Passive preamp vs. powered

Just a "shout out" to blindjim for what I thought (imop) was an insightful post.

What I can say about gain is the improvement it can make to your system. I have an ML amp and 326S preamp, and I can set the preamp to o gain, 6db, 12db, and 18db. Each step up from zero improves the sound, I like the 12db, but I recently tried the 18Db, and what I have experienced is a more relaxed sound, more open, more dynamics in the bottom end, and just a more pleasant and natural sound without any downsides. 12Bd sounds more sharper and detailed but not as natural as the 18db, So gain does make a sonic impact which is why buying a new preamp with more gain than you had before will sound different for sure and most likely better. My vocals are now in the room with body and openness. I guess much less like a recording. So you need gain, yes lesser sounds detailed but not real like music sounds. 

I think I know what ambient information means, it puts the instruments within a specific space or venue. So ambient information provides that additional sense of instruments in a particulat environment, not simply localization within a soundstage. If that is what it means, then it makes sense to me how this allows for some of sense of "truthfullness".

You all make good points. Ralph, I think that's a very interesting observation - that the retrieval of ambient information effects the perception of truthfulness relating to imaging.

Phaelon, hearing everything on the disc can sound so natural, it never draws your attention to the detail, as it becomes part of the whole package. Blocking out detail detracts from the trueness of every part of the performance, every singer, and every player.

Phaelon, quite simply, it sounds to me as if you are after the truth. That is very different from not liking imaging, its all about getting as close to real as possible. Part of the issue of course is hearing recordings made in the spaces that you commonly hear performances in.

A pet peeve of mine does have to do with imaging. In a system that properly retrieves ambient information, the ambient information will make the musicians seem less distinct in the soundfield. So a system that does that might get docked because a lessor system that is unable to retrieve the ambient cues has the images portrayed in a stark fashion. But the system that can portray the ambient information is the one that I would say is 'better', because it has the organic quality that is what you hear in real life.

BTW this is one of the areas that I find a good line stage to outshine any of the passives- PVC or TVC- that ability to reproduce all the low level detail, all the ambient information. However, I have seen a lot of passives beat out active line stages that are not up to snuff, so its no surprise to me that a lot of people might be convinced that passives are ultimately better.

Hi Phaelon, I do know what you mean about detail that can drive you to distraction, and truly accurate timbre and dynamics are much more important to me then imaging, as I really don't find much imaging in live music, more like a wall of sound. I'm not sure if this is a problem of recording techniques, but I suspect Rleff is right about that, my only point is that if for good or bad, if it is in the recording something might be suspect if the equipment isn't conveying those what is in the recording. Now whether it is in anyway a necessary part of enjoying a musical performance, I would say it is fairly low in my list of priorities. Besides, I never disagree with Clio09:)

I always thought imaging/depth was more based on the recording miking technique used by the recording engineer(s) as can be heard on chesky's ultimate Demonstration disk and I am sure there are others as well.

Good points Phaelon.

Hi Paul,
I don't dispute your point. What I took exception to is the assertion that, because I don't walk lock-step with the majority of the audiophile community in certain subjective values, my opinions are disqualified.

Let me attempt an analogy: I assume that one of the goals of a movie set designer, when constructing models of a set, is to facilitate the audience's "suspension of disbelief". High-definition video, like high-end audio, is concerned with extracting all the recorded information. Consequently, I now find that in some movies, high definition reveals Hollywood's magic tricks. Whereas before I was able to suspend disbelief and see a castle, I now see a plastic model. Likewise in audio, pinpoint imaging can sometimes serve as yet another reminder that I'm listening to a recording.

Phaelon, if the imaging is in the recording and you're not hearing it, why would that be? Not that it should be a goal to have imaging per se, you are right, it doesn't really exist in live music, at least not much in my experience, but if it is in the recording and it doesn't come through in the reproduction doesn't it suggest that something is missing that shouldn't be? It would seem to suggest a loss of information, whether "real" or not.

