To preamp or not to preamp?...that is the question


I'm looking to change my CD setup. I'm considering getting a CD player with a digital volume so I can connect it directly to my amp. What are the pros and cons of bypassing the preamp? What CD players have the volume control capability (I know Wadia does)? My preamp is Innersound ( a very transparent preamp), Innersound ESL amp, Innersound Isis speakers.
Thanx for your input.
Check out the Theta Miles (about $1200 used), the Mark Levinson 39 (not sure if the model # is correct) or the Spectral SDR 1000 (about $2500-$3500 used)

If you want to drive an amp directly, this kind of unit works best if you can keep the length of the interconnect relatively short -- not over ten ft -- otherwise you start losing dynamics & impact; music can start sounding "homogenized."
Best of luck,
Avoid using CD volume controls that do it in the digital domain. Use ones with analog controls, or use a passive preamp with any CD player. This is tricky because of the impedance of the passive preamps with resistive volume controls. If you pick a passive preamp with transformer volume controls, such as Bent Audio or Silver Rock, you will not have this problems with impedance.
I recently bought a Resolution Audio Opus 21 cd player that has a built in analog volume control. I was prepared to keep my SF Line 3 but found the Opus 21 run direct much more transparent, pure, focused, and dynamic. The SF Line 3 had a little bit more body, but was noticeably less transparent, more diffuse, and the PRaT was greatly reduced. Some may prefer the Line 3's more relaxed presentation by comparison. My amp's sensitivity (.8v/47k ohm) and speaker's efficiency (91spl) are reasonably high. The Opus 21's output is rated at 2.5v SE and 5v XLR at 100ohm. I'm not sure what other factors are at play, but running direct in my system is more enjoyable.
I agree with Twl, an analog volume control is preferable to digital, as unless you run the digital volume with little or no attenuation (some Wadia models such as the 860 and 861 have an internal adjustment in the unit to enable you to do this more easily, I don't know if the 831 fits in that category) the sound seems to degrade. However, you should be sure that the analog volume control is as well-executed as the analog preamp you're replacing, which in your case will not be easy. Personally, having heard your system, I'd stand pat!
I tried it and gave up. Medium priced CD players (marantz and Denon) don't have high enough quality volume controls with enough steps. I was told that they can be modified but is it worth it? Secondly, the ones I experimented with only controlled volume for the analogue outputs. This meant that I was stuck with the internal DAC.

My solution was a Creek OBH-12 passive pre-amp until my budget allowed more. The Creek is totally transparent but the IR sensor tended to pick up too many stray signals and was always going louder/softer when I used a different remote. The other deal out there is an Audio Alchemy D/A with a built in volume. The quality is great. Try or to find these.
thanx guys...i was considering the ML 39 fits right in my budget and i heard it does pretty good with volume control (in analog domain)...and Russ, you're not helping man!
There are pro's & con's to both approaches...
It depends upon the reactive output / input characteristics of your equipment, & how they interact with each other & with the cable interface. The only way to know what's REALLY going to happen is to experiment. My own situation: the player doesn't like longer cabling & it doesn't work well through a passive pre either, even with very short cabling. Works great with an active pre, but still wants a short cable. Your equipment is different so YMMV.
Despite Rcprince's knowledgable endorsement, as the owner of an InnerSound preamp, I can attest to the fact that however transparent it may be, my DAC sounds even better if I take the amp inputs from the line outs rather than the main outs, thereby bypassing the preamp's active gain and attenuation stages, and surrender all control over volume level (my DAC doesn't have that feature). You can test this with your current digital front end by setting your preamp's volume control to "79" (unity gain on this preamp - try to choose audition disks that aren't encoded at very high levels so as not to get blown away, or forget about this test entirely if you never listen at anything approaching the "79" setting), and then listening switching between the regular main outs, and moving the interconnects going to your amp over to either the monitor outs or the processor outs. This gives you the most fair comparision, because you are maintaining the same number of interconnects and I/O jacks in the circuit, thereby revealing the exact contribution of the preamp itself (it's also easier to swap the test conditions quickly this way); the difference you hear once you connect your new DAC directly to the amp and eliminate one set of IC's and jacks will tend to be even greater for their loss, but worse for the added question of your new DAC's attenuator quality, which may or may not equal the InnerSound's. Unless there's something unusual about the electrical interface of your DAC's output and your amp's input, I think you will find a surprising improvement with the preamp's guts taken out of the loop in this test.

I would encourage anybody to try this kind of test to hear just what contribution (or subtraction) your preamp is making to the sound of your digital front end, provided your preamp's unity gain setting can be determined, either through math or through trial and error, and if it has either processor loop outs or unbuffered tape outs. I posted a thread on this topic before (see my threads), but no one who responded at the time seemed to have tried this for themselves.
Zaikesman, I agree. I have made this test with both phono and CD, with my highly modified MFA Magus preamp. There is no doubt that using, in my case, the tape outputs, which bypassed the attenuators and line stage main output, was much more detailed and better, than using the main outs. The attenuators are largely responsible for this, but the line stage plays a part in it too. This is why I am going to get a Bent Audio transformer passive, and put it after my preamp, using the tape outs instead of the main outs. I had considered getting a resistive-element passive pre, but the impedance problems are too much. The transformer passive pre, has a much better impedance relationship, and is more transparent than any resistive attenuators. Even Caddocks.
How much $$$ do you want to spend?

It all boils down to money.

If money was not an issue, I would not go with any digital device that regulares volume. I would make this recommendation because I have never heard a DAC or CD player that regulated volume sound better than a top of the line preamp matched with it.

Why is this the case? Whatever technology a company is using in a CD player or DAC to regulate volume is not as good as the technology that is in the best preamps to regulate volume. And most of the time the technology in CD players and DACs is a form of passive volume control.

Personally, I do not think passive volume controls are the way to go in the long haul. Maybe at your budget (I do not know your budget though), passive may be the way to go. However, I have not been impressed with any of the passive preamps I have ever used or ever heard (having used about 5 or so through the years in my system). Music tends to sound veiled and not dynamic played through passives when compared to top of the line active preamps. There is a good reason why there are not too many passive preamps made today.

Anyway, define your budget, and I can give you better advise. Because it all boils down to money.

I have a Theta Miles -I have tried it both ways with and without preamp -and having a quality preamp in the chain will reward you with more of everything detail,soundstage,etc.Hope this helps.