maybe you need a shift to high efficieny speaks, low power SET since you listen so low. What's the point, don't get me wrong, with mono-block class A biased hot beasts and you are listening to what 70-75 db? You might want to research high efficieny systems. Great dynamics at low levels too. either way you are back on the merry go round...enjoy your ride!

dpac996 October 12, 2007 20:46

Tboooe, one other piece I left out w.r.t. preamp volume controls: If a design claims to be true balanced (differential) then each phase(+/-) will require its own attenuator. Therefore 4 such attenuators actually compose the overall "volume control": left/right differential phase. I'm not that familiar with the Esoteric but what the spec sheet shows does not indicate that this is so. I think the volume control is simply done single ended and then they use op-amps to generate the inverted/non-inverted outputs (based on what I see in the product literature).
I think to optimize your maximum objective performance in your system you ought to use the fixed outputs from the DAC and run that to a true balanced line stage.

dpac996 October 08, 2007 13:38

not sure why the dbl post.
Have you tried any solid state pre's from Ayre or Classe?

dpac996 October 08, 2007 02:42

warning: long boring technical details:
To obtain the level of fidelity we usually seek, the role of the preamp is hugely important, perhaps the most critical element in the chain. The main function we realize is "simply" to control the volume. The usual methodology of modern preamp design is for the line level signal to first hit the volume control. This passive device can be a basic potentiometer, a rotary (think shallco) ladder or shunt, a packaged integrated circuit (these contain switching elements, and resistive elements, and have a digital interface with a microprocessor for attenuator select), or a transformer volume control (TVC). Of course there are many ways to fabricate the attenuator but these are the most common.
The IC's typically are very inexpensive solutions but neatly solve the problem of fine volume control with easy integration to remote controls. Unfortunatley they do contain active elements in addition to the resistive ones that, for one make analysis more difficult, and may ultimately be the limiting factor in an otherwise well implemented preamp design.

The simplest path for the signal (fewest parts) is more desirable than one that requires the signal to flow to many differing elements.

The main problem the designer faces is noise. All resistive devices generate noise that is directly proportional to the resistor value. Another issue involves maintaining a constant input impedance (or close) to the sources. I beleive it is this stage that ultimately determines the dynamic range potential and accuracy of the preamp. If the low level content of our precious signal is lost in the noise floor here, there is no chance of regaining it down the line. We know it is the low level detail that gives rise to microdynamics, sense of space, and air, and overall presence.

The next stage is gain and sometimes buffering. The signal that emerges from the passive volume control is now amplified by a fixed gain and maybe buffered such that it presents a low enough AC output impedance to not significantly be affected by long cable runs and/or low input impedance amplifier front ends (these usually run from 10k to 100k). I beleive it is this stage that ultimately "flavors" the resulting character of the signal passing though the preamp. The gain functions can of course be implemented with solid state devices (bipolar, mosfet, jfet) or with vacuum tubes. The choice of tubes usually brings with it the need to isolate the plate voltage from the external world, and as such dc blocking capacitors are the usual choice. One could also use a transformer here (just like the output transformers in tube power amps but on a much smaller power scale).
So of course it is more trade offs here. The tube circuit carries with it the penalties of additional design requirements to make sure the output is safe and will not kill the downstream component. One can dispense with these additional requirements if solid state is chosen.
Of course there is the power supply...(tube regulation, solid state regulators, toroid/ei core/c core...)

These statements reflect my understanding of the basics of preamp design and really don't even scratch the surface. When we decide on a preamp we are paying for these design choices based on research and development (experience), trial and error, measurements, and of course sound quality.

The tradeoff you face in any source that has a variable output is that usually this piece is given the least slice of development dollar pie, and is quite difficult to assess its performance as a preamp. This preamp/volume control is also mixed in with digital elements and noise issues here require extra care in the PCB layout and isolation to avoid noise in addition to the basic preamp problem...It is usually an inexpensive potentiometer, or maybe a digital control that comes with its own headaches. When you buy a dedicated unit, such as the REF 3 you had, you are paying for a direct solution to the volume control problem.

dpac996 October 07, 2007 19:30

warning: long boring technical details:
To obtain the level of fidelity we usually seek, the role of the preamp is hugely important, perhaps the most critical element in the chain. The main function we realize is "simply" to control the volume. The usual methodology of modern preamp design is for the line level signal to first hit the volume control. This passive device can be a basic potentiometer, a rotary (think shallco) ladder or shunt, a packaged integrated circuit (these contain switching elements, and resistive elements, and have a digital interface with a microprocessor for attenuator select), or a transformer volume control (TVC). Of course there are many ways to fabricate the attenuator but these are the most common.
The IC's typically are very inexpensive solutions but neatly solve the problem of fine volume control with easy integration to remote controls. Unfortunatley they do contain active elements in addition to the resistive ones that, for one make analysis more difficult, and may ultimately be the limiting factor in an otherwise well implemented preamp design.

