Finding just the right spot
Join Our Community Subscribe to Paul's PostsMost preamplifiers have a zone on their level controls where they sound best; typically higher on their dials.
Finding that perfect spot on the dial isn’t too hard, but getting there can be because much depends on the loudness levels of the source and the sensitivity of the speakers.
Most sources don’t have level trim controls to help match their gains to the rest of the system.
If you have a DAC, like our DirectStream, then it is an easy task to set the gain to match the sweet spot on your preamplifier. For example, depending on the system I am using, I like to set the DirectStream at around 80 on its level control. This places most tracks in the upper 40s and 50s on the BHK preamplifier, and the softest tracks bumping into the high 70s.
It’s tempting to think preamps sound the same at any level setting, but it isn’t true. Not for most preamps, anyway.
Finding just the right spot on the preamp level dial can bring hours more enjoyment to your system.
Well now that you mention it i am wondering why I didn’t consider it a possibility and seek the answer out of curiosity. Apparently I wouldn’t of any time soon. And for the prompt I thank you Paul. Can hardly wait for the neighborhood to wake up. I will lower the Gain on my PS phono preamp (wonder where it’s sweet spot is) so i can raise the Gain of the BHK pre amp to around 70…..never been there before….usually hanging around 30 for the room’s sweet spot. Then I will be looking for the sweet spot on the contact of a golf ball for the rest of the day. Ode to find the sweet spots. Story of my life.
Finding the sweet spot is always nice. Whether it’s in audio or on the golf course.
Hit ‘em long and straight, but remember it’s the 100 yards and closer where you’ll really cash in.
Let us know what you find!
Okay…I am spinning a CD …Live recording…Marice Mobetta Brown Nola Jazz Fest 2019. It was a great set…BHK Pre at 75 on The pot. DSjr at 40-50. Feeding M700 Stella and a BHK 250 to four towers made up of 89 db Invisa Golden Ear Mids 5-7″ and two REL Gibraltors
Very noticable is that the Dynamics are more pronounced. Bass mids and highs are more defined and clearer..sound stage defined. This alternative gain shift has stepped up my system to another level. I will probably be staying around this sweet spot a while..
So it’s going to be any for me and many of us to try this.
With jRiver the output is variable. Lower that, increase the pre- .
Listen
Or is it unfair— the jRiver lower output also lower quality?
Off to try it…
… easy for me …
note to self. Respect audience by proofing before posting.
I found this out quite a while ago. I installed an older school tube line source tube preamp which brings out a sound stage my current Dac (with volume control) can’t or won’t. I also have the added benefit of the Dac providing a remote volume / mute control. In fact I also have another older solid state line source preamp that I have been driving my subs with. (It is fed from an active crossover at around 38 Hz between the Dac and pre’s) The combination of the 2 pre’s has given me the sound qualities of the mids, the highs and a well defined large soundstage I want, along with the bass control I was looking for. It also has the added benefit of being able to cut / push the bass levels conveniently based on any given recording.
The numbers that are referred to above, other than 80 on the volume control, make no sense to me as I don’t have BHK Amps.
The time consuming part was matching output levels of the preamp for the amps with the variable Output level of the DAC as there a fair amount of combinations. In the end it was well worth it.
I started with the “less gain – less pain” philosophy.
I’ve always thought that preamps were designed at first with no level control. In fact, I asked the manufacturer of the last preamp I owned for a modification to lower the gain so that I could use it at a higher level setting. They obliged (I seem to recall a change from 17dB to 10), the setting became higher with sound level meter checks, but I could never decide if there was improvement in sound quality. Certainly it was no worse.
This is the same problem as the cable problem. In this case you have a source, the potentiometer which is a series and parallel resistor, and the load. To reduce the effect of the potentiometer on the quality of the sound the stage before the potentiometer should have a low output impedance like an AB amplifier with an output impedance below one ohm, and the next stage should have a very high impedance, as high as you can get it, say 1 megaohm or more. At this point the impedances of the potentiometer should be negligable compared to the rest of the circuit. AC electricity 101. When you consider a so called passive preamp you can see how the problem is made even worse especially with solid sate amplifiers that often have an input impedance of 5k to 10K. Why don’t output stages of low level devices have a very low output impedance using a class AB circuit but instead a cathode follower or emitter follower circuit? Becaue we’ve always done it that way. Once that would have been very expensive with tubes. Now it’s dirt cheap with transistors.
I’ve also wondered about the cathode / emitter follower for gain control but maintaining soundstage, dynamics and tonal balance. Maybe a gain cell but with a gain of 1 or less?
