How important are preamps (comparatively speaking)

[Paul R]

Whether or not you hear a difference between your receivers preamp section and a dedicated preamp depends on the dedicated preamp. I know that I can hear differences between preamps in my system, but it depends on the rest of your system of course, and how much importance you place on sonic attributes such as soundstage, imaging, etc. If you just want a volume knob, then what you have is fine.

 

Thanks so much for that - I suppose you feel that any equipment with a price tag under $10K has no soundstage, imaging, or other common elements of good sound? I of course, would quite dispute that.

 

By the way, hearing or not hearing a difference is the *only* measure here that has any relevance whatsoever. I would suggest you might reconsider your remark about volume knobs.

 

-Paul

[Mike Mcsweeney]

 

When more engineers start designing power amplifiers with far less gain to suit CD/Digital output levels, then the inevitable trade offs will be reduced. In a typical domestic listening requirement we often need as high as 30dB attenuation.

Alex

Just curious...the NAD amp I bought is rated at 225 watts/channel. If it doesn't have a volume knob, is it using all 225 watts all the time regardless of the volume from it's input? Am I wasting a lot of electricity if I only listen to it at a fraction of it's capability since there are no volume controls on it? Or will it be pulling less current based on the input signal??

[sandyk]

Digital solution

Now go audition and buy a pure active digital and DSP room optimising system.

You will like the sound at home, if you liked the sound in the store.

No surprises, sounds good in any room (as well as possible), perfect for a combined stereo / surround rig.

 

Make sure that you also try the DSP with demanding classical music such as Mahler's 9th , as well as high quality, high resolution material, as it can result in a marked loss of transparency with such material. Many DSP fanatics seem to believe that anything more than 16/44.1 is a waste of time !

[sandyk]

Just curious...the NAD amp I bought is rated at 225 watts/channel. If it doesn't have a volume knob, is it using all 225 watts all the time regardless of the volume from it's input? Am I wasting a lot of electricity if I only listen to it at a fraction of it's capability since there are no volume controls on it? Or will it be pulling less current based on the input signal??

 

Mike

I haven't checked out the specifications, but if it uses typical Class AB topology it will not waste power at lower listening levels. In a typical domestic situation, (not when SWMBO and the family aren't around) average listening power is likely to be only a couple of watts or less. That's why we may need to use as high as 30dB of attenuation, with some DACs sounding degraded if you use much more than 10dB of attenuation. Many recent DACS are far better in this regard though.

If the amplifier manufacturers got their acts together we wouldn't need to use such high levels of attenuation with digital dources. IIRC, Charles Hansen has an amplifier that has the best of both worlds with selectable gain.

 

Alex

[jimbones]

I use a Burson Conductor with a built in preamp and i have an SP8 dedicated preamp. The SP8 is better that the Burson when using as a preamp. I recommend a high quality preamp.

[Skeptic]

I would avoid a pre-amp if at all possible. While you are technically reducing the SNR of your system with digital volume attenuation, there are generally fewer drawbacks to that than adding a pre-amp to your system as long as the volume attenuation is being dithered correctly.

 

haha...if i haven't read some of your posts about $10K speakers, i would ask what you are talking about...but your budget is just a tad out of my reach (grin). Maybe if the world discovers what you have found to be true, that the technology will be mass produced and i can buy some of those digital speakers for $300 (wink)

Well they're down to about $1500 with the new 8320+GLM bundle or $2200 for a pair of 8330+GLM. (converted price from euros)

While that's nothing like $10,000 it's still very far from $300 though.

 

I do wonder just how much better something like the 8330 is going to be compared to say a pair of properly set up JBL LSR305's (probably the best speakers for $300?) especially if you run room correction software on your PC. You can get an inexpensive mic and use free software rather than having to buy Dirac/Acourate.

 

 

I do see the appeal of the all-digital Genelecs, where even the room correction is handled by the speaker, but they do seem very expensive for their specs.