"...it is true there are those who do not like imaging, bass extension, smoothness or clarity. I've met them, but generally I find that I don't care for their opinions as they are so far from reality"

Hi Ralph,
I'm probably overreacting to my pet peeve but I'm tired of people suggesting that I don't value "reality" because I don't place imaging as highly as others do on my list of priorities. At its best, imaging is the representation of the "miking" in the recording process. It's actually a nice perk that high-end audio has over live events. I know that you are technically correct - that since imaging is on the recording, it should be reproduced. But since pinpoint imaging is so seldom present in my live event experiences, its presence is less vital for me to achieve a sense of reality. In my humble opinion of course.

Mrtennis, I agree with you in that there is an element of subjectivity in what we like or don't like, there is certainly room for personal preference, but I think there is a limit to that argument as well, there is after all good taste and bad taste with some range of difference of opnion, but a speaker that has large anomalies in frequecy response, or lacks balance, or images poorly, a whole slew of "objective" criteria that is measurable is poor by any measure, and if one likes those kinds of abberations from neutrality I think that person's opinion is not likely to be very useful to most people - there is room for taste, but reproduced sound does exist within the range of a basic recipe based on some level of accuracy to the source signal. Whileone might not make a decision on "objective" data alone, it is not a bad starting point either.

Mrtennis, it is true there are those who do not like imaging, bass extension, smoothness or clarity. I've met them, but generally I find that I don't care for their opinions as they are so far from reality. It is my opinion that the more it sounds like reality, the better :)

Tholt,
Dude you beat me to the post. I was about to post my reply and saw that you already mentioned the TVC. You are damn right about the TVC. I use the Promitheus Ref C-Core and it is everything I wanted. When mated with a proper amp, the combination is awesome!! The sensitivity of the power amp is very important though. Preferably less than 1.5V. Quoting a audio guru - "with a high sensitive amp, a TVC will work its magic by increasing the current and lowering the output impedance for the signal it sends to the amplifier."

And YES - all the aspects of music are preserved by the TVC - dynamics, body, texture, weight, etc. But remember - you need a highly sensitive power amp.

IME the one thing that passives have over the actives I've had is transparency -- that 'air' between instruments and voices. Contributing to this is that there are no active electronics so noise floor is lower as well.

It seems like it comes down to body vs transparency in most of these arguments. I am using a Promitheus Ref TVC since most of what i read about passives is that TVC's are superior and play nicer with others then other passive variants.

For the record, i love my TVC. it doesn't seem to suffer, to my ears, to the lack of body argument. What I do run into is lack of gain. This has to do with the other components in my system, including 87db sensitive speakers, but it can be an issue as is well documented.

hi ralph:

i appreciate your specifics--denotation and connotation, of what better is. however, as audio is one of many aesthetic endeavors of life, opinion is the final arbiter.

if i say it is beter its is better for me, but perhaps not better for you. you can choose objective criteria. hwoever, within that arbitrary context which is not knowledge, someone else may create other objective criteria which disagrees with your assertions. thus, it is still a matter of opinion.

OP, I guess the answer is it depends. It depend on the system context, and it depends on your preference for the type of sound that appeals to you. I will see that in a properly matched system (CD with 100Kohm input impedance on the amp and low capacitance (or short) ICs) it is pretty darn hard to beat the value of something like the Bent Transformer or Autoformer (I prefer)TVCs. I can tell you that it is very well designed, sounds great, and will give most if not all active linestages a mighty tough time justifying the cost difference, which doesn't mean you won't fine a wonderful tube preamp that does something for you that makes the price worth paying.

Up to this point my comments have been directed at Passive Volume Controls. TVCs are another matter- if done properly they solve a lot of the issues that PVCs cannot address; I think they represent far greater bang for the buck than PVCs.

