Any thoughts on removing a preamp from your system

An audio-friend of mine has always found it better not to use a separate hardware preamp in his setups, especially since his latest DAC/preamp (the Danish developed/manufactored Blue Cheese Audio Roquefort http://www.studiosound.dk/cddac/roquefort/) sports a dedicated preamp section with digital volume attenuation. The separate preamps he's tested against it have all failed to deliver equally overall, until a very expensive preamp entered the setup in the form of a Belles LA-01 (driving his Belles SA-100 poweramp). While the inclusion of this hardware preamp to his ears doesn't necessarily translate into a win-win sonic scenario in all respects compared to the stand-alone BCA DAC, he's smitten especially by the added sense of "drive, dynamics and transient abilities - as if the existing components are harnessed into a fuller, better controlled potential in many respects," as he'd more or less put it. This is an intesting observation to me, also insofar it would take such an expensive preamp to finally turn it into (again, in some respects) an even more satisfying sonic experience.

This example - among others, actually - tells me that separate hardware preamps are a potential blessing in some vital respects, but are at same time an added component in the audio chain where many variables combine to make it a challenge for it not to impose too much of a character of its own (read: the challenge of transparency, if you will). I guess for some the above mentioned traits coming in the wake of a hardware preamp overshadow an added layer of coloring/character, where it might be more pronounced, whereas others (like me, for instance) would find it a nuisance - depending of course not only on taste, but also and not least the setup where these evaluations are made.

The motivation behind above mentioned friend trying out a hardware preamp in his setup was essentially due to the planned investment of a turntable, one might add. To me, with a digital source only and a very successful mating of DAC and poweramp direct-coupling, the inclusion of a hardware preamp would have to be so utterly convincing (not least in light of its expected severe cost for it to make a real difference) to have me forget the other areas where the same or less amount of money could make a difference. I've heard many preamp-based setups, and most of them to my ears truly lack the coherency, truth of tone, and snap and power found through my own setup - using no separate hardware preamp. A hardware preamp is not necessarily a sonic blessing in and by itself, and a preamp-less setup is not necessarily marred by what is so generally found in above postings. Just saying..

Hi George

Thank you for your comments and corrective remarks on my use of the term 'preamp.' Not to appear too apologetic I'm guessing I intended to use the term as a means to address the effort made with the analog output stage of the BCA Roquefort, and that this in a sense pointed to its deliberate use as a "preamp" (where none is) simply by virtue of having a volume control in the digital domain and a collection of digital in- and analog outputs.

If it makes any difference, here's the link to a Danish review of the Roquefort (albeit a prototype) with a picture of the left backside:

http://nerds.dk/review/?rid=155

Mapman --

YEs, but the question is, why?

I can see how the proper eletronic mating might be trickier with a passive, but I cant see a disadvantage if done right, other than that various active pres might provide more flavors of sound to please more people. Not everyone likes vanilla best.

My thoughts as well. I'd wager most active preamps are inherently limited by a lack of transparency, or certainly an added sense of character, an issue that is revealed the more obviously when compared to a successful poweramp to DAC direct-coupling or a similarly well-integrated passive preamp, and of course also relative to the active preamp used. Moreover, where the synergy of a setup is "dialed in" around the use of an active preamp and its negation results in the overall sound falling by the wayside, so to speak, this is not necessarily indicative of the preamp's merits but could as well point to its colorations and/or a less than ideal in-/output impedance match in its stead.

To those considering skipping both an active and passive preamp, and go DAC/poweramp-direct: Digital volume controls in the 24-bit domain (or higher), preferably dithered and where the source is PC-based, are a brilliant solution. In practicality their use, even down to some -40dB attenuation, seem not to impede in any way noticable to my ear (going by JRiver MC19's volume control), and with the typical poweramp gain level and speaker sensitivity most would likely use digital volume leveling in the -10 to -25dB range, which is more or less inside the (theoretically) safe confines before bit stripping/truncation is said to occur. However, even outside this spectrum (i.e.: above ~-25dB ) I can't to the best of my hearing abilities hear any signal degradation with "normal" listening levels, or even lower, which in my case is typically an average ~65-75dB (measured via iPhone SPLnFFT v4.4 noise meter. Put more faith in thy ears than mere numbers and theoretical deductions..

Herb --

Thanks for your comments. Your findings on by-passing the VTL preamp are interesting, and overall are impressions I share with the direct-route in my own, albeit different setup. It goes to show there are sonically very worthwhile combinations without a preamp, and that neither dynamics nor the sense of body and vitality are necessarily sacrificed - or so I find myself. Nonetheless keeping your VTL seems like a good idea.

With regard to the synergy mentioned I believe in getting it in place, as an outset, via as few components as possible. My speakers are 2-way (w/2 units per side) with a very simple cross-over (6/12dB); my Class-A poweramp (sporting a relatively simple topology) is non-balanced and built with few by very high quality components; I use no powerstrip but instead connects my DIY power cables conductor-direct via screw terminals (though not on the component side); no connectors are used on the speaker cables (solid-core silver/gold round wire and copper foils in single-wire parallel), etc. To reiterate: simplicity not for the sake of simplicity, but as an outset and maintained where it is sonically superior or at least the equal.

How is the testing with named components proceeding?