The 8320 is in the realm of affordability for me but then it's probably going to be at least $4000 on top of that for a pair of DSP subwoofers (no price for the 7350 yet) since their frequency response only extends down to 55Hz.

And I still don't know how good their room correction is compared to something like Acourate.

[DigiPete]

Make sure that you also try the DSP with demanding classical music such as Mahler's 9th , as well as high quality, high resolution material, as it can result in a marked loss of transparency with such material.

 

As you should with any audiophile equipment, DSP or not.

 

 

Many DSP fanatics seem to believe that anything more than 16/44.1 is a waste of time !

 

That is new to me. Or old.

Are you sure this wasn't for DIY'ers 5 years ago

[k6davis]

What is this talk I hear of having a preamp vs not having a preamp? Doesn't everyone's system have something that functions as a preamp? I can't imagine a system without volume control at a minimum. So then it's a matter of the quality of the implementation of your "preamp".

 

I certainly have heard a bad preamp in my system. It was an old Rotel (good brand, I think something was wrong with it). At first I blamed the power amp, thinking the preamp couldn't have that much impact, but I was wrong.

 

Presently, I have a high quality, tube preamp in my Lampizator DAC with a single analog input (which I use for video sound) and their premium analog volume control. I've noticed that any sound that I run through the analog inputs greatly benefits from the excellent "preamp" in the DAC.

 

So I don't understand any debate about whether having a dedicated preamp is categorically better. I do understand arguments against digital volume control, but even there, I'd hope that DSP will soon evolve to the point were it becomes sonically transparent even at low listening levels.

[speavler]

I try to stay open-minded (a straightforward all digital system that Pete describes sounds intriguing), but once i was introduced to a tubed pre and power amp based system and the musicality that ensued (combined with DSP in the low-mid bass range), i'm pretty much hooked. my experiments with taking the pre out of the system resulted in nice smooth tonality, but also narrower and less defined soundstage. With my preamp, I can also drive 3 amps in 2 separate systems which was also important for my setup.

[Allan F]

Unfortunately, with few exceptions, those preamps tend to list in the $10K region and above.

That's where those into DIY have a marked advantage with both the analogue and digital areas.

It helps of course that you don't need to include your own labour costs.

 

True, Alex, but people like me would probably electrocute themselves if they went the DIY route. Fortunately, by buying selectively and, in many instances, on the used market, I can afford to enjoy the system I have.

[sandyk]

Quote Originally Posted by sandyk View Post

 

Many DSP fanatics seem to believe that anything more than 16/44.1 is a waste of time !

That is new to me. Or old.

Are you sure this wasn't for DIY'ers 5 years ago

 

Have a look at the more prominent names in the DSP section of the forum, and you will see quite a few members of the " bits are bits" brigade who also believe that there is no advantage to any more than RB CD, and that in many cases 320 MP3 is more than adequate, and that Class D amplification is every bit as good as the better Class A and Class AB amplifiers.

Many of those Class D amplifiers have to have a rolled off HF response in order to meet RF/EMI legislation requirements, which many DIY implementations are unable to meet. What type of amplification do Peter St. and Miska use in their systems? I would be surprised if Miska used Class D due to his never ending and worthwhile quest to obtain the widest possible bandwidth, combined with low distortion and high S/N ratios from his digital sources. A good 7kHz square wave response from a DAC would need to be followed by much wider bandwidth amplification stages , themselves with impeccable S/N ratio too in order to take better advantage of all his research. Perhaps Peter can chime in here, with what class of amplification he uses to mate with his exceptional Phasure NOS DACs ? What is the point of amplifiers/preamplifiers with a -3dB point a little over 50kHz with the most recent DSD and 24/192 recordings ? As for the majority of speakers, very few have a reasonably flat response to even 35kHz.

[phusis]

I agree wholeheartedly with Barry.

 

+1

[sandyk]

+1

 

Barry doesn't use DSP either. Barry goes to a great deal of trouble with his choice of microphone cables,interconnects and power cables at the recording stage, so why use additional DSP later and destroy those subtle but worthwhile gains ?

