Eliminated my preamp with amazing results

@cdc 

I tried those Harrison attenuators a while back and they killed the sound. Didn't work for me.  Paul McGowen is using them?

@atmasphere 

Make no mistake- for a DAC to drive a power amp directly the signal must be amplified to meet Redbook standards and that is done with an analog circuit similar to what you find in a preamp line section.

If the DAC has an amplified signal, which I agree it does, why do I need to add a second line gain in the preamp? Isn't that redundant?

All I need is to attenuate the signal DOWN not up. Controlling the volume DOWN using my passive TLC-1 adds NO line gain. 

@wolfie62 

Don’t you risk overloading your DAC this way??

No. The signal is attenuated in Audirvana and then sent to the DAC. The DAC has the same demand as when using the preamp. 

@markalarsen 

I've watched Pauls video where he explaines, at one time , loved no preamp. For many years! I can't help but imagine that Arnie came to Paul and said something like..." Hey bonehead...we manufacture electronics and YOU don't like preamps??" "What gives? It could be a big expansion of our product line." 

After so many years...POOF... just like that...now he loves preamps. 

Money can certainly change someone's perspective and as a manufacturer you'd be a fool not to make them yourself. Arnie woke him up to this reality.  IMHO.

@eoj4952 

Same thought different piece. Can a preamp be replaced by a cd player with volume control, be hooked directly into a 450 watt amp. Or would the speakers explode when turned on. I only play CDs

If the volume control works properly there is no reason the speakers would explode. It should effectively attenuate the signal going to the speakers just as a preamp would. If you're running this CD player through a preamp then you have 2 volume controls in the chain which is unnecessarily redundant and possibly affecting the sound negatively.

One way to find out.

This brings up the question..."what is the function of a preamp?"

My understanding is that it has 2 main functions. #1 is to control volume. #2 is allow selection of various source components. I didn't think the preamp was intended to 'add' anything to the signal and a good preamp does as little damage/degradation to the signal as possible. Adding gain does make the sound more lively but can amplify unwanted artifacts. For some, tube distortion is a positive thing. To each their own.

For some, it appears the purchase of a preamp may be an unnecessary expense and may even improve the sound by removing it.

@wsrrsw 

Thanks !! Wow, That Lumin with LEEDH sounds like a perfect solution. Researching it now. I'm curious if they'll be at the Tampa show in February since I'll be there. Would be nice to talk to them. I wonder also are there any other companies making similar units? Very interesting.

@kraftwerkturbo 

So PC-software-DAC-amp brings up the question: what software/volume control to use to play PC files. I only experiemented to simply find the volume control/software that allows the highest output (amp input not sensitive enough). Didn't consider quality (and haven't concluded yet on easy of use regarding software choice). 

Paul McGowen (PS Audio) got me started on this whole idea. He pointed out how a volume control is a restrictive device. Restricts resolution. Like putting on the brakes in a car. He said you should get the volume knob as high as possible so it does as little damage as possible. He said he likes the volume knob UP around 2 to 3 o'clock position. He said the higher volume position has a "HUGE" impact on the resolution/sound. 

How the heck can you accomplish this volume position? This led me to use the Audirvana software using a 64 bit high quality controller(Roon also). This allowed a higher position on the preamp volume knob BUT now I was using two volume controllers. So now... lets eliminate one. Get rid of the worst and use the best and most simple. 

It's possible that the reason a straight DAC sounds better than a passive preamp is the complete elimination of the restrictive volume control.

I also think people are fooled when they hear a preamp that has a boosted gain. The more dynamic sound is immediately noticeable but at what cost? 

I experimented with a Melos tube preamp that adds 20db of line gain !!! Had a big sound with plenty of dynamics. "A fun sound". "Big and Blowsey" (as per stereophile) Couldn't get the volume knob up past 9 o'clock. Way too loud. Having high resolution music source then restricting the resolution with the volume knob seemed counterproductive. 

FYI... higher end preamps use better quality 'digital volume controllers' or 'stepped attenuators' to deal with this problem. 

@antigrunge2 

In the latter instance a passive should beat any active preamp on distortion, in the former the solution might be a better DAC. I have yet to hear a concise argument why a separate preamp with additional cables and innate additional distortion should beat a high quality DAC. For most modern designs arguments about impedance mismatches are irrelevant.

Agreed. It might be far better to allocate the money spent on a preamp and instead put it into a better DAC with a better volume control that may yield a much better quality sound. The DAC chips, jitter filters and proper volume controls should have a much bigger affect on the sound. 

@lanx0003 

The closest reference I could find to Paul's narrative on this subject is a post he made six years ago. Essentially, his comments align with what has been underscored below, in contrast to what you have cited. Could you please provide the source?

Here you go. This video is from from 4 years ago. I did cite that Paul said the preamp should be of a certain quality level. Specifically BHK series quality. But don't use a lesser quality or "you won't be happy"

@mitch2 

Also, I am curious, are you running the direct (unbuffered, i.e.,  purely passive, volume control only) outputs from the TLC-1 or going through the buffered outputs.  I believe the buffered outputs provide unity gain, which should not result in any loss of dynamics and/or bass response.

Using neither. I have tried both outputs. Buffered sounds better imo but currently the preamp is completely disconnected. Perhaps the elimination of the volume control and cables is having a positive effect.

@amtrod 

Resolution, sound stage, detail, and drive are all very accurate, and I find the center image a LOT stronger.

Agreed. Much more holographic. The bass is tight and textured and the highs are just wonderful. 'S' sounds are clean. Overall more engaging.

