CD direct to Amp/Current TAS issue ?


In the current issue of the Absolute Sound, the reviewers are asked to put together reccomended systems within certain price ranges (this is a great issue, BTW). One of the reccomended systems has an amp and CD player, but no preamp. The reviewer says something to the effect of "Because the CD player has an analog output level control, a preamp is not required and that money can be put into other areas of the system." Does this work with any CD player/Amp combination as long as the CD has an output level control? Is there any risk of damaging the amp or speakers by using this "no preamp" configuration? Other than being limited to only one input source, are there any drawbacks to going direct to amp? I appreciate any light you can shed on this subject, especially if any of you are actually running your systems in this configuration.
daddyo
I run my cd player directly into my amp. A cd player has to have a special set of VARIABLE outputs specifically designed to go directly into an amp. These CD players should have line level outputs for preamp use as well. If you try to connect your amp directly to line level (or non-VARIABLE) outputs you will probably blow up your speakers. Most CD player's these days output a strong enough signal that a preamp is generally lowering rather than increasing the output signal. I have heard some people state that the variable outputs are superior to using a preamp and vice versa. I found the variable outs sounded better in my system though this may have been a cheap cable issue. A nice advantage of using the CD player's variable outs is that I can use the CD remote for everything. Some CD players actually have digital input's so you can use them as a preamp in an all digital source system.
You need a CD Player that has analog outputs (most do) and includes volume control. I've got a Meridian 508.24 and, just out of curiosity, I tried to plug it directly into my amp. Just to be safe, I used the quietest CD track that I own (the opening of the Schneck/Chicago recording of Barber's Prayers of Kierkegaard), and the volume levels were extremely loud. Tolerable on the quiet section, but I didn't push it through any loud points, since this might have damaged the speakers, and it wasn't possible to decrease the volume. The sound was very clean, though, and I kind of wish I had bought the Wadia that I tried out(with digital volume control), instead of the Meridian. This is not to say that the Meridian is a bad CD player. In fact, it is probably the best part of my current set-up. I don't really use any other sources, though, so the Wadia would work great for me. Hey, if anyone is interested in trading a used Wadia 830i or an 850 for a Meridian 508.24 (with a little scratch to make up the difference with the 850), let me know (kjeffers@gll.com).
Why do people make tube amps that sell for thousand of dollars? because it acts as a tone control. If you bypass the preamp, then the benefits of the pre are negated.
you need to use a cd player w/ volume control. on the low end are units like the marantz cd67, i think cal audio has one or two, then resolution audio 50, a couple others and the wadias. the thing is, to get the best sound you need an excellent volume control(attenuator). thats where the wadias (all of them) excell- all done digitally. none of these options will hurt your system. also the wadias have inputs for other digital sources. good luck.
Hi Daddyo; I enjoyed the latest issue of TAS too, and like you, especially the various stereo systems they put together at different price levels. Anyway, just for the helluva it, I ran good ICs from my Sony CA9ES ($700. MSRP) variable out terminals directly to my amp (very good amp). The sound was so incredibly detailed, etched, wiry, and shrill that it almost made my ears bleed. I blame the cheap variable volume control of the Sony CD player for the harsh sound (control is on the remote, and it worked fine). I quickly learned that if you're going to do this, you need a CD player with a high quality volume control. I replugged the CD output back into my outboard DAC, tube pre-amp, and went back to being relaxed and happy. Happy listening. Craig
... Of course the CD player also has to have a high quality built in DAC to sound good, and the CA9 doesn,t. I also use the well regarded Sony XA7 that has an excellent built in DAC. I'll have to try its variable outs (it's harder to get to). Craig.
To achieve the best possible sound you must get a CD player that uses an analog volume control like the Wadia, Theta or Resolution Audio. Many other cd players use digital volume controls that just throw away bits to reduce volume. Great Pre-amps should be transparent so that even if you where to connect a CD player through it it should sound the same as connecting the CD player directly to the amp since the main function of the pre-amp is to provide switching of multiple sources and to control volume. Even though many people use pre-amps to change the quality of the sound a perfect pre-amp should in no way effect the sound of the source, just pass the sound without adding or subtracting anything. If your only source is going to be CD then save the money you would spend on a pre-amp and the extra set of cables and put that money towards a high quality CD player with analog volume controls, you should be very happy.
