We don't have to listen to your system, you do. Just because some of us don't care for BAT means nothing. If you like it, that's all that matters. Every single brand in existence has people that don't like them. BAT's no exception.

My recommendation would be to explore some of the other brands everyone here has recommended. You may come to prefer something else, or you may stick with what you currently have. There's no right or wrong here. It would just be unfortunate if you let us talk you out of a BAT preamp, if that's what you really like best. You shouldn't feel guilty or wrong about keeping something you like.
Thanks folks. I didn't realize the Ayre has a passive line stage. That gives me another avenue to explore.
Slanski- Glad you're still here! I used to own a BAT and would never talk them down. The question of passive vs. active has been the focus of much of the discussion, engendered by your comments about how much attenuation you are employing, which indicates excessive overall system gain, which has sparked the discussion about passive "pre-amps". You may also know that Georgelofi is designer/builder of the Lightspeed Attenuator aka LSA. He has very generously made his design available to the DIY community and also sells finished product. Obviously, he is a strong advocate of passive pre-amps and as many have stated, the LSA may be the biggest "bang for the buck" item currently available in high end audio. However, that does not guarantee that it is the best product to help realize your goals for your system. Maybe yes, maybe no. Another, similar option would be a tube buffer w attenuator/volume control. Others w more technical knowledge than me can tell you why that might be an appropriate option under certain circumstances.
"You may also know that Georgelofi is designer/builder of the Lightspeed Attenuator aka LSA."

I didn't know that. I take back my recommendation! lol. Get the Placette instead.
Zd- I've never heard a Placette. It has some distinct features that would appeal to many (remote and/or input switching) but it's 2 - 2.5X the price of the LSA. Have you ever heard one? Regardless of George's proselytizing, it's a damn good product. The fact that he has made the circuit publicly available and provides support for DIY'ers makes me think he deserves some slack.
03-23-15: Zd542
"You may also know that Georgelofi is designer/builder of the Lightspeed Attenuator aka LSA."

I didn't know that. I take back my recommendation! lol. Get the Placette instead.

There was an A/B done here:

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1276356977&openflup&1421&4#1421

And before that, he had a TRL pre.

Cheers George


Proselytizing, I don't think I do to much of that, as I'm not going blind, yet! And you know what mother used to say.

Cheers George
I was just kidding. I didn't think anyone would take my comment seriously.
I see a lot of good replies especially Ralph's from Atmasphere.
Got any idea on how you are going to proceed slanski62?
so How and Why would a active premamp, tube or solid state sound better than a more direct connection.

Would capacitors, opamps in the signal stage of an active be better than a single resistor, or similar ldr, autoformers?

Every opamp, resitors, capacitors sounds different, possibly changing the sound to ones preference. Adding on your favourite powercord, interconnects, vibration control on these active component adds to the variables you hear, hence the difference in sound.

There is no right which sounds nicest, but the less the variables and carefully matching wiring and connectors will give the best, less molested sonics.

If one has a robust sounding front end, a passive will give equal or less coloured sound. Impendence matching and possible size of speakers room etc will cause possibly a lack of gain required for the amp and speakers to perform or rather not sound thin or dead.

Conclusion would be a matching choice of factors.

The best part is passives are way cheaper and can provide just as good a sound as a $10k or higher preamp.

There is just so much more ways to tune the sound say with capacitors in the signal. Some sound clean or bright or warm or more open pr more distant, the list goes on...

Add the same capacitor in a passive and the traits will start to show.
^^ The quick answer is here:
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1426779273&openflup&16&4#16 (earlier in this thread).

The longer answer is that mathematically, no passive control is going to work perfectly as intended if it is driving an interconnect cable. The longer the cable the more noticeable the artifacts become (one solution is to build the control into the amplifier, which works very well). These artifacts can be so profound that a properly designed line section can actually sound more neutral.

Consider the source, which has an impedance, usually no more than a few hundred ohms and often quite a bit less. It is driving an interconnect cable. The lower the source impedance, the longer the cable it can drive and less artifact will be heard from the cable. If you install a passive volume control, essentially the source impedance driving the interconnect cable after the volume control (and the amplifier as well) is raised by the value of the volume control setting. This is often a multiple of the original source impedance.

