To Pre or not to Pre? Here is my take

  Hey uberwaltz,  I have tried going without a pre a couple times.  What I can tell you is that the sound without the pre seems better at first, with more detail, but then after a couple of days it seems that I am missing my pre.  There is just more emotion to the music with a good pre, and more meat on the bones if you will to the sound.  Just my 2 cents.

What does this tell me?
That absolutely the ls preamp is adding its own sonic signature to the mix, in theory that equates to probably a more "dirty" sound but to me this was the sound I preferred.

Two things going on here, that need to be addressed.
 
1: You may have a system/room problem where the preamps sonic signature (colouration) is doing a cover job on, as the Esoteric direct into the Bat has a better impedance/drive than the LS2 has.

2: When you went direct, your Bat's input sensitivity is just 1.5v in for full power out, and your Esoteric is 2.2v out.
This means your digital domain volume control in the Esoteric must have been turned down quite low.
It's well known that digital volume controls "Bit Strip" the music (you lose resolution) when they are turned down below 75% of full.  No matter what the manufacturers advertise.
You would have been better off doing this comparison with the Esoteric full up and a cheap $49 Schiit Sys doing the volume in the analogue domain.

 http://schiit.com/products/sys

Cheers George

#1/ For sure I know my room is terrible but it is what it is, due to space restrictions that is something I cannot change right now but will be changed in under 2 years when I move.

#2/ Interesting as I found just the opposite, running through the ls2 I used only a small amount of gain, running direct from the Esoteric I was at 80% of volume att for about same volume.
Your statement makes sense but my results do not??

Then you have digital gods like Thorsten Loesch designer of all AMR digital stuff saying this.
" Turn down the volume even the tiniest bit using the digital volume control and the sound quality to a massive hit. "

Cheers George

To pre and not to pree that is my answer. Different components predict what sounds better. My preDAC sounds smooth analog detailed sweetness without my yba alpha. While others do do better with a pre slipped in.

I tried for a while my PS audIo DS as a pre with my Hegel H30. I only got to know what i was missing  once i jntroduced a P30 preamp in the chain.
I did never go back to the DS again.

Way too many variables in the audio chain to make a general conclusion. Results are completely system/cable dependent. Worth the experimentation nonetheless.

I use an Ayon CD5s which in additon to transport and DAC has a great built in pre with analogue volume control - This works better than adding a different pre

What is the relevance of this post ? Is this for anyone who happens to have exactly the same components and room to not use a esoteric as a preamp and use the arc ? OK Got it . Thanks

IMHO, linestage and wire designers are more chefs serving up tastes  than engineers solving problems. It can be argued that there is really no problem to be solved with braided quality copper wire or a good signal attenuator (ignoring the digital resolution issue.) Even if there were engineering issues, forty years is more than enough time to solve them.  Not to be a curmudgeon, but I suspect most of what is being engineered in wire and linestages are differences marketed to different tastes.  Sometimes they're just bright shiny objects we desire.

There's nothing inherently wrong with that, and I have an aftermarket power cord, silver interconnect, SR Black fuses, and still undecided on whether I want my Benchmark HGC to be my linestage or spend extra on a tube pre.  In the end it's the joy we get from it all.

  "What is the relevance of this post ? Is this for anyone who happens to have exactly the same components and room to not use a esoteric as a preamp and use the arc ? OK Got it . Thanks "

Just to say that even though this shows to me that my pre is definitely adding something to the original signal which some would say is negative, but to my ears in my room and my music I prefer the sound

So maybe not everything that is technically incorrect is sonically incorrect to the individual listening.

But if you find this post of zero relevance feel free to pass........ its a free world......

" Way too many variables in the audio chain to make a general conclusion. Results are completely system/cable dependent. Worth the experimentation nonetheless. "

I agree entirely, move my equipment to another room and the result could be entirely different. Or bring another set of ears in and they may hear it differently to myself.
Not trying to make a general conclusion, just stating my experience is all.