I'm not getting rid of my preamp just yet. However, the sound is getting better the more I listen. 

BTW... Audirvana has a 'master volume max limiter'. If by chance you accidentally hit the volume slide bar it won't go over a prescribed level. I think Roon has the same protective feature.

@wsrrsw 

FYI... Steve Huff gave a great review for the "Eversolo DMP-A8" as a more affordable (Just under 2K) streamer/preamp/DAC alternative to the Lumin U2 for thousands less. Worth a look.

@lanx0003 

OK, no more speculating on my part. Lets look at the real story of exactly what Paul said...

For years he happily used a Direct stream DAC straight to amp because it sounded better without a preamp. Arnie had him listen to his 'Aesthetix Calypso' preamp. ($5000/7000) Paul agreed it was better.

Paul then went home and plugged in the best preamp PS Audio made and it sound WORSE! Why??? Arnie told him the reason it was worse was " You're not using a good enough preamp".

At that time they were using the Aesthetix in the main listening room. Arnie said..."Ya know, probably doesn't make sense to be using someone else preamp. Ya outta just make your own."

Paul set out and developed(with the late Bascom King) the BHK series ($7000)to be as good as the Aesthetix.

Paul summarized very clealy..." if you're not able to afford something as good as a BHK preamp($7000)DO NOT put a lesser preamp between the DAC and the amp. Go direct DAC to AMP" "it will sound BETTER".

I don't interpret this as Paul being an advocate for preamps, I see it as being an advocate for high end preamps ONLY. If you don't have the money (which some people can't afford) then avoid the preamp and going direct will sound better.

His words...not mine.

@retiredfarmer 

Thank you for such a thoughtful reply! So sorry to hear of your accident. I truly wish you the best.

I think we're on the same page. Without experimentation how does one know if there system is as good as it can be or how far you can take it? These experiments (including subwoofers, room placement,  etc...) have given me a better understanding of meaningful changes. I always say..."how do you know you're doing it right unless you do it wrong?"  

I believe many people just plop down their money take it home and plug it in. Since They paid a lot of money surely it sounds amazing!  Especially subwoofers. Most people are clueless to the importance of phase, gain and crossover adjustments. Like buying a Ferrari and not realizing it's tires have low air pressure or poor alignment.

This recent experiment of DAC direct to amp has again opened my eyes to what's possible. In my case, for the preamps I've used,I think there is one common denominator that I can point to as being bad. Older or lower quality potentiometers are NOT good. Even in a passive unit like the TLC-1 I'm starting to believe the POT is causing a loss in resolution making it lose dynamic presence. DAC direct restored the missing resolution (thanks to Audirvana and it's ability for high quality volume control.) A higher quality preamp with a proper volume control should certainly be equal to OR better than. I agree with you and will do experiments with other preamps shortly. For now I'm done with my current preamps. They're out.

The other issue I'm struggling with is why are manufacturers adding all this gain? The DAC adds gain then goes to the preamp that has more gain and now you can't get the volume knob up over 9 o'clock. I don't see any reason that streaming music needs this. In fact, looking at the recent trends, manufacturers are making units that have less gain and go more direct DAC to the amp with just volume control. 

So, for anyone to suggest a system is better with a preamp have they tried something like the Lumin or Eversolo ? If not, then they don't really know what's possible. It's highly possible that money spent on these units INSTEAD of a preamp may yield a higher performance. Especially the advancements in DAC chips have a huge effect on the sound. 

Trying not to be bias but I will admit that the idea of running the signal through more electronics is not appealing to me. However, as you suggest, I will keep an open mind.

Best of luck in the new year!

@skinzy 

Thanks for sharing this info.

This says it all... 

By definition, a conventional preamp takes in the audio-industry standard signal and boosts it up to full volume for the sole purpose of turning it down again! MSB’s ladder DACs put out full volume, so no such gain is needed. The signal of the hybrid DACs only needs to be attenuated (turned down), and this is accomplished using MSB’s preamp module with its newly invented passive attenuator—a constant-impedance, passive volume control with no active circuitry in the analog path.”

@gfguillot 

Controlling the volume is a huge challenge and only the best preamps can do it without losing anything in the signal. 

With all due respect... that's not true. Audirvana has an excellent volume control. (Roon also). No preamp needed. It doesn't lose resolution as you turn it down so it sounds good at lower volume.

So the question is... what exactly is a preamp doing that makes it sound so good?? Adding gain. Colors the sound and, in the process, adds dynamics. Perhaps a bit of the Fletcher/Munson curve for better low level performance. Perhaps add tubes for some 2nd harmonic distortion.

Tests have shown that people, in general, clearly prefer this sound.

However, it seems a bit counter intuitive. We want to get the highest resolution music stream source and components with the lowest possible distortion levels. We seem to want the music as it was mixed from the studio but then add gain/distortion/color back via the preamp. Two steps forward and one step back!

Using Audirvana without a preamp, If so desired, I could add the Fletcher/Munson curve via EQ without adding any gain or distortion and achieve a much cleaner end result that sounds GREAT at low levels. The added dynamic "Magic" is there with no added distortion. Clean with added headroom.

To be clear... no signal should get gain/boosted in EQ. It's opposite. From zero gain line the 'Curve' is created by pulling DOWN the midrange frequencies. Nothing gets 'boosted' above that line. The bass and treble are in a more extended curve WITHOUT adding gain. IMO a much better way to introduce the Fletcher/Munson curve than boosting gain distortion with a preamp. 

Boost it up with a preamp (which the signal DOESN'T need), adding distortion, then try to clean it up the best you can. No wonder a good preamp is so expensive.