Adding a pre amp

[firedog]

27 minutes ago, GUTB said:

So, to address the usual rounds of misinformation on this topic: pre-amps are required.

 

The output stage of a DAC is not a pre-amp. It will just take the small signal out of the D/A stage and generate a 1-4v for transmission down a cable. Most DS-type DACs will offer a digital volume control which is adjusting the signal down (attenuation) that is passed into the output stage. As we've discussed and analyzed in the past, digital attenuation is trash and should be avoided. Some DACs, notably the Myteks, have the option of using low-quality analog control (via chip) in addition to digital attenuation. The output stage still has to be good -- the preamp won't fix it -- but to realize the best sound you still need the preamp.

 

An active, discrete class A gain stage (triodes, FETs, etc) with serious voltage amplification and power supply capability is required for good sound. Every single experienced audiophile knows this. The less experienced have a perception that a line stage is just for volume control, and if it's just for volume control you don't need it if you can control volume digitally -- either through digital attenuation or via software before the DAC.

 

The noise question. Preamps deal with small signals, and they have a higher noise floor than DACs and often times more than power amps. Don't worry about the noise floor, worry about the quality of your sound. If you want rich harmonic textures, full bass, a good soundstage and dynamics, you want a preamp. If you're a non-audiophile who doesn't place a high value on sound quality you may be fine without one.

As usual, broad generalizations - presented as "TRUTH" -about what every "experienced audiophile" knows - except for all of those that don't agree and don't think the generalizations make sense, either sonically, or as a matter of fact. 

[firedog]

3 minutes ago, barrows said:

Additionally, digital attenuation, as long as it is used within its capabilities (without using too much attenuation), is transparent, whereas analog attenuation is not.

And I'd add that there are digital attenuation systems at very high bit depth (see http://www.totaldac.com/principles.htm for one example) have the ability to give you all the attenuation you need, without any signal degredation. 

 Here's what totaldac say about  their volume control:

Volume control:
I have made many different volume controls, including high end pots, relays, Shallco + stepper motor, LDR...
The best sound was with the digital volume control made inside the FPGA of the DAC d1, made with a 69bit resolution.
It was the only way not to "listen" to the volume control components.

 

But of course, all "experienced audiophiles" know that the digital attenuation in a totaldac (and similar devices) is "trash".

[barrows]

Even with a 32 bit digital volume control you have 8 bits of transparent attenuation for 24 bit source files.  8 bits of attenuation allows for -48 dB.  If you need more than -48 dB in your system you have very poor gain matching between amplifier and source and that gain mismatch should be addressed.

[sandyk]

49 minutes ago, barrows said:

The output stage of the DAC and the input stage of the amplifier do not ADD distortion as they are necessary.  By inserting an additional component (a preamplifier) between them one is then adding (unnecessary) distortion.

 

 You didn't address my concerns about using 2 transformers, one at the output of the DAC, and another at the input of the amplifier. My main concerns are phase changes and HF roll-off. Transformers are not distortion free either.

A good DAC should not need additional HF filtering, especially by using transformers at both ends.

I.M.E. wider bandwidth sounds better too .

BTW, my Class A Preamp has very close to 4 Zeroes in it's distortion figures. Neglecting the series 100 ohm resistors at the output, which sounds better with most interconnects of 1M or so, it's output impedance at 1KHZ is .002 ohms .

(calculated by an E.E. friend)

Unlike GUTBs recommendation, my preamp only has a gain of around 3.2  x to reduce the need for too much attenuation ,and the loss of more than necessary S/N

[GUTB]

Willful ignorance is phenomena that effects many people. For example, take people who deny anthropogenic global warming: of course they are aware of the fact that literally every significant research body related to the topic is in broad agreement; they simply chose to ignore that reality in order to hold a certain political position.

 

As it is with the subject of preamps. Every experienced audiophiles knows an active preamp stage improves sound, and of course the deniers know this well. The deniers know that the Internet, press and industry in general is covered with praises for the benifit of the preamp — they just choose to ignore it in order to hold a counter position. That’s called willful ignorance.

[Spacehound]

This is SO  easy.

 

If the DAC has a volume control it's:

DAC------->POWER AMP------->SPEAKERS

Any given DAC  (with a volume control) is going have an output stage near enough the same any give preamp. Each box adds a small amount of distortion, it can never  'improve' the signal it receives.