I am looking forward to hearing the latest 24/192 recording session from Barry that was done in a church, using those new cables. Even the "making of" video that is on line shows it's potential, despite the audio being limited to 187kilobits .aac audio.

[cjf]

I have used many different configurations in my system over the years. Sometimes I didn't use a dedicated PreAmp and instead just used the built-in analog volume control found on the DAC/Pre combo at the time which then drove my amps directly. I thought things sounded great and that there was zero need to have a dedicated PRE UNTIL I bought a "Good" dedicated PreAmp and compared the SQ differences between the two configurations.

 

Each and every time, having a "GOOD" PreAmp always sounded much better then not having one. Obviously the key word here is "Good"! There is no doubt that a shotty PreAmp will quickly ruin an otherwise excellent system but using a good one will just as quickly take your system to the next level.

 

As already mentioned by a few others though, be sure to bring your wallet if your seeking a "Good" Preamp that won't do more harm then good.

[Jabs1542]

Barry doesn't use DSP either. Barry goes to a great deal of trouble with his choice of microphone cables,interconnects and power cables at the recording stage, so why use additional DSP later and destroy those subtle but worthwhile gains ?

 

I think we have apples and oranges, my speakers use a DSP between the preamp and amps in order to provide room correction and balanced sound (this was done during the installation, I am 20-20k +/- 2 dB sitting in my listening chair in my house - no anechoic chamber required). Talented engineers like Barry go through painstaking details in order to ensure that they preserved the proper sound when recording, and I suspect his listening rig is just as accurate. But what about ours, with furniture and windows and such? DSP can play a huge role in that regard and DigiPete is pointing out a relatively reachable entry point into that market.

 

Dont get me wrong, I still enjoy the analog side of my rig - which gets us to preamps. The anal-retentive purity fanatics are going to crucify me for this statement but a preamp allows you to provide a "sound" for your system, much like buying speakers. My preamp adds bloom and 3 dimensionality to my system, something I like to hear in the music I listen to - regardless if that's proper. And if you think a preamp is tricky to design, check out phono-preamps.

 

Is a preamp more important for SQ? That depends on your amp, your chain is only as strong as your weakest link.

 

Mike McSweeney - Your NAD amp is a very good amplifier (I used to have a pair of 208's), back when I sold audio NAD was known as having "dynamic headroom" which meant extra grunt. Good find

 

JimBones - Nice job on the AR SP8, looks like a really good preamp that punches well above its weight class

[bluesman]

Just curious...the NAD amp I bought is rated at 225 watts/channel. If it doesn't have a volume knob, is it using all 225 watts all the time regardless of the volume from it's input? Am I wasting a lot of electricity if I only listen to it at a fraction of it's capability since there are no volume controls on it? Or will it be pulling less current based on the input signal??

The output of an amplifier is roughly proportional to the power at the input "(roughly" because no amp is perfectly linear). Most listening at normal levels drives a power amplifier to only a few RMS watts, with transient excursions well above that but so brief as to be....um.....transient.

 

The average output power of your NAD driven to any reasonable listening level in any reasonably normal room never gets above 10 watts into any speaker load above 2 ohms at any frequency. Even on the finale of the 1812 at 100 db 3 feet from your speakers (which is probably louder than most of us ever listen to anything anywhere except a rock concert), your NAD is putting out a fraction of its maximum rated power.

[sdolezalek]

Mike: If you think about a signal path that is Digital Source>>DAC>>PREAMP>>AMP>>Speakers, the preamp can really only have two functions a) volume control and b) switching between inputs. Given that many DACs now give you volume control, why would you add another piece of equipment into the signal path unless you needed it as a component switcher (as between your DAC, your turntable, your CD players, etc.)? You would need to be certain not only that the attenuation in your preamp was better than that in your DAC, but also that just the additional cabling and connectors didn't so degrade the sound that the quality of the attenuation no longer mattered.