Uberwaltz, I found your post to be very relevant to my situation. I have a tube pre and am about to try a DAC with volume control. Like you, I am just wanting to try the alternatives for myself. I will get back after.

I don't always listen at the highest volume I sometimes do, often less than 80% of that. If a DAC can't be sonically at it's best at less than 80% volume then use of a volumed DAC seems less than ideal.  

Not only is your ARC LS2 preamp adding something to your amp's sonic signature,  ALL preamps do.  (I've had an LS2,  an LS3,  and a good many other preamps in my system over the years as well.)

I've also added a "passive" preamp to my system and discovered that I prefer "regular" preamps better.  While much has been espoused regarding preamps that "get out of the way" and allow the most pure of signals to be heard,  switching out a good many of them over the last few years tells me that every manufacturer produces a different sound.  The same can be stated for amplifiers.  Generally speaking I really enjoy ARC products,  but I've recently - within the last year - settled upon a BAT VK3i tubed pre for my Pass Labs X150.5 amp and I love the combination so much I've pretty much stopped "s'perimenting" with my system.  

To my humble ears the BAT is a tad narrower in the soundstage than the ARC pre's I've had are,  but nothing that I've found to be negative or detracting from all its other qualities.  If I were to find a tubed ARC preamp within my budget - which is an occasionally temperamental thing regarding audio stuff - I would definitely toss another in the chain just for the hell of it.

Good to hear on the arc as i have had this one now for over 3 years and have yet to feel the desperate need to change...lol. But you know how that goes!
I was watching a bat vk31se on ebay as i thought it may make a good mate for the bat vk600 power amp. so will possibly give that a whirl if the price stays fair.
guess i will be content with knowing I am "colouring" my music regardless.

" What does this tell me?
That absolutely the ls preamp is adding its own sonic signature to the mix, in theory that equates to probably a more "dirty" sound but to me this was the sound I preferred."

That can be true in some cases, but not all. There's several variables involved when driving an amp directly from a source, and you can sometimes have a bad match. In a case like this, using a preamp may be a less colored option. 

" It only took a couple of tracks to confirm
I just did not like this sound, bass was much thinner, soundstage not as wide, vocals not as smokey for want of a better description of Mz. Hales style. Hooked the ls2 back and joy was restored!"

When I read that statement, it sounds like your system is doing a better job at reconstructing the original recording with the preamp in the chain, than without. At this level we can only speculate, but in your case using the preamp may be the more "accurate" solution.

" I remember reading in many places that the best preamp was no preamp. "

That can be read more than one way. For example, if you were evaluating 2 or more preamps, the best option would be the preamp that is the most transparent (least colored). Another way to look at the situation, and I make this statement quite often myself, is no preamp is better than a cheap preamp. A volume control on a source (digital or analog), or a passive, will usually outperform a low to midrange active line stage. Keep in mind, though, all this is a judgment call that you need to make. Every situation is different.

and you can sometimes have a bad match. In a case like this, using a preamp may be a less colored option.

OP: " It only took a couple of tracks to confirm
I just did not like this sound, bass was much thinner, soundstage not as wide, vocals not as smokey for want of a better description of Mz. Hales style. Hooked the ls2 back and joy was restored!"

When I read that statement, it sounds like your system is doing a better job at reconstructing the original recording with the preamp in the chain, than without. At this level we can only speculate, but in your case using the preamp may be the more "accurate" solution.

In that OP’s statement you quoted. He did have a perfect impedance/drive match when he went direct, and he wasn’t "bit stripping" because he was at 80% of the digital domain VC.
So it comes down to that he preferred the "colouration/distortion" of the active preamp that aided in fixing a system or room imbalance, and not because the preamp was more "accurate" to what was coming out of the source.

Cheers George

George, Active preamps can also be fixing poor recordings or manufacturing problems that cannot be fixed by greater transparency in the home system.