 

So unless you HAVE have some 'analogue'  inputs  adding a preamp just distorts it some more. If you don't accept that you aren't interested in high fidelity (equals 'good sound'). Take  your fancy equipment to the local dump and go  buy a fifty dollar ghetto blaster.

 

[Spacehound]

On ‎12‎/‎02‎/‎2018 at 8:42 PM, coot said:

tI highly recommend adding a pre. I did so acoupla months ago. It improved SQ by "fleshing out", providing a fuller, richer body over all.  You will like the improvement.

 

On ‎12‎/‎02‎/‎2018 at 8:42 PM, coot said:

I highly recommend adding a pre. I did so acoupla months ago. It improved SQ by "fleshing out", providing a fuller, richer body over all.  You will like the improvement.

"Fleshing out"  is distortion whether you like it or not. Fine, it's your money.

 

But  do you think it's a good  idea to suggest  to others that they deliberately distort their sound? You haven't even put any kind of  'qualification' in.

[sandyk]

36 minutes ago, Spacehound said:

Any given DAC  (with a volume control) is going have an output stage near enough the same any give preamp.

 

 That is simplistic bullshit !

A decent Preamp doesn't use just a couple of  generic cheap output I.C.s either.

 Many Preamps also use discrete circuitry, as my DIY Preamp does, and a high quality, wide bandwidth attenuator.

Data sheet for DACT audio attenuators.htm

[diecaster]

47 minutes ago, Spacehound said:

This is SO  easy.

 

If the DAC has a volume control it's:

DAC------->POWER AMP------->SPEAKERS

Any given DAC  (with a volume control) is going have an output stage near enough the same any give preamp. Each box adds a small amount of distortion, it can never  'improve' the signal it receives.

 

So unless you HAVE have some 'analogue'  inputs  adding a preamp just distorts it some more. If you don't accept that you aren't interested in high fidelity (equals 'good sound'). Take  your fancy equipment to the local dump and go  buy a fifty dollar ghetto blaster.

 

 

Sigh. 

 

I don’t care so much about the distortion my tube preamp may add to the signal. I do care about the sound quality I hear. My tube preamp increases the pleasure I get from listening to music. You can quote all the theory you want. The proof is in the listening!

[Spacehound]

1 hour ago, diecaster said:

 

Sigh. 

 

I don’t care so much about the distortion my tube preamp may add to the signal. I do care about the sound quality I hear. My tube preamp increases the pleasure I get from listening to music. You can quote all the theory you want. The proof is in the listening!

Good for you. But you are NOT seeking "sound quality", which is entirely objective, you are just buying what you personally prefer. Which is fine.

 

I have seriously thought about   buying both a tube preamp and a tube power amp.

 

But if I do that  it will be with   full awareness  that  it is not high fidelity  (=  sound quality)  that I am seeking. Which is why I have not done it.

[diecaster]

If the only path to “high fidelity” were less distortion, amps with the best specs would sound the best. There is more to great sound than spec sheets. 

[Summit]

There are difference between different DACs output and between different pre amps. Even with a Chord DAVE direct to HP he prefer the Wells Audio Headtrip Reference Headphone Amplifier.

 

https://audiobacon.net/2018/02/15/wells-audio-headtrip-reference-headphone-amplifier-15000-musical-indulgence/ 

[Kimo]

On 2/12/2018 at 2:50 PM, mustafakaiser said:

Hello guys.

 

At the moment I have a PS Audio Direct stream DAC with a JEFF ROWLAND 625S2 power amp and use SOTM set of 3. I am thinking to add the PS audio BKH pre amp. 

 

Can anyone shed some light on this?  

Cheers

Obviously, your path to sonic nirvana is much clearer after asking this question and reading the replies, but I will add one more piece of wisdom.  I suggest demoing the BKH preamp in your own system, and you tell us how it sounds.  Shouldn't be too tough to find a demo out there.  Of course, no matter what you find, fully one half of the posters will tell you that you are wrong, but that is okay.  You will have heard it for yourself.

[firedog]

3 hours ago, GUTB said:

As it is with the subject of preamps. Every experienced audiophiles knows an active preamp stage improves sound, and of course the deniers know this well. The deniers know that the Internet, press and industry in general is covered with praises for the benifit of the preamp — they just choose to ignore it in order to hold a counter position. That’s called willful ignorance.

