Why preamp "helps?"


Hi, first-time poster.  I'm sure it's been discussed ad nauseum, somewhere, but here goes.

I have a couple of digital pieces with built-in volume control/attenuation (e.g., Oppo 95 and Cary DAC200ts).

In monkeying with the components, I find that I prefer to have preamps in the chain--whether they are tube or solid state.  In two of the setups, a preamp would be entirely un"necessary."

It just doesn't quite make logical sense to me that putting another component in the chain with the extra "stuff" and cabling that the signal goes through would or should sound "better."  Seems logical that having a more direct signal to the amps should be an "improvement."  Sure, the tubes do their thing, but, in a secondary/tertiary system, even for an Emotiva solid state preamp?

I'm not trying to start some sort of debate, but any thoughts on why or how a typical, arguably superfluous, preamp makes it "better?"

Thank you.


stfoth
If the volume control in the source component operates in the digital domain, you should actually expect the volume control to have a negative effect on the sound. Digital volume control operated by dropping bits, so reducing the volume will also reduce the resolution and subsequently the sound quality. A digital volume control would only have full resolution at 100% volume. The further you get away from 100% volume, the more resolution you will lose. Now this is the simplistic explanation of digital VC and there are things that can be done to lessen the effect. However, I've always heard you should avoid digital volume control.

That said, I have a purely passive Placette Passive pre-amp that uses only very well matched, very high quality and very expensive resistors in the VC circuit. It is the most transparent "pre-amp" I've ever heard and I do not notice any loss of dynamics vs any active pre-amps I've used. My ears, my system, but that's what I hear.
Your first statement was absolutely correct. This topic has been discussed ad nauseam. And, the jury is still out....
Ralph Karsten (atmasphere) has discussed and explained the pre-amp conundrum here a few times, providing everything you need. Do a search of the subject, and look for his contributions.
Yo dude check out Ralph!!!!!
The pre amp is the most important piece to get right, IMO. Also, Having a proper volume control is very important. So many of these preamp/Dacs today do not spend $$ on high quality volume control....its more of an afterthought.


Matt M
So you have some digital components with built in "preamps".  How much effort do you think was put into those, compared to a stand alone preamp?

You already have something else "in the chain".. just a really cheap one.

See if you can demo a good preamp and take it home to give a listen.  I bet you'll understand after a few minutes with it.
I have a couple of digital pieces with built-in volume control/attenuation (e.g., Oppo 95 and Cary DAC200ts).
Reubent has put you on the right path, you can use your digital volume control if it's at or higher than 75% of full, if lower than 75% you will start to "bit strip" ie loose resolution 14bit 12bit the lower you go..

The other alternative is to leave the digital volume up full and use a passive volume control, this one is great as if you don't like it you can send it back for a refund.

 http://schiit.com/products/sys


You are also very right say this
" It just doesn't quite make logical sense to me that putting another component in the chain with the extra "stuff" and cabling that the signal goes through"

This is Nelson Pass one of the wisest in Audio.

Nelson Pass,

We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.

Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.

Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.

What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp."



Cheers George 
@stfoth - Oppo volume control applies to analog output (rca and/or xlr) only, not digital (hdmi). I have no clue whether or not that means the control itself is in the digital or analog domain. Others on this forum likely do know and can weigh in on that if they care to. Further, the Oppo output volume has a "variable’ and "fixed" option. Variable allows for a setting other than 100 (max). Fixed disables the control and sets the output to 100. So my question is why would you set it to anything other than "fixed"?
@georgelofi 

Thanks for that Nelson Pass excerpt. Coincidentally I was reading his "First Watt" FAQs and other literature today.

Can you "translate" the portion about the volume control at the 9 o'clock position please? I'm honestly confused as to whether or not he means the volume control position on the pre-amp or the amp, and whether or not the "throwing away" portion of that statement is a desirable or un-desirable thing.
On the simplest terms, power and control.
Can you "translate" the portion about the volume control at the 9 o’clock position please?
Yes what he’s saying there is that todays sources have enough gain to be able to drive poweramps to full power, so there’s no need to have an active preamp in between with even more gain and so not being able to use the volume past 9 o’clock because it will be too loud.

