Adding a pre amp

[GUTB]

3 hours ago, pkane2001 said:

 

So because 'SQ is subjective' is a truism you can just ignore it and treat it as false? I'm trying to follow your logic. Is that statement true or false?

 

 

This is why I asked to be real for 5 seconds. SQ subjectivity is a truism, but a truism by itself doesn't mean its useful for the truth that matters to us. In reality, the truth at the heart of it, the truth that matters to us is that something can sound better than something else.

 

SQ is subjective; this is a true statement. However this statement does not adequately encompass the bulk of interested listeners' experiences and preferences. Its true in a technical sense but also misleading when narrowed down to the experience of audiophiles.

 

Useful communications requires generalisations, averaging, context and culturally accepted standards.

 

For example, we can say that a $10 clock radio sounds worse than my $14k stereo system. The above statement is false from a technical sense, but also true in the context of the useful, normal sense. In the course of processing all of the implicit and assumed information present in that statement, the reader will agree with the statement as true.

 

I'm 100% neuro-typical. Everyone knows that something can sound better than something else. 

[KingRex]

Agreed there are definitely design and implementation as well as products that are "better" than others.  My point is a low quality DAC with integrated volume does not give a more high quality "better" sound than a high quality DAC feeding a high quality preamp.  It works the other way too.  A low quality preamp will not give as high quality a sound as a nice DAC with integrated volume.   Subjectivity is true when all products involved are of the same caliber.  

[KingRex]

I am a preamp person myself but a friend has the Dave and Blu.  He does not use a preamp. The DAC is his volume control.   He is blown away at how amazing the SQ is. 

[pkane2001]

13 hours ago, GUTB said:

 

This is why I asked to be real for 5 seconds. SQ subjectivity is a truism, but a truism by itself doesn't mean its useful for the truth that matters to us. In reality, the truth at the heart of it, the truth that matters to us is that something can sound better than something else.

 

SQ is subjective; this is a true statement. However this statement does not adequately encompass the bulk of interested listeners' experiences and preferences. Its true in a technical sense but also misleading when narrowed down to the experience of audiophiles.

 

Useful communications requires generalisations, averaging, context and culturally accepted standards.

 

For example, we can say that a $10 clock radio sounds worse than my $14k stereo system. The above statement is false from a technical sense, but also true in the context of the useful, normal sense. In the course of processing all of the implicit and assumed information present in that statement, the reader will agree with the statement as true.

 

I'm 100% neuro-typical. Everyone knows that something can sound better than something else. 

 

GUTB, I think I can actually agree with most of what you said here. I do think this is a first for me

[TubeLover]

On 2/27/2018 at 8:42 PM, KingRex said:

I am a preamp person myself but a friend has the Dave and Blu.  He does not use a preamp. The DAC is his volume control.   He is blown away at how amazing the SQ is. 

The elevated price range the Chord Dave falls into is the point where I have seen more implementations of a DAC directly to an amplifier that are successful in terms of sound quality. Seldom have I seen it happen with less than high end/expensive DAC's of $11-12k or more. 

 

JC

[Ajax]

7 hours ago, TubeLover said:

The elevated price range the Chord Dave falls into is the point where I have seen more implementations of a DAC directly to an amplifier that are successful in terms of sound quality. Seldom have I seen it happen with less than high end/expensive DAC's of $11-12k or more. 

 

JC

If you believe that then I suggest you investigate pro audio gear such as the Benchmark Media range. The HGC PRE / DAC at $2,200 or the older refurbished DAC1 HDR (which I own) for only $1,200 . Exceptional engineering with zero bling.

 

https://benchmarkmedia.com/products/benchmark-dac3-hgc-digital-to-analog-audio-converter

 

"Benchmark DAC1, DAC2, and DAC3 converters are designed to directly drive power amplifiers and speakers. Benchmark converters feature adjustable low-impedance passive attenuators at the XLR outputs that can be used to optimize the interface to the power amplifier (or powered monitor). This unique Benchmark feature optimizes the gain staging between the DAC and the power amplifier. Proper gain staging cannot be overemphasised. When audio stages are properly matched, each component in the audio chain is able to operate at its optimum signal level, and the system performance is significantly improved."

