Do we still need pre-amps?

I guess if you've got things well matched electrically, say a tape deck with a volume/output control mating well with a pair of monoblocs, or a single stereo amp, you could get by, same with a digital volume control on a CDP.

I have a bunch of different sources, phonostage, SACD/CD player, CDP/recorder and I've had an external DAC that I've fiddled with, so a preamp with 4-5 inputs suits my needs.

Since my Sony SCD-1, my Alesis Masterlink 9600, my Sonic Frontiers Phono 1 SE don't have volume controls on them, I do need my Blue Circle 3.1 Galatea preamp.

Now, in my second system, my Nakamichi RX-505 tape deck and my Dynaco FM1 tuner have volume controls, so I could dispense with the Bottlehead Foreplay, but the Denon DCD-1600 DVD~Audio player does not, so I really need that preamp there, to be sure.

Chris

No, Only Food, Clothing and Shelter.....................nt, posted on June 21, 2012 at 17:28:31

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RE: Do we still need pre-amps?, posted on June 22, 2012 at 04:35:08
tmsorosk Audiophile Posts: 1407 Location: Sprucegrove Ab. Joined: October 31, 2010	A few years back I experimented with a Preamp free system, One negative was losing the vast input options . As far as sound, the preampless system was a quite a bit harsher and grainier sounding not to mention more fatiguing, good enough in some ways with a more direct sound but certainly smoothed out with the proper application of a good preamp.

RE: Do we still need pre-amps?, posted on June 22, 2012 at 05:54:57
knewton Audiophile Posts: 231 Location: Mid-Atlantic/Northeast Joined: May 18, 2010	What did you use to control volume? _ Ken Newton

RE: Do we still need pre-amps?, posted on June 22, 2012 at 07:42:39
antigrunge Audiophile Posts: 75 Location: London Joined: June 20, 2007	In a nutshell: digital sources in most cases need only an analogue attenuator but not a preamp; if you are into playing vinyl the answer depends on the phono stages electrical characteristics: usually passive attenuators work less well. Switching between sources doesn't need any electronics. Digital attenuation tends still to be a nono in high quality sound reproduction

Some do..., posted on June 22, 2012 at 10:58:33

mkuller
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...and some don't.

Depends on two things:

1. Number and types of sources and inputs needed.

2. Matching of impedence between source and amp.

I've been using my CD player (with digital volume control) connected directly to my tubed amps for over 10 years now with great results.

Lost code, posted on June 22, 2012 at 16:37:16

Sumflow
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>Matching of impedance between source and amp.<

Do you have to match impedance between source and amp with active speakers?

>I've been using my CD player (with digital volume control) <

Acting only on the digital stream of numbers, how can the digital volume control work, without removing bits of code (degrade the source) to reduce volume?
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RE: Lost code, posted on June 22, 2012 at 18:31:09
mkuller Audiophile Posts: 28804 Location: SF Bay Area Joined: April 22, 2003 Contributor Since: December 28, 2003	...of course you have to match the source with the impedence of the amp in active speakers. My digital volume control doesn't audibly lose information as long as it played above 75/99. It has internal switches to raise or lower the level so that can be accomplished.

RE: Lost code, posted on June 22, 2012 at 19:31:45

Sumflow
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mkuller > ...of course you have to match the source with the impedance of the amp in active speakers.

You mean when the manufacturer makes the speakers. Nothing a user has to worry about. Can't we send in any signal from any pre-amp?

mkuller > My digital volume control doesn't audibly lose information as long as it played above 75/99.

What do you think happens to it at lower volumes?

mkuller > It has internal switches to raise or lower the level so that can be accomplished.

If it lost some of the information how can internal switches replace what appears to be lost data?
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RE: Lost code, posted on June 22, 2012 at 21:04:49

mkuller
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>You mean when the manufacturer makes the speakers. Nothing a user has to worry about. Can't we send in any signal from any pre-amp?>

The manufacturer matches the amp to the speakers. You still have to match the source to the amp - that's what a preamp can help you do.

>If it lost some of the information how can internal switches replace what appears to be lost data?>

The volume control only begins to lose a bit of informatin below the 75 setting.

RE: Lost code, posted on June 23, 2012 at 00:29:46

Sumflow
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mkuller:> The volume control only begins to lose a bit of informatin below the 75 setting.

You said that, but I want to know how you think the data was consumed?

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Do me a favor please..., posted on June 23, 2012 at 01:44:40
Chris Garrett Bored Member Posts: 16062 Location: Miami, Florida Joined: October 9, 1999 Contributor Since: June 19, 2000	dial back the rhetoric a bit, OK? You're not off the the best of starts. Thanks, Chris

RE: Do we still need pre-amps?, posted on June 23, 2012 at 03:04:31
gshepardbuster Audiophile Posts: 18 Location: Illinois Joined: April 10, 2012	I love the idea of bipassing a preamp in a single source system. The only problem is every time I've tried it, 3-4 times now, well it didn't work out. I would describe it similar to what the "haters" of digital say. The music loses life and seems sterile, definetly not my flavor. "that there Clarks an RRRR VVVV....don't get too attached...we're taking it with us when leave next month..."

RE: Lost code, posted on June 23, 2012 at 03:56:55

Sumflow
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Why would it lose information below 75 and not above it?