So use a passive volume control which has no gain allowing to use ALL what the source has, and therefore the volume control of the passive will be much higher than 9 o’clock giving more usable volume control range. Benefits of using a passive will be:
1: less background noise,
2: less distortion,
3: less colouration,
4: wider frequency response because it’s DC coupled to infinity,
5: a more transparent/dynamic sound.
6: better volume control range

If your power amp has input volume control use it, and connect your source directly to it, as it's most likely a passive volume control on the input of the amp.

Cheers George

"Further, the Oppo output volume has a "variable’ and "fixed" option. Variable allows for a setting other than 100 (max). Fixed disables the control and sets the output to 100. So my question is why would you set it to anything other than "fixed"?"

If you want to use the Oppo's volume control you need to set it to variable. If you are not going to use the Oppo's volume control they tell you to set it at 100 for a reason. If the volume control is digital, you need to set the volume at the max setting to get full resolution. When you lower a digital volume control, you lose a little resolution. The lower the volume, the more resolution you lose. That's why its best practice to set it to 100. That said, I find the actual effect on sound quality is very low to none. Most of my CD players have digital volume controls, and I can't hear a difference as I lower the volume. I even had a few friends do some listening with me, and they couldn't hear a difference either.

"I'm honestly confused as to whether or not he means the volume control position on the pre-amp or the amp, and whether or not the "throwing away" portion of that statement is a desirable or un-desirable thing."

Pass's argument is that if you have a source component that puts out more gain than you need, using an active preamp is a waste because you don't need to amplify the line level signal before it gets to the amp. The preamp will be choking it down because the signal is already stronger than needed so the preamp is a waste. Instead of an active line stage, all you need in a situation like this is a passive volume control.

If you're thinking about doing something like this, I would recommend you do some listening first. Like anything in audio, results vary. Some systems respond very well to a passive device, while others don't. In my own systems, I get good results with both passive and active line level components.

Can you "translate" the portion about the volume control at the 9 o'clock position please? I'm honestly confused as to whether or not he means the volume control position on the pre-amp or the amp, and whether or not the "throwing away" portion of that statement is a desirable or un-desirable thing.
Its not a good thing, and it would be the volume control on the preamp.

One thing not mentioned so far is how a preamp drives interconnect cables as opposed to how a DAC does it. Its a funny thing, but its also a fact that the design of whatever is driving the cable can make a difference in the sound. Quite often active preamps reduce the artifact from the cable; passive volume controls seem to be susceptible to the most artifact from the cable, and DACs are usually somewhere in-between.

A preamp often makes the DAC's job of driving the cable much easier, plus you can often run the DAC's volume control all the way up and use the buffered volume control of the preamp instead. Quite often that practice gets you more resolution from the digital system which can account for the difference all by itself (YMMV on account of not all volume controls in DACs are the same!).
Benefits of using a passive will be:
1: less background noise,
2: less distortion,
3: less colouration,
4: wider frequency response because it’s DC coupled to infinity,
5: a more transparent/dynamic sound.
6: better volume control range
As stated, this is false. To correct it, the word 'will' should be replace with 'can' or 'could'.

Many audiophiles using passives experience increased coloration (lack of bass impact for example) and as a consequence, certainly less bandwidth (cable capacitance further contributes to the loss of bandwidth as well).

Rather than repeat myself, I will just copy myself for further explanation; this is from a similar thread:

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.
I’m honestly confused as to whether or not he means the volume control position on the pre-amp or the amp, and whether or not the "throwing away" portion of that statement is a desirable or un-desirable thing.
"Throwing away" means your not using all of the sources output, by cutting it back with the active preamps volume control. It’s always better to use ALL of what the source has, as you gain the benefits of what I outlined above 1 to 6.
So use all of the sources output, get rid of the preamp and use your volume control/s on the amp if you can get loud enough level, doesn’t matter if your at 3 o’clock or 5 o’clock so long as it’s loud enough.