So it is harder to beat TVCs with a good line stage whereas beating a PVC is like shooting fish in a barrel. The problem you run into with TVCs is ringing due to improper loading of the transformer, and I find that there are still the losses that I always find transformers doing. Proper design can reduce these issues! Nevertheless they do not have the 'turn down the volume = turn down the bass and dynamics' problem that PVCs have.

Mr. Tennis, your remarks address mediocre equipment quite well but there is a league of equipment transcendent to such comments. 'Better' refers to greater resolution, wider bandwidth, natural dynamic punch, more natural tonality, improved soundstage... You can always ask me to clarify and I will be happy to do so. My use of the term 'better' in this thread does refer (but is not limited to) to the prior list of attributes.

Paul, we have gone down similar paths with passives and in the end our preferences have led us to different end points that we mutually respect. It helps that you and I have spent some time understanding each others systems and have listened to different systems together at a previous RMAF. I can certainly see understand why tube actives are your (and others) preference, although both your systems are passive friendly.

There have been times I've been tempted to try a VAC preamp to mate with my VAC amps. However, as I kept listening to my passive preamps, the thought just faded as I realized how pleased I was with the sound I already had.

Tony, I think you and I have gone through a similar path and respeonded to passives in the same way. Ultimately a very good tubed preamp just gives me the kind of sound I prefer. I was going back and forth with the Bent Tap-X Autoformer and decided to stick the Joule and Atma-sphere preamps. Now, the fact that something so much cheaper is in the running tells you a little bit about how much bang for the buck you get from passives. The rest does seem to be personal preference and that is hard to prejudge for another person.

Love to do a shootout. What passive do you suggest that is transformer based?

In response to both yours and Shakey's comments I will say this. I have had an S&B MkI TVC and loved it (replaced a Joule Electra LA-100 MkIII and Cary SLP-98). However, I have to say the autoformers offered by Dave Slagle that are now used in the new Bent Tap-x are superior. I purchased a minimalist version of the Bent using Dave and John's new Slaglemam modules. It's not pretty, but sounds great and replaced a Jeff Rowland Capri in my system.

I used to also think that the transformer models were superior to the resistive models. After hearing a Lightspeed Attenuator in my system that uses opto-couplers with a resistor I'm not of that opinion any longer. Since I own both types direct comparisons were easy.

While everyone talks about impedance matching, etc. with passives, and that is important, let's not forget the role the actual attenuator switch plays. Using quality attenuator switches (Seiden, Shallco come to mind) is important in passive designs and influences the sound IMO. However, the Lightspeed attenuator is the only design I have run across that renders the attenuator switch irrelevant.

Bill - if you're interested in checking out an autoformer let me know. I might be able to let you borrow mine for a bit. Email me offline if interested.

Grannyring-Maybe you can get Ralph from Atmasphere as well his pre amps must be in the top 5 of anything out there;it would be a interesting evaluation.

Shakey,

What is it in "To me....." that you do not understand?

What about "All of the above are just my opinions base on what I heard of course." ?

Go and find a better active preamp.

The H2O Fire is the only preamp that sounds marvelous on my speakers. It is just starting to turn heads.

I have owned preamps using the S&B Mark I and II trannies (much preferred the Mark I). I have heard a Sowter TVC, owned a Sonic Euphoria PLC and now have the Bent Audio Tap-x. I would say all of them are very good to excellent.

Shakey

Interesting

Love to do a shootout. What passive do you suggest that is transformer based?

I am near Minneapolis, MN

Granny,

Yes, you are right. It's all about what makes YOU happy.

However, I have heard passives such as the Placette, the FT Audio LW-1, Mccormack Line Drive and Reference Line Preemineence 2. None of those can hold a candle to the transformer variety. A completely different animal.

Shakey

Shakey,

Yes they are good and I haved owned several of them and several much better then those you listed - active.

I have owned passives from TRL, BV Audio and Placette.

Your sound preference may lean to the passive route. Great for you! Others will want a different sound, like myself.

