[medium jim]

Hi roscoeiii, no!,the amplification will amplify the noise as well as the audio signal...

Have another guess 

Not so fast,  all tubes will have some microphonics, at the same time will still have a black sound floor.  It is when you have to over saturate a tube is when you begin to introduce noise.  Gain introduced in preamplification actually reduces noise.

Jim

[G Georgopoulos]

Not so fast,  all tubes will have some microphonics, at the same time will still have a black sound floor.  It is when you have to over saturate a tube is when you begin to introduce noise.  Gain introduced in preamplification actually reduces noise.

Jim

Hi,thanks for correcting me Jim...

[Freo-1]

There is some good data here.  This is a good topic for audiophiles to discuss and understand. 
Personally, with digital sources, the integrated amp seems like it could be the best solution.  For example, the Pass Labs INT-150 seems to provide a slightly superior performance compared to a separate preamp/power amp Pass Labs setup.  From a noise perspective, it certainly has the potential to be quieter.  Nelson Pass has written about how many systems have excessive gain in the preamp/power amp combo.

Frank makes some excellent equipment (including integrated amps).  Would like for him to weigh in on the advantages/disadvantages of an integrated vs. a separate preamp/power amp combo.

[doug s.]

The source will always be the most important component. The greatest preamp on the planet, active or passive, can't fix a mediocre source.

i disagree.  no one here is talking about using a mediocre source.  i will simply repeat what i said earlier in this thread, which explains why i disagree:

"give me a good active preamp, and it will make any quality source have life.  even tho i might prefer one particular source over the other.  w/o a quality preamp, all the sources will be lacking.  as sj david mentioned, before the sound ever escapes the speakers in your listening room, the signal has been thru a myriad of stages.  there's no way i'm gonna compromise the single-most important one - that which amplifies the fragile source signal..."

what "the greatest preamp on the planet" will do ls make your fave source sound better...   

imo, of course! 

doug s.

[FloridaBear]

I fail to understand how a preamp can provide more dynamics to a signal. If it is altering the sound in some way, that to me is a completely undesirable trait. If you have a competently-designed DAC that is capable of driving the input stage of an amplifier directly (and assuming 24 bits used for digital volume), what possible benefits can a preamp provide? It can only add noise and distortion, it can't take it away. Certainly if a DAC cannot provide enough voltage to obtain the required volume, a preamp would be required, but short of that, I fail to see any point at all.

I suppose all of you who expressed a preference for a preamp in the chain have done ABX testing?

[I know I'm going to ruffle some feathers here...it's meant to be thought-provoking]

[roscoeiii]

Hi roscoeiii, no!,the amplification will amplify the noise as well as the audio signal...

Have another guess 

I was talking about the tube amp's gain potentaily adding noise. Not noise that may be present from the signal coming into the amp.

When I had an Atma-sphere amp and very efficient speakers, I employed attenuators that Atma-sphere supplies to lower the gain. That nicely lowered my noise floor.

[roscoeiii]

I fail to understand how a preamp can provide more dynamics to a signal. If it is altering the sound in some way, that to me is a completely undesirable trait. If you have a competently-designed DAC that is capable of driving the input stage of an amplifier directly (and assuming 24 bits used for digital volume), what possible benefits can a preamp provide? It can only add noise and distortion, it can't take it away. Certainly if a DAC cannot provide enough voltage to obtain the required volume, a preamp would be required, but short of that, I fail to see any point at all.

I suppose all of you who expressed a preference for a preamp in the chain have done ABX testing?

[I know I'm going to ruffle some feathers here...it's meant to be thought-provoking]

See Frank's first post in this thread. In particular, I would attribute this to his point on current. But just a guess, as I have not

[doug s.]

"...If it is altering the sound in some way, that to me is a completely undesirable trait. If you have a competently-designed DAC that is capable of driving the input stage of an amplifier directly (and assuming 24 bits used for digital volume), what possible benefits can a preamp provide? It can only add noise and distortion, it can't take it away...."

a dbx 3bx will make a highly compressed recording sound much better - more dynamic.  still better than not having one, for those compressed recordings.  even if the sound is "altered".

if the "altering the sound" and "distortion" of a preamp is making the recording sound more like real music and less like a recording - which is all it is, after all - bring it on!!!   

i still cannot comprehend the "logic" that "more pure", etc., necessarily means better sound, when it comes to something as artificial as recorded music playback.  there are still far too many unknowns regarding what makes something sound "real"...  distortion figures of 0.0001% instead of "only" 0.09%, for example, does not mean the lower-distortion unit will sound better...

doug s.

[DustyC]

Preamps still rule, BUT, a little less gain might be nice. It seems like just a "little" turn of the volume knob and things get WAY too loud. Perhaps no gain in the line stage?  (a buffer perhaps, to drive cables and amps?)
My speakers are only 83db with 1 watt and it seems like no matter preamp I use I still have limited range of the volume control.