My two cents worth.. I agree with many but not all of the above points. One key point is that a preamp is usually easier to drive than a power amp - particularly some low input impedence solid state power amps. So in the design of a DAC's output stage, the easy task of driving a preamp will usually be in mind - but not so with players like Wadia, Resolution etc that are specifically designed to drive power amps. Whereas in designing a preamp the more difficult task of driving a power amp will be in mind. So you need to try it out and check you do not encounter typical drive problems such as tonal thinning, or loss of dynamics. Second point is just in response to CDguru's point - I am sure some people do think buying a tube preamp is beneficial because of its effect on tone (even though they are misguided), but it is not accurate to suggest that this is the only reason. The other reason is that people prefer tube preamps in order to eliminate the unnatural and unmusical characteristics of many solid state preamps. Both solid state and tubed preamps are flawed, but in different ways. And before anyone accuses me of preferring the colouration of tubes - I currently use a solid state preamp.
...A few cents more. Many of the respondents have made valid points concerning the use of a CD Player to direct drive a power amp, but a few points of clarification are in order. None of the Wadia units, cd players or processors, use analog volume control. All Wadia products use pure digital control. The "Throwing away of bits" issue is relative to units with fixed variable output. By this I mean that at maximum output, the unit will pass X volts, period. Wadia uses adjustable output via internal dip switches which can be configured to give the optimum output at maximum resolution depending upon the rest of the components in one's system, without throwing away bits at low volume levels. I know of no other line of products which are able to be adjusted to match maximum output to the other gear in the system to allow max resolution at customary listening levels. Units such as the Levinson #39, Theta Miles, CAL CL-15 and so on ,use analog volume controls for adjustable gain. IMHO, any Pre-Amp and extra interconnect in the signal path will degrade the sound of the signal by the time it reaches the speakers drivers and ultimately, your ears. There is no way that electrical signals can be passed through so much additional wire, circuitry, interconnect cables and the like ,without the basic character of the signal changing, however slight this may be. Wadia products may be configured with multiple digital inputs and outputs, and can be used in conjunction with a high quality A/D converter for the importation of other analog sources for the person who wishes to use one of their units as a digital source, switching device and volume control in lieu of a conventional pre-amp. If you like networked cables, tubes, application specific cables, super power cords or whatever, realize that they all will color the sound, it will not be accurate, but I am not saying that accurate neutrality is to everyone's taste...we like what we like, that's the first rule of enjoying this hobby. If it sounds good to you, then it is.
The TAS reviewer probably did not mention that what he was attempting to do was imitate a Passive Attenuator setup in the system. You can go direct from any component with a voltage output to your amps through passive attentuators. Check the EVS website. $225 a pair. The component does not require a volume control, ie DAC's. (The PA's are the volume control). The purest signal, the best sound you will achieve is by eliminating as many stages, switches, and wires, between the source and the amps as possible.
I am using mine this way, and there a zero compromises with the Resolution Audio CD50, only advantages. COMPARISONS WITH PLAYERS LIKE THIS SHOULD NOT BE MADE WITH STANDARD CD PLAYERS AND PASSIVE ATTENUATOR PREAMPS, because the tow have nothing to do with each other. The CD50's components are without compromise (discrete bi-polar output devices running in class A, with the highest quality microprocessor controlled volume, the same as used in the very best linestages). It is designed to drive a power amp directly, and it is the best digital source for CD's under $10,000 in existence, at least of the ones that do not upsample.............I can see why guys would want a tube linestage to help a lesser CD player along (and blur some of its grain), but if you got one of these, you certainly wouldn't be worried about that. Good luck.
gee carl,next time leave something for me to say!!! resaudio cd-50 without a doubt,it's just too good of a value performance to ignore,alfred