Oh boy. *grabs popcorn*
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It really depends on the quality of the volume control. According to many, analog volume controls using sound better in most systems. Passives too, but the gain issue then comes into play for many.
IMHE, usually an active preamp with analog volume sounds best to most ears. A good tube preamp like the Cary SLP05, Modwright, Backert Labs, Audio Research, Herron, BAT..many options all are good choices.
You can try a cheap pair of passive attenuators for an idea of passisves in your rig. Of course, I'd borrow/demo a preamp first if possible. Cheers,
Having enough gain in a source component is not all that is necessary to get the best sound out of that component. The output stage of a good pre-amp is engineered to drive the input stage of a power amp, while any given DAC or phono stage may or may not be.
In a related topic, it is for the same reason that many listeners (no pun intended---see below ;-) find the sound of a passive pre-"amp" to lack something (see Art Dudley's column in the current Stereophile).
However, over these last years dedicated DAC/preamps have arisen that are neither comparable to stand-alone DAC's in the traditional sense nor passive preamps; instead their purpose being precisely to act as preamps in addition to being DAC's, and hereby successfully driving a power amp on their own - as a singular component. Not only are they effective in doing this, but they also rid you of extra sets of power cables and IC's with shorter signal paths to boot. Indeed this discussion seems to have become somewhat dated in light of the development in this field for some time now.
Thanks for asking, George. I have the PS Audio DirectStream DAC and their Memory Transport CD unit. I also have their Phono converter phono section. I really appreciate the help; I'm not really close to any place where it's easy to audition stuff, so all the advance advice I get is greatly appreciated.
Like many people, I tried to save money and eliminate the preamp. If you're happy with what you hear without it, then good for you. Ultimately I opted for a preamp. I can't remember which Sterophile writer said that "the preamplifier is the beating heart of a system" I fully agree. I'm using a Classe CP700. I can't imagine doing without it.
Your PS Dac has from it's single ended output has 100ohms output impedance at 2.8v from it's "Resolution perfect volume and balance controls"
Your Spectron amp has 50kohm input impedance at 26db of gain.
These are a perfect match for each other to go direct with, and will give you the best transparent/dynamic sound you can get.
By putting a preamp into the mix you are just throwing money away to colour the sound with.
I submit the answer depends on the components involved. I had a PS Audio DSD DAC and compared to the Parasound JC2 preamp, I initially preferred the DSD direct. After extended listening I felt I lost dynamics and detail. I sold the DSD and Parasound JC2 to purchase a Bricasti M1 DAC. In my system the Bricasti was a definite improvement over the DSD. The dynamics were there, detail, but I still felt like something was missing. I went from the Bricasti M1 directly into my Jeff Rowland 525, to the M1 going into the Jeff Rowland Continuum S2 integrated. It sounds better than ever. I don't know if it's because the amp section of the Continuum is that much better, the added preamp section, or a combination of both. I prefer music with a preamp.
The burden of proof should always be on adding anything to the signal path that is not an obvious necessity. In this specific case a preamp is not an obvious necessity, and per George's analysis (with which I agree) the odds appear to be in favor of that burden not being met. However, as others have indicated the only way to know for sure is to try it.
Good luck. Regards,
A P.S. to my previous post: If you do eventually have an opportunity to try a tube (or other) preamp in your system, and if you find the resulting sonics to be preferable to no preamp, keep in mind the possibility that the root cause MIGHT be a less than optimal tonal match between your power amp and your speakers. Particularly in view of the impedance characteristics of the speakers (4 ohms nominal, 0.8 ohms at 20 kHz), which could conceivably result in an over-emphasis of the upper treble in conjunction with some solid state amplifiers.
Should that ever prove to be the case, changing power amps would probably be a better solution than adding a preamp.
And if there is any uncertainty in that regard, researching reported user experiences involving the use of Spectron amps with Martin Logan speakers may be helpful.
