Who's right ?

Guy 13 · « **on:** 15 Jun 2010, 05:56 am »

Hi all.
They say that a pre-amp gives more dynamics to the system, right?
They (Also) say that the more direct the signal path is, the better, right ?
Then, if you add a pre-amp to the system, you have double the interconnects and the connections, right ?
Then, which is better ?
A pre-amp with all the signal degrading extra connections or no pre-amp ?
If your amplifier can gets enough voltage from the source, do you really need a pre-amp ?
Even good silver interconnects have connections that degrade the signal. Right ? (Anyway, that’s what they say !)
Anyone wants to share their comments with me and others…
Guy 13.

werd · « **Reply #1 on:** 15 Jun 2010, 06:29 am »

Quote from: Guy 13 on 15 Jun 2010, 05:56 am

Hi all.
They say that a pre-amp gives more dynamics to the system, right?
They (Also) say that the more direct the signal path is, the better, right ?
Then, if you add a pre-amp to the system, you have double the interconnects and the connections, right ?
Then, which is better ?
A pre-amp with all the signal degrading extra connections or no pre-amp ?
If your amplifier can gets enough voltage from the source, do you really need a pre-amp ?
Even good silver interconnects have connections that degrade the signal. Right ? (Anyway, that’s what they say !)
Anyone wants to share their comments with me and others…
Guy 13.

Preamps generally drive amps better than sources with volume controls. Pre amps have better quality volume controls. This to me is what a pre is all about, a good volume control and switching, and you don';t get that with just a source driven volume control.

werd · « **Reply #2 on:** 15 Jun 2010, 06:33 am »

Also, once you start building up or improving the volume control in the source you basically have preamp component in the same chassis as the source. This really isnt recommend.

Guy 13 · « **Reply #3 on:** 15 Jun 2010, 06:44 am »

Quote from: werd on 15 Jun 2010, 06:33 am

Also, once you start building up or improving the volume control in the source you basically have preamp component in the same chassis as the source. This really isnt recommend.

Hi.
I was not talking about a source with a volume control, but an integrated amplifier with a volume control.
You say the pre-amp is better than the source ? Should it be the source better or equal to the pre-amp and all the other components of the system as well ?
Also, you don't mention the possibility of the interconnect degrading the signal ?
Guy 13.

werd · « **Reply #4 on:** 15 Jun 2010, 06:52 am »

I am not sure what you are asking? If you have a intergrated amp why are you bring the question of a preamp into it?

Guy 13 · « **Reply #5 on:** 15 Jun 2010, 07:00 am »

Quote from: werd on 15 Jun 2010, 06:52 am

I am not sure what you are asking? If you have a intergrated amp why are you bring the question of a preamp into it?

Hi again,
yes you are right, now I realize that my concern about interconnects and pre-amplifier is irrelevant for an integrated amplifier.
Sorry about that, I guess I made a foul of myself, well won't be the first time, neither the last...
Guy 13

werd · « **Reply #6 on:** 15 Jun 2010, 07:50 am »

Quote from: Guy 13 on 15 Jun 2010, 07:00 am

Hi again,
yes you are right, now I realize that my concern about interconnects and pre-amplifier is irrelevant for an integrated amplifier.
Sorry about that, I guess I made a foul of myself, well won't be the first time, neither the last...
Guy 13

Lol, dont worry about it.....

Guy 13 · « **Reply #7 on:** 15 Jun 2010, 08:59 am »

Quote from: werd on 15 Jun 2010, 07:50 am

Lol, dont worry about it.....

Hi,
I am back...
Why go with pre-amp-power amp. combo, instead of integrated amp.?
Guy 13.
(I hope I am not starting to be a pain in the neck with all my stu... questions ?)

Niteshade · « **Reply #8 on:** 15 Jun 2010, 12:48 pm »

I like both integrated amps and power/preamp amp setups. Our integrated amps use a passive voltage divider circuit to control volume and it works very well.

The pro's of a passive setup: There is absolutely no noise induced into the signal path. As long as your source's voltage output is 1.5v or higher, this system works very well. The amp's input has to be sensitive as well.

Active preamps: My favorite is a nearly straight through design using triodes. Actives have the uncanny ability to bring out subtleties in music when properly mated with a good amplifier. Even though active preamps are in attenuation mode 80% of the time, a triode preamp still 'reaches in' and gathers information that is sometimes lost.

Note: Just like amps, preamps are tools and sometimes it is better to use a passive system for volume control. It all depends on the setup.

rollo · « **Reply #9 on:** 15 Jun 2010, 01:18 pm »

Passives seem to work best with SET amps with a low input sensitivity [ the lower the better] and sources with a 2V [ 3V or more perferred] or more output. Transformer based, Autoformers, Slagleformers or LED based can be a nice combo.
Saying that what an active introduces is weight, body and soul. What the passive has is better clarity and detail. System dependant , no question.
If done properly either can bring nirvana. What I would be curious to know which scheme would render less distortion through measurements. A outboard Pre with all the cables connectors and such as oppossed to Nightshades suggestion.

charles

werd · « **Reply #10 on:** 15 Jun 2010, 03:15 pm »

There is really no particular advantage unless you want to get into big power. Just by nature of the size these two units are usually split.

If you use a passive preamp the source has to be able to drive the cables, input of the pre, all the circuitry, and the output of the pre and the input of the power amp. So you need a good source with good output drive to do that to have a musical signal.

