Any one who is blind to the fact and doesn’t believe that an active stage has noise, distortions ect, and any increase in gain of that active stage also increases any noise ect coming into it and within it’s self. Your better to raise the passive master and let more of the source signal through, than to lower it and to raise the gain of the active stage and keep the master low, as your throwing away the sources signal level only to make it up again with added gain of the active stage. I’m over saying it, and so is Nelson Quote NP: " Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up. And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp." Cheers George |
In summary: the OP removes his
Audible Illusions L1 preamp and drives his amplifier directly from his Oppo BD105. He thinks it sounds better. He asks: how much money do I need to spend to get a preamp that will sound better than this straight wire?
Answers (boiled down from this long and contentious thread):
1. It is not possible to spend enough money to improve the sound beyond what you hear with no preamp. Preamps add some noise and distortion. Wires don't. Sell your preamp and take a trip to Paris in the spring.
2. Some people like the euphonious distortion that some electronic components add to the signal. Often, the more money they spend on the component, the better they think it sounds. Spend about as much as you might budget for a new car on your new preamp, and you are likely to feel it sounds better than no preamp.
3. Although not presented as a possibility by the OP, a class of responses caution against adding a passive preamp in place of no preamp. These arguments talk about the impedance of the upstream and downstream devices and should fall into the category of why don't you try it and see what you think? Sadly, this advice seems instead to be: don't ever try this, it's theoretically unsound and your house might burn down.
Did I miss anything? |
Several prior threads here have addressed the major points of contention in this thread. One of them was this one: https://forum.audiogon.com/discussions/is-no-preamp-really-better-that-a-good-preamp? On page 3 of that thread I quoted some insights PS Audio’s Paul McGowan provided on that subject, and added some further thoughts of my own. I think those posts are worth repeating here: Almarg 10-4-2015
Interestingly, Paul McGowan, designer/manufacturer of the OP’s DAC, has just in the past few days been posting thoughts on the very question being discussed here in his blog at the PS Audio site. Some excerpts:
My adamant stance against inserting a preamp between a high quality DAC like DirectStream and the power amplifier should be no surprise to readers of this blog. As well, my subsequent turn around embracing the exact opposite should lift no eyebrows either. But why would inserting an extra piece of gear in the signal path sound better than a more direct approach? How could this make sense? ....
... For a long time I found that DACs with no-loss digital volume controls sounded better, cleaner, livelier, directly into the power amplifier. Whenever I inserted a preamplifier it sounded different–but not better. That is until I tried a different preamp. My first revelation happened with the stunning Aesthetix Calypso preamplifier. Placed between the DAC and power amplifier, music took on a life and dimensionality that took all of 10 seconds to find it was better–not just different....
... I had written earlier that it’s likely I am asking the wrong question. How could adding more to the signal path make the system sound better, not worse? It turns out the logic is correct: it cannot. So why does sometimes adding a preamp between a DAC and power amp help the system sound better?
Because it’s helping the DAC not sound worse. And that bit of logic is key to answering the question....
... Imagine we have a DAC with an identical output circuit to that of a preamplifier. How would this respond driving a power amplifier directly? Theoretically as well as a preamp and, perhaps, better because we haven’t another component in the mix. But here’s something you may not have thought about.
DACs are significantly more sensitive to power supply changes and noises than preamps. When an output stage struggles to drive a complex load, it is the power supply feeding its output stage that sees these changes. If this occurs in a preamp, it has little effect. But that same situation, when applied to a DAC, has very different results indeed. Small changes in power supplies have big impacts on sound quality–especially jitter.
So this is one reason, and there are more, some preamps can help a DAC.
Makes sense to me. So if Paul McGowan can do an about face on this issue, at least under some circumstances, I guess I can too :-) But I believe that in general the opinion I expressed in my first post in this thread still stands:
09-23-15: Almarg
The burden of proof should always be on adding anything to the signal path that is not an obvious necessity. In this specific case a preamp is not an obvious necessity, and per George’s analysis (with which I agree) the odds appear to be in favor of that burden not being met. However, as others have indicated the only way to know for sure is to try it.
Almarg 10-4-2015
... I suppose an additional possibility is that high frequency noise resulting from a ground loop condition between a DAC and a power amp could enter the DAC’s output circuit and find its way via grounds, power supplies, stray capacitances, etc. to the D/A converter device and/or its surrounding circuitry, causing an increase in jitter.
Of course, depending on the specific designs introducing a preamp between the DAC and the power amp could either resolve such a problem, introduce such a problem, or make no difference.
Almarg 10-6-2015
An excerpt from today’s blog post by Mr. McGowan on the same subject:
Our newest DAC, DirectStream, ... has zero loss at any level setting–a major achievement. So, how could a control with zero resolution be suspect? That’s a question I have been mulling on for some time now.
One piece of the puzzle seems obvious. We know that tiny changes in the way internal FPGA process are organized make significant differences in sound. Even changes to the display affect sound quality. It’s a delicate process when jitter, power supply and the tiniest of changes can be heard and must be attended to. What’s to stop us from believing that different level settings have different sound qualities–despite the fact there are no measurable resolution losses?
Were it to be found true much would be explained. For instance, we know not all preamps sound better than DACs directly into power amps. In fact, most don’t. This observation lends credibility to the explanation that it is not preamps that make DACs sound better, rather, it is preamps helping DACs not sound worse. This theory can only be true if the preamp is of sufficient quality to add less degradation than using the DAC’s volume control. That all kind of makes sense.
But, just because something makes sense, doesn’t mean it’s true. How do we make this determination to see if this theory holds water? Regards, -- Al |
Paul McGowan: My adamant stance against inserting a preamp between a high quality DAC like DirectStream and the power amplifier should be no surprise to readers of this blog. As well, my subsequent turn around embracing the exact opposite should lift no eyebrows either. But why would inserting an extra piece of gear in the signal path sound better than a more direct approach? How could this make sense? ....
Almarg: Makes sense to me. So if Paul McGowan can do an about face on this issue, at least under some circumstances, I guess I can too :-) But I believe that in general the opinion I expressed in my first post in this thread still stands:
Almarg: The burden of proof should always be on adding anything to the signal path that is not an obvious necessity. In this specific case a preamp is not an obvious necessity, and per George’s analysis (with which I agree) the odds appear to be in favor of that burden not being met. However, as others have indicated the only way to know for sure is to try it.
Good luck. Regards,
-- Al
Al, a smiggen of imagination here, did you know he made this about face Oct 2015, during the development period of his next to be released product in 2016 the BHK active preamps, hmmmmmmm? Cheers George |
As far as Oppo direct to Amp, I am told by someone who should know that the digital volume control on the Oppo produces a signal that is not lossless. I tried Oppo to amp a couple years ago and it sounded better with the preamp (Classe SSP-800) in the circuit.
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