Preamps can color sound considerably. Surprising?

I was a dedicated passive guy until I one day decided to try an active.

The “meat on the bone” sound blew away the passives.

It was an Audible Illusions current model with John Curl MC phono stage.

I have since moved on to an A-S MP-1. Sure, a good passive cannot be beat for transparency. But a good active is also quite transparent and adds musicality.

A good active becomes the beating heart of a system. A passive, the liver?

A good active becomes the beating heart of a system. A passive, the liver?

Not to be argumentative, but I don't think that this analogy works.

Not to be argumentative, but I don't think that this analogy works.

Maybe a kidney?

No, I don't think that audio components to organs is a fair comparison, but if it was, I don't think you could compare one type of preamp to a certain organ and then compare another type of preamp to a different organ. 

I assumed they was referring to the removal of waste and toxins?

I assumed they was referring to the removal of waste and toxins?

Hmmmm . . . interesting . . . but is that the function of a preamp?

Gawd only knows…

Maybe like a power conditioner?
But I am not sure what the meaning was in the poster’s statement, so it is only a guess as to what the meant might have been.

Maybe heart=center of the system

Liver= contributing but not the center

scm: Thanks re Tortuga LDR, I'll try to listen to it sometime. But it needs external power, and so it is not truly passive. I have a 12 VDC battery-powered Dodd Audio preamp which is not passive, but it's absolutely silent. Can you switch the Tortuga to battery power?

ozzy62:I'd bet that most Hattor users are also using the optional external 12 VDC...probably in order to power the signal through the attenuator, but I'll try to listen sometime.

wolf-I've heard Schitt Freya--excellent, but not passive. With 6922 or 6NS7 or other great tubes, why wouldn't it be wonderful?. 6922 type tubes are glorious with the Dodd, and I love 6SN7 as well.

In general, I hate use of these long-stretch analogies with audio. They mainly serve to further derail a discussion that was already careening off track. Don't have relevant experience to the topic at hand? No problem! Anyone can make up a wild analogy!

Anyways, I'm surprised that team passive preamps hasn't compared the active preamp to an appendix 😅

Personally, I‘m rather in awe of the “Gallbladder machines“ one sees for sale from certain Chinese audio merchants….

It‘s funny how people argue about this subject. Attenuation and amplification are fundamentally different and the simple fact of the matter is that dacs only require the former. So what may be useful in amplifying a phono signal with rare exemptions become distorition when a dac is used.

@condosound.. 

"scm: Thanks re Tortuga LDR, I’ll try to listen to it sometime. But it needs external power, and so it is not truly passive. I have a 12 VDC battery-powered Dodd Audio preamp which is not passive, but it’s absolutely silent. Can you switch the Tortuga to battery power?"

.I have mine hooked up with a battery supply and it made for a much ’blacker’ back ground.

It‘s funny how people argue about this subject. Attenuation and amplification are fundamentally different and the simple fact of the matter is that dacs only require the former. So what may be useful in amplifying a phono signal with rare exemptions become distorition when a dac is used.

But one can also just use an amp as a buffer to change impedance.
If the DAC does the volume, and not other things need to be switched, then one does not need the attenuation nor the amp.

One of the rare exceptions is to drive the cables better to the amps, should the output be driven to very low listening levels. If the OP is not using horns and a high gain amplifier, and not listening at a low level, then they have less to consider.

But which arguments were you referring to?

More than anything else a good active preamp will provide a more 3D soundstage.Of course they have to synergise with the power amp to do that but when you get the combination right it can make the difference between a good sound and a really great one.It is simply sounds more involving because it is revealing more of the stereo effect that is encoded in the recording.It is higher resolution.

Some active valve preamps will add tonal colour and some are tonally neutral.Some SS active preamps add tonal colour too.It is just a matter of finding the one you prefer.

I have found the Supratek 6SN7 based preamps to be tonally neutral.Very clear and open and 3D but neutral.I have heard SS preamps that sound very similar but they are very high end Swiss designs that cost 4-5 times as much.

I like a little salt on my steak.

Your pre-amp and your speakers account for most of the systems SQ.  The "Tone" of a system can be changed with different cables...power cords....and power conditioners. That's why we are always Tweaking.....

