To Pre or not to Pre? Here is my take
But most sources use them whether we like it or not.Sorry Ralph, but I do many mods to hi-end later model dac/cdp's and most good ones are direct coupled. It's just mainly the ones that have tube output stages that are capacitor coupled. The majority of good s/s ones, are direct coupled. Cheers George |
This is why 99% of everything out there uses coupling caps.In tube equipment yes, but try to tell designers like Dan Agostino, John Curl, Jeff Rowland etc etc. that. They are firmly in the direct coupled camp, from go to whoa. I've seen many problems with pieces of even expensive equipment that is capacitor coupled, in that one the cap is not big enough in uF(microfarads), two they use poor quality caps, three sometimes they use electrolytic caps, even I've seen bi-polar electrolytics used. Still the best cap is no cap. Cheers George |
The issue is that the output impedance can vary with frequencyYes of course it can, especially if capacitor coupled. (best cap is no cap) This is why my system is direct coupled from dac convertor chips output pins all the way to the speakers, with dc servos at each stage taking care of any dc offset. Cheers George |
The source impedance is not always linear with frequency- quite often it is considerably higher at 20Hz than it is at 1000 Hz (look up the measurements on various CD playersThis is also just as true with just as many preamps outputs, not just sources, especially tube ones also some solid state ones. Today many sources have just as strong/drive (low output impedance) as most preamps have. (excluding sources with tube output stages). Cheers George |
uberwaltz Before you spend big bucks on a newer AR pre on a hope it will be better than what you have now, try this with the volume on the Esoteric full up or if it has the fixed output. For $49, and it’s refundable as well. http://schiit.com/products/sys Or the passive or tube one, also refundable http://schiit.com/products/saga. Or the balanced, passive tube active, or solid state active. http://schiit.com/products/freya Cheers George |
George, the perfect recording has not been made yet and probably won’t be made in our lifetimesI like to hear my best recordings as they come from the dac, and if the bad ones don't sound so good, so be it, at least I'm not colouring both. If no preamp works for you, great, but active preamps may work better for some others. In fact, I’m sure they can.Like I said before, some may like a certain colouration a preamp gives to their system. And that they all sound different. It's up to the owner/buyer of a preamp to get the one with the right colouration to address their problem. I myself like to address the problem directly and fix it, without the need to hunt for the right preamp to colour the problem. None sound like a straight piece of wire, otherwise all would sound the same as going direct. Cheers George |
and you can sometimes have a bad match. In a case like this, using a preamp may be a less colored option.In that OP’s statement you quoted. He did have a perfect impedance/drive match when he went direct, and he wasn’t "bit stripping" because he was at 80% of the digital domain VC. So it comes down to that he preferred the "colouration/distortion" of the active preamp that aided in fixing a system or room imbalance, and not because the preamp was more "accurate" to what was coming out of the source. Cheers George |
What does this tell me? Two things going on here, that need to be addressed. 1: You may have a system/room problem where the preamps sonic signature (colouration) is doing a cover job on, as the Esoteric direct into the Bat has a better impedance/drive than the LS2 has. 2: When you went direct, your Bat's input sensitivity is just 1.5v in for full power out, and your Esoteric is 2.2v out. This means your digital domain volume control in the Esoteric must have been turned down quite low. It's well known that digital volume controls "Bit Strip" the music (you lose resolution) when they are turned down below 75% of full. No matter what the manufacturers advertise. You would have been better off doing this comparison with the Esoteric full up and a cheap $49 Schiit Sys doing the volume in the analogue domain. http://schiit.com/products/sys Cheers George |