I have had every combo uiu can think of. An added flavor of not ,to sound 
Natural is thd goal.  Direct from a dac, or passive just gas No amplifier gain stage 
Which is essential for dynamics, especially J Der duress of a large orchestra 
The performers should always be rock solid and in place where all performers can be picked out. With passive it at times can be  unfocused  and the sound stage 
Indecisive.  Vacuum tube preamps are by far the best balanced  with a Solid State amp. Vacuum tubes gave their own distortions that are natural to thd ear 
Whrn a solid state devise starts to distort it is Odd harmonics and sharper to yhd ear. With Vacuum tube distortions are more Even harmonics  with bloom 
That is in mist cases appealing.  Fort a Solid state preamp to be warm with similar characteristics  to a tube  uding Mosfets,Bipolar  or other methods and normally  2-3 X the cost  on average, also with Vacuum tubes each brand gives a different sonic signature which then allows you to Taylor your system to your specific taste.

Best preamp is no preamp.  Possibly but that all depends on the volume control and how that output from the source can be handled by the amplifier as mentioned above.  Most preamps have caps in the signal path so yes you are listening to the sound of the output resistors and the caps.  Many to choose from.  I build a preamp with no caps in the signal path and a multi- option switch to let you select the resistor for your system.  How do I choose what you like?  Anyway I have my preferences but they might not be yours.  Also not all preamps add distortion.  Some can really add space, air, placement, clarity, details around vocals and instruments.  Some can really add tone that you cannot get without using a preamp. 

Happy Listening.

And I agree with just about everybody here and appreicate them taking the time and trouble to comment as it helps my mindset somewhat.
I am fairly content with knowing that in my room, with my equipment listening to my music with my ears that my arc ls2 sounds good to me...lol
so much so that i have just bought a gold lion 6922 tube for it and will see how i like that sound, after all that was only $35...
happy listenings indeed!

"What does this tell me?
That absolutely the ls preamp is adding its own sonic signature to the mix, in theory that equates to probably a more "dirty" sound but to me this was the sound I preferred."

I disagree.  What it tells you is that the volume control - i.e. PREAMP - in the Esoteric is not nearly as good as the ARC.  If anything, the signal after the Esoteric preamp is clipped and muddied in ways you probably can't even comprehend.

Most digital components that offer a "volume control" are thrown in as a ploy to get you to pony up thinking "hey I can save $$ by not needing a preamp".  There's no free lunch, and a good preamp is crucial to a high performance system IMO.  :)

George, Active preamps can also be fixing poor recordings

I don’t think so, the "perfect" active preamp is said to sound like a straight piece of wire, it should not add or take away from what the source is giving, but that perfect preamp is yet to be made.

Cheers George

George, the perfect recording has not been made yet and probably won’t be made in our lifetimes, so the right preamp can help ameliorate the deficiencies in the recordings we do have. If no preamp works for you, great, but active preamps may work better for some others. In fact, I’m sure they can.

Uberwaltz,  If it sounds good to you that's what counts.  It's all about enjoying the music.

George, the perfect recording has not been made yet and probably won’t be made in our lifetimes

I like to hear my best recordings as they come from the dac, and if the bad ones don't sound so good, so be it, at least I'm not colouring both.

If no preamp works for you, great, but active preamps may work better for some others. In fact, I’m sure they can.

 Like I said before, some may like a certain colouration a preamp gives to their system. And that they all sound different. It's up to the owner/buyer of a preamp to get the one with the right colouration to address their problem.
I myself like to address the problem directly and fix it, without the need to hunt for the right preamp to colour the problem.
 
None sound like a straight piece of wire, otherwise all would sound the same as going direct.

Cheers George

 

Of course an active preamp will alter the sound one way or another and if you prefer the sound your preamp produces then go with it. The lead Tech at PS Audio used to advocate the use of passive preamps for years and just recently reversed his conclusion in favor of active preamps. But keep in mind that some quality amps have a higher input gain that makes them an ideal companion for a passive preamp or a direct connection, delivering excellent dynamics, mids, and highs

"...and one passive preamp to rule them all....."

