CD direct to amp vs active preamp

How many of you folks have ever tried running your digital source with a built in "high grade" volume control directly to your amp and compared that to the digital source feeding your active preamp and then the amp ? I am just curious as to the results and if you noticed any major differences. Obviously, we would have to add not only the preamp, but also another interconnect to make all of the connections. If you've done this "test" with a passive or buffered line section, feel free to join in. Sean
I have an evs millenium ii, I bought the option for second single ended outputs and have ultimate attenuators (hi quality volume control) It is very nice but I miss the flexibility of having multiple sources.

My Arc LS5 preamp adds body and depth to the output only setup. The music is a touch more engaging. Probably due to the large beefy power supply of the old Audio Research gear.

sean: a few system iterations ago, i had an accuphase dp-75, which like the 75v, has a high-quality volume control that (as i recall) operates in digital domain. after experimenting with various setups, i sold my preamp, since the dp-75 run direct was vastly better sounding than when it went through my rowland consummate. run directly, the cdp had better focus, a wider and deeper soundstage and, most importantly, sounded like a fairly thick veil had been removed from my speakers (then avalon ascents). i have several friends who own the accuphase 75v and they all run them directly into their amps of choice. -kelly
The only reasons not to run direct are if you have other sources and don't want the hassle of switching interconnects, OR you have a source with a wimpy output stage that doesn't work well directly into your amp. For a high-quality cd-only system, direct is the way to go. The adage that the best interconnect is no interconnect is true, and it goes for preamps too. Think about it, how can another component possibly improve on the signal? It can't, it can only degrade it. I have, however, read posts by some tube-o-philes who just had to have the euphonic color of a tube preamp in the chain. So if that's what floats your boat, go for it.

I don't have much love for passive attenuators because every one I've ever tried or heard has sucked the dynamics right out of the music. I know this was probably due to less-than-stellar output sections on the source end, but it's been my experience nonetheless.
In one of my systems, I'm running a Mark Levinson 390s CD player directly into a Pass Aleph 3. It sounds good. The 390s has an analog volume control. (Digital volume attenuation involves losing data.) Compatibility with the Aleph 3 is fine; I am able to drive it to loud volume levels. (My speakers are Red Rose R3s with a Sunfire True Sub Mark II. Before the R3s, I had good results with Proac 1 SCs.)
Sean, I've tried 2 different setups. 1st, a few years ago, was a Wadia 850 direct into a BAT vk60. Then I added a VK50Se preamp. In that scenario, the preamp's volume control was much better at lower volume levels-in all respects. At normal or high volume, the gap closed and I'd say the detail/intimacy was a little better direct, everything else better with preamp.

2nd, currently, is DCS Delius direct into VK60 with/without vk50SE preamp. Same conclusion. With a caveat, that I recently added 30 ft interconnect to the amp, now the preamp takes the edge in all areas.

For the money, direct is hard to beat, for the best, without regard to cost, I prefer the preamp in the chain.
I run my Resolution Audio direct to my Lamm's
I have yet to hear a better system
I use Valhalla balanced
Direct is the way to go
Another theorem: If you have all your sources with volume control all you will need is input selector that you can get from Bryston.
I ran my theta miles directly into my VT100MkII for almost 2 years first with balanced straightwire serenedes and now with purenote epsilon balanced cables. Speakers are Magnepan 2.5Rs I recently upgraded the speaker cable to purenote epsilon reference. Since I wanted to get back into vinyl (another story) I purchased an ARC LS16 and added it into the system. The sound is more dimensional with a more clearly defined soundstage using the pre-amp. Truthfully I had not expected to hear an improvement (fewer components in the chain the better), but that's what my ears tell me.
how do you control volume if you run cd direct? sorry for the newbie question.
Dear Rockhead,

Some CD players have built-in volume controls. These can be operated using knobs or buttons on the CD player or buttons on the CD players' remotes. Often the manufacturer will describe the volume control as digital or analog. Analog is better. Digital works by discarding some musical information to attenuate the volume. This can cause audible degradation in the sound. If your CD player doesn't have volume control capability, you need a preamp or a different CD player.
Sean, with your interest in recording, you should take a peek at the Z-Systems rdp-1 digital pre-amp/equalizer. While expensive at $5K, it's da bomb. Charlie
Contrary to the general opinions here, my Levinson 39 was working great into Levinson 20.6 monoblocks... UNTIL I put a burmester preamp between them... There is NO comparison - the preamp was better in Every Single Possible Way.