The simplest path for the signal (fewest parts) is more desirable than one that requires the signal to flow to many differing elements.

The main problem the designer faces is noise. All resistive devices generate noise that is directly proportional to the resistor value. Another issue involves maintaining a constant input impedance (or close) to the sources. I beleive it is this stage that ultimately determines the dynamic range potential and accuracy of the preamp. If the low level content of our precious signal is lost in the noise floor here, there is no chance of regaining it down the line. We know it is the low level detail that gives rise to microdynamics, sense of space, and air, and overall presence.

The next stage is gain and sometimes buffering. The signal that emerges from the passive volume control is now amplified by a fixed gain and maybe buffered such that it presents a low enough AC output impedance to not significantly be affected by long cable runs and/or low input impedance amplifier front ends (these usually run from 10k to 100k). I beleive it is this stage that ultimately "flavors" the resulting character of the signal passing though the preamp. The gain functions can of course be implemented with solid state devices (bipolar, mosfet, jfet) or with vacuum tubes. The choice of tubes usually brings with it the need to isolate the plate voltage from the external world, and as such dc blocking capacitors are the usual choice. One could also use a transformer here (just like the output transformers in tube power amps but on a much smaller power scale).
So of course it is more trade offs here. The tube circuit carries with it the penalties of additional design requirements to make sure the output is safe and will not kill the downstream component. One can dispense with these additional requirements if solid state is chosen.
Of course there is the power supply...(tube regulation, solid state regulators, toroid/ei core/c core...)

These statements reflect my understanding of the basics of preamp design and really don't even scratch the surface. When we decide on a preamp we are paying for these design choices based on research and development (experience), trial and error, measurements, and of course sound quality.

The tradeoff you face in any source that has a variable output is that usually this piece is given the least slice of development dollar pie, and is quite difficult to assess its performance as a preamp. This preamp/volume control is also mixed in with digital elements and noise issues here require extra care in the PCB layout and isolation to avoid noise in addition to the basic preamp problem...It is usually an inexpensive potentiometer, or maybe a digital control that comes with its own headaches. When you buy a dedicated unit, such as the REF 3 you had, you are paying for a direct solution to the volume control problem.

dpac996 October 07, 2007 18:08

Tboooe if you go SS preamp you might want to consider the Boulder 810.

I think this would be a stunning accent to your system.

IMHO, there are trade offs to reconcile when you select sources with variable outputs. There is no free lunch.

Regards.

dpac996 October 07, 2007 01:21

Organic is not always good. First time we shopped at Whole Foods, we bought some food that made us really sick. All those years of fast food i'm fine...and what is considered to be a health nut store makes me sick...go figure.

recordings are like photographs. You want to relive happy moments as captured on the photo, but time passes and it will never be the same. Live shows (anywhere) are much the same way. We are (usually) experiencing it with others, are totally relaxed and having collective fun...though we hang on to such events we can't relive these moments...Such is life. Live music is live music and recorded music is what it is. Totally different no matter how you "timbrally" slice it ( or is that timbre-ly... gotta love these made up terms). For me, life is too short to get caught up in obsessive comparisons between the sound of, say, a live trumpet, and a recorded one (furthermore it won't even be the same time/space trumpet we are comparing unless we are in the studio and part of the recording chain...so the whole argument is further cast into meaningless-ness)

on a diff note,
A'gon can be such a dog and pony show, but the only thing that really matters is if it makes the owner happy. If it sounds good, how can it be anything but good?

dpac996 October 04, 2007 13:41

Oh i did not read your overall system thread. I skimmed. I see...Ok, well then how about pushing that rear wall out :)

I bet you get great dynamic slam in that room.

I read that one review on those pass amps from that classical composer and since then i have been dreaming about those amps. Do not sell them!! Take a break and get back to it.

I also share a living room; it's a bizarre L shape, but it actually sounds coherent and wide with a spotlit central image. Go figure. Hopefully when the market comes back to life (perhaps on a geologic time scale) we will sell and get a bigger pad.

dpac996 August 27, 2007 18:16

Have you tried pulling your speakers out, oh about 4 feet? I used to have mine about 36 inches from rear wall, but once they migrated to 55 inches the 3D thing happens much better, as if they "breath". Free tweak too!

dpac996 August 27, 2007 03:27