It's all in the impedance. if the Cd out can mate with the amp in... ok. If the CD uses a digital volume control, I would hate to use it. (imagine your 1 and 0's trying to do it in 1/100 the 64 step range...)
If the CD has a $200 analog volume control, hmmm maybe. (but the likelyhood of the Cd player having a super high quality volume control is near zero.
Then you get an external volume control, which is at it's most basic is what a passive preamp is. So then the issue is impedance. can YOUR amp hadle the sort of signal the CD puts out?
It's a "you listen and decide" sort of thing. I personally would not run the Cd player on it's own attenuation, no matter what.
Now lets' hear from the folks who like this....
You have to absolutly get one thing straight first. Price is the only issue when choosing between using a preamp and not using a preamp period, end of story. The better 8 grand and up preamps absolutly blow away any passive/direct to amp set-up in absolutly every area there is. Notice I said "better" and "8 grand plus", If you are talking 4 or 5 grand preamps, it better be one of the hand full of best there is at this price point to better (a good passive or going direct using one of the best cd players there is with an analogue only volume (digital volume does not cut it ever). For a complete explination of why this is, just go to the Placette web site and start reading. Now when you get to under 3 grand preamps, preference comes into play and it's completly your choice which you prefer and you need to ask yourself, could you better use the money saved from not buying a preamp elsewhere in your system, like on better amps etc. My personal preference is to buy the best preamp you can afford first and build your entire system around it with your budget left over. Either do it right the first time or not at all with preamps. Otherwise you go into trade-up fever for years to come. What stinks about preamps is that they are the one item in the entire audio chain, that currently keep getting much better as the price goes up and they don't stop getting much better until around 10 grand. I thing cd player top out at 3.5-5 grand and amps at around 6 grand for comparison.
I don't know what preamps add beyond gain, but they do (perhaps it's their on character). It's like power cords. How the hell could they make a difference; it's just electricity. But they do! I've run a CD player with volume control direct and with a preamp. I liked attributes about both, but preferred using the preamp. The direct route was cleaner, but using the preamp made it more dynamic. I've experienced this when comparing active and passive preamps. Mahandave is correct; expensive preamps are worth it. They pass on the siganl "as-is" from the source while doing the preamp thing. I should add that I prefer tube preamps. They provide a realistic soundstage. Also, preamps allow using multiple sources (FM isn't dead yet!).
That was a great response, Elizabeth.
Budrew, the oft used statement equating an inert wire with a complex preamp is sophomoric.
Mahandave, you must know you are ommitting a great number of exquisite pre amps that sell new for less than $10,000.
I once started an archived thread basically about this topic, check it out at Ever Perform A Preamp Bypass Comparision Test?
if you are interested...
I'm wondering for example if I should get a Classe CP-60 preamp which is $3600 new with a $1500 Classe CA-100 power amp, or just bypass the preamp and get a CA-300 power amp being run straight in
I would echo the above and say that in your price range, you are probably better off spending money on the amp and cd player and going direct. I haven't owned the Miles, but the Wadias, of which I've owned several, are quite happy running direct to the amp. I haven't tried any $10k preamps yet but have used several very good ones in the $2-4K range and there is no improvement, if anything it's not quite as good as direct. The only issue is that you have to adjust the output voltage to your typical listening volume, which requires pulling the cover every time you want to change it. If it's adjusted properly, and you run near the top of the adjustable output range, there is no discernable loss of sound quality.
The top of the line Adcom is a very nice preamp is rated Class A by Stereophile and can be found used for less than $1000 or by it new for about $1500 it sounds great.
If you want to run with out a preamp, you would need to by a fairly expensive CD Player.
I would recommend the Levinson #39 or #390s. These units sound great without the preamp and are built to be played that way. You should be able to find a #39 for about $3000-$4000 on Audiogon or audition and buy an new #390s at a dealer and you'll still be way ahead.
The cool thing about these units is that if you want to add a preamp like the #380s or other high quality preamp as funds appear you can still do so and still have one of the best CD players out there in the #39 and #390s.
Another upside would be that if your preamp ever needs updating/service you could still use the #39 for both in your system and not be out of tunes.
>>I would echo the above and say that in your price range, you are probably better off spending money on the amp and cd
player and going direct.
I agree if you are not doing Lps. You have to give it a little thought so you don't have an impedance mismatch with the source or load.... but the results can be very good.
I don't agree w/ above that the pre is where you should necessarily spend all your money or build your system around the pre with the "budget that is left over". The small signal in a pre makes noise a big factor (then again it always is) and things have to be done right. If you look at tube stuff the amp has to deal with power and the output transformer of a tube amp is critical and expensive. That amps top out at retail of 6k (Dave's comment above)is not true in my experience. At least with tube amps. Again, start with the amps output tranny. If you carefully spend about 5-6k for parts and Diy you get a very nice one.
If your system is under 15k and cd only, this is the vast majority of systems (discount used price), I'd consider going without a pre.
I checked out the Placette site above and I'm not familiar with their stuff but I think it is why I moved to DIY. If their prices are in the ballpark of Dave's post... geeeze. I only read the "details" page at that site but all they talk about is Vishay resistors (a couple bucks a pop), quality volume attenuators (they ain't that expensive) and proper source loading.
Here is an article that talks about some of the basic issues.http://www.harmonicdiscord.com/forums/viewtopic.php?t=6576
The above is limited to tubes. Just mho.
There are pros and cons to both sides of the equation. Personally, I think there's an added sonic benefit to running through a quality pre-amp ... One thing nobody has mentioned is the need for a pre-amp when using more than one source (tape deck, tuner, phono). In most of today's systems, a pre-amp will be necessary to use secondary sources.
I have a Spectron MII (digital) amp, a Supratek Syrah (tube) Pre and a Granite 657 (tube) CDP. The CDP has an analog volume control. I have run the system with and without the pre. My experience was that, though the sound was cleaner direct without the pre, overall I preferred the sound with the pre. The pre seemed to do a better job of driving the amp (more bloom, as I think someone put it above).
I have four sources. Doing without a preamp is senseless for me.
I still would not buy a high priced cdp so I can bypass a pre amp. My pre amp allows me to adjust gain for each channel, or just go passive. I like the versatility.
My $1600 (used) pre is single ended class A. The cdp will use an off the shelf op amp. That is a serious discrepancy for me.
There are wonderful pre amps both used and new, that can be bought for less than five grand. They all will have more sophisticated volume and gain circuitry than any cdp.
I don't think there's anyway to tell if a particular direct
CDP to Amp combo will work in your system until you try it.
The same can be said of passive preamps. Many CDPs have inputs for other sources, both analog and digital.
Like Disc, I'm using a MII and look forward to getting the digital input board for the amp, which will allow the use of just a CD transport or A/D output.
Is anyone using an A/D to run their analog sources into a
multi-input CDP like the Wadias?
A preamp should not make your cd player/system sound better. If it does, then something is wrong with output/input compatibility of your cdp and amp. Having said that, a high quality attenuator (like the Placette) is really all you need.
Unless I needed more power, I would rather put the money I would have spent on the preamp into the cdp.
It has been my experience the cdp is something you can spend way too much for.
In my case a pre amp is necessary to make my cdp sound better. A cdp just does not have the ability to saturate my amps. The highs and lows just roll off.
Also, no one can tell me that a cheap op amp can out perform a sophisticated pre amp circuit.