And why shouldn't it be? You have a CD player with, say, 1/5 of the price going into a little preamp section versus a dedicated preamp costing twice (retail) what the CD player cost, 10 times more than the itty bitty CD preamp. And more money does buy you great sounding music, if not love :-)
Count me among those who run the Accuphase DP-75V directly into the amp. Like Kelly, I too sold my preamp which at the time was a Rowland Synergy II (previous to latest surface mount board technology) powered by Rowland's own battery power supply (BPS2?). I believe this rig retailed somewhere around $8000-9,000 at the time, yet the DP-75V running direct (into Rowland Model 10 amp) sounded better. IMO a lot of money for swiching and balance functions.
I auditioned the following setups at dealer showroom.

Pass Labs x-350, Wadia 860, Thiel 2.3’s, and Pass Labs x-0.

I preferred the x-0 in the chain to the Wadia direct. The Wadia sounded thin and digital with their preamp section.

Pass Labs x-350, Wadia 860, Thiel 2.3’s, and Pass Labs d1 and x-0.

I much preferred the d1 without having the x-0 in the chain. Smoother sound, with a better overall presentation.

Mark Levinson 39, 36’s, and Martin Logan Prodigy .

Very musical. Overall did not like the presentation and did not purchase the 39.

As always it’s a matter of personal choice and system dependent.
I was just curious as to the various results. Thanks for taking the time to post and share your experiences and observations.

Like Audiotomb, I have a DAC with two different sets of outputs. I can run direct via the built in shunt style stepped attenuators with 4 volts of output available or run into a preamp at line level. I've done both, making all of the "necessary" cable changes along the way, and noticed no discernable differences. Keep in mind that the level of resolution that this system posesses may not be nearly as high as some others. Then again, neither is the money that i've invested in it nor my bank account. I'm simply trying to work with what i have and can afford : )

Since this specific preamp seems to do nothing but add versatility and it is FAR more convenient, i'm going to leave it hooked up. I have several other sources within that system and having a "transparent switchbox" is pretty handy. After all, who actually "enjoys" hooking / unhooking various components ? That is, unless you just picked up a "new toy" : )

My guess is that those that did not like the CD direct approach ran into loading problems. It is my opinion that playing with various interconnects ( and the different impedances that they present ) may have resolved most of that situation. That is, so long as there was enough drive coming out of the DAC section to push the amp ( easily ) to full power in the first place. Unfortunately, one may not be able to swap cables around, do multiple time consuming comparisons, etc.. especially if you are doing all of this on site at a dealer's location.

Since recording levels and amplifier gain ( input sensitivity ) can vary so much, i don't think that some amps ever get the necessary drive level that they should when fed directly from some players / DAC's. I have known a few folks that have tried running "cd direct" and not been able to achieve the desired listening levels that they could with the addition of an added gain stage ( active preamp). This obviously reduces ones' listening enjoyment, as the music may lack drive and intensity.

Between the lack of gain and loading problems, this might account for the majority of "lacking dynamics / tonal & timbre mismatch" situations mentioned. After all, if introducing a preamp into the system makes it sound "better", you have either corrected the above mentioned deficiencies OR added colouration to the amplification chain that is more to your liking.

Before someone gets all jacked up about my last comment, i personally don't think that there is anything wrong with "tilting" the response to your liking. Since we all have to listen to our own systems, i would prefer having one that i can actually enjoy and "sounds good" rather than one that supposedly "looks good" on paper or measurements and impresses others. The bottom line is to set your own personal and system goals and then strive to reach them.

Just by reading some of the various comments on these forums, it should be fairly obvious that many of us "dance to the beat of a different drummer". The nice thing about all of this is that we can compare notes and draw from any / all of our experiences and knowledge as needed. I know that i've learned quite a bit from others and have applied many of those things to my own personal systems. At the same time, i've tried to pass on some things that i've learned along the way.

Hopefully, we can agree that sharing knowledge and experience helps us all out. Whether or not we agree on specifics may be a completely different story : ) Sean
Hi Sean,

I've read many responses that basically says digital attenuation isn't desireable because you are taking away 1 bit of resolution for every 6 db attenuated.

For now, I am going direct from Alpha dac to amp. I don't have a fantastic preamp, so this is the best method so far. Attenuation is done with a digital preamp, Meridian 518.

