he will need a phono stage to boost and correct the frequency response of the TT before the signal goes to the LS2 line stage. Phono cartridges do not output a strong enough signal to drive the line stage properly and there are also physical challenges inherent in record-making that required the audio signal to be modified before being transferred to vinyl. Those modifications have to be compensated for. Both of those things occur in a phono stage. Some pre-amps have a built-in phono stage, many modern ones do not. Those that do not are often called line stage pre-amps. Those that do are often called full-function pre-amps. The LS-2 is a Line Stage pre-amp. Signals from a CD or SACD or the analog signalk from a computer source can go directly to any input on a line stage. The signal from a TT needs to go to a phono stage first, If you want to learn the technical details, google RIAA equalization or phono stage equalization.
Total newbie question here about completing a system
Hello all: Forgive the novice nature of this, but I'm trying to help my son build out a system and I'm a bit lost. Here's what we have so far: Adcom GFA 5500 amp, Audio Research LS2 preamp, Klipsch RP-160M reference premiere bookshelf speakers (new), an old Yamaha turntable, plus a tuner and CD player that we're not certain we'll use. We seem to be missing an equalizer, correct? Also, I should note my son plans on using mostly digital (Pandora, etc.), plus some wax. Please advise on what we need to round this out. The digital feed needs to be converted, correct? Again, so sorry for the basic questions, but most of these components are inherited and I don't have enough understanding of putting this together. All wit and wisdom welcome.
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There are two ways to get a digital signal to your amplifier. The first is to use a computer. Computers have inbuilt Digital to Analogue Converters (DAC) but these are rarely any good. So you need to use their digital output, and that is almost always usb (and not optical or coaxial). Next you need an external DAC (or an amplifier with an inbuilt DAC, as more and more now do). Such external usb DACs exist at many price levels, from the pretty good and dirt cheap Behringer UCA 202 (still a lot better than the DAC in almost any computer), to the very good and very affordable ODAC, to the ultimate in a DAC like the Benchmark DAC3. The ODAC is good enough for an ambitious system. Another way (instead of using a computer) to get digital input is to use an external streamer like the Apple Airport Express, the Sonus Connect or the Google Chromecast Audio. These all have inbuilt DACs. Even the cheapest of these, the Chromecast Audio has a pretty good inbuilt DAC: http://archimago.blogspot.nl/2016/02/measurements-google-chromecast-audio.html I use it into a pretty revealing system with Quad electrostatic speakers, and the sound quality is fine, as was to be expected from the excellent measurements. So why not start with the analogue output of the Chromecast, and see if you think it is good enough? However, if you want something better, these streamers all have optical digital outputs that can be used with a better external DAC. Since such a streamer is not necessarily the only digital source (think also of an (UHD Bluray) disc player or a television) it is worth using a DAC with multiple inputs and variable output such as the Pioneer U-05, the rather more expensive Benchmark DAC3 or, alternatively, a modern disc player like the Oppo UD 205 with its additional optical input for a streamer like the Chromecast Audio. But all these options are rather more expensive (and double up with the existing pre amp). If you are considering using the analogue output of the Chromecast Audio (as I would, at least initially - it is just some $35), realize that there is a setting that you have to decide on: high dynamic range, or not. Google says HDR is for ambitious gear, and ordinary is for basic gear such as table radios, but this is misleading. In reality the difference is not in the dynamic range, but in the output level. HDR is at the standard 2.0 Volt that is also used by CD players, and the ordinary setting is simply a lower voltage. If your amplifier's input sensitivity is on the high side (as is often the case) using the lower output level is actually beneficial (HDR would clip/distort the input). |
+1 swampwalker regarding need for a phonostage. If using a computer for streaming you will want to purchase a digital to analog converter (DAC). Another option is the Bluesound Node 2, which will serve to replace computer and DAC, or the Bluesound Vault 2 which adds CDs ripping capabilities. Do some research on phonostages (ohono preamplifiers), DACs, and music streamers. |
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