Cheers George
Many audiophiles using passives experience increased coloration (lack of bass impact for example)
Exactly the statement Nelson Pass says some make.

You have problems elsewhere if this happens, in 90% of cases it won’t, just try it and you’ll be better off, and believe what Nelson Pass says, as no one here has the knowledge he has. 
And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp."
Cheers George
Welcome! stfoth

the pre-amp is the heart of any system. Get it "right" and you will be musically rewarded. Any system can benefit from a high -quality volume controller.
stfoth,
Please pay particular attention to what Atmasphere wrote in his final paragraph Of His FIRST post.  This is true more often than not. A "high" quality line stage can "increase" resolution and transparency rather than diminish it. This will vary depending on source components and overall system assembly.

In some circumstances a direct source to power amplifier or utilizing a passive preamplifier will be the preferred option. Upper quality active preamplifiers have stood the test of time for a reason. Either method can be very sucessful, it just depends on individual circumstances and goals.
Charles
believe what Nelson Pass says, as no one here has the knowledge he has.
I can guarantee that Nelson will agree with my post. The math is pretty easy.


high -quality volume controller.
Yes and inside a passive preamp is the best place to put this high quality volume controler. " and you will be musically rewarded."  

Cheers George
As long as we are quoting Nelson Pass, Mr Pass also says this about active vs. passive preamps in an interview with Audiophile Review:

AR: What's your position on passive versus active preamps?

NP: You'd think that a minimalist switch and variable resistor in a box would be as good or better than active stages, but often it is not.

Some of the issues are well understood; for instance if the resistance value of the potentiometer is low, the source can have bass issues due to the output coupling capacitance and higher distortion due to greater load current. At the other extreme, if the resistance is too high it can create distortion and high frequency issues by presenting a high source impedance to the power amp.

Then there are things that don't show up in the usual measurements and we simply observe that the active circuit sounds better than the passive.

I file these under "How About That".


George always forgets about this quote.
Here is the link: http://audiophilereview.com/amps/nelson-pass-interview.html

From my experiences, I know that I have never found a passive preamp to work better than an active preamp in my system.

Cheers,
John
John,
I have noted in the past that the Nelson Pass quote often cited by George doesn’t represent the full measure and ideas expressed by Mr. Pass. Those additional quotes from him are definitely in line with the experiences of many knowledgeable listeners. It seems that Pass and Atmasphere are on the same wavelength. This shouldn't surprise anyone. 
Charles

The matching for passive preamps is prefect in 90% of sysetms.

If your source has low output impedance, <1kohm across the band which most are.

And the poweramp is higher than >33kohm input impedance which most are.

Use good quality low capacitance <2mts interconnects.

The maths are perfect for a 10kohm passive volume control, to get all 6 of these advantages
1: less background noise,
2: less distortion,
3: less colouration,
4: wider frequency response because it’s DC coupled to infinity,
5: a more transparent/dynamic sound.
6: better volume control range

And the result will be as Nelson Pass (god) says.
What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.



Cheers George
Thank you for the clarity georgelofi, mgreen27 and atmasphere. I'm truly grateful for your replies to my questions.
Att: stfoth
The OP’s Cary DAC200ts source, has an output of 3.0V RMS (at 220 Ω output impedance) perfect match for a passive preamp

This 3v is way more than what’s need to drive all poweramps to clipping, so no need for active preamp with even more gain added. And with the Cary up full, the volume control on an active preamp will be at nearly zero for loud music, and you’ll have no range to play with for lower levels.

A passive preamp will be far better, with the range of volume control and sound quality.