The result is that the capacitance, inductance and resistance of the interconnect cable is no longer shunted by a low impedance (the source impedance). Instead the shunt impedance is much higher (the value of the control dominates this value and changes with the setting; you can see that as the control setting is changed it may be that the sound changes with it, and indeed many people experience this).

In this situation the resulting system is very sensitive to the issues of the cable and cable artifacts result. Anyone who has set up a successful system with a passive volume control knows this: the choice of cable in such systems requires careful selection as the cable artifacts are so easily heard.

There are other issues/phenomena; some are source dependent and others are amplifier dependent and so do not occur in all systems. Hence the extremely variable results that cause so many of these threads to exist.
Atmasphere,

"A preamp does these things:
1) provide volume control
2) provide any needed gain
3) provide switching for various sources
4) control artifact from interconnect cables."

Looking at the post you referenced on what the preamp does, I have a question. I've heard this before, where people list these things and say that's all a preamp does, almost like its a trivial matter. (In general, I'm not singling you out.). Why is it then, when you put different active preamps in a system, the sound changes so much? Imaging changes, dynamics, contrast, etc... And a related question. I hear all the time comments to the effect of, a preamp can't add anything. It can only take away. If that's the case, how do account for something like image size getting much larger when switching from a passive or source with a volume control, to an active line stage? There are some big differences, not subtle ones. It makes perfect sense that a preamp can't add anything to a recording, but listening clearly proves otherwise. (Maybe no proves, but something is going on that's audible.)
Going direct like the OP can do, will not add or subtract anything that the source is presenting. As his source (PSA) has perfect impedance match and voltage output to drive his Cary amps and the "interconnect".
Any active pre that is put between, will colour the sound, he may wish to do that but, he will also get way too much gain as well.

Cheers George
^^ This post is incorrect, as the problem is not the control but the interconnect it drives, and of course the drive actually comes from the source- I explained this in my prior post.

Why is it then, when you put different active preamps in a system, the sound changes so much? Imaging changes, dynamics, contrast, etc... And a related question. I hear all the time comments to the effect of, a preamp can't add anything. It can only take away. If that's the case, how do account for something like image size getting much larger when switching from a passive or source with a volume control, to an active line stage? There are some big differences, not subtle ones. It makes perfect sense that a preamp can't add anything to a recording, but listening clearly proves otherwise.

Thanks for your thoughtful question! The first comment I have is 'compared to what?'. Is it that the line section is reproducing the image incorrectly or is it the passive? This really is very system dependent! Some line sections introduce colorations without any doubt, so I am usually careful to qualify my statements about what a line section should do with a phrase like 'properly designed' or similar.

IMO/IME it is a statement on how dreadful some line stages are that a passive control can sound better; if the line stage is designed and built correctly that simply can't happen. But in real life it does so that says to me that there are a lot of marginal line stages in use otherwise this debate would not occur over and over.
Atmasphere,
With all due respect - have you heard all possible permutations/combinations of amp+preamps that exist in the world? If not, then it is simply YOUR view that actives are always better than passives. Folks have been very happy about TVC preamps, which are considered to be passives. I love my TVC. Does it mean, it will work in all systems? Heck no! Try my preamp with a power amp that has a sensitivity of > 1.5V and it will sound pathetic at best. If you have heard a passive that was introduced in a system that needed the gain, I am sure it would sound bad. At the same time, in my system I cannot introduce any source that gives out less than 2V.
So, it is all system dependent. A properly put together system can shine as much or better than an active line stage, if it used a passive preamp. It has been asked before - why would Nelson Pass make active line stage, if he likes passives? The simple reason could be - because people have behemoth loudspeakers, whose sensitivity is so low that they need tons of GAIN in their system. The amps that drive these loudspeakers are low sensitive amps, mostly >1.5V for full power.
Milpai, I offer to bring my active to your home and guarantee you will like it better. If not, I will eat one part inside my active :)

Are you close to MInnesota? I have no doubt you will say " I like your active better". No doubt.