 

"Benchmark Media Systems’ DAC3 HGC is evidence that an engineering-focused company—one that seems to spend more time staring at instruments than testing its devices with their ears, and that cares more about transparency than it does about whether or not you like the sound their products make—can produce a product of astonishing fidelity and emotional expressiveness. Science works ... never underestimate a good geek."

- Jim Austin, Stereophile

 

"The Benchmark DAC3 offers extremely low levels of harmonic distortion from all its outputs. Intermodulation distortion was similarly vanishingly low. No power-supply–related spuriae can be seen, and the random noise floor lies below –160 dBFS! When the DAC3 decoded dithered 16-bit and 24-bit data representing a 1 kHz tone at -60 dBFS, the increase in bit depth dropped the noise floor by more than 30 dB, indicating that the Benchmark’s resolution is at least 21 bits. This as good as a DAC can currently get! All I can say is 'Wow!'" 

- John Atkinson, Stereophile

 

They also manufacture the excellent ABH2 power amp for around $3,000, which was awarded Stereophile's Class A recommended component category.

 

https://benchmarkmedia.com/products/benchmark-ahb2-power-amplifier

 

For a total of $5,000 the DAC3 and ABH2 combination is all you will ever need for a front end, just add speakers, large boxes and blue lights!

 

All the best,

 

Ajax

 

[barrows]

9 hours ago, TubeLover said:

The elevated price range the Chord Dave falls into is the point where I have seen more implementations of a DAC directly to an amplifier that are successful in terms of sound quality. Seldom have I seen it happen with less than high end/expensive DAC's of $11-12k or more. 

 

JC

Nonsense...  It does not require 5 figure DACs in order to employ a decent output stage capable of driving an amplifier directly.

[KingRex]

Why would a passive attenuator such as a step ladder resistor or autoformer not be as good as any Internal control from the DAC.  Is there any difference.  The DAC probably uses a semiconductor.  I don't know that that is any better or worse a way to drive the output.  

[KingRex]

1 hour ago, Ajax said:

If you believe that then I suggest you investigate pro audio gear such as the Benchmark Media range. The HGC PRE / DAC at $2,200 or the older refurbished DAC1 HDR (which I own) for only $1,200 . Exceptional engineering with zero bling.

 

https://benchmarkmedia.com/products/benchmark-dac3-hgc-digital-to-analog-audio-converter

 

"Benchmark DAC1, DAC2, and DAC3 converters are designed to directly drive power amplifiers and speakers. Benchmark converters feature adjustable low-impedance passive attenuators at the XLR outputs that can be used to optimize the interface to the power amplifier (or powered monitor). This unique Benchmark feature optimizes the gain staging between the DAC and the power amplifier. Proper gain staging cannot be overemphasised. When audio stages are properly matched, each component in the audio chain is able to operate at its optimum signal level, and the system performance is significantly improved."

 

"Benchmark Media Systems’ DAC3 HGC is evidence that an engineering-focused company—one that seems to spend more time staring at instruments than testing its devices with their ears, and that cares more about transparency than it does about whether or not you like the sound their products make—can produce a product of astonishing fidelity and emotional expressiveness. Science works ... never underestimate a good geek."

- Jim Austin, Stereophile

 

"The Benchmark DAC3 offers extremely low levels of harmonic distortion from all its outputs. Intermodulation distortion was similarly vanishingly low. No power-supply–related spuriae can be seen, and the random noise floor lies below –160 dBFS! When the DAC3 decoded dithered 16-bit and 24-bit data representing a 1 kHz tone at -60 dBFS, the increase in bit depth dropped the noise floor by more than 30 dB, indicating that the Benchmark’s resolution is at least 21 bits. This as good as a DAC can currently get! All I can say is 'Wow!'" 

- John Atkinson, Stereophile

 

They also manufacture the excellent ABH2 power amp for around $3,000, which was awarded Stereophile's Class A recommended component category.

 

https://benchmarkmedia.com/products/benchmark-ahb2-power-amplifier

 

For a total of $5,000 the DAC3 and ABH2 combination is all you will ever need for a front end, just add speakers, large boxes and blue lights!

 

All the best,

 

Ajax

 

Amps are a whole other can of worms.  I don't think any amount of talk is going to convince someone SS vs Tube has some sort of "better " sound.  I know a guy with $100,000k in SS who just got a set of tubes.  He's not getting rid of the SS.  He just wants choices as both bring a party to the table.  