Cheers George

Is this my imagination or I have read the same exact posts on at least two other threads, within the past couple of months? So, for the sake of completeness and while we are throwing quotes from Mr. Pass, let me remind everyone the Pass Labs makes some of the most sought after and expensive (solid state) preamplifiers in the market today. Not a single passive, of course excluding the (First Watt) B5 that is just a buffer.
To add to all that has been said above, a reason why it may sometimes be sonically beneficial to insert a preamp into a system that would theoretically seem perfectly suited to do without one was stated a while back by Paul McGowan of PS Audio.  Following are excerpts of a blog post he made on the subject, as quoted by me on 10-4-2015 in the this thread, which addressed the same subject that is being discussed here.

Interestingly, Paul McGowan, designer/manufacturer of the OP's DAC, has just in the past few days been posting thoughts on the very question being discussed here in his blog at the PS Audio site. Some excerpts:
My adamant stance against inserting a preamp between a high quality DAC like DirectStream and the power amplifier should be no surprise to readers of this blog. As well, my subsequent turn around embracing the exact opposite should lift no eyebrows either. But why would inserting an extra piece of gear in the signal path sound better than a more direct approach? How could this make sense? ....

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

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

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

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

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

So this is one reason, and there are more, some preamps can help a DAC.
Also, FWIW, I agree with all of those who have indicated that the answer to this perennial question can be expected to be highly equipment dependent.  While at the same time it seems to me that the burden of proof should be placed on anything that adds complexity to the signal path.  And in general, once mismatches and misconfigurations that can be identified by analysis of technical specs have been eliminated from consideration that burden can only be met by listening and comparing.

Regards,
-- Al
 
The fact that Pass himself designs, manufacturers and sells active preamps speaks volumes as to their many assets and importance in audio systems.  I don't believe that he'd do this if he felt an active preamp was superfluous.  In numerous systems this component is a very vital key to extracting the full sonic glory of one's system. 

I can surely vouch for the upper echelon performance and sound quality of Atmasphere's MP-1 preamplifier as I've heard with both my amplifier and his own amplifiers.  It would upgrade the sound quality of many systems IMO.
Charles 
Thanks, everyone, for the info and responses.  I refined my search terms and saw that there are several similar discussions, some even recently.

Having tried these (Oppo & Cary) with and without separate (active) preamps, both tube and solid state, I found that I preferred going through the separate preamp--which just seemed somewhat counterintuitive and was curious about other, more knowledgeable, folks' thoughts on it.

With the criticism and issues with the digital volume control and "stripping bits," the idea of a passive preamp just seems to make sense, when both have strong enough output to drive amps, with the idea that a simpler, more direct path could be generally "better."

hk_fan.  Thanks.  I hadn't thought of it quite that way, conceptually.

gdhal.  I have the Oppo set at "fixed" with the separate preamp.  I had it at variable when I was monkeying with it direct to the amp(s).

Georgelofi.  That's my experience with the Cary.  At full up, through a separate preamp, there is very little room on the preamp knob.  I actually have it turned down to about 2 volts.  I even wonder if, for some reason, that 3.0 volts could be too "hot" or potentially damaging to an active preamp?  Cary, I believe, suggests that its volume be set to max, but can be "level-matched" with other sources.  I see you suggested the Schiit passive (for $49!).  I suspect there is a review thread, somewhere, but.

Might folks have experience with the Schiit who could give a quick thumbs-up or down?  Heck, might be worth $49 just for S&Gs.

Anyway, thanks, folks.  For a little more color (and I'm not fluent in audio vocabulary), I found the Oppo going direct to the amps, comparatively, to be very detailed and "crisp," but maybe "shallow" and "electronic" in the midbass on down.  Voices less "real" and full.  Just wasn't nearly as fun to listen to as with including the preamp(s).  The Cary was much more "alive" than the Oppo particularly with the tube output selected, but, still, I preferred the sound through preamps.  Just my ears, I guess.

So, I run an Oppo 95 at fixed volume to the Cary DAC for CD, and the Cary at about 2.0 volts to the active preamp.  That's where it seems to sound best to me, whether or not I initially thought it was particularly logical.





Pass Labs makes some of the most sought after and expensive (solid state) preamplifiers in the market today.
Of course he does, because people will still buy them and it's profitable. He's not an idiot!

