Am I the only one still puzzled by the differences between amplifiers? I know I'm not alone, as I just had a PM conversation stating as much. I was well on my way replying to him when our new kitten erased the entire message.
I figured I might as well try to initiate a discussion about it here.
Did we really hear that much difference between amps? If I hadn't been there myself I would have doubts about it.
Lets go over the amps one more time.
I'll start with my Pioneer, it has a smooth sound (even if it was acting up lately) which has served me well for a long time. Replacing it with the other amps did make me wonder though.
The Roender was more detailed. What was this extra detail I heard? I don't know. But it did not get me into the music. I'd still keep the Pioneer given the choice.
The Fetzilla was something else. It really startled me in the midrange. It sounded more detailed than the Pioneer, but way more inviting than the Roender.
The Goldmund Clone shocked me with it's bass notes. Powerful notes that hit home. That was so different that I did not seem to be able to make up my mind on it's midrange performance.
The My Ref Fremen did not catch my attention after the previous two amps.
It didn't do much wrong, except the bass did not keep up with the Goldmund. It did not capture my attention like the Fetzilla did.
In hindsight it seems most amps had a little brighter presentation than the old Pioneer. But what else is different there. Why did I hear a difference.
Those bass notes weren't a subtle change. Is this an impedance thing? Does the FR balance change ever so slightly between these amps/speaker combo?
To me it seems that Goldmund really grabs the cones and controls them. Can that really be happening? I've read a lot on damping factor and that always seems to go all over the place. Some are convinced it's important, others say the effects won't influence the sound. Yet to me, if anything, that seemed to be the biggest difference?
My impedance curve is nearly flat with a rising top end (still have that compensation circuit in line):
Could this account for the differences in the top end between the amps? The amount of detail heard? The FR balance changes making up our preferences?
I like to learn from this experience, but I'm not sure if I'm able to find the right answer here. All I know I changed the FR curve ever so slightly with the Goldmund, to get it closer to my Pioneer in the midrange. The Goldmund seemed a touch bright, I added a 0.7 dB dip at 6 KHz, Q=1.
It's not the first time I've noticed how a small tweak can make a rather big sonic difference. I experienced a 'haze' on vocals, both in center and sides.
That little tweak got rid of it. My first gamble was 4 KHz, but 6 KHz nailed it for me. Silly huh?
Too small to tell right? Not for me .
I feel like an audiophool
Help me out here...
I figured I might as well try to initiate a discussion about it here.
Did we really hear that much difference between amps? If I hadn't been there myself I would have doubts about it.
Lets go over the amps one more time.
I'll start with my Pioneer, it has a smooth sound (even if it was acting up lately) which has served me well for a long time. Replacing it with the other amps did make me wonder though.
The Roender was more detailed. What was this extra detail I heard? I don't know. But it did not get me into the music. I'd still keep the Pioneer given the choice.
The Fetzilla was something else. It really startled me in the midrange. It sounded more detailed than the Pioneer, but way more inviting than the Roender.
The Goldmund Clone shocked me with it's bass notes. Powerful notes that hit home. That was so different that I did not seem to be able to make up my mind on it's midrange performance.
The My Ref Fremen did not catch my attention after the previous two amps.
It didn't do much wrong, except the bass did not keep up with the Goldmund. It did not capture my attention like the Fetzilla did.
In hindsight it seems most amps had a little brighter presentation than the old Pioneer. But what else is different there. Why did I hear a difference.
Those bass notes weren't a subtle change. Is this an impedance thing? Does the FR balance change ever so slightly between these amps/speaker combo?
To me it seems that Goldmund really grabs the cones and controls them. Can that really be happening? I've read a lot on damping factor and that always seems to go all over the place. Some are convinced it's important, others say the effects won't influence the sound. Yet to me, if anything, that seemed to be the biggest difference?
My impedance curve is nearly flat with a rising top end (still have that compensation circuit in line):
Could this account for the differences in the top end between the amps? The amount of detail heard? The FR balance changes making up our preferences?
I like to learn from this experience, but I'm not sure if I'm able to find the right answer here. All I know I changed the FR curve ever so slightly with the Goldmund, to get it closer