Let's do the active throw-down!
Grannyring,
I like your confidence, the problem is it is near impossible to account for another person's taste or preferences, very hard to do despite how good your active preamp may be.
Grannyring,
Thank You for the offer. But I am a bit away from you - near Cleveland. I would be eager to know your system, in the first place. At least that will tell me why you felt your active would sound better in my system.

The next paragraph is for EVERYONE in general and not just you Grannyring.

I feel folks who come here for sincere audio discussions should post their system so that the other party can understand why the poster is so exited about his/her system. I think we all have gone through a certain phase of changes/upgrades, to arrive at what we like. So why not post your equipment here for others to see and then decide why the poster is exited about what he/she is recommending.
I feel folks who come here for sincere audio discussions should post their system so that the other party can understand why the poster is so exited about his/her system.

Good call, Milpai.
have you heard all possible permutations/combinations of amp+preamps that exist in the world? If not, then it is simply YOUR view that actives are always better than passives. Folks have been very happy about TVC preamps, which are considered to be passives.

Of course I have not heard everything. But I did go to school and got taught engineering principles, and if you look at my posts you will see I was careful to be talking about PVCs and not TVCs. So as far as I am concerned, your comment is a strawman, as you are attacking an argument I did not raise.

However we can have that discussion if you like...
I decided to pull my system for privacy and safety concerns I don't want to get into here. I used to have mine posted and had an "issue". Sorry.
Charles, I fully understand your point as you know. Yeah, I am still confident :)
Hi Bill, you had a wonderful system posted on this site, I'm sorry you felt the need to delete it. I have had my system posted for the past 4 years and fortunately have had no issues or problems, I hope that continues to be the case.
I do have the LS attenuator coming for a 4th time and I will try it yet again!

I have a Yamamoto DAC with an output of 3.1volts, three different amps ranging from PP tube, DHT SET tube, and SS monoblocks. Input impedances range from 80kohms to 200K ohms. Amp input sensitivity range from 350mv to 1 volt .My speakers are 92 db effecient and an easy 8 ohms to drive never going below 6 ohms. Simple two way speaker with very few crossover parts.

I will bring a host of ears over for a listen. I am prepared to eat a part of the active pre if not better to all. Perhaps a small part like a resistor!

I do like the LSA as I have owned it twice and tried it three times in various passive friendly systems. Very clean sounding and does everything right. It would be my choice if I could only spend $1,000 or less on a preamp. Quite good indeed.

For all my family listeners and close by Aphiles it was not up to the the musical standard of my active. Why am I trying it a 4th time? Because I am completly astounded and confounded by all the positive press the LSA garners. It beats out $20,000 preamps and the like according to the long thread here on the Gon. I cannot wrap my mind around this as my experiences were quite conclusive three different times with different gear. Yes... all passive friendly.

I am open minded and would love to own a $500 passive that moved me like a $20,000 active. Who could possibly want to spend more just to spend more? Well, ok some would. Not me.

My music room is stocked with gear that will make this comparison fun and interesting yet one more time.
Grannyring that is an interesting thing to do. To keep trying the LSA. I appreciate your enthusiasm and earnest work to get good sound. That has been documented on Agon for all to see. And that has benefitted me and I am sure others. Thanks. And by looking, your system is quite a bit more expensive than mine. So it maybe more refined. You and I like Van the Man and I get him in all his glory through my system I feel.
Now I think the LSA needs to have a system built around it and not just dropped in to an optimized sytem for another pre amp if all the small things matter. I think that the LSA without that sounds ok. Doesn't seem to do anything real error prone. But doesn't have the more real feel of what I associate with real instuments in real space. I have no real good idea but I think that feel is in the lower mid range to the upper bass part of the spectrum and when that is excentuated I think that contributes to the feel of the the music along with the hearing it. And when that happens in a good balance it becomes more appealing to listen to. But just my thought. It doesn't matter because we know when we get it to sound like each one likes it to sound.
Marqmike, I own your speakers in a second system for my wife. Very musical speakers. Love the amp you put on them also. Good match. Your system is well matched and looks to be very musical. Well done.