Why would you want any degradation of sound?
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RE: Lost code, posted on June 23, 2012 at 08:58:25

mls-stl
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It appears you may have an incomplete understanding of how digital volume controls work, particularly when playing standard redbook CDs though a 24 bit DAC. There are 8 bits added to the 16 bit CD data, but they are all zeros. This allows a substantial degree of volume control with no loss of information.

It is also a mistake to think that analog volume controls lose no "information" when you reduce the volume. Our playback equipment (particularly if an analog source) and listening environments all have noise floors. If a recording has any dynamic range at all (often a big "if" these days), the bottom end of the dynamic range quickly moves toward the noise floor and is "lost" as far as your hearing is concerned.

Note that if, for background listening or whatever other reason, you've reduced the volume of the music from your "reference" level, you've already made a decision to lose or obscure some of the music.

I do not use a preamp, but have my digital playback source configured so that my reference listening sessions use the digital volume in the top end of its range. That works fine for me.

RE: Lost code, posted on June 23, 2012 at 16:41:37

Sumflow
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mls-stl:> This allows a substantial degree of volume control with no loss of information.

That's good to know

mls-stl:> Note that if, for background listening or whatever other reason, you've reduced the volume of the music from your "reference" level, you've already made a decision to lose or obscure some of the music.

Are you referring to data loss, or sensitivity to equal loudness contours. Because a great pre-amp can compensate to a large degree for lower volumes.

mls-stl:> my reference listening sessions use the digital volume in the top end of its range.

Does that mean that you are flat at your normal listening volume, only losing something when you drop the volume?
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RE: Lost code, posted on June 23, 2012 at 17:45:12

mls-stl
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>> Are you referring to data loss, or sensitivity to equal
>> loudness contours. Because a great pre-amp can compensate
>> to a large degree for lower volumes.

I was not referring to the Fletcher Munson curves regarding the loss of hearing sensitivity above and below the midrange. That's a separate issue.

To use an analog example, a good LP recording has perhaps a 70 dB dynamic range if you're lucky. A good concert hall or recording studio would probably have a background noise level of 20 dB or so. You'd probably be very lucky to get 30 dB in a home environment.

If you are listening to the record at a reference level that gives you 100 dB peaks, the lowest signal level on the record would be right at your room's noise floor.

If you decrease the volume to casual or background listening levels -- say 70 dB peaks -- you've now got the bottom 30 dB of your recording masked by your residual room noise.

I won't argue with you that preamps are capable of changing the sound quality of a source, but unless you're using a loudness contour button, the frequency balance and dynamics are not going to be substantially affected as you reduce volume. You've simply got low-level information that gets moved into the background noise.

Psycho-acoustics, not information theory, posted on June 23, 2012 at 18:21:53

Tony Lauck
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Every recording has an optimum volume at which it should be played. Playback at anything other than this volume will result in a loss of realism and/or musical impact. A 1 dB change in volume is just barely adequate for this purpose, and a 2 dB change is too coarse. It is not possible to fix matters by bass boost. If there is no volume setting where playback sounds natural, then there is probably something wrong with the recording or the playback system may be unsuited to the scale of music.

Generally, the optimum volume corresponds to the volume used to monitor the recording during the final stages of production. The actual sound pressure level will depend on the type of music and the style of recording (e.g. close or distant sonic perspective). Use whatever combination of digital and analog control works best for your system when playing your recordings. If you have a coarse analog volume control you may find it worthwhile to fine tune using a digital volume control. IMO it is desirable to have stepped volume control or some other repeatable means of control.

When listening to background music one can turn down the volume any convenient way. It doesn't matter exactly how things sound. Presumably there are other more important matters than music, otherwise why was the music turned down?

Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

RE: Lost code, posted on June 23, 2012 at 18:37:13

Sumflow
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mls-stl :> unless you're using a loudness contour button

I was thinking people used pre-amps to take advantage of the loudness contour button. But yes if listeners do not compensate for the way ears work, lower volumes will supply less information.
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RE: Psycho-acoustics, not information theory, posted on June 23, 2012 at 18:53:27

Sumflow
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I learn a lot from what you say Tony, but I may turn the volume down out of politeness, or so that they can hear me. The reason that I do not turn it off, is because at that moment there are not more important matters than hearing my music.

I was talking on the phone. As usual I had the music as loud as I could and still clearly hear the person on the phone. My dad said to turn the music down. I said "why, I can hear ok?" He said maybe they cannot hear me. That is why I turn the music down. It is the same as seeing a cop on the street, I immediately back off the gas, whether I am speeding or not.

The fact that for thirty years my pre-amp's loudness adjusted the music to the ears ability to hear at each volume, is just another reason that I never expected any degradation of sound.
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RE: Do we still need pre-amps?, posted on June 25, 2012 at 20:58:05

Theron D
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In my case No...

Oppo BD83 going through a Placette Passive Pre amp into some Dynaudio BM5a powered monitors sounds great! No pre amp necessary. I also use it to attenuate my phono channel which is a Nighthawk phono pre and that sounds excellent as well.

The input resistance for the Dyns are 47K (per dynaudio ) I measured DC resistance at 100K.

-Theron Day

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Do we still need pre-amps?

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