BAT preamps are my reference. I’ve had 5 of them, and never had a bad one. I appreciate the “color” of a BAT. Same with a Threshold T2 and T3 Preamps. Old school I know, but they were very good products. I’m stuck in the past. 

Isn't that what they're supposed to do? 

While electronic design of preamps (or any component) is important, so is the choice of specific components… resistors, capacitors… etc. each choice makes a difference.

The head designer of one of the premier electronics companies (MBL ?) said, I can make a component sound whatever I like. If I want it warmer I use X capacitors… if I want it detailed I use Y resistors. I can make a component sound like anything I want.

So, the very best designers craft the sound to satisfy their clientele. This company decided there was a limited market (and appreciation for) for their very highest level products. So were creating a product line for the less discriminating tastes. I think there average component was well over $50K… so they wanted to get some of the chicken McNugget folks in the $20K range.

Your absolutely right. Preamps have their own characteristic sound. When I did a demo in my first home system  with 3 preamps before I purchased. All were on my turntable and speakers in my room. What matters is what type of sound do you like and are you happy with it. The three power amps also were different. The right combo was the winner.

@baylinor 

Well said!

I choose silver because I wanted more sparkle color in the highs!  Silver has proven to provide that in every situation!

Best

jh

Yes. I am wondering…as I ponder adding my Marantz 7025 AVR to my lineup of : Bluesound Node and Tube Amp ( Cary CAD-808), will I “lose” anything?

thanks from Nashville-

Dave

What?  We talk about it exactly that way.  Thats the central tenet of being an audiphile.

If a preamp isn't making my experience more enjoyable why should I buy it?

@moose89 

If you are planning on using the marantz as a preamp, I did this once with a different model marantz avr and it sounded horrible. You can give it a try though, as it doesn't cost you anything but a little bit of time.

Great topic and completely agree, since I require no switching or phono stage, what is this but a volume knob? Having had the Freya + to play around with tubes, I was puzzled when it blew up and needed a replacement when it was out for repair. The electrocompianet preamp I got from the dealer naturally went with the amps I loved and purchased from that company, but overall veil lifted and all that nonsense was true. I actually think the preamp is more important than the amp. Driving Maggies isn’t easy but somehow everything sounded better. Need to put the Freya up for sale, it’s great but no comparison. 

get all the components from the same manufacturer....they'll work well together

As a manufacturer, each tube has a different sound 6922/6DJ8 - 6SN7 - 101D - etc.  We designed a preamp where you could change output resistors from metal, carbon, etc., etc,.  It actually was an easy way to change the sound based on the recording and in our opinion save time in changing interconnects.

Every time we build a component, we end up feeling that the one we just built is more important that the last one.  At this time after building Class A tube mono blocks, we think that this is the most important part of a system. While the DAC and preamp are important, these Class A amps are just stunning in every system we have demonstrated them in from horn systems, to Sonus Faber, to Vivid, to YG Acoustics.  But keeping on subject, you have to determine what sound you prefer in your system and be happy with what you select.

Happy Listening.

Thank you for the nice comment about tube amplifiers.

Big problem is most dealers don't carry a variety of high-end components and comparing them it's not practical

If my two preamps sound similar, and it is not night and day.

Is it because they have the same tube type?
 

Preamps vs no preamp, tube preamp vs SS preamp - I don't believe one can make a global generalization on which is better because it differs depending on the components chosen in one's audio chain.  

From Cary Audio regarding their SLP 05 preamp:

. . . so yes, I would say that Cary is cognizant their preamps "color the sound."

when compared to a good passive, it's just no contest.

I've tried many passive preamps, thinking "that must be the answer". It isn't--they  are all dry and flat.

Passive Volume Controls are very susceptible to interconnect cable interactions, combined with the output capacitance of the source and the input impedance of the amp. If properly set up they can be excellent and if anything is off the very same unit can sound 'dry and flat' because of adverse interactions.

In any event you have to be careful of the interconnect cable; if you've auditioned cables and heard differences you know what I'm talking about.

Active tube preamps usually have output coupling capacitors which, no matter the quality of that part, will color the sound. In addition they are often single-ended circuits and so too are susceptible to interconnect cable interactions.

If you really want to hear what the recording sounds like, you have to eliminate the interconnect cable as a variable. The balanced line standard (AES48) offers a means to do that, but you have to adhere to its tenents to do that and most balanced high end audio preamps do not. 