Interesting comments on your experience with the LSA. It certainly sounds good in the right system. I agree with all you said, but wonder how prudent it is to build a system around a passive preamp. I know you did not suggest we do that, but I guess I don't think a passive is that hard to use or work into a system. Most digital front ends have plenty of output and many amps are of sufficient input sensitivity and impedance. Can it be the LSA is pure Magic in 1% of all system combinations:). No. I do t think that is the case. I think it works in many more systems than that.
Atmasphere,
I think you were generalizing that Actives were better than passives. I do not think I attacked your statement in any way. I was suggesting that we cannot make generalized statements. Isn't TVC a passive component?

Grannyring,
It is not worthwhile to eat even a small coating. We are not trying to win anything here. I want to stress the importance of system matching. You may try LSA for the 4th time in your system. But if that did not work for the previous 3 times, what makes you think it will work the 4th time? Also, I suggest you try a very high quality TVC like Music First or Bespoke. You seem to have some expensive gear, so I am suggesting you these expensive TVCs. I would have suggested Promitheus Signature TVC - but I have my reservations against delivery times and customer service. The TVC I have is excellent component. I have compared it with a Line stage that costs $4500 and had to return that $4.5K component back.
Hope you have a great shootout and an enjoyable one at that!
Hi Bill, well, you have had the Light speed on three separate occasions and each time you felt your active provided better sound. I honestly don't see how you expect the difference the fourth time around to change but we will see. You will do the comparisons again but in my opinion the Yamamoto DAC
will sound better with your active line stage,it will be more musically complete and realistic sounding. As you know Bill, I have used this DAC for the past four years and it is marvelous. It is really terrific in connection with my active line stage. Tonality and harmonically sorted out with excellent dynamics and musical flow and pace. It should mate beautifully with your custom Dude preamp. I look forward to your listening impressions.
Charles
"I feel folks who come here for sincere audio discussions should post their system so that the other party can understand why the poster is so exited about his/her system. I think we all have gone through a certain phase of changes/upgrades, to arrive at what we like. So why not post your equipment here for others to see and then decide why the poster is exited about what he/she is recommending.
Milpai (System | Reviews | Threads | Answers | This Thread)"

Listing ones system, in no way, better qualifies the advice they give. How could it? How do you know the system someone lists is a completed project. They could be currently going through the mistake phase. Or any other phase, for that matter. Most of the stuff I recommend, I don't even own.

I firmly believe that to be successful in putting a system together, you need to take responsibility for your own actions. If you're fool enough to take a review or recommendation without personal verification before the purchase, you've got no one but yourself to blame. Even though we sit and listen to music, audio is a very hands on hobby. If you want good sound, you have to go out and get it for yourself. You can't just let someone tell you what to buy and expect to be happy. Its like asking a life guard to tell you how to swim, and then go jump in a lake.
Zd542,

While I agree that seeing a listing of others' megabuck systems doesn't necessarily make them better qualified to make recommendations, I do think seeing system setups can be very helpful in evaluating poster's comments.

Seeing systems, the way they are set up and the rooms they are in can definitely help us all when reading various comments. I've seen systems set up in obviously bright non treated rooms on non carpeted ceramic or wooden floors with rear ported speakers backed up against a wall or sliding glass door and thought "note to self, take anything this guy says with a grain of salt" because I'll know withy a doubt that what he's hearing in a setup like that will have zero correlation to what I'll get in my room.

Wouldn't you agree that what sounds great in a room like that might not sound good in a treated deader room with more open speaker placement?
Zd542, don't feel offended just because you have not listed your system here.

But I found this statement funny :-)

Most of the stuff I recommend, I don't even own.

Are you telling me that you are recommending stuff on a whim? We were not talking of putting together a system for the OP. It is the OP's responsibility. We can only recommend or only advise based on our listening or personal experiences. Like you said, it is only up to the person to validate and then make a purchase - especially when it is recommended by folks who don't even own the components :-))
But listing your components at least gives the recommend-ee an idea of what the recommend-er really likes and then think if his/her own listening habits match with the recommend-er. I would never recommend a component which I do not have experience with. And things that I have auditioned, I would "only suggest" and mention that I have just auditioned.
My system has new passive friendly components that are different then before, thus I will try the LSA again!

Charles, I just hooked up the Yamamoto for the first time today and I will wait to give my full impressions. The first hour it was pretty dark and closed in and muddy in the bass. I think it needed to settle into my system. My CEC transport is known to be dark sounding.