I am getting an ARC integrated amp. Most posts I've read claimed their Wadia suffered from lowered resolution at lower volumes. I don't feel I lose any resolution with the Meridian. I'd see if I get higher resolution using ARC's preamp secion instead of the Meridians.

Regarding the gain, I have two dacs to compare. One Sigma and one Alpha. The Sigma is 2.0v and Alpha is 3.5v. I hear no difference in volume between the two when directly connecting to amp, at least not obvisouly so. The Alpha obviously sounds better, but I doubt it has anything to do with the difference in output gain.

Regarding impedance, I don't know how to figure these things out. Before I went direct, I asked some gon members whether Cal dacs can go thru a passive preamp to my Aragon amp in regards to their impedance compatibility. They said I can't because their impedance didn't match. Well, they are working great being directly connecting.

One thing I don't understand is digital cables. I expressed my feelings to Rick at Virtual Dynamics that analog cables sound better than digital cables in my system. He then told me his digital and analog cables are one and the same. He also added digital cables are the furthest behind in terms of technology. My D-60 sounds harsh. I bought it used and burned it in for a week already.

To connect dac straight to amp, my best configuration is to use analog cables throughout; trans to pre to dac to amp.

I hope my two cents help.
there is a simple, relatively inexpensive solution to the passive approach that to my ears outperforms ANY active preamp i have heard....the Placette RVC. at $1000 list price it is within the budget of most folks and only requires one additional short (the shorter the better) interconnect to use in any system. the Placette Remote Volume Control is placed next to your amp(s) and allows any source with sufficient interconnect drive capability to be used direct into your amps without bass or dynamic limitations.

since i have 3 sources i use a custom passive switchbox that allows me to switch sources and mute from my listening chair.

i do think that the passive/active argument is very situational but that in general additional active circuts cannot add "good things" to the signal and that theoretically passive has more potential when properly executed.
I can see and understand both platforms when it comes to the active vs passive debate.

As to passive's or unity gain designs, you will still have colouration due to internal wiring, signal degradation and loss from passing through various components and contacts, be subject to loading problems, etc...

Active has all of the same problems but can increase gain and alleviate many of the loading problems. The key is to find an active unit that alters the signal as little as possible while passing on all of the benefits.

As to a unit that uses a remote control, how much noise do you think is internally generated from the drive motor that rotates the potentiometer, the infra-red or rf based sensor circuitry, the power supply to feed the motor and remote sensors, etc ???? You might as well "go active" as you've got almost as much "junk" within the box. Sean
Well, here I go with my 2 cents... I have a complete Cello system (Mark Levinson's last "cost no object" company that went out of business and is now being resurrected). Instead of using an active preamp, Cello or otherwise, I use a Cello passive attenuator called an "Etude". The unit has 4 selectable inputs to one output (all RCA). The attenuator (volume control) is the same hand-wound 60 position dial as found on their $20,000 Audio Palette. With the exception of the Audio Pallette, I have not heard any active preamp that I like better than the Etude, and I have tried quite a few! To my ear, active preamps always seem to put a veil over the speakers. The passive attenuator adds no coloration nor removes anything from the music. Providing you have sufficient gain comming out of your D/A (or whatever source you are using) and impediance is not an issue, passive gets my vote! Ken G.
I know one of Cello's biggest clients is none other than Kenny G....

nice comments

sean wrote - "Between the lack of gain and loading problems, this might account for the majority of "lacking dynamics / tonal & timbre mismatch" situations mentioned. After all, if introducing a preamp into the system makes it sound "better", you have either corrected the above mentioned deficiencies OR added colouration to the amplification chain that is more to your liking."

many purists would like to point a finger at preamps as adding to the signal. I for one think a very neutral dynamic preamp is the single most important piece in the system, maybe baring speakers. My own preamp upgrades have been significant, and made th emusic more involving and dynamic. Are we dealing with colorations? I tend to go as tonally balanced as possible and key into acoustic instruments - pianos, acoustic guitars, sax. Knowing the tonal qualities of guitar and piano from playing them, if something doesn't sound right, I don't want it in my path.

That said I think many blame the preamp for coloring the signal but then buy a power amp with it's own colorations.

I haven't gotten the tube power amp bug, and don't want to go there. A neutral tube preamp and a well done solid state power amp is a good combo in my book.

I sometimes record discs to my nak tape deck straight from the source and it never has the depth or detail it has compared to running the source through the preamp. Cheaper volume controls and less regulated power supplies don't quite cut it, subtle, but give me my preamp anytime