[barrows]

25 minutes ago, KingRex said:

Why would a passive attenuator such as a step ladder resistor or autoformer not be as good as any Internal control from the DAC.  Is there any difference.  The DAC probably uses a semiconductor.  I don't know that that is any better or worse a way to drive the output.  

A passive attenuator adds resistance to the line.  Resistance is not without problems.  Resistance adds noise, and the more resistance you add, the more noise there is.  A digital volume control does not have this problem.  Additionally, if you think the DAC's output stage cannot drive the amplifier directly, it will have an even worse time driving the amplifier through a passive attenuator, as the passive adds even more impedance.  An active preamp will at least have an active buffer circuit after the (resistive) attenuator to achieve low output impedance, with a passive, it increases the output impedance as you attenuate the signal.

Transformer/autoformer based VC has different issues, it can actually reduce impedance as you add attenuation, but it adds much more distortion.

 

The problem here is that a lot of audiophiles seem to think that analog methods of reducing volume are without fault, but that is not the case.  Resistors add noise and distortion, transformers/autoformers add noise and distortion.  Digital volume controls do not share these (analog domain) faults.

[mansr]

6 minutes ago, barrows said:

The problem here is that a lot of audiophiles seem to think that analog methods of reducing volume are without fault, but that is not the case.  Resistors add noise and distortion, transformers/autoformers add noise and distortion.  Digital volume controls do not share these (analog domain) faults.

What about a variable-gain opamp stage?

[barrows]

2 minutes ago, mansr said:

What about a variable-gain opamp stage?

What about it?  The variable gain approach to preamp design is probably the best solution if you really need a preamp in the first place.  And variable gain circuits do not need to be Opamp based either, that is just one way.  Generally, variable gain circuits will also have one optimum point where distortion is lowest, so they are not necessarily "perfect", but if I had to have a preamp in my system, I would probably choose an Ayre KXR Twenty preamp with their variable gain transimpedance volume control (if I could afford one).

But for many people there is no need for this, if you have a single source (DAC) might as well just use the DAC to amp direct and avoid the issues of analog volume control altogether.  With an active preamp you are adding at the least the following additional components to the signal path: 2 additional connections (jacks and plugs), an additional interconnect, some type of source selector switch,  at least one gain stage of some type, and an attenuation circuit (unless variable gain is used).  Every one of these things is not entirely transparent and adds distortions.

[Panelhead]

On 2/25/2018 at 5:45 PM, Spacehound said:

fo

  This is why I like the digital attenuator function of the ESS dac chips. With a good output stage it just works. 

  Prefer the sound of AKM dac chips, but the digital volume controller seems better in ESS. 

  

[Ajax]

4 hours ago, KingRex said:

Amps are a whole other can of worms.  I don't think any amount of talk is going to convince someone SS vs Tube has some sort of "better " sound.  I know a guy with $100,000k in SS who just got a set of tubes.  He's not getting rid of the SS.  He just wants choices as both bring a party to the table.  

 

Hi KingRex,

 

My post wasn't about SS vs Tube amps but was in response to earlier posts arguing whether or not adding a pre amp would improve or denigrate the sound. Maybe I wasn't very clear, however, my intention was to demonstrate that Benchmark produced exceptional DACs specifically designed to be used as pre amps. As they also manufacture power amps they know exactly what is required to make the combination work flawlessly. i.e with a Benchmark DAC there is absolutely no need for a pre amp.

 

Since 2010 my office system has consisted of my laptop hooked up to a Benchmark HDR DAC 1 feeding pair of ADAM A7 active speakers. For a total of $3K ($2k used today) I have a very simple, inexpensive system with extraordinarily transparent sound, especially when fed high quality recordings such as those produced by the Society of Sound ( joint venture between Pater Gabriel and B&W speakers, which provides 24 beautifully recorded albums in 24/96 for an annual subscription of US$60).

 

http://www.bowers-wilkins.net/Society_of_Sound/Society_of_Sound/Music/Subscribe.html?c=set&_ga=2.91767903.412480989.1519935640-1333250593.1519935640

 

I therefore share the position of previous posters that adding a pre amp simply adds another totally unnecessary device into the chain, creating more issues such as additional cables and more distortion for absolutely no gain (pardon the pun).

 

All the best,

 

Ajax

 

 

 

[diecaster]

1 hour ago, Ajax said:

I therefore share the position of previous posters that adding a pre amp simply adds another totally unnecessary device into the chain, creating more issues such as additional cables and more distortion for absolutely no gain (pardon the pun).

