Is a preamp always necessary? [Archive] - Audio & Video Forums

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max11499439z
03-02-2009, 06:34 AM
My system:
Rotel 1070 CDP
McIntosh 2205 amp
Martin Logan Ascent speakers
Signal Cable Ultra cables

Note I do not have a preamp as I use the gains on the amp to control volume. The signal appears balnced. How much would a quality preamp improve on this?

Ajani
03-02-2009, 09:13 AM
It probably wouldn't..... it might change the sound (possibly more or maybe less to your liking)... Less items in the chain is generally better than more... so no point adding a preamp, unless you like the way it alters the sound of your setup....

IBSTORMIN
03-02-2009, 10:52 AM
Note I do not have a preamp as I use the gains on the amp to control volume. The signal appears balnced. How much would a quality preamp improve on this?

In addition to what Ajani said, you also add another interconnect into the flow which will alter the sound.

nightflier
03-02-2009, 02:50 PM
Why would you? Doesn't the Mac have enough inputs?

markw
03-02-2009, 02:58 PM
In addition to what Ajani said, you also add another interconnect into the flow which will alter the sound.Perhaps in a theoretical sense, but in the real world, this ain't happenin'.

02audionoob
03-02-2009, 04:43 PM
Some audiophiles believe the best preamp is no preamp. As long as you have a method of controlling volume and, if necessary, switching sources, you're good to go. I tried my Adcom setup without a preamp for a while, then with a passive controller, then decided I like the preamp best.

max11499439z
03-03-2009, 06:24 AM
I contacted a Rotel expert who reported that the outputs of the 1070 cdp are balanced to within 0.5 dB. Given this info and the fact that my system sounds great-amazing soundstage- as it is I'll hold off on a quality preamp for now.

basite
03-03-2009, 01:59 PM
maybe if the output impedence from the rotel, and the input impedence on the Mc don't match, it might be a good idea to get a preamp. But from your descreptions, it doesn't seem to be a problem :)

there are lots of people who use the gain controls on their amp, or a variable output on the source (not a fixed output, it's actually a very basic preamp built in to the source, making different output voltages possible)...

good for a basic system, problem when you decide to add a turntable or another source...

Keep them spinning,
Bert.

E-Stat
03-03-2009, 02:02 PM
How much would a quality preamp improve on this?
So long as gain and impedance is matched, I don't see how as long as we're talking sound quality not convenience. The trick is how to determine whether or not a given situation is a good candidate. I've been a big fan of passive-attenuator setups since I built my first attenuator box back in '02. I have a nice preamp, but use it only for playing vinyl where the additional gain and phono stage are needed.

The math on your situation works out well. What is needed is low impedance driving high impedance and short cabling. The Rotel has a low 100 ohm output driving 100k ohm input on the Mac. Your amp also has switchable input sensitivity as high as .75v (vs. lower 2.5 v). Great match. My main rig is similar with a 75 ohm / 4 volt CDP driving a 132k ohm amp through 10k attenuators. Some CDPs, however have an output more like 600 ohms and many modern SS amps have relatively low (10k) input impedance. Those situations start to get iffy - with the result being the top end gets rolled off. The same is true if long or high capacitance ICs are used.

Another concept I like is the DAC / line stage concept. In my vintage system, I use a Manley Sigma Delta DAC which has a built in tube line stage and analog gain controls. No input switching, but it can drive an amplifier directly. Pick your transport. Preamp not needed.

rw

IBSTORMIN
03-03-2009, 08:44 PM
Perhaps in a theoretical sense, but in the real world, this ain't happenin'.

???????????? I hear differences. Can't you?

E-Stat
03-04-2009, 06:37 AM
Perhaps in a theoretical sense, but in the real world, this ain't happenin'.
It doesn't in my case since I use very short, low cap cables between source and attenuators, but it can in a passive arrangement if one is not careful.

rw

IBSTORMIN
03-07-2009, 09:10 PM
It doesn't in my case since I use very short, low cap cables between source and attenuators, but it can in a passive arrangement if one is not careful.

rw
I've just got to ask. Are you guys comparing really expensive cables to other really expensive cables and that's why you can't hear a difference? I just don't understand the "careful" part. Cables I have heard sound different, they just do.

Feanor
03-08-2009, 04:26 AM
I've just got to ask. Are you guys comparing really expensive cables to other really expensive cables and that's why you can't hear a difference? I just don't understand the "careful" part. Cables I have heard sound different, they just do.

Among low-mid ranger cables my experience has been no significant differences. I'm talking $35 Blue Jeans Cable on one extreme to $150+ Kimber, QED, IXOS, Monster on the other.

Notice I'm not saying there IS no difference; notice I'm not saying that I absolutely can't hear a difference, just that I didn't notice any. The days are over when I will spend 2-3 hours of A-B'g to drive out tiny differences that I don't notice after a couple of hours on normal listening.