Cheers George 
the idea of a passive preamp just seems to make sense, when both have strong enough output to drive amps, with the idea that a simpler, more direct path could be generally "better."
That’s great you can see the light that Nelson Pass has directed you to.


Georgelofi. That’s my experience with the Cary. At full up, through a separate preamp, there is very little room on the preamp knob. I actually have it turned down to about 2 volts.
Correct you have too much gain, so get rid of the preamp.


I even wonder if, for some reason, that 3.0 volts could be too "hot" or potentially damaging to an active preamp?
No they should be able to take this


Cary, I believe, suggests that its volume be set to max
But can be "level-matched" with other sources.
Yes this is so there’s no chance of "bit stripping"
Cary puts out 3v others source can be 2v, your in the lap of the gods without modifying the gain of the highest one to match up with the lowest.


Schiit, Heck, might be worth $49 just for S&Gs.
You have a trial period, so it can be sent back, if you don’t want it, but for $49 it’s a no brain'er, and a prefect match for what you have.

Cheers George

I had the original Pass Aleph P that had the ability to add whatever active amplification you wanted in each channel, which then fed a master passive volume control.  So you could go from no active to some active, and I think it was just based on personal preference.  If I can find the owner'manual I'll post Nelson's comments.  There were two versions of the Aleph P and I'm not sure if the 2nd version included this arrangement.  For all  the simplicity and exotica, I really wasn't blown away by it.
Pass Labs makes some of the most sought after and expensive (solid state) preamplifiers in the market today.
Of course he does, because people will still buy them and it's profitable. He's not an idiot!

Cheers George

Maybe it's time for you to fess up and admit that you have some skin in the game here George. You are not merely an audiophile like most here, you are a manufacturer.......of passive attenuators.

You are on these boards trying to steer folks towards the type of product you sell, hoping to make more beer money for yourself.
You like to cherry pick quotes from Nelson Pass, and refer to him as (god), then turn around and claim that he (NP) is simply scamming the naive public by selling his wares. All for the chance to increase your bottom line.

A little transparency please.

Cheers,
John
Post removed 
Gain is not the only factor in play.  The preamp / volume control source output impedance is a big deal, also, particularly with low input impedance amplifiers and long cables.  In these cases, an active preamp with low output impedance provides a better match to the load presented by the amplifier.  

So the real answer of passive or active depends on what you are using it with, particularly on the load side.  Tube amps tend to have high input impedance, so a passive preamp can work well.  Many solid state amps have lower input impedance, and for FET-based driver stages, high input capacitance.  For these loads active preamps work better.  As in all these considerations, use your ears to make the best decision on which way to go, for YOUR system !

10kohm passive preamps (like the $49 Schiit Sys) work very well and could sound better than mega dollar active preamps, if your system meets these requirements, 90% of systems will.

1: The source is lower than 1kohm output impedance across the audio band, which most are, except for some bad designed tube output stages, on some sources.

2: The power amp needs to be 33kohm or higher input impedance, which most are, except for some Class-D’s.

3: Keep your interconnect low capacitance, which most quality ones are, and 2mts or less in length.

Cheers George

Post removed 
jmcgrogan2, thank you for pointing out that georgelofi is a manufacturer. I had not picked up on this....
 I went through a stage in my Audio life where I was convinced that a passive would be better. On paper it seem to make sense, I had also read Nelson pass comments on the subject and was determined to make it work. However contrary to what George would have you believe, 90% of the time it does not sound better. I would put the percentages at the exact opposite of what he is stating.  My results mirrored the OPs  experience, it sucked the life out of the music. You end up with a highly detailed rendition with no body and lacking in bottom end.  We had an evening at my place with a Bottlehead beepre, an antique sound labs passive and a Teo passive.  The TEO was probably the best I had heard out of a passive but was definitively behind the Bottlehead.  The antique sound labs was producing and odd artefact in the base which was causing it to sound very bloated. This was an anomaly as I had heard that unit sound very good in another set ups.  We suspected and impedance mismatch but didn't look into it much further. The Bottlehead was definitely more realistic sounding  
 But I agree that all should experiment and satisfy their own curiosity. 
I have owned a Schiit Sys for several months now and it works as advertised. Its basically a two input switch with a volume control, adds nothing and removes nothing as long as you keep the interconnects very short and don't mind the small size of the volume control. No brainer for $49.
@analogluvr , +1, my experience mirrors yours. I tried a couple different passives many years ago. It seemed like a good idea, and I wanted it to work. Maybe even convinced myself that it was working for a few months. However, after switching back to an active preamp, the difference was obvious, active is better for me, as I'm sure it will be for 90% of others.