A preamp line section has 4 functions:
1) control volume
2) select an input
3) add any needed gain
4) control the interconnect cable
The two latter functions are not done by passive controls of any sort. That 4th function is also poorly understood, not only by audiophiles but designers too. Often if you have a digital source, you may not need the gain and so a passive might seem attractive. But the interconnect cable will be far more critical with a passive control.
Quite often if a passive is involved, people report a loss of bass impact and overall dynamics as the volume control is reduced in level from full on. This is likely due to the source having some sort of coupling capacitor at its output, which is then in series with the control. Unfortunately, the Red Book specification for CD demands that the output of the CDP or DAC be high, in fact so high that it can clip all known amplifiers if the signal is not somehow reduced. So a volume control is essential.
Now if you don't need the gain, the obvious solution is a buffered volume control. This is essentially a volume control with some sort of follower circuit (either tube or solid state) that has no gain but does isolate the control from the interconnect cable. This allows for vastly reduced coloration due to the interaction of the volume control and the cable.
Since I listen mostly to LPs, a buffered control in my system is insufficient as the extra gain is handy! But if you plan to play only digital the buffered volume control is your best bet if you don't go with an active line section.
Rustler, if your satisfied with your current power amp, I want you to look at the addition of a preamp as talorying the sound to your liking, bringing out the best qualities from your power amp, both complementing each other. Some power amps need the drive to sound their best. A direct connection sometimes can prove to be very trying in the long run, not very musical. If this direct connection can be proven to be true as more desirable then all of us need to dispense with the preamp and you might build your system around something that only you might like. If you can figure out a way to dispense with the power amp then I need to get a new hobby.
Driving the inter-connect cable---what a concept!Maybe another reason why the sound of any given cable is so system-dependent---it's interacting with the volume control in the pre-amp of every system it's put in.
This is either tongue in cheek, or your so wrong.
Just in case it was not tongue in cheek. The volume pot in a preamp has nothing to do with the interconnect cable, as there is and active buffer between them, totally isolating the pot from the interconnects
Georgelofi, you are not seriously asking me to recommend a preamp when I have no idea what amp or speakers the Op is using. You sir are asking me to put the horse before the cart. However I'm advocate for using a preamp. Detail as you seem to be hung up on as in your past posts does not necessarily result in an engaging or musical presentation and further there are many other aspects that define a good sounding system hopefully not excluding detail.
Cheers to you!
Rustler ... I have a similar set up using Martin Logan and Spectron running both digital and analog sources directly for a while. I eventually added a tube line stage. While I cannot say the sound was better per your original question, I enjoy the flexibility of having a different presentation. I always like the analog source passing thru the line stage, but for digital it depends on how I want to feel or the music I am listening to. If I want to feel upbeat and engaged, the digital source goes directly to the amp and if I want to feel relaxed, I add the line stage to the signal path. Others might feel the opposite, but for me this is what happens.
Umm, maybe using the forums for financial gain?Hmm! So designers cannot participate in forums when they are not pushing their own products?? One believes in active and the other passive or no preamp with supporting arguments.
Personally I find their posts valuable with ACCURATE information especially Atmasphere since I'm also a tube guy and believe in active preamps.
This is getting beyond me, but I appreciate all the input. To summarize: I power Martin Logan Spires with a Spectron Musician III Mk 2. I also use PS Audio DirectStream and their Phono section. I would actually love suggestions as to what preamp under $5K would be a strong match. I listen to all kinds of music, and I love clarity, especially in the mid and upper ranges, more than all other acoustic qualities.
Yes Bdp24 that goes for everything active or passive from the source output to the poweramp input.
If impedances matching is not correct (Ohms Laws) and the current is compromised (Kirchoffs' Laws).
No amount of voodoo speak will solve the problem. This is why I asked Phd to name preamps that can drive better than the output of the OP's PS Audio Dac.
BTW: I don't know how passive came into this conversation, maybe it was just a bit of baiting?? The OP question was just "Is no preamp really better that a good preamp?"
Rustler: Almarg and I have both told you have a great match to go direct, and adding an active pre is going to do nothing but colour the sound and put a hole in your pocket.
I believe technical questions are best handled by contacting the manufacturer(s) directly via private email.
