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Is no preamp the best preamp of all?

As an experiment I hooked up my OPPO BDP-95 (which has a volume control) directly to my amp. I was very pleasantly surprised to hear a significant improvement in clarity and sound quality. Typically I have the analog outputs on the OPPO running through my preamp in Analog Direct. I have heard that the circuitry within preamps can cause cross-talk in the analog signal, deteriorating the quality of the signal. So, would having no preamp (and therefore no other circuits to interfere with the signal) be better than an expensive analog or digital preamp running in Analog Direct? I am not really interested in Room Correction or DSP of any kind. I was considering purchasing a Bel Canto PRe6 (which I've read is excellent for multichannel analog), but would it be better to just have the OPPO running directly to the power amp?
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daverz
487 posts
 
Well, let's say my analog volume is cranked up so that peaks are at 90dB above the threshold of hearing, 0 dB, on my dB meter. I can hear 90dB of signal above my threshold of hearing (for simplicity I'll ignore the high noise floor of the typical domestic listening room). Now I lower my analog volume so that peaks are at 60 dB. Details that were at 30 dB and under are now below my threshold of hearing. How is that not a "loss of resolution"?
atmasphere's avatar
atmasphere
12,038 posts
 
Daverz, it does not work that way. If you turn the volume down, and assuming that 0db is your 'floor', the quietest portions will still be at or above that floor. This is true of any volume control.
orpheus10
8,668 posts
 
I'm late to this one. They are all good before you marry them. In re to preamps, "I don't think so".
georgehifi's avatar
georgehifi
10,312 posts
 
08-26-11: Daverz
I'm aware that I'm losing information when I use digital attenuation, but how does this translate into what one hears that is different that what one hears when an analog volume is lowered. Saying that one "loses resolution" is not really telling me anything as I don't know how a "loss of resolution" sounds different from just a lower volume.
Daverz

Below around 75% on a digital volume control, you start to get what's called "bit striping" this sounds like the early 1st gen 14bit Marantz cdp's, sweet smooth but a loss of air and detail/dynamics compared to the harsher sounding 16bit Sony's of the same era. The lower you go with a digital volume the more bit striping happens, 12bit 10bit and so on.

Cheers George
daverz
487 posts
 
@Atmasphere

I don't follow. Why doesn't it work like that? I'm not trying to be obtuse, I just don't see what you're trying to get at. We agree that detail that was at 30dB before the volumen was turned down is at the very threshold of hearing afterwards, and that the detail that was between 0 and 30 dB is no longer audible, right?

@Georgelofi: Thanks for that subjective description of the effect. Do you mean "bit stripping"? Googling "bit striping" only gives me a bunch of pages on RAID. I'm aware that as you lower the digital volume you are losing some of the least significant bits.

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