The only willful ignorance here is yours. By definition, any statement you make saying "every" experienced audiophile "knows" is incorrect, or at the very least not verifiable. No one can argue with your opinion or taste. Please stop presenting your personal opinions as fact and truth. Do you not know the difference?

Have you not noticed there are well known designers and manufacturers, as well as "experienced" audiophiles who disagree? That doesn't make us deniers. Makes us people with a different opinion. Not everyone agrees on what the most accurate reproduction sounds like.

[Spacehound]

1 hour ago, diecaster said:

 

 

If the only path to “high fidelity” were less distortion, amps with the best specs would sound the best. There is more to great sound than spec sheets. 

There is a school of thought, of which I am a  member, that the more money you spend the more everything should sound the same. (Playing the  same  recording  of course )

 

You want what is possibly the best 'high fidelity' amp in the world? Try  the Cambridge Audio 851 power amp. It's only about 1,500 dollars. You probably won't like it, as it is totally 'characterless',  as a  good amp  should be. Play a different recording.

 

 

[Kimo]

37 minutes ago, Spacehound said:

There is a school of thought, of which I am a  member, that the more money you spend the more everything should sound the same. (Playing the  same  recording  of course )

 

You want what is possibly the best 'high fidelity' amp in the world? Try  the Cambridge Audio 851 power amp. It's only about 1,500 dollars. You probably won't like it, as it is totally 'characterless',  as a  good amp  should be. Play a different recording.

 

 

If almost every amp has a character, how do you know which one is characterless?  Your concept of character appears to be based on specs.  Nothing wrong with this approach, but loads will vary and character will follow, in some cases much more than others.

 

Your best shot at a characterless sound is going to come from active speakers.  I have heard a number of pro monitors and I certainly wouldn't say that they all sound alike, however. 

[Spacehound]

2 minutes ago, Kimo said:

If almost every amp has a character, how do you know which one is characterless?  Your concept of character appears to be based on specs.  Nothing wrong with this approach, but loads will vary and character will follow, in some cases much more than others.

 

Your best shot at a characterless sound is going to come from active speakers.  I have heard a number of pro monitors and I certainly wouldn't say that they all sound alike, however. 

Amps with 'character' impose it on everything they play.

This applies to everything, active speakers included.

 

If they don't sound alike some of them are 'broken'.  Maybe all of them are. A  true full specification  which is far more accurate than your own personal opinion ('red cars are better than blue ones') will tell you.  It's that easy. 

 

HiFi is simple engineering, not difficult, and well understood. No magic is involved. It's  just  a 'consumer durable', like a washing machine. 

[Kimo]

2 minutes ago, Spacehound said:

Amps with 'character' impose it on everything they play.

This applies to everything, active speakers included.

 

If they don't sound alike some of them are 'broken'.  Maybe all of them are. A  true full specification  which is far more accurate than your own personal opinion ('red cars are better than blue ones') will tell you.  It's that easy. 

 

HiFi is simple engineering, not difficult, and well understood. No magic is involved. It's  just  a 'consumer durable', like a washing machine. 

Apparently, you missed every point I made, and they weren't that obtuse.  You only wish to spew the tenants of your audio orthodoxy, so there is no point in talking about this any further.  

[Spacehound]

35 minutes ago, Kimo said:

Apparently, you missed every point I made, and they weren't that obtuse.  You only wish to spew the tenants of your audio orthodoxy, so there is no point in talking about this any further.  

I didn't miss a  word/point as there weren't many of either  to miss.  I just don't believe in magic. Nor  the claims of small companies with  correspondingly  small resources.

 

I just buy stuff I take  a fancy too, same as everyone else.  I didn't take a fancy to the  Cambridge 851.

 

Will this do?

Lenovo tower PC, unmodified----->dCS Rossini---->no preamp----->Naim NAP250DR------>Tannoy Kensingtons.

 

And you did ask me, after all, Orthodox things are orthodox because they work, I don't want an untested flying saucer that is claimed to operate by magic, I want  a Boeing 747.

[Kimo]

37 minutes ago, Spacehound said:

I didn't miss a  word/point as there weren't many of either  to miss.  I just don't believe in magic. Nor  the claims of small companies with  correspondingly  small resources.

 

I just buy stuff I take  a fancy too, same as everyone else.  I didn't take a fancy to the  Cambridge 851.

 

Will this do?

Lenovo tower PC, unmodified----->dCS Rossini---->no preamp----->Naim NAP250DR------>Tannoy Kensingtons.

