Discussion in 'Preamps' started by Cspirou, Jul 26, 2016.
No they really don't. Resistor thermal noise will be a hell of a lot lower
Passives have the disadvantage of potential impedance mismatch. Resistor thermal noise is a non-issue.
And yeah - tranny volume controls. Good ones are made out of money.
ok but, there still is noise there isn't there? i think that was the point i was trying to put out. either way though there is a compromise somewhere as usual and nothing is perfect.
i know but, just the pot and the components themselves will have an affect some sort of way was what i was just saying. either way nothing is perfect i guess.
See here how bad it can get - http://www.daycounter.com/Calculators/Thermal-Noise-Calculator.phtml
Mods, please move this to the new 'preamp' subforum
I'm mentally dickering with the notion of DAC line out with no preamp into a pair of Genelecs, 8020c specifically. They have an 80dB input sensitivity control which is more than enough to throttle them to my general max listening limit. What I need volume control for then is mostly turning sound down so I can hear the kid, wife, phone etc. or for pretty narrow rage adjustment. I'm wondering how heinous it would really be to just do that bit digitally in JRiver and use one of the JRiver remote options: http://wiki.jriver.com/index.php/Remotes
[Edit] One of these might be pretty cool: https://www.amazon.com/Griffin-Technology-NA16029-Multimedia-Controller/dp/B003VWU2WA
My Powermate is just collecting dust, stupid gadget. I always have a mouse in hand, so it makes sense to map volume control to scroll wheel etc.
A lot of DAC chips can do volume control directly on the chip. Obviously this means you can't use SPDIF as you need USB to communicate with the DAC chip. The AK4490 chips that Schiit uses can do it but they haven't done the implementation. Audioquest Dragonfly DACs have the implementation. All this talk about stepped attenuators and other complicated schemes might be unnecessary and maybe we should just accept digital control.
Of course this doesn't work for vinyl or other analog sources. Also wouldn't work DACs that don't have on-chip volume control. Sure you could still lower the volume through software but it might result in a degradation in quality.
Just like any pots and resistors and extra connectors and cables "might" result in degradation. Instead of fancy expensive passive stuff, might just get some attenuators if needed and finetune 1-2 bits volume even from software. Here's some cheap XLR attenuators with proper line level impedances etc, got some myself from there (f**k Rothwell ):
Did you read the link I posted? It's not the same. Resistors and pots don't increase the noise floor like badly implemented digital volume does.
I think everyone knows how digital volume works, but theory and measurements are just that. Can you hear degradation from say 6-12dB digital attenuation? I don't. But my ears and gear are mine. Anyway, when there's a proper analog attenuation, one can usually listen at 100% anyway. I don't think anyone is suggesting using -40dB digital volume.
Also I think having attenuator directly in amp/speaker input etc is better than using a passive box with long cables going out. Khozmo didn't work for me at all that way. But that was active speakers, of course separate amp is usually near the preamp..
So related to the original topic of this thread, are there any caveats or gotchas to be aware of when using headphone amps as preamps? Because I tried hooking my Bimby/Lyr 2 stack up to my speaker amplifier (a Parasound one) in place of the AV receiver that normally drives it from its pre-outs, to see how it would sound, and the answer was... really bad. Super-thin, with a midrange that was almost missing.
If there were more variables to check, I'd be convinced that I must have done something wrong; but it's a straight-up pre-out to amp-in RCA connection, and I tried both high and low gain, and I'm not sure what else I could have checked. Headphones out of the Lyr still sounded great.
So I'm not sure if there's a variable I'm missing, or some type of interaction I wasn't expecting or what, but I was definitely taken aback by that.
weird. i would think the lyr2 would be fine driving the power amp and actually perform bit better than the av receiver. the bimby should have enough voltage to swing as well.. maybe it's connection issue or something. it shouldn't sound thin sounding or anything at all.
Check the gain setting on the back of the lyr2
I've been using a Jot with DAC as a preamp while I wait for my McIntosh C22 (2015 version). It works well, is simple to set up and operate, and drives my MC275/Harbeth setup to reasonable levels. But it can also sound harsh and "small" in terms of the soundstage it projects. These aren't criticisms -- it's an inexpensive all-in-one -- but the drop-off in overall S is noticeable, so much so that I find myself listening less to my speakers and more to various HPs, which the Jot drives beautifully.
I've actually been thinking of getting a ZDS to use as a pre-amp and head amp. Was going to integrate my desktop setup into the speaker setup, so I could play speakers during the day and headphones at night. So it would be PC > Gumby > ZDS > HD650 and/or amp >ELAC B6 or future speakers. Would also have a VPI Classic 2 going into it. Was actually curious if that sounded feasible or if that would be "too much" going on in the turntable setup. So it would be
Classic 2 > Phono (mani?)> ZDS doing pre/headphones > amp (Vidar?) > Speakers.
Currently am using an Onkyo TX-8020 receiver that has a phone input into ELAC B6 and I plan to upgrade those, but I snagged the deal on the Classic during Black Friday so that's eaten up my audio budget for a while. Maybe during tax break season....
The ZDS seems to be a bit much for a pair of Elacs, unless you get some of their high end stuff. IMO, the Schiit Jotunheim is ideal for your situation.
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