Using the forums for financial gain, under the guise of "providing information", is both unethical and inappropriate. And it's the usual suspects time after time.
Audiogon provides a classified section for vendors to sell their products.
I guess we disagree.
Using the forums for financial gain, under the guise of "providing information", is both unethical and inappropriate. And it's the usual suspects time after time.Georgelofi produces a passive preamp and he advocates going direct from DAC to amp bypassing PREAMP. Where's Georgelofi financial gain? In fact, he's offering his honest opinion and potentially hurting sales??
Rustler: Almarg and I have both told you have a great match to go direct, and adding an active pre is going to do nothing but colour the sound and put a hole in your pocket.This is true only if the signal from DAC is PERFECT and NOT colored. If not, adding a preamp can improve or degrade the original colored signal.
Also spec (a great match) doesn't necessary equates to great sound. Otherwise all components with the same spec will sound the same and from my experience, it doesn't.
Rustler, there's no definitive answer so only way to know is experiment forself.
Rustler, awesome system. If you like clarity, looks like you have optimized things with your amp/speaker combination. I don't think you will have a problem with a passive with your sources and certainly not with an autoformer.
Vinnie Rossi makes the LIO products where you can get a linestage with autoformer (passive) and also a tube stage. Even better, you can switch the tube linestage out of the signal path so you can try passive only (autoformer). It looks like a great product to me. It uses a fantastic autoformer module made by Intact Audio (good explanation of how autoformers work at their website). I think it should work with your PS a audio components (the direct stream uses transformers at the output, which is terrific). And if it doesn't, you still have a tube linestage with superior volume control in the autoformer.
No affiliation with Vinnie (never used his products) but I myself am interested in this product as a linestage. I use Naim components and also Intact Audio's autoformers with a Berning amp.
I have found the autoformer to be superior to tube linestages I've owned. They don't lose dynamics or bass and provide superior tonal correctness. The cable paranoia is overblown and more than likely only an issue if you are running very long interconnects.
If you are seeking romance, then look for a tube linestage...I like preamps that use tubes like 6SN7 or older. They provide a "fat" sound in the right design.
Many thanks to all of you, especially Almarg, Georgelofi, Jcharvet, Knighifi, and Plinko. Really useful input. Andrew9405: I did contact the manufacturers, but they are loathe to recommend any other components. You seem more interested in criticizing other postings than in offering useful input. What gives?
09-26-15: RustlerAs I've said in some past threads, the main usefulness of specs, IMO, is to allow candidates to be ruled OUT from consideration, based on poor or questionable technical compatibility with the other components in the system, or on the basis of user preferences such as cost, size, weight, appearance, remote control capability, etc.
In this case I believe you are fortunate in that from a technical standpoint it appears that your existing system would be compatible with the vast majority of both tube and solid state preamps. The one slight question mark that occurs to me involves some preamps, such as certain Conrad Johnson models, which provide very high gain (e.g., 25 db or more). Gains in that vicinity, or higher, MIGHT cause you to have to operate the preamp's volume control undesirably close to the bottom of its range if (as would presumably be desirable) the preamp were used with the volume control on the DAC set at or close to the top of its range.
Beyond that, all I can suggest is that you research what kinds of preamps others have reported to provide good sonic results with the same or similar speakers and amplifier. "Similar" meaning, at least, Martin Logan speakers and high powered class D amplifiers.
Good luck. Regards,
Ah!! now that's another ball game, if you want to colour the sound in some way instead what you get going direct, this will be a bit of a merry go round, as all preamps have different sound signatures, and no one here could give you the right answer to which to get unless they are you.
It's not really about the specs, although impedance matching should be considered. Go back and read Atama-Sphere's response. Pay attention to #3 and #4. IMO If you do not need the gain, the source variable output section can control the interconnect, and you like the sound then you should stop there.
Once again, please anyone who wants to put their head on the chopping block.
Using and quoting the laws of electronics (not just voodoo speak) what is not matched with the OP's PS Audio Dac 100ohm 2.8v output running direct into the Spectron's 50kohm 26db of gain input.