After being on 4 hours things are getting better. The highs are coming in and the sound is opening up. Please understand both the Yami and CEC were fresh off the UPS truck!

The Yamamoto is easy on my ears and pleasing to listen to. Not at all harsh or bright with not a hint of glare. All very good stuff!
Hi Bill,
Just off the UPS truck, yes it will open up substantially, just give it time. It is a well balanced blend of transparency and very organic character . Keep me posted. It became even better with the Duelund CAST capacitors.
"03-27-15: Milpai
Zd542, don't feel offended just because you have not listed your system here.

But I found this statement funny :-)

Most of the stuff I recommend, I don't even own. "

No one likes a good laugh better than me. No offence at all. Just the opposite actually.

"Are you telling me that you are recommending stuff on a whim? We were not talking of putting together a system for the OP."

No. Not everyone has the same taste as I do. Sometimes what an OP will ask for is clearly not to my personal taste. It would be selfish of me to recommend only things I like, knowing full well that its not the best advice. For example, I don't like Magnepan and B&W speakers, but I would never think of talking someone out of them if that's what will make them happy.
I think you were generalizing that Actives were better than passives. I do not think I attacked your statement in any way. I was suggesting that we cannot make generalized statements. Isn't TVC a passive component?

No worries- but apparently what you were thinking is not exactly what I was saying since I was careful to not generalize. If you review my posts you will see that I make a point of also saying that not all active line sections are created equal. The phrase I like to use goes like this: 'It is a statement of how poor many line stages are that passive volume controls can beat them'. So I am always careful to use the phrase 'properly designed'.

So far this thread has really been about active preamps vs PVCs (Passive Volume Controls).

TVCs (Transformer Volume Controls) should not be considered in the same realm as PVCs. The math regarding how they function is quite different.

TVCs involve a transformer or autoformer with taps. They have a different set of issues- for example if improperly loaded the device will not express the turns ratio correctly and so bandwidth will not be flat (inter-winding capacitance can start playing a role). This means that the designer has to provide the proper loading for each step in the setup, taking into account that the amplifier (which might have an input impedance anywhere from 10K to 100K or more) is part of that load.

A lot of TVC designers don't take all that into account. So some of them are easily beaten by active line stages because the active unit is more tonally neutral). OTOH, there are TVCs that have all the design parameters sorted out and they can have impressive performance if used correctly.

If a TVC provides gain (and sometimes even if it does not) and depending on the type of amplifier used, the interconnect cable may well play a serious role in the results! Cables have capacitance and TVCs are all about inductance- the two together can result in a high frequency resonance that varies with the control setting.

If you can hear big differences between interconnect cables, what you can safely conclude is that the 'good' cable you have now and the one that didn't make it are both wrong. The why of it is simple- did you audition all the cables out there? Will the manufacturer of the cable you settled for make a better one next year?

A properly designed active preamp eliminates this issue- the cable plays a far less of a role in the tonality and resolution of the system. A good active will force the cable to do its job- to pass the signal without editorial. I don't see PVCs or TVCs really doing that.
I agree that I have not auditioned all the cables that are available. Will the manufacturer make a better cable next year - chances are most likely yes. Isn't advancement in technology supposed to do that? Nordost, Siltech, Shunyata, etc, all come up with new improved cables over a period of some years. Folks have done A-B comparison with the new-old and preferred one of the other. Does it mean that these cables are wrong?
There are tons of users on this forum who use very highly regarded active preamps (probably 3X-10X the cost of my entire system), and have experienced a better sound when their cables were upgraded. Does it mean that all these highly regarded active preamps also have not been designed properly? So which one would you say is wrong: cables or active preamp?


Scare tactics of the capacitance of interconnects with passive preamps are off the mark. As most good interconnect cables are less than <100pf (picofarad) per foot. And at 1-2mts are fine.

Only when you get into cheap nasty cables do these scare tactics come into play, when they have >200pf per foot or higher, and those types of cables have no right in hi-end audio.

Cheers George

Just to add to the above, when these high capacitance interconnects (>200pf per foot) are used, they can cause a high frequency filter, not only with passives but also with the many tube preamps.
This is another reason they have no place in hi-end audio. Thank god there are not too many of them around.