Now, as George says, for $49, and a free return, it is certainly worthwhile for someone to see for themselves. I don't need to. Been there, done that.

@georgelofi , please don't compare yourself to Ralph. Ralph Karsten has too much class to make a statement like this:

Pass Labs makes some of the most sought after and expensive (solid state) preamplifiers in the market today.
Of course he does, because people will still buy them and it's profitable. He's not an idiot!

Cheers George

Ralph would never insinuate that a SS designer was simply stealing money from his clients. Ralph is a man of integrity.

jetter265 posts02-04-2017 7:12amjmcgrogan2, thank you for pointing out that georgelofi is a manufacturer. I had not picked up on this....

See George, many here do not realize that you are a manufacturer of passive devices. The OP even said he was a first time poster here.

While manufacturers and dealers are most welcome here, and encouraged to join into these discussions, they should be responsible enough to disclose any industry bias that they may represent. Your bias is clear to more experienced forum members, but your lack of transparency enables you to prey on the less experienced.

So next time you want to mock Mr. Pass about just taking money from idiots willing to buy his product, make sure that you enlighten ALL as to what makes you profitable!
Step out from behind the curtain, and into the light.
This thread makes me glad I purchased an integrated (MF M6si) amp :)

"10kohm passive preamps (like the $49 Schiit Sys) work very well and could sound better than mega dollar active preamps, if your system meets these requirements, 90% of systems will."

I can't see how that would be an optimal solution. Volume controls have a big effect on sound quality. A high end volume control is not a cheap or easy thing to make. The $49 Schitt uses a fairly low end, off the shelf pot. To spend all that money on the Cary and the rest of the system, and then put a cheap pot in the signal path would be foolish. (At least I think so). As always, you get what you pay for. It costs a lot more than $50 to get a high quality passive. And one of the reasons for this is they don't use pots. Instead, they get a 100 or so resistors and wire them so the signal travels through just 1 of the resistors at a time. If you want to see a passive that's done right look at this one. There's other good passive as well, but the Placette is the most popular.


Having owned and used 2 passive volume controllers in my desktop system (excellent components except for speaker, which are good but not great, the rest are high end" in this context). And I've learned a few things about how passives behave.

For years I used an inexpensive PVC purchased from NHT. It sounded pretty good and worked extremely well. The gain match with my system (which constantly changed) was always optimal, and the sound quality from this device never seemed to change, despite equipment coming and going. I'm reasonably sure this inexpensive device contained a transformer, rather than just a volume pot & wiring.

Eventually, after months of research, I upgraded to an expensive passive with a stepped potentiometer (47 steps). To my horror, this device sounded miserable in my system--bright, bass impact greatly reduced, with an obvious gain mismatch (had to turn the stepped pot rather far up to get sufficient volume). I realized this device was simply reacting to the impedance/capacitance profile of what it was connected to. I had the choice of changing/upgrading almost everything in my system to get this passive sounding better--or move on. I chose to move on & sold it.

I now realize that the transformer-coupled passive gave me pretty decent (but not great) sonics that never changed despite cable & component switches; vs the stepped pot passive, which clearly had the build quality & capacity to reveal greater sonics (but would not do so in my system).