I have found that using my Audio Research LS27 tube preamp in my system, everything sounds much better.  I have found that using a top quality tube preamp is the single most significant important part of an audio system other than the speaker system and audio source itself.  And for them to work to their finest, again the tube preamp can make it all come together.  I previously had an Ayre K1xe and it could not even come close to my Audio Research LS27.  Even on television audio it makes a huge difference.  Just hearing the human voice it is so much more enjoyble sound.  Also I have an Rega Osiris integrated, and again it can not compete.  Also I am only using an Odyssey Khartago amplifier with my LS27-on high gain it seems much more powerful.  Also using the monitor output of the LS27 to a Stax headphone system,it is again quite apparent that an audio source will sound much superior if run thru my LS27 rather than directly from audio source to the Stax system itself.  So it is obvious to myself how a true quality tube preamp is the way to go.

There is no preamp which sounds as good as no preamp. It is add by subtraction. , I have Audio Flight and Custom Tube [Magic] pre amps and both are very good but neither are as unforced or clean as my Townsend passive. If you will check the HiFi Critic site I believe that it was the highest rated component of any kind that they have tested. These are of course my ides and you can have your own. I will forgive you if you do! [humor]

"There is no preamp which sounds as good as no preamp "

And that was my initial thoughts and point behind this post
But my ears with my system in my room and my music just tell me different, and at the end of the day what I LIKE the sound of is what counts whether it is technically incorrect or not.
So throw me into the corner with the other dunces who like dirty distorted sonics from their tube preamp!

I think this topic was discussed ad nauseam in an earlier thread and the final conclusion was that there is no conclusion. I was so curios that I even went out and bought a Schiit Sys passive to experiment the hypothesis. In my case, I initially thought the music sounded more dynamic with the "direct" connection but I ultimately reversed and put the active pre back in the loop. For me, the direct route felt a little dry and too analytical whereas the active pre added a bit more warmth and sort of took the edge off the corners. All in all, this is a sort of thing that is so dependent on the components (and cables) that you won't be able to get a consensus of which is a better way to go. For example, I could have had a completely different experience if I had bought an uber $ passive vs. a $50 unit. To make it even more subjective, the preference may also depend on the type of music played through the system.

To make it even more subjective, the preference may also depend on the type of music played through the system.

Exactly!
I listen to rock music only and just found the direct path too cold and sterile for my taste
I know I am listening to some type of sonic inferiority according to theory but tbh, I really do not care!

This is one of those discussions where there is no right general answer only individual taste.  I'll briefly share my experience.  A friend of mine has an MSB Analog DAC with the preamp/volume module.  Awesome DAC by the way.  I played it by-passing my ARC Ref 10 preamp and using the ARC by-passing the MSB pre.  What struck me first was the difference between the two set-ups.  I have always believed and also experiened the adage that "the pre is where all the damage is done."  The MSB Analog pre section is very good.  Wide soundstage and excellent resolution, particualry on the lower octaves.  However, it could not match the depth, detail, blume and densness of the ARC.  Also the ARC just made subtlties and nuances clearly more real.  Lastly, as one would expect, there was more air around everything with the ARC.  So my taste favoured running the source signal through a very good pre.

Ray

The more and more I hear other peoples observations with ARC, the more I feel it is a pre I should never get rid of! Maybe upgrade it or even a newer ARC but for my ears this ARC tube sound just sounds well right for want of a better word.

uberwaltz

Before you spend big bucks on a newer AR pre on a hope it will be better than what you have now, try this with the volume on the Esoteric full up or if it has the fixed output. For $49, and it’s refundable as well.
http://schiit.com/products/sys

Or the passive or tube one, also refundable
http://schiit.com/products/saga.


Or the balanced, passive tube active, or solid state active.
http://schiit.com/products/freya


Cheers George

As I've posted elsewhere on Audiogon, I compared both the Creek OBH 22 SS Passive Preamp, and the ARC Ref 3 Tube Preamp.  I got the Passive Pre, initially, because I wanted to eliminate the preamp, but retain a remote volume control.  