I use recordings I made that are on LP and CD so I know what the recording is supposed to sound like. They are very helpful when a reference is needed (is it too lush or too dry or whatever...) to know what is going on...

@atmasphere,

could you kindly also get into the differences between attenuation and amplification? It seems hard to get across that most dacs only need the former whereas adding a pre by definition adds distortion. (While this may run counter to commercial interests, a degree of intellectual purity seems desirable in this discussion…)

Pretty much all capacitors inside a preamp Color the sound. Are capacitors the sole culprit in coloring the sound? Great capacitors, like Teflon, allow the dynamics to be where they should be. The peeks and the valleys are respected. Assuming you have a great amplifier to go along with us.

You hear preamp manufacturers touting our device gets out of the way it doesn't interfere with the music.  This could not be further from the truth. 

Call it is what it is.

could you kindly also get into the differences between attenuation and amplification? It seems hard to get across that most dacs only need the former whereas adding a pre by definition adds distortion.

@antigrunge2 

The problem we're all up against is that Redbook requires for more voltage than any power amplifier would ever need. So the signal has to be attenuated to do any good.

That means that in the case of a passive the control value becomes critical. Lower values like 10K work better, but most sources won't support driving 10K- they are more comfortable driving higher impedances. This can result in a loss of bass and distortion on the part of the source if its having issues.

Active preamps do indeed add distortion. However they tend to be less susceptible to interconnect interactions. There are four functions that any line stage should have:

1) volume control

2) input switching

3) supply any needed gain

4) control the interconnect cable to prevent interaction

Of these the 4th is least understood in home audio but well understood in pro audio, which is why they can use inexpensive cables and still get neutral sound.

If the active line stage is good at controlling the interconnect cable it stands a very good chance of being more neutral than a passive device and possibly also lower distortion, depending on the passive device to which its compared.

So its a mixed bag, which is why this conversation persists.

@atmasphere 

If the active line stage is good at controlling the interconnect cable it stands a very good chance of being more neutral than a passive device and possibly also lower distortion, depending on the passive device to which its compared.

So its a mixed bag, which is why this conversation persists.

Such a keen point. 
I n theory and on paper, the passive approach should be more invisible/transparent, more out of the way. Yet in practice, a high quality active will often yield the better or more realistic sound quality. It is indeed a “mixed bag.”

Charles 

@charles1dad it has been some of covered in a few places…

In theory and on paper, the passive approach should be more invisible/transparent, more out of the way.

In theory it starts to barf when the passive is doing more control.
Running “wide open” the passive is essentially a wire.

Remember that the passive pre is attenuating both voltage as well as impedance.

The pros and cons from my list:

• A high output impedance source = con
• Low output impedance source = pro
• High input impedance amp = pro
• Low input impedance amp = con
• High listening levels = pro
• Low listening levels = con
• Low sensitivity speakers = pro
• High sensitivity speakers = con
• High gain amp = con
• Low gain amp = pro

So the worst situation is driving some highly seniors give horns, at low volume through an amp with high gain from a high impedance source.

The volume is then cranked around anticlockwise, and the passive is attenuating the already high output impedance of the source to become tens of hundreds of kohms. 
 

If it is less sensitive speakers listen to at higher volume then the passive does not attenuate nearly as much.

If we add in ICs with high capacitance or inductance then we get a filter.
At that point it is often better to have a preamp than a passive, when the passive is trying to go very low… and it’s better to run a passive if it is doing very little attenuation.

@atmasphere,

many thanks for answering, a really helpful contribution. Am I right in saying that most digital devices are designed to have low output impedance?

@antigrunge2 Can you find it for your specific DAC?

In the example I gave above, one would likely be better off to adjust the DAC’s output level much lower, and then a passive pre would be cranked around louder.

I suppose those with a passive pre and a DAC with adjustable output level, could do this at home and tell us if there is a difference or not?

A DAC without the output level adjustment should not be as good (if all else was equal)…

@holmz 

my Dac is an Antelope Zodiac Platinum with a relay based attenuator and an output impedance of 56 Ohms unbalanced into my Wavac EC 300b power amplifier with an input impedance of 100kOhms. Hard to see where the problem might be with a 200x span. I’d love to try Ralph Carstens ClassD monos on balanced; this raises the Zodiac’s output impedance to 112 Ohms for his 100kOhms input impedance. Most problems discussed around attenuators deal with marginal situations, which on modern designs to my knowledge are rare. Your last sentence only applies to digital attenuation, which is lossy.