Fun for all!

Amandarae,

"I always examine the equipments of the owners reporting the claim and make my conclusion as to what they have or had and build my impression from there."

Here are some active preamps I have owned (in no particular order):

AI Modulus 3A
CJ Premier 17LS
Lamm LL2
GNSC modded Audio Research SP9 II
Art Audio VPS DM
Gill Audio Alana
Cary SLP-98
Dehavilland Ultraverve II

Do you think any of those would qualify as "decent to a very good design active preamp "?

Shakey

>All passive models I have listened to have been a disappointment ultimately<

Jallen I would be willing to bet you have never heard a passive device using autoformers or transformers. Maybe Grannyring hasn't either. In an appropriate system one of these types of linestages can whip the pants off far more expensive active preamps. At least that has been my experience.

Shakey

Very interesting thread. My experience with highly regarded passive preamps vs great tubed active has always been the same.

The passive ones seem to sound more transparent, fast and detailed. After longer listening and comparisons one resounding thing became clear to me time and time again.

The perceived greater detail etc... of the passsive was actually the absence of body, texture and weight.

Threadbare sound can often seem more transparent at first, but in the end the passives lacked the meat of a great tube preamp.

It's a relative thing to be sure.Some passives have meat, body and texture, however not as much as a great tubed active preamp.

In the end the passives I've tried over the years simply lacked the meaty,earthy and substantial weight/authority of an active.

But, this is key. I don't like a thin, fast and detailed sound. I'll give up detail for natural musicality.

So my opinion does not mean actives sound better for all - just to me and what I like my music to sound like.

Passive preamp + MIT cables with impedance correction = fantastic match.

This is typical of the passive vs. active discussions you will find. A real mix of experiences and preferences. One thing I will say, is that every passive I tried offered alot of bang for the buck, they are very good in many ways and hard to beat for the money assuming proper impedance matches, a tube amp is almost always a better choice due to its high input impedance. Ralph knows 10,000x more about this than I do, and I have to believe his position is proabably sound, and it may be that an amp with a built-in passive volume control would provide the best option. I can only say that as much as I wanted to love them, because of their simplicity and price, over time, I prefered my CAT, Joule, or Atma-sphere tubed preamps. The only answer to this, is for you to try it and draw your own conclusions because you never going to get a defintive, conclusive answer - it really is a matter of going with your ears and deciding for yourself. On a budget, I think choosing a passive is a no brainer, and for some, even when money is no object.

In my case, I never heard a passive preamp that impressed me. Be it the high price Silver TVC's from S&B or any other manufacturer etc. I always find them weak in the "attack" department. Passive preamp to me have that "sleepy" tone and tends to sound "slow" as you increase the volume. Besides, they are not flexible in terms of what electronics to use and with real world cable lengths applications. I mean, why do you have to add a parameter to the whole system equation if you can avoid it.

To me, I do not believe that passive preamps strength is clarity, ever! If it is, then I assume that the one reporting never heard a decent to a very good design active preamp especially those with low output impedance and can drive the amp in use better. I always examine the equipments of the owners reporting the claim and make my conclusion as to what they have or had and build my impression from there.

As always, system matching is the key but for me given the choices, I will never own a passive preamp anymore. FWIW, there are many circuits floating around for tube preamp designs and maybe you can expand your consideration in building one yourself. As you read more about them, you will notice that proven designs that even use NOS tubes like 10Y, 76, 26, 27, etc. are available and users reported lots of good praises about them.

All of the above are just my opinions base on what I heard of course.

Caveat: I own a preamp that uses 76 tubes.

Read this:

S&B

Count me as a passive fan. I have a few different types lying around - AVC, resistive, opto-coupler - and listen to them regularly. Sold my last active preamp and not intending to go back.