 

And you did ask me, after all, Orthodox things are orthodox because they work, I don't want an untested flying saucer that is claimed to operate by magic, I want  a Boeing 747.

So, it really is a religion for you.  You preach one thing, but follow another.  You are still missing most of what I said, though.

 

You do get points for the Tannoys.  They really do some wonderful musical things to enhance listener fun.  Too bad the Germans are now dragging the company down to an ugly finish.

 

I must add that I bet your system would sound better with a matching Naim preamp...

[pkane2001]

5 hours ago, sandyk said:

 

 That is simplistic bullshit !

A decent Preamp doesn't use just a couple of  generic cheap output I.C.s either.

 Many Preamps also use discrete circuitry, as my DIY Preamp does, and a high quality, wide bandwidth attenuator.

Data sheet for DACT audio attenuators.htm

 

There is a school of thought that simpler is better. I subscribe to it. Unless you have a very good reason to do so, why would you put another component in the sound path, with more power supplies more cables and many additional electronic parts multiplying the chances to distort and add noise?

 

Personally, I’ve not yet found a preamp that is more transparent or cleaner sounding than no preamp. And I’ve tried, and I’m about to purchase yet another headphone amp just to try again. I’m somewhat hopeful but I’ll be sure to test it thoroughly and it’ll go back on sale if it isn’t completely transparent.

[barrows]

7 hours ago, sandyk said:

 You didn't address my concerns about using 2 transformers, one at the output of the DAC, and another at the input of the amplifier. My main concerns are phase changes and HF roll-off. Transformers are not distortion free either.

Because this is not concern here!  You are talking about something separate from the OP's question and it is off topic.  He is not adding transformers in his components, they are already there and at a minimum he needs his DAC and amp to play music.  The question is whether or not adding a preamp is a good idea, not whether transformer coupling is a good idea, that would be a different topic.

If you want to discuss the merits of transformer coupling in component design, that would be another thread. 

[barrows]

7 hours ago, GUTB said:

As it is with the subject of preamps. Every experienced audiophiles knows an active preamp stage improves sound, and of course the deniers know this well.

I do not appreciate your (obvious) assertions that I am basing my point of view on a lack of experience.  These assertions are insulting and mostly reveal something about your character, rather than anything about me.  When you attack the "experience" of those who do not believe in your point of view, you show the weakness of your point of view.

 

I am "experienced", with forty years as an audiophile and twenty years working in the industry.  I have both a high degree of technical understanding of this subject as well as direct experience of testing DACs with and without preamps in the system.

 

You do not appear to have a clear understanding of either DAC or Preamp design, as you suggest that there are fundamental differences in their output stages: this is not the case.  Preamp and DAC output stages are fundamentally the same thing: line level low output impedance drive circuits designed to drive a cable and a high impedance input stage.

 

My point of view is NOT that every DAC and amp combination should be used by direct connection, there are some combinations which may benefit from the insertion of a preamp.  It will depend on the design of each component.  But it is factually incorrect to suggest that every system needs a preamp between DAC and amplifier to achieve the best possible sound.

[Spacehound]

13 minutes ago, barrows said:

SandyKBecause this is not concern here!  You are talking about something separate from the OP's question and it is off topic.  He is not adding transformers in his components, they are already there and at a minimum he needs his DAC and amp to play music.  The question is whether or not adding a preamp is a good idea, not whether transformer coupling is a good idea, that would be a different topic.

If you want to discuss the merits of transformer coupling in component design, that would be another thread. 

Sandyk is doing this:

[mevdinc]

I've been listening to digital only for sometime now, and so far, I've managed to avoid having to put a preamp in my system. I find direct connection always gives better results.

I also happen to believe in 'best preamp is no preamp'. Provided, of course, that the DAC has a very good volume control. I had a Zodiac Gold DAC before, and now using Lindemann Musicbook DSD 20, both with very good analog volume controls.

I have also been using active speakers for over 20 years for similar reasons; no speaker cables, better matched amps and speakers etc. by the designer. ATC are well known for both driver and electronics design and implementation.

I know some friends who use preamps not to improve but change the sound a little to their liking; perhaps warmer, less analytical sound etc.

Of course, this subject is very subjective and everyone's experience is different.
IMHO, I believe that the biggest distortion comes from the mains and any improvements there gives better results than most other areas. For example, I clearly experienced huge SQ improvements using battery power with my Zodiac Gold DAC.