 

I admit I'm making a BIG assumption here and that is that no piece of equipment can ever add anything to the sound, it can only modify or take away. I know some of you agree, but others here might strongly disagree.

 

Of course there is also the preamp/preprocessor route (which most of us using surround sound have in our systems). That tends to add a fair amount of digital decoding and processing into the pre/pro but it immediately also becomes your default DAC (the best have a high quality analog bypass route, but that just makes them a standard preamp for that bypass). Typically it would make no sense to feed a DAC into a pre/pro any other way because then you would be going digital>>analog>>digital>>processing (DSP)>>analog, in which case you might as well just skip the first DAC.

 

I, for one, would love to see a high quality multichannel DAC (like the Exasound e-28) also have broader switching and DSP capabilities (which would clearly make it much more expensive) and ideally be able to process both USB and HDMI inputs (yet more licensing expense and price increase), thereby turning it into a pre/pro with 8 (7.1) high quality DACs inside. Something like a Bryston SP-3 probably comes close, but I'm not sure it would equal the e-28 for playing multichannel DSD files from a computer source (anyone here know?).

 

Similarly, for those interested in DSP, it seems to me that you would want it to occur in your computer and upstream from your DAC, otherwise you are again re-going through an A/D and D/A process downstream that probably nullifies the benefits of your original DAC.

 

I'm not sure we are yet at the point where audio manufacturers have really rethought their equipment configurations to deal with all of this (particularly in multi-channel). The easiest way to avoid it is to stick to stereo and some (like DigiPete if I remember correctly) might prefer their signal path to be as simple as computer source directly feeding an active speaker that incorporates a digital crossover, an internal DAC and multiple internal amps (one for each driver) all housed in a single enclosure.

[Mike Mcsweeney]

The output of an amplifier is roughly proportional to the power at the input "(roughly" because no amp is perfectly linear). Most listening at normal levels drives a power amplifier to only a few RMS watts, with transient excursions well above that but so brief as to be....um.....transient.

 

The average output power of your NAD driven to any reasonable listening level in any reasonably normal room never gets above 10 watts into any speaker load above 2 ohms at any frequency. Even on the finale of the 1812 at 100 db 3 feet from your speakers (which is probably louder than most of us ever listen to anything anywhere except a rock concert), your NAD is putting out a fraction of its maximum rated power.

 

Cool..thanks to both of you...nice that we have engineers here (wink)!

[Mike Mcsweeney]

Mike: If you think about a signal path that is Digital Source>>DAC>>PREAMP>>AMP>>Speakers, the preamp can really only have two functions a) volume control and b) switching between inputs. Given that many DACs now give you volume control, why would you add another piece of equipment into the signal path unless you needed it as a component switcher (as between your DAC, your turntable, your CD players, etc.)? You would need to be certain not only that the attenuation in your preamp was better than that in your DAC, but also that just the additional cabling and connectors didn't so degrade the sound that the quality of the attenuation no longer mattered.

...............

I, for one, would love to see a high quality multichannel DAC (like the Exasound e-28) also have broader switching and DSP capabilities (which would clearly make it much more expensive) and ideally be able to process both USB and HDMI inputs (yet more licensing expense and price increase), thereby turning it into a pre/pro with 8 (7.1) high quality DACs inside. Something like a Bryston SP-3 probably comes close, but I'm not sure it would equal the e-28 for playing multichannel DSD files from a computer source (anyone here know?)..

 

Yes, for volume and input swtiching mostly. (I still like my vinyl too!)

 

In second paragraph above you are looking for a DAC with more switching and DSP capabilities....that almost sounds like today's current recievers (grin)....just a high end one.

 

Recievers I know have a bad name, but that is direction i am going. You can get good recievers with DSD and FLAC decoding and DLNA etc... To me i am not convinced that a cheap dac over PC usb is better SQ than streaming DSD to a receiver and let it do the decoding. You avoid pc issues (os, power supply, usb, dac power supply, etc...) by streaming. Onkyo has burr brown dacs and you can buy a used reciever and have your dac, network streamer, DLNA, USB, preamp, all in one $195 box, and then just use the preouts of it to a nice amp. At least this is route I am going to try next. I have tried many things already including dragonfly, low cost usb dac, Sony highend Dac, and i am not convinced the SQ has been any better than DLNA to an AVR DSD decoders....at least for the lower end budget usb dacs.