Emitter and Cathode followers have a gain of just under one or less. Their output is in phase with the input. Usually a shunt resistor to ground defines the source impedance. In the tube era you not only needed two tubes but an impedance matching transformer as well and output impedance was still high. Today an extra transistor forming a class AB stage that can deliver a little more power, say the equivalent of a 10 watt amplifier will have extremely low output impedance and the next stage having a Mosfet input can have a very high input impedance. This arrangement reduces the significance of what is in between whether it’s a wire or a potentiometer.
I set the gain by the amplifier, not from the source. My amp has two gain settings. The manufacturer recommends the lower setting for balanced interconnects, which puts the preamp settings into the 40’s to low 50’s out of 90.
I tried this “trick”a few times in the past. Set my DSJ gain between 80 and 90, but never was satisfied : (some) resolution/transparency is lost, although the manufacturer, as any manufacturer, says that this will not happen.
Others may not hear this and will be totally satisfied with this solution.
So now the dac gain is 98 (100 is max.) and the volume is adjusted with my pre amp.
I got from Ted within the DS 80% discussions, that this is the sweet spot of the DS volume control…are you sure you’re hearing the sweet spot of the preamp in fact?
Two things about listening levels —
First, for me different music begs for different levels with playback, unless the system is extremely veiled. Yet many of my audio friends tend to play almost everything at the same level when I hear their systems.
Second, as I understand it, the now old-fashioned volume potentiometer has less resistance as you increase the level. Someone once said the ideal system could be played back wide open at the highest volume level the owner would ever listen. Yet most of us tended to listen with the volume pot never past the half-way point.
Surely this depends on the design on the pre-amp. The only pre-amp I ever owned was passive and had a stereo pair of 48-step attenuators. such a design should operate identically at any setting.
If the preamp was completely passive with no buffer stage one would expect definite sound changes with VC settings.
I believe that was the rationale for stepped attenuators, to deliver identical sonics at every setting.
But they were more expensive, and many who tired them complained either there were not enough steps, or they were too far apart when a desired level fell somewhere in between. So they didn’t become as common as standard volume pots.
It was actually 64-steps of 1db. It was not expensive as it was sold direct. They would become vestry expensive if sold through dealers and distributors. It certainly gave me no problems, just wen t back to an integrated unit.
Paul, I hope you can expand on this idea. One of the most useful tips you’ve offered me — very early when I began following these posts — was that each recording has its own “sweet spot” when it comes to volume. I have found that to be absolutely true.
Allow me to describe my own system and ask what you advise, because I think it may also help others.
I have a McIntosh MA6500 integrated amp, so no separate preamplifier. I also have a Direct Stream DAC and a Stellar Power Plant. In fact if I remember correctly, an advisor in your tech department urged me to set the volume on the Direct Stream at 100% as often as possible. That did not seem to coincide with your advice that the best volume settings vary per each recording.
So what I’ve done is this. I have s volume setting on my McIntosh which I rarely change. It is not particularly high, it is an old-fashioned knob control set around 10:00 o’clock. I then adjust the volume of the Direct Stream depending on the recording. One reason I do it this way is that the Direct Stream has a screen telling me what adjustment I am making to the volume as I control it with my remote from my chair. I can also control the volume of the McIntosh from my chair but there is no digital read-out I can see when I do so.
In light of your post, I am inclined to turn up the volume on my McIntosh so that most recordings sound best when the Direct Stream is set at 80, and then adjust individual recordings on the Direct Stream via the remote. But as thing stand now my Direct Stream is usually between 85 and 100.
Again further explanation and advice from you would be welcome. Thanks!
Well, part of the issue is with the DirectStream itself in this case. The latest few firmware versions sound best at 80 to 85. Ted’s proffered some technical reasons why, which I have forgotten. But, none the less, it is true with DS.
On the whole, my comments in the post still stand as a general rule.
Paul thanks. If someone could offer a link to Ted’s explanation of this issue it would be appreciated.
As I said, someone in your tech department — who I am certain was offering the best advice he knew of — did not pass that on. My Direct Stream arrived in December so that advice is fairly recent. And I am running the latest software.
Thanks. It isn’t a big deal but the difference in sound quality is noticeable. I dug up what Ted had written in a post on the forums.
“we are always trading off volume for ease/headroom, the lower the volume the more headroom you have and hence the more dynamic the material can be.”
Again, this is not a huge deal and the easiest way to decide is to simply give it a listen. I vacillate between 100 and 84 depending on what else is going on in the system. I find that with the DAC set at 100 it’s a bit punchier sounding and a bit more lively. At the lower gain setting it’s more complex and rich with info, harmonics are more noticeable, but it’s a little laid back.