The Passive Preamp did seem to offer a bit greater clarity... but... the Ref 3 Preamp seemed to have almost as much clarity, with a slight bit more richness, warmth, and liquid body... and... perhaps a bit larger soundstage and air.  These differences were pretty small, but enough for my wife to quickly decide she preferred the sound with the Ref 3 Preamp - called it more real, and life-like.

However, many would be very happy with the Passive Preamp, especially considering the premium price of the Ref 3 Preamp (10-15 times the Passive Preamp) to produce a very slight improvement in sound.  

Very Interesting products George, however it would have to be the balanced as I am using xlr and the bat only takes xlr input unless you buy the xlr to rca adapters
more food for thought....

I have read and I believe I understand what you are suggesting. What I would also suggest, in reference to your characterization of what you heard as "dirty" sound, is, despite the absolute negative connotation of distortion as always undesirable, that some forms of distortion can actually be desirable. What you are hearing may or may not be distortion but the point is that we all have our preferences as far as what we think is "good" or "not good" sound. As a case in point, it is my understanding that Oppo has publicly admitted that they are attempting to purposely introduce "some desirable" distortion into the output of their universal players. This seems absolutely contrary to what I think many of us have been taught over the course of following this hobby. Something that has always puzzled me is that most concerts we attend generally include massive amounts of distortion generated from one source or another but yet we strive to produce the sound of a live performance in our listening rooms and if we hear, or think we hear, distortion we think that takes us away from the live performance experience.

I have been fighting this same issue.  I have a Cambridge Audio 851N connected directly to my Halo A21 via balanced cables and it sounds very analytical too me with a small soundstage.  Speakers are KEF R300.

I almost think my second system with lesser components sounds more musical (B&K ST2140, Rotel RC-980BX,  Paradigm Monitor 9s).  I'm in the process of combining my two systems and will be able to test when I throw my Rotel pre into the mix. I think the room where my second system lives is much better suited to music so that could also play a part.

A keen observation and test-  uberwaltz

the pre-amp, as it were, is the heart of any system. I want the very best piece of hardware to do its duty. Get it right and one will be musically rewarded.

Well nearly as good as buying a new pre and all just $35
Installed the Golden Lion tube today ( nice my pre only has one tube!)
To start it was awful but as the tube "broke in" somewhat the music unfolded and what music.
Very familiar tracks took on new life, wider soundstage, tighter bass lines and less chestiness to the vocals.
A change I can definitely hear and this is only 3 hours of run time on the tube!
Very happy camper......

Still getting better and better for very little dollars.
Now have fitted a Herbies tube damper cost $22 shipped and yes, another audible improvement.
Even more clarity and depth to vocals and wider soundstage.
If this carries on you will have me believing a fuse can actually make a difference I could hear.....lmao

Even if there were engineering issues, forty years is more than enough time to solve them. Not to be a curmudgeon, but I suspect most of what is being engineered in wire and linestages are differences marketed to different tastes.

This statement is false to the best of my knowledge. Any designer worth their salt is doing the best they can.

This engineering issue is in fact solved. There is a reason why passives don’t always work- it has to do with the interconnect cables and what the source is. The engineering issue is that its usually a Bad Idea to have a volume control driving an interconnect cable. It is also true that sometimes you can get away with it. Sometimes the control acts to reduce the effectiveness of the output coupling capacitor in the source device. So as you turn the control down from full volume, you get a reduction in bass. This phenomena has been documented for decades. That is why you rarely see volume controls at the output of electronics without some sort of buffer from the interconnect cable, unless the interconnection is known to be very short.

I agree entirely, move my equipment to another room and the result could be entirely different. Or bring another set of ears in and they may hear it differently to myself.

I think you will find that this has nothing at all to do with the room and everything to do with your equipment!

Here’s how it works. The source has an output impedance that must drive the interconnect cable and the input impedance of the amplifier. The source impedance is not always linear with frequency- quite often it is considerably higher at 20Hz than it is at 1000 Hz (look up the measurements on various CD players, phono sections and the like and you will see this quite often). The source drives a cable, which then is connected to the PVC. The output impedance of the control often **appears** low, since quite often its the wiper of the control and at low volumes its close to ground.

