Any thoughts on removing a preamp from your system


Hello guys

This is my first post and I have been on Audiogon for a number of years now.

My question to the group is, have any of you removed your preamp completely from your system? Run your front ends straight to your amp? And, what benefits have you noticed, if any.

And finally, if you have used a passive preamp in your system, what are your thoughts on the setup?

I understand one would need to have some sort of "pot" in the signal path to regulate volume.

Herb
hcalland
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..
For a while I had the Promitheus Audio Reference Dual Box C-Core TVC in my system driving the Spectron mono-blocks. This was a fantastic unit. Totally transparent and free of artifacts. I have also tried the Benchmark DAC1 and the DAC2 HGC feeding the Spectron mono-blocks as well.

None of these units are a true contender to the Joule Electra LA-300 ME tube preamp. The 300 ME brings in perfect pitch definition and the correct weight to each instrument. I'm used to listening to live classical music, and these two qualities in audio playback is something that's missing in both, the Promitheus and the Benchmark units. Both of these units will sound amazing as far as hi-fi sound is concerned, but when you compare them to live music, they do fall short of making me believe that the musical performance is happening in front of me.

I recently just listened to the Benchmark DAC2 HGC going directly into the mono-blocks for a few weeks. This unit gets closer to my analog playback. Anything you would want in audio reproduction is there, except that it lacks the same pitch definition and weight that the Joule Electra brings in.

If I didn't have the Joule Electra, I could definitely live very happy with either the Promitheus or the Benchmark units. In the end, one decides to live with things we appreciate the most, and to me the accurate reproduction of live music is essential in audio playback.
After more than a decade of testing my system, I have now eliminated my de Havilland Mercury 2 preamp. My CD player - Audio Aero Capitole Ref SE seem to do a better job direct to my power amps. It is more natural, fluid, organic and delicate. The preamp added more liveliness, speed and scale but also made it more mechanical.
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?
Hello Phusis.

Interesting synergy comments. I have not looked any further into simplifying my system other than the direct to amp configuration. I use two power conditioners mostly because I had experienced some low level hum, which has all but vanished with them in place. My mono amps are point-to-point wiring, and my speakers are a 3 way design. My speakers could, at 89db be more efficient for the low 20 watt Monoblocks, but I don't play my system at high volumes, so it all works.

The direct to amp did not work so well with my SS phono amp. I suspect the mono cartridge used in this configuration is the blame. It has always had very low level and tolerable hum. A condition common to the design according to the Japanese designer. But with the direct-to-amp setup the hum was remarkable. My preamp evidently helps control the noise level.

I did not try the SACD player because as you well know, digital signals will always need to be tamed. I figure the VTL preamp can only help in that setup.