 

You certainly are allowed your opinion. But so am I. My 40 years of experience in audio tells me your position, while logically sound, falls apart in the real world.

 

Even amp designers such as BHK agree that what should be true theory is not in practice. Well designed and implemented preamps, especially tube preamps, improve the listening experience.

[Ajax]

5 minutes ago, diecaster said:

 

You certainly are allowed your opinion. But so am I. My 40 years of experience in audio tells me your position, while logically sound, falls apart in the real world.

 

Even amp designers such as BHK agree that what should be true theory is not in practice. Well designed and implemented preamps, especially tube preamps, improve the listening experience.

Hi Diecaster,

 

Thanks for letting me have my opinion  , however,  think the point that you and KingRex are missing is that the Benchmark DACs ARE pre amps. From their web site:

 

DIRECT CONNECTIVITY TO POWER AMPLIFIERS

Benchmark DAC1, DAC2, and DAC3 converters are designed to directly drive power amplifiers and speakers. Benchmark converters feature adjustable low-impedance passive attenuators at the XLR outputs that can be used to optimize the interface to the power amplifier (or powered monitor). This unique Benchmark feature optimizes the gain staging between the DAC and the power amplifier. Proper gain staging cannot be overemphasised. When audio stages are properly matched, each component in the audio chain is able to operate at its optimum signal level, and the system performance is significantly improved.

SONICALLY-NEUTRAL STUDIO MONITORING

All Benchmark converters are designed for maximum transparency. This transparency is absolutely essential in the studio monitoring chain. For this reason, DAC3 converters are ideal for critical reference-quality professional systems. Unlike many competing products, the DAC3 is not designed to add "euphonic" coloration to the audio. Instead it is designed to be as uncolored and natural as possible.

 

I recommend to you the link regarding euphonic coloration in their second paragraph.

 

All the best,

 

Ajax

[mansr]

14 minutes ago, diecaster said:

You certainly are allowed your opinion. But so am I. My 40 years of experience in audio tells me your position, while logically sound, falls apart in the real world.

 

Even amp designers such as BHK agree that what should be true theory is not in practice. Well designed and implemented preamps, especially tube preamps, improve the listening experience.

So if you put a DAC and a preamp in the same box, you still need a separate preamp?

[esldude]

27 minutes ago, mansr said:

So if you put a DAC and a preamp in the same box, you still need a separate preamp?

Obviously you do.  How else could it be?  Audiophile experience and all.  

 

A preamp always improves things even when it doesn't.  And if one preamp is good how can two not be better still.  I really think they should be treated like USB de-evilizers.  That people should put multiple preamps in series.  I mean if one improves sound by buffering, then why would a second one not improve it more with more buffering.  Who knows the audiophile delights that accrue to someone smart enough to series 4 high quality preamps between DAC and amp.  Heck, it may sound practically analog!!!!!!

 

Think of it, one may have incredible soundstaging, and another terrific pace, and another tremendous space and airiness.  Combine them all and you need not compromise.  You can have it all.  Each pre contributing its unique strengths in a way that can only become synergistic without end.  

[diecaster]

26 minutes ago, Ajax said:

Thanks for letting me have my opinion  , however,  think the point that you and KingRex are missing is that the Benchmark DACs ARE pre amps.

 

20 minutes ago, mansr said:

So if you put a DAC and a preamp in the same box, you still need a separate preamp?

 

As someone pointed out earlier, let's not confuse a DAC output stage, even if it has an attenuator, with a preamp.

 

These attenuated output stages may or may not be active. For example, the attenuated output stage in my DAC, the PS Audio DirectStream, is passive and digital. The digital attenuator adds nor takes away anything from the analog signal put out by the DAC other than the level. This, according to theory, should be the perfect output with volume control to the amp. Yet, like other passive preamps in my experience, leave the music output lacking.

 

I have never heard a Benchmark DAC so I am unable to comment on what that output stage sounds like.

 

I have yet to find a setup where a passive preamp or a DAC passive attenuated output stage out performs an active preamp, especially a tube preamp.

[esldude]

1 minute ago, diecaster said:

 

 

As someone pointed out earlier, let's not confuse a DAC output stage, even if it has an attenuator, with a preamp.