Ralph made a good point about eliminating the cable by placing the passive volume control in the amp. You might look into EVS attenuators which plug into the amp inputs and accept a cable from your source on the back end. This is a nice solution if you only have one source to deal with.

implied in mmany of the comments so far is that a is better than b. so many times this position has been taken --opinion assumed, but there has been no statements(s) as to what constitutes "better". having both active and passive preamps, i would refute the statement that actives are "better" than passives, since better is what i think is better. any comments ?

by the way generalizations are usually wrong in all aspects of life..

Rleff, It is the interaction between the cable, the source resistance (which is a combination of the passive control and the actual source, including the cable from the source to the passive) and the input impedance of the amp that creates the bass/dynamic filter that many passives are guilty of being. The only way around it is to use really low impedances, something that most sources cannot handle.

So in effect passive controls are a form of tone control. The fact that they can sound better then some actives is simply the measure of how bad those actives really are. The only way I have found to make a passive work is to eliminate the cable between the control and the amp, IOW put the control **in** the amp. This eliminates convenience but then the control works.

Wow, lots of responses - thanks for the input everyone.

Am I off in my hypothesis that the input impedence on an amplifier would make all the difference in the world? I mean, as this varies, it will react differently to a given output level of the pre-amp... One might boost the signal before it hits the output stage to a fixed level... whereas another might not alter the level at all, making the effective output MUCH more dependent on the signal level it receives.

I digress... maybe I'm not making sense here.

The manual for my AR PH3-SE states that it will not perform its best with a passive preamp.

All passive models I have listened to have been a disappointment ultimately. The Adcom is clean, but the stage is so much smaller, and flat, the Creek is almost as clean, but also small sounding, but both very clean and uncolored, and others have been of a similar genre. I would rather have a bit of color from an active line amp and get the size, drive and control in the bass. My choice is a good tube line amp/preamp with 12AX7 or 6922 /7308 drivers. Try all you can....jallen

Few active preamps are as good as a good passive. The best active ones are better but cost much more. The current issue of HIFICRITIC tests three active preamps. The Aesthetix Calypso got a score of 20 with current production tubes, 26 with NOS ones. The Bryston BP26 got a rating of 16; the Roksan PR15B scored 20. The control passive was 30. On the other hand something like the CJ CT 5 would be 70 or above so active is better if you have the money but not all expensive ones are worth it. On yet another hand not all systems will work well with passive so proceed with caution whatever you do.

this hobby is very subjective. i own a passive and three active tube preamps. i won't say one is superior to another. rather they sound different.

there is too much hype and so-called knowledge expressed which is unjustified.

just listen and make your own decisions. this dictum applies to other issues in audio as well as the subject of the thread.

I would like to add that building a volume control that sounds the same at all levels is expensive and/or difficult. Just stick a pot in the front of your system and listen. This is a good reason to use a digital volume control when you can.

The clarity of passives is very impressive at first, it sounds so different than actives in that regards that it is very alluring. But after several tries, I ultimately decided that active stages provided a better listening experience for me. I don't know why that would be technically so, passives seem to have such a minimalist appeal to them, but something always seemed to be missing for me (output impedance, gain, sensitivity, input impedance, and cable capactance were not limiting factors); others love passives for what they don't do to the signal so you just have to listen and make your choice. You will find folks who will be in one camp or the other on this. Count me in for the active crowd.

Thanks Ralph that is one point that I never would have ever considered;is it the extra resistance and capacitance of the cable that the passive has a problem with?

If the designer of the preamp line stage has done his homework, that preamp will sound better than any passive made. Passives cannot control the interconnect cable and that is one thing that a good line section **can** do (although not all preamp designers realize that what I just said is possible, so you will see a lot of variance as a result).

You may have noticed that as you turn down the volume of your passive, there is a loss of bass and punch. Any preamp made will prevent **that** although with most you will still have to be careful about the interconnect cable. A good preamp design will free you of even the choice of cable and its length!

I have owned, built, and heard many passive preamps, and they all shared the advantage of clarity at the expense of dynamics. You pays your money......