I acknowledge what some 'philes do not:

My mood and state of stress can significantly affect my impression of the sound;
I am biased to hear differences and prefer one component over another based non-sonic input. I don't entirely trust my ears. Granted I'm more inclined to trust them if what I hear is contrary to my expectations for a given component.

Ajani
03-08-2009, 06:01 AM
The days are over when I will spend 2-3 hours of A-B'g to drive out tiny differences that I don't notice after a couple of hours on normal listening.

:thumbsup:

That's a major part of why there is so much debate in audio.... Many audiophiles are willing to spend countless hours agonizing of minor sonic differences, and once they find them, they expect everyone to be convinced that these differences exist and are important.... A difference has to be noticeable with a simple A/B comparison, for me to consider it worth my time (and possibly money)... anything that takes hours just for me to be certain it exists, is too minor for my consideration...

As for cables: I've yet to hear a difference between freebies and inexpensive ($30 - $50) Audioquest & Monster Cables (unless the connectors on the freebie cables were really bad and caused the signal to kick out occasionally)... However, I stick with inexpensive Audioquest anyway (because they look cool and give me more peace of mind than freebies)...

E-Stat
03-08-2009, 06:12 AM
I've just got to ask. Are you guys comparing really expensive cables to other really expensive cables and that's why you can't hear a difference? I just don't understand the "careful" part. Cables I have heard sound different, they just do.
All I'm referring to here is having low capacitance. You can get that pretty inexpensively from sources like Blue Jeans cable. The LC-1 offers about 40 pf / meter.

Yes, I also have some more expensive JPS Labs stuff, too.

rw

markw
03-08-2009, 07:46 AM
???????????? I hear differences. Can't you?I'd say that the preamp n between those cables would have more of an effect, wouldn't you?

IBSTORMIN
03-08-2009, 06:55 PM
I'd say that the preamp n between those cables would have more of an effect, wouldn't you?

It depends on the cables and preamp. All I was saying, when you eliminate the pre-amp you also eliminate the need for one more interconnect. Your comment was that in the real world, the interconnect will not make a difference. I think the pre-amp and the interconnect can make a difference, more or less, depending on the type of each used. In theory, you could end up with the same sound using a high quality pre-amp and a cheap interconnect vs a lesser pre with a high quality interconnect. To have no change in the sound you would need high quality on both so he is better off without the pre-amp and money in his pocket. Of course he could always use the money to upgrade something else.........

IBSTORMIN
03-08-2009, 06:59 PM
All I'm referring to here is having low capacitance. You can get that pretty inexpensively from sources like Blue Jeans cable. The LC-1 offers about 40 pf / meter.rw

I have and like the LC-1. My DVD connects to my pre/pro with a DB-25 computer cable and sounds much better than the LC-1. I've found differences in the sound of different DB-25's too. The best sounding DB-25 I've found was a gold plated Hewlett Packard I bought at a Goodwill store for $1. So I will not be looking at expensive RCA interconnects with the equipment I currently have.

IBSTORMIN
03-08-2009, 07:11 PM
Among low-mid ranger cables my experience has been no significant differences. I'm talking $35 Blue Jeans Cable on one extreme to $150+ Kimber, QED, IXOS, Monster on the other.

Notice I'm not saying there IS no difference; notice I'm not saying that I absolutely can't hear a difference, just that I didn't notice any. The days are over when I will spend 2-3 hours of A-B'g to drive out tiny differences that I don't notice after a couple of hours on normal listening.

I acknowledge what some 'philes do not:

My mood and state of stress can significantly affect my impression of the sound;
I am biased to hear differences and prefer one component over another based non-sonic input. I don't entirely trust my ears. Granted I'm more inclined to trust them if what I hear is contrary to my expectations for a given component.

Agreed on the mood influencing. Agreed on the not taking hours comparing. I hear a difference comparing the BJC LC-1 to a Monster set at (don't remember series, their top a couple years ago) $125? The $35 BJC sounds better, heard it right off and it did not take much A-B'g to confirm it!!!

IBSTORMIN
03-08-2009, 07:22 PM
:thumbsup:

That's a major part of why there is so much debate in audio.... Many audiophiles are willing to spend countless hours agonizing of minor sonic differences, and once they find them, they expect everyone to be convinced that these differences exist and are important.... A difference has to be noticeable with a simple A/B comparison, for me to consider it worth my time (and possibly money)... anything that takes hours just for me to be certain it exists, is too minor for my consideration...

I TOTALLY AGREE!!!

IBSTORMIN
03-09-2009, 08:48 PM
My system:
Rotel 1070 CDP
McIntosh 2205 amp
Martin Logan Ascent speakers
Signal Cable Ultra cables

How do you like the Ascent? There is a local guy wanting to sell a pair for $1900 and I'm thinking about it. What can you tell me/what have you compared them to/switched out from?

max11499439z
03-10-2009, 10:42 AM
I have listened to B&W 703 speakers and the Ascent, and both are excellent, although the Ascent soundstage was more expansive and aesthetically superior. Bass extension similar for both, maybe an edge to the Ascent.

In the end, I chose the Ascent and have been extremely happy with their performance.