 

These attenuated output stages may or may not be active. For example, the attenuated output stage in my DAC, the PS Audio DirectStream, is passive and digital. The digital attenuator adds nor takes away anything from the analog signal put out by the DAC other than the level. This, according to theory, should be the perfect output with volume control to the amp. Yet, like other passive preamps in my experience, leave the music output lacking.

 

I have never heard a Benchmark DAC so I am unable to comment on what that output stage sounds like.

 

I have yet to find a setup where a passive preamp or a DAC passive attenuated output stage out performs an active preamp, especially a tube preamp.

One of the best sounds I ever had was a Wadia 25 which included a sledgehammer output stage and digital volume control.  I paired it with an ADC and no analog preamp came close to matching it other than perhaps a Spectral.  

[diecaster]

4 minutes ago, esldude said:

Obviously you do.  How else could it be?  Audiophile experience and all.  

 

A preamp always improves things even when it doesn't.  And if one preamp is good how can two not be better still.  I really think they should be treated like USB de-evilizers.  That people should put multiple preamps in series.  I mean if one improves sound by buffering, then why would a second one not improve it more with more buffering.  Who knows the audiophile delights that accrue to someone smart enough to series 4 high quality preamps between DAC and amp.  Heck, it may sound practically analog!!!!!!

 

Think of it, one may have incredible soundstaging, and another terrific pace, and another tremendous space and airiness.  Combine them all and you need not compromise.  You can have it all.  Each pre contributing its unique strengths in a way that can only become synergistic without end.  

 

Go ahead a mock my opinion. It is shared by many people including amp designers. If the consensus was that passive preamps were the best way to go, the market for active preamps would have died long ago. Passive preamps have a much smaller share of the preamp market than active preamps. I guess everyone that uses active preamps is just stupid.....

[esldude]

1 minute ago, diecaster said:

 

Go ahead a mock my opinion. It is shared by many people including amp designers. If the consensus was that passive preamps were the best way to go, the market for active preamps would have died long ago. Passive preamps have a much smaller share of the preamp market than active preamps. I guess everyone that uses active preamps is just stupid.....

I've used all the combinations.  The best by far have been DACs with digital volume control directly feeding a power amp.  Not all DACs are built for this.  Those that are work just fine.  There is nothing an additional active analog preamp could contribute other than coloration or being so good it might as well not be there.  Tube pre's often have a sound of their own.  Many like it, but it isn't fidelity.  These days if you have a wimpy DAC that needs a pre, dump it, dump the pre, and get a better DAC.  

[barrows]

56 minutes ago, diecaster said:

 

You certainly are allowed your opinion. But so am I. My 40 years of experience in audio tells me your position, while logically sound, falls apart in the real world.

 

Even amp designers such as BHK agree that what should be true theory is not in practice. Well designed and implemented preamps, especially tube preamps, improve the listening experience.

If this were actually the case, then it would be even better to add two preamps in series, and so on...  It is nonsense.  Now, there are some specific cases where the DAC in question might not have enough current drive to drive a certain amplifier directly, but even in this case, there would be a lot of preamps which could not drive that amplifier correctly.  I will add that these cases are the exception rather than the rule these days.

 

I think it is probably not the best to get your opinion from companies/people who have a direct vested interest in selling preamps!

 

My current DAC has 4.7 ohms of output impedance, this is far less than say, a BHK preamp (which has much higher output impedance).  So my DAC is actually BETTER at driving an amplifiers input than the BHK preamp...

[Kimo]

6 minutes ago, esldude said:

I've used all the combinations.  The best by far have been DACs with digital volume control directly feeding a power amp.  Not all DACs are built for this.  Those that are work just fine.  There is nothing an additional active analog preamp could contribute other than coloration or being so good it might as well not be there.  Tube pre's often have a sound of their own.  Many like it, but it isn't fidelity.  These days if you have a wimpy DAC that needs a pre, dump it, dump the pre, and get a better DAC.  

My dac doesn't even have a volume control, because, I believe, the designers think it would be a compromise.  There is a also tube at work for each channel.  Wimpy with no fidelity,  not sure what the guys at Aqua would think  Pretty sure they know their engineering, though.  

[diecaster]

You guys know who Nelson Pass is, don't ya?

 

Look here:

 

http://audiophilereview.com/amps/nelson-pass-interview.html

 

Specifically:

 

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".