Just try it and see. I have never been a fan of McIntosh and their sound, so I am probably the wrong person to ask about what to do as far as going in direct, but you can probably guess which way I’d try first. 🙂
Thanks Paul. I’m aware of your views on McIntosh and we can easily agree to disagree there. My system has never sounded better than with my newer PS Audio products through the McIntosh, so I’m very happy with that combination.
Not sure what you mean by this:
“I am probably the wrong person to ask about what to do as far as going in direct, but you can probably guess which way I’d try first.”
I can’t guess because I don’t know what you mean by “going in direct.”
The DS manual refers to driving, “a power amplifier directly, or as another input on a preamplifier.” How that might apply to an integrated amp is not something I understand. Any clarification is welcome.
Oh, sorry, didn’t mean to be cryptic. I forgot yours is an integrated. Yes, we recommend going direct with the DS unless one has a preamplifier that betters the sound quality of that arrangement (like a BHK pre, the Aesthetix Calypso, etc.).
Unless DS is your only listening path, then there’;s probably not much you can do (like go directly into the integrated’s amplifier) that would make sense.
If it’s working, and it sounds like it is and you’re happy, then there’s nothing better than that! Often times the synergy of a system outweighs just about anything else.
Thanks again Paul. Like so many others, I try to remind myself that if the system sounds good to my ears — and mine does now — I should stop tinkering. But…then a new suggestion comes along and of course I want to figure out if I can make any use of it.
Of course! That’s half the fun of it. We get itchy because we know it can be better. I have to scratch my itch every few weeks or go nuts.
Paul:
This is probably a silly question but does Ted have a different opinion of the 85 target on the DS if you have it in the -20DB attenuated mode? I
He agrees with this finding too.
I discovered this a while ago. I surprised myself that inserting a preamp in the signal path between DAC and power amp sounded better than directly driving the power amp from the DAC. (“Straight wire with gain” thinking suggested a different result.) But, Paul, it seems there are (at least) two explanations. How can you choose between them? For background, I am using an NAD M51 DAC and an Auralic Taurus MkII preamp. I found the “sweet spot” with the DAC digitally attenuated by 25 dB and the preamp knob at something like 85% of full scale. In other words, I’ve shifted the analog gain from the DAC to the preamp. Explanation #1 is yours; preamps are happiest near full scale. Explanation #2: my preamp is just a better analog gain stage than my DAC’s output stage, as good as it is. How do you decide which explanation is correct?
Listening is the best way to decide what sounds best, believe it or not ; ) You can talk yourself into one theory or another about it in advance if you like, then feel happy about your choice as it is backed by theory, many folks do.
If you want to get into the weeds with us on the forums, there is a lot more on it here:
https://forum.psaudio.com/t/life-at-80-to-90-is-great-click-bait-title/10007
I agree that there is a volume sweet spot for every preamp and every piece of music and it varies a lot between sources.
So Paul, If the volume control is out of the signal path at full volume and your sources have adjustable outputs, would it be best to set them for max volume when the preamp is set to full volume?
Volume controls sound best when they are at full, yet the problem is, they cannot be full without clipping the amp. Since most sources are set to somewhere around 2 volts out, which generally clips the amp, and preamps offer additional gain, you simply cannot do what you’re proposing.
That leads to where is it best to attenuate.
Since most sources don’t have volume controls, let’s imagine we treat all sources as full output all the time.
That leaves the volume duties to the preamp.
Thanks for the answer. That is what I thought.
If I can squeeze in here I thought Paul recommended some time back to turn the volume on the preamp up all the way and then control the volume of your system with your DAC. No?
One of the things I admire about the guy is his ability to change his mind once convinced of a better way of doing things : )
I agree with Paul and the general trend here based on about 50 years of being an audio enthusiast; source at 75% – 80% or so, never 100%. I have always used the preamp to control the volume. No matter what, I always go back to those source settings. For me, I find it gives the most satisfying overall musical experience. I have found this to be true regardless of the source–if it has a gain control.
So, how would the Stellar Gain Cell Dac fit into this conversation, if at all? I have an SGCD/S 300 combo with two digital inputs, iMac via USB, and Panasonic Ub–820 Blu-ray player, as well as a couple of analog inputs. The only input with volume control is the iMac, from which I stream Tidal via Audirvana. Should I reduce the volume on Audirvana and increase the SGCD volume, or leave the Audirvana volume at 100% and adjust SGCD appropriately? Since none of the other inputs have a volume control, I simply adjust the volume with the SGCD, which is typically in the 15 to 25 range for acceptable listening levels. Of course, that’s nowhere near a maximum level for the SGCD.
The SGCD is a different beast because of the Gain Cell, which is a variable amplification stage as opposed to an attenuator. The level of the SGCD doesn’t affect the way it sounds.