My advice to anyone considering passives is 3-fold:

1 - If you don't follow recommendations 2 & 3 below, at the very least, purchase the passive of your choice w/the ability to return it for money back, if it doesn't sound good in your system.

2 - Alternatively, get one of the rather expensive passive designs that contain a transformer.

3 - Or, if you don't want that, consider a transformer-less passive that is spec'd to your system (ie, matches the output voltage of the source device & the input impedance of the amp/powered speakers that will be connected to the passive's output). The only mfr of passives that I know of that does this is Luminous Audio: the Matrix II device is affordable, and the company's owner is a gentleman.

And no matter which passive you end up, common sense dictates that you use the shorter IC w/the least capacitance to connect it to the device downstream in your system.
I’ll agree with George on this point for experimentation and an educational exercise. Buy the Schiit Sys for 49 dollars and just listen. If you find it as good or better than an active preamplifier, then congratulations, you’ve save money and have satisfyingsound. You just never know.

My experiences mirror John and analogluvr’s in that a good active preamplifier provides more body,natural tone, dynamics and life, yes, more musical flesh and blood, thus emotional involvement. Some will retort by saying that those qualities are simply "pleasing colorations"

I vehemently disagree with that assertion. How can increasing the realism and emotional involvement of music be an artifact/coloration?
It seems to me that some believe that a leaner, thinner sound quality with emphasis on the attack and transients =transparency. This type of sound presentation is IMO less realistic. It sacrifices natural warmth, instrumental body/fullness and natural decay of musical notes. As will always be the case, YMMV.
Charles
The $49 Schitt uses a fairly low end, off the shelf pot. 
  There's other good passive as well, but the Placette is the most popular.
Yes it is a cheap pot, but for $49 it's cheap way to be introduced into the transparent sound of going passives, with a return policy if not liked. The Placette is far more than that.
Sure there are better far more expensive passives, but for audiophiles who wish to dip their toes and buck the naysayers into the world of passive preamps, this is a good intro for them. As they will see what it's all about.

Cheers George     
I had a crazy experience several years ago with a SM Pro Nano patch passive ($40 ) . Bought a $7,000 Marantz sc7s2 Preamp . I preferred the Nano patch in the end .

I can see why some like the actives . They seem to add bass (with all the caps) They can accentuate the highs as well .

The Marantz was terrific with recordings that matched well with those added frequencies but horrible with recordings that those frequency boosts didn't match well with . For all around the passive won .

The lower noise floor of passives can be sensed as less dynamic . If you boost the highs and lower the lows artificially it gets sensed as more dynamic with actives.

Definitely try anything and everything you can it's the only way to gain knowledge in this hobby.
I actually tried Georges Lightspeed before that . I was running my system with very long interconnects at the time and used very long wires that were problematic .

Sold it here and the next owner was very happy !
I think Arthur Salvatore described it best,

"Active Versus Passive Line Stages - A Mainly Circular and Fruitless Argument
Only when the original signal source has the required energy to directly drive the power amplifier, without any sonic compromises, can a passive line stage ever be used with complete success, since the only function remaining at that point is signal attenuation. This basic technical fact is why audiophiles talk past each other when they argue which is better; passive or active. This is because the actual results completely depend on the specific system in question; in particular the source’s energy output and the amplifier’s energy input requirement.

Those audiophiles who have the sources with the required energy (a minority), will not be able to understand how anyone would want to listen to the inevitable sonic degradations of any active line stage, when there are no corresponding sonic benefits. Meanwhile, those audiophiles whose sources do not have the required energy (a majority), will not be able to understand how anyone would prefer to avoid some relatively minor audible problems while simultaneously ignoring the much larger and more easily noticeable sonic benefits they are experiencing. Both sides are undeniably correct, because they are experiencing two very different realities, though all of their experiences are consistent with the laws of acoustics and electronics."


Those audiophiles who have the sources with the required energy (a minority),
Sorry, most of today’s solid state sources have output stages that are the equal some better than many active preamps especially most tube ones.

Cheers George