[Le Concombre Masqué]

Funny toy system you're bragging so proudly about...

. . . all the way.

 

 

Forget the DAC's, the pre amps, the tubes, the mono blocks and the passive X-overs.

These are all legacy products, signal degrading dinosaurs in the digital world.

 

 

 

I can not vote for a single one of your options.

Other or None at all I could give my vote.

[fmak]

Would you say preamps are more important, as important, less important than the amplifier for SOUND QUALITY?

 

colours sound, some more euphonic than others, and I am talking about Stereophile Class A ones including Pass,

Accuphase, Audio Research etc.

 

I now use a custom balanced Placette Audio and an older Carver lightstar balanced passive. The former is constant

10k impedance.

[One and a half]

For the Phonitor 2 headphone amp, the buffering to me gives better sound quality, from the preamp rather than DAC --> Phonitor 2 direct. On paper the DAC can drive direct, but subjectively it misses out.

[Le Concombre Masqué]

From Wikipedia : "The preamplifier provides voltage gain (e.g. from 10 millivolts to 1 volt) but no significant current gain. The power amplifier provides the higher current necessary to drive loudspeakers."

is this moot in the digital age ?

[bdiament]

In summary, I guess, if reading correctly...is that most believe that unless you have big budgets the lower end (sub $500) stuff really won't make much difference. No preamp is better than using a preamp, and if you use a preamp, the power supply will likely be the most relevant in SQ. Of course, certainly I will try many, since I am always buying and selling.

 

Hi Mike,

 

Speaking for myself alone, of course, I don't agree. Design, not price, is what makes the difference. (I'd much rather have an Outlaw receiver than many separate preamps/amps costing quite a bit more.)

 

No preamp will certainly remove all the problems created by most preamps but that would likely mean you only get to hear a single source (unless you switch connections to switch sources) and the volume is wide open, full up all the time. I think that would last a whole second or two before one found it not the best way to go about enjoying music. ;-}

 

Power supplies, as I said, are the heart of electronic components. Basically, we are listening to the AC power, modulated by the input signal.

Power supplies are important but they are not the whole design. Again, volume controls are where a great deal of the sonic damage is done.

(This last can be proven easily if you've got a recording that is low enough in level where it can be heard with the volume wide open. If you have such, try listening to it in a system where the source feeds the power amp, with no preamp (and volume control) in between. The differences in transparency can be stunning.)

 

They key, in my view, is not to get hung up on a single factor (price, power supply, volume control, etc.). Such an exclusionary path will lead *away* from the best possible results, not toward them. The signal, after all, must pass through the whole design within a component and through all of the components in the chain, before we hear it.

 

Best regards,

Barry

Soundkeeper Recordings

The Soundkeeper | Audio, Music, Recording, Playback

Barry Diament Audio

[sandyk]

From Wikipedia : "The preamplifier provides voltage gain (e.g. from 10 millivolts to 1 volt) but no significant current gain. The power amplifier provides the higher current necessary to drive loudspeakers."

is this moot in the digital age ?

 

A suitably designed discrete preamplifier can provide significant current gain. A Class A preamp/HA like mine with a 100mA bias, and many others, are capable of driving low impedance headphones. Replacing the series output resistor with a Zobel network would permit it's use as a low powered speaker driver. Some makes of headphone amplifiers can put out a couple of watts into low impedance headphones, in fact, enough power to destroy some headphones and damage your hearing too if you aren't careful.

Some commercial preamplifiers (and the occasional DAC) use output current buffers such as the BUF634 which (supposedly) makes them virtually impervious to SQ differences between interconnects.

If more DACs used decent output buffer stages, there would be less need for expensive preamps ?