Ericus Rex · « **Reply #11 on:** 15 Jun 2010, 04:10 pm »

Preamps can be more susceptible to trannie noise too. Theoretically, a separate pre with an external power supply MAY be a little more quite than an integrated. Not completely sure I buy my own argument though.

Larkston Zinaspic · « **Reply #12 on:** 15 Jun 2010, 04:12 pm »

If the designer of the preamp line stage has done his homework, that preamp will sound better than any passive made. Passives cannot control the interconnect cable and that is one thing that a good line section **can** do (although not all preamp designers realize that what I just said is possible, so you will see a lot of variance as a result)....

It is the interaction between the cable, the source resistance (which is a combination of the passive control and the actual source, including the cable from the source to the passive) and the input impedance of the amp that creates the bass/dynamic filter that many passives are guilty of being. The only way around it is to use really low impedances, something that most sources cannot handle.

So in effect passive controls are a form of tone control. The fact that they can sound better then some actives is simply the measure of how bad those actives really are. The only way I have found to make a passive work is to eliminate the cable between the control and the amp, IOW put the control **in** the amp. This eliminates convenience but then the control works.

--Ralph Karsten

FullRangeMan · « **Reply #13 on:** 15 Jun 2010, 04:33 pm »

Pre-amps are a necessary evil. I would prefer a player driving direct the power amp or a integrated amp like Bryston B100 if it was a monoblock(integrated monobloc).
In the early 90 NAD had a CD player with 5V output very praised in HiFi-Choice UK magazine to drive Krell power amps.
An 5V-10V output source is my personal preference, good preamps are very expensives and add a new chain in the system.
Regards

FullRangeMan · « **Reply #14 on:** 15 Jun 2010, 04:54 pm »

Please look this beautiful image below, it is a SCD-1 test, mod by Richard Kern at :
http://www.positive-feedback.com/Issue1/images/kern_bench02_openSCD1_web.jpg&imgrefurl=http://www.positive-feedback.com/Issue1/draudiocom.htm&usg=__vQme3qiPpz6wMuE50M_5ptCwR-c=&h=384&w=288&sz=33&hl=pt-BR&start=6&um=1&itbs=1&tbnid=zDe1WEQ0SVJ1CM:&tbnh=123&tbnw=92&prev=/images%3Fq%3Dpositive%2Bfeedback%2Bscd-1%2Bmod%26um%3D1%26hl%3Dpt-BR%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:pt-BR:official%26tbs%3Disch:1
Mr.Kern system is a no pre-amp, a SCD-1 driving direct a AR-VT100 and to a Avalon Arcus speaker(low SPL 86dB, 5 ohms) Good example of no pre-amp system

konut · « **Reply #15 on:** 15 Jun 2010, 08:36 pm »

As evidenced by the replies thus far, passive attenuation is fraught with pitfalls and is more particular than active pre-amps. More attention must be paid to input and output sensitivities and impedance's, and cabling resistance, inductance, and capacitance. This is why it is not more popular. A thorough understanding of these issues is almost mandatory if one is to put together a satisfying passive setup. If you can live with the limitations of the number of sources, and other peculiarities of passive setups, you'd be rewarded with a system capable of more articulation and resolution. The so called "lifting of the veil" of active systems the OP referred to in the 1st post.

FullRangeMan · « **Reply #16 on:** 15 Jun 2010, 09:48 pm »

Quote from: konut on 15 Jun 2010, 08:36 pm

As evidenced by the replies thus far, passive attenuation is fraught with pitfalls and is more particular than active pre-amps. More attention must be paid to input and output sensitivities and impedance's, and cabling resistance, inductance, and capacitance. This is why it is not more popular. A thorough understanding of these issues is almost mandatory if one is to put together a satisfying passive setup. If you can live with the limitations of the number of sources, and other peculiarities of passive setups, you'd be rewarded with a system capable of more articulation and resolution. The so called "lifting of the veil" of active systems the OP referred to in the 1st post.

Good post, I agree. I like this part: More attention must be paid to input and output sensitivities and impedance's, and cabling resistance, inductance, and capacitance. This is why it is not more popular.
Someone have a any tip, or a practical info about it?? Looks a interesting new ground, with great rewards in sound quality for less money...

bummrush · « **Reply #17 on:** 15 Jun 2010, 10:21 pm »

I have a Coda pre amp.and to tell the truth i can add gain in one db steps if i want to,never felt the need to,but when its at unity gain,am i essentially using it as a passive?

Niteshade · « **Reply #18 on:** 15 Jun 2010, 10:50 pm »

A passive preamp is one that does not have anything in it which can amplify. Passives are unity gain devices. Perhaps calling it an attenuator is more suitable.

You can have a unity gain active 'preamp'. They're most commonly called buffers because they can provide extra current to drive sources, but will not add any gain to the system.

FullRangeMan · « **Reply #19 on:** 15 Jun 2010, 11:16 pm »

Quote from: Niteshade on 15 Jun 2010, 10:50 pm

A passive preamp is one that does not have anything in it which can amplify. Passives are unity gain devices. Perhaps calling it an attenuator is more suitable.

You can have a unity gain active 'preamp'. They're most commonly called buffers because they can provide extra current to drive sources, but will not add any gain to the system.

At least it add some current. Wonder what is the audible sound flavor a Tube Buffer Pre-amp add to the music??
Regards, Gustavo