Cheers George
"Does it mean that all these highly regarded active preamps also have not been designed properly? So which one would you say is wrong: cables or active preamp?
Milpai (System | Reviews | Threads | Answers | This Thread)"

Neither is wrong. Audio components are usually designed with the understanding that they will be used in a wide variety of systems. Its impossible for any designer to make products that will be optimal in all systems. It just can't happen. That's why there's nothing wrong with the cables or the preamp. They just can't work for everyone in every situation.

Just to give an example,
A 10kohm passive preamp which all solid state sources can drive, has a worst case 2.5kohm output impedance.

In the worst case of 2.5kohm, this passive preamp driving reasonable quality interconnects of 100pf per foot at 2mts long will give a high frequency roll off at -3db @ 106khz!!!

And with just one meter interconnects it is -3db @ 212khz!!!

And this is interconnects of 100pf, if you get good quality ones that are 50pf per foot, the HF roll off point off doubles again
To -3db @ 212khz for 2mts!!
And -3db @ 424khz for 1mt!!

As you can see only dogs and bats can hear this kind of HF filtering.

Cheers George


Here is the graph of a 10kohm passive output impedance.
On the left (vertical axis) is it's output impedance, for the given volume resistance (horizontal axis).
As you can see at half volume rotation it is at the worst 2.5kohm output impedance, either side it's output impedance is lower.

http://i.stack.imgur.com/cVUCc.png

Cheers George
I'm using my PS Audio Direct Steam with a BSG QOL unit (awesome) into a Pass Labs X350.5 Amp.

The BSG QOL unit provides added gain and so much more texture than when I used my former Pass Labs Preamp.

I use the PS Audio Direct Stream volume, and it usually runs between 60 and 65. With the PS Audio High filter engaged, the volume on the PS can run in the high 90's.
However, I prefer to run it without the filter with the volume in the 60's.

The BSG QOL also provides added analog inputs and outputs.
One of the inputs is used for my Denon Home theater pass through in which the Denon controls the volume while playing Blu Rays from my Oppo.

The BSG QOL also has dual analog outputs in which I run my dual JL F113 Subs.
An active pre-amp plays a big part in how a system sounds. It serves as an analog signal processor in a sense in that how all sources used actually sound are affected.

So if you like the sound you gotta give the pre-amp some credit for that.

The option is to take it out and see how each source sounds and perhaps then tweak with that to get the sound you like again.

Either way can work well. If you like teh sound out of teh active pre-amp you have, then be grateful to it for that. It's far from "useless". Unless you try something different that works out even better. Then you might consider putting it out to pasture but still give it its due accolades for a job well done.
I agree that I have not auditioned all the cables that are available. Will the manufacturer make a better cable next year - chances are most likely yes. Isn't advancement in technology supposed to do that? Nordost, Siltech, Shunyata, etc, all come up with new improved cables over a period of some years. Folks have done A-B comparison with the new-old and preferred one of the other. Does it mean that these cables are wrong?
There are tons of users on this forum who use very highly regarded active preamps (probably 3X-10X the cost of my entire system), and have experienced a better sound when their cables were upgraded. Does it mean that all these highly regarded active preamps also have not been designed properly? So which one would you say is wrong: cables or active preamp?

I understand your consternation! It took me a while to get my head around this issue, but to your first question- does this mean that these cables are wrong the simple answer is 'yes'.

What if you had a setup where the cable made no difference in your system and an inexpensive cable sounded just as good a really expensive cable- which is to say that they both played so well it was as if they were simply a direct line to the music? Would that be of interest?

This is what I am talking about when I talk about eliminating interconnect cable artifact. Now if you prefer to throw as much money as you can afford at the cables to get better sound- by all means be my guest. That is one approach and it is the one most commonly used by the 'tons of users on this forum' to which you refer.

But if you want to get off of the interconnect cable merry go round and not have to worry about cables ever again in your whole life then go back and re-read my posts on this thread. That system to allow that has been around for about 60 years and it works really well.
Its good advice to take the cables out of the "how things sound " equation as Atmasphere recommends. Its one less thing to have to worry about in getting everything to play optimally together.