But from the source point of view things are different. If the control is all the way up, the source drives the interconnects and the amplifier directly. As you turn the volume down though, the source has to go through an increasingly higher resistance to get to the amp. If the source already has a variable output impedance that is higher at lower frequencies, the fact is that the ratios of the control vs the output impedance means that the source simply isn’t going to make as much voltage at those frequencies where the output impedance is higher (like in the bass).

Result: lack of bass impact (a tilt towards the high end) results. People report this all the time; now you know why it happens.

It can be avoided by an output impedance that is linear with respect to frequency. The problem here is that to do that often requires a larger output coupling capacitor in the source (which pushes the rolloff down to a point below human hearing). A larger coupling cap often means additional coloration on the part of the cap itself (increased inductance accompanies increased capacitance as capacitors are rolled into a cylindrical shape). On top of that, the designer has to avoid an overly-large coupling cap that might allow the bandwidth of the circuit to exceed the power supply’s low frequency bandwidth (else low frequency instability can occur which can manifest as IMD, muddiness, even thumping). So there are constraints on how large the output coupling capacitor can be.

This means that this conversation will continue for some time, as people will continue to encounter variable results; its 100% equipment dependent.

At least now you know why it happens.

The source impedance is not always linear with frequency- quite often it is considerably higher at 20Hz than it is at 1000 Hz (look up the measurements on various CD players

This is also just as true with just as many preamps outputs, not just sources, especially tube ones also some solid state ones.
Today many sources have just as strong/drive (low output impedance) as most preamps have. (excluding sources with tube output stages).

Cheers George

The issue is not what is the output impedance; whether its tube or transistor. The issue is that the output impedance can vary with frequency while not at the same time having flat frequency response into a certain load impedance. IOW the output impedance curve is not the same as the frequency response!

I've seen this phenomena with solid state CD players and tuners- its really a function of that output coupling cap. You can't always make it as big as you want; the cap construction itself often restricts what is the largest expedient value to use for best sound. This is particularly true of film caps; electrolytic coupling caps have a bad reputation but they do allow for much higher values.

We avoid the issue altogether in out preamps by using a direct-coupled output we patented. In such as case the output impedance curve looks exactly like the frequency response curve.

The issue is that the output impedance can vary with frequency

Yes of course it can, especially if capacitor coupled. (best cap is no cap)
This is why my system is direct coupled from dac convertor chips output pins all the way to the speakers, with dc servos at each stage taking care of any dc offset.

Cheers George  

^^ That's pretty unusual (and also explains why a PVC works in your system)!

The problem you often run into with direct-coupling is the circuit can have bandwidth that can go lower than the actual power supplies (which always have some sort of time constant, unless powered by batteries). 

If this is not handled correctly IMD will rise and there can be low frequency instability.

On top of that servos can be a bit tricky (we use servos as well in our direct-coupled outputs) and in general will have some sonic artifact unless there are at least two poles in the servo's bandwidth.

If the servo isn't right, IMD can rise and there will be low frequency instability.

If you can change the servo IC or other component in the servo without changing their values and that results in a change to the sound of the system you know you have a problem.

This is why 99% of everything out there uses coupling caps.

This is why 99% of everything out there uses coupling caps.

In tube equipment yes, but try to tell designers like Dan Agostino, John Curl, Jeff Rowland etc etc. that. They are firmly in the direct coupled camp, from go to whoa.

I've seen many problems with pieces of even expensive equipment that is capacitor coupled, in that one the cap is not big enough in uF(microfarads), two they use poor quality caps, three sometimes they use electrolytic caps, even I've seen bi-polar electrolytics used.
Still the best cap is no cap. 

Cheers George

^^ I’m not arguing that point; we don’t use coupling caps at the outputs of our preamps or amps as I previously stated.

But most sources use them whether we like it or not.