[roscoeiii]

 

Preamps still rule, BUT, a little less gain might be nice. It seems like just a "little" turn of the volume knob and things get WAY too loud. Perhaps no gain in the line stage?  (a buffer perhaps, to drive cables and amps?)
My speakers are only 83db with 1 watt and it seems like no matter preamp I use I still have limited range of the volume control.

What amp do you have? How much gain does it have?

[rockadanny]

... a little less gain might be nice ...

That is one of the reasons I purchased a Mapletree Audio pre - customizable gains built in for each channel.

[doug s.]

What amp do you have? How much gain does it have?

you beat me to it!     amps can be driven to full power typically anywhere from 0.5v to 2.5v...  more sensitive amps mean the preamp's gain needs to be reduced...

doug s.

[doug s.]

That is one of the reasons I purchased a Mapletree Audio pre - customizable gains built in for each channel.

and any decent tech should be able to reduce the gain of your preamp simply by adding or replacing a resister in each channel...

doug s.

[rockadanny]

and any decent tech should be able to reduce the gain of your preamp simply by adding or replacing a resister in each channel...

Nice to know. Never considered that. Thanks for the tip. 

[BobRex]

Preamps still rule, BUT, a little less gain might be nice. It seems like just a "little" turn of the volume knob and things get WAY too loud. Perhaps no gain in the line stage?  (a buffer perhaps, to drive cables and amps?)
My speakers are only 83db with 1 watt and it seems like no matter preamp I use I still have limited range of the volume control.

Actually, depending upon your amp, a lot less gain.  There are many SET amps that reach full output with 1 volt or less.  Given the output of a typical CD player / DAC or phono stage you will always be in attenuation mode.  At that point the gain is useless.  So do you operate your volume control below unity gain? 

It's all a case of balance, knowing what each stage contributes can help determine if line stage gain is really necessary. 

[doug s.]

other alternatives to reduce gain:
http://www.goldenjacks.com/
http://www.rothwellaudioproducts.co.uk/html/attenuators.html
http://www.parts-express.com/pe/showdetl.cfm?partnumber=266-244

or roll your own.  i built a pair of interconnects w/a 2-resistor attenuation circuit in 'em over 10 years ago, when i first got my art di/o dac, which outputted 7v (pro audio spec) before mods...
http://www.uneeda-audio.com/pads/

doug s.

[rollo]

  It comes down to matching the preamp with the amp. Gain wise that is. Some preamps IMO are to hot. If you are using a CDP with 2v r more output that as well impacts gain.
   Synergy and matching come with experience. Just throwing money at something without a knowledge of the outcome is futile. Most go laterally with no gain. It all comes down to balance and compatibility.
    So buy a AVA pre and amp and be done.


charles

[avahifi]

Actually we do have one passive preamplifier in production right now!

It is the front end of our Synergy Control Amplifier.

In this case we were able to achieve the necessary overall voltage gain by simply engineering a high gain version of our Synergy power amplifier circuits.  This is matched with a passive preamp secton with nearly identical functions as our Insight+ SL preamplifier but without the active gain stage.

Since the loads the passive section needs to drive are well known to us and the input and circuit capacitance is very low (very short runs) the effects of loading are eliminated.  The functions this configuration cannot support are Line Out circuits and a RIAA phono option.  We can't expect the passive section to drive external equipment so no line outputs, and there just is not room in the chassis for a phono section, it is full of heat sinks, audio and regulated power supply circuits, and a humongous power transformer.

The sonic quality is excellent and it makes 100W/Ch and drives our inefficient speakers (Salk HT3 and B&W 801) just fine.

The price is $1799, lots less than the equivalent separates and with great musicality and no "compression" at all.

Regards,

Frank Van Alstine

[trackball02]

I think I need line level attenuation for my system, probably due to my efficient Zu speakers. Whenever I use my Avastar pre with either Ultravalve or FET Valve 400r, I really can't turn my volume knob much more than 9-10 o'clock, without blasting my room with sound. Fine volume control can be difficult.

I assume that the attenuator with be attached with the RCA interconnects between the pre and the amp? Can anyone give me the approx. dB attenuation that I should use?

Thanks.

[medium jim]

My McIntosh MX-110 has gain controls to allow the user to adjust the gain from 0 to 20db.  I suspect via a series of resistors.  My speakers are 86db and with 10db of gain have no audible distortion, compression and has a very black sound floor. 

I had the Bottlehead pre in my 2nd system which consisted of a factory wired Dynaco ST-70 and Dynaco A150 speakers (similar to A25's and around 91db) and it also was dead silent. Note:  The Bottlehead now resides in my main system as it sounds better.

It is true that you can have too much gain, but it has already been pointed out that gain can be easily changed via a simple resistor or more, depending on the circuit.

If you can achieve aural nirvana with a truly passive pre, more power to you

Jim