That is super low output impedance, compared to a CD player or other sources with 600-1000 ohms.
It is the stuff in ~1k ohms or the 10k ohms range that would then get knocked down 40dB (or maybe it is 20dB in both volts and impedance… so one goes from 1k ohm to 100k ohms, and trying to drive the amp with a 100 k ohm input impedance.

A 112 ohms output impedance going through an attenuation of -40dB should be 11,2 k ohms?
It is probably better to run the knob at -20 and knock down the DAC by -20dB to get to -40dB.
 

Your last sentence only applies to digital attenuation, which is lossy.

I am running an RME, so I knock my DAC down by 10-15dB just to get the DAC and the other sources to be about the same, which are 4 RCA sources and 2 XLR sources. It seems OK, but I could see knocking down 6 bits off of 16 would be a problem. Especially if only 12-13 bits were in action.

We will see what @atmasphere says, but half the reason I post is to get corrected if my thinking is off… but I think/believe I have this right.

My Tortuga passive and has plenty of power, punch, clarity and detail. Width is nicely presented and depth too.

I use a 1/2 meter  Audience IC that goes to a Modwright phono stage from the Tortuga.

I am using 1/2 meter Kimber KCAG IC`s from the Tortuga to my ATI 3002 amp. The ATI feeds a pair of Revel F52`s. 

I use a 1 meter pair of Zu IC`s into a Dayton Audio SA 1000 subwoofer amp which powers a Revel Ultima Sub 15 subwoofer. I have 3 other subs in the mix too.

This is my recipe for a very satisfying, enjoyable sounding system.

This works well and It will play as loud as you would ever want.

Try a Tortuga passive, you might be pleasantly surprised by what you hear 👍 

Am I right in saying that most digital devices are designed to have low output impedance?

@antigrunge2 

No. They are likely deigned to have good sound and or good performance (which are not always the same...). Some have tube outputs and are designed to have as low an output impedance as the tube will permit... at any rate, low output impedance isn't usually the goal although its usually desired.

One of the main reasons we've sold line stages over the last 25 years and right to this day is that analog volume controls often outperform digital volume controls. With an active preamp you then set up the DAC to have the volume all the way up so there is no resolution lost, and then control the volume with an analog control.

The problem with a passive is the volume control is a series element with the output impedance of the source. This means the source impedance is raised quite a lot insofar as the interconnect cable between the passive control and power amp is concerned (and also as far as the power amp is concerned).  So controlling the interconnect cable, even if the control is 10KOhms is a lost cause. That is why passives are so susceptible to interconnect cable interaction.

My Tortuga passive and has plenty of power, punch, clarity and detail. Width is nicely presented and depth too.

I use a 1/2 meter  Audience IC that goes to a Modwright phono stage from the Tortuga.

I am using 1/2 meter Kimber KCAG IC`s from the Tortuga to my ATI 3002 amp. The ATI feeds a pair of Revel F52`s. 

I use a 1 meter pair of Zu IC`s into a Dayton Audio SA 1000 subwoofer amp which powers a Revel Ultima Sub 15 subwoofer. I have 3 other subs in the mix too.

This is my recipe for a very satisfying, enjoyable sounding system.

This works well and It will play as loud as you would ever want.

Try a Tortuga passive, you might be pleasantly surprised by what you hear 👍 

@scm yes ^that^ is a recipe.
We don’t know your source’s output impedance nor the amp’s input impedance.

So it is a nice story, but doesn’t answer why it seems to sound OK.
But we at least have a combo that is good, and we can say why it is good then that is even better.

I am pretty sure that it the witches brew of cables are good, and they are short, which is also good.

@holmz ...The source output impedance is VERY low according to what I see listed for my ModWright 9.0X phono stage. Couldn`t find anything showing exactly what it is.

The amp`s input impedance is 28K ohms

Every amp I own, and have owned, is / has been rated to reach full power with less than 2 volts at the input. If you have a good 2 volts to work with, impedances are well matched, and the system caters to your desired volume level ( s ), when does the preamp’s additional voltage kick in? Most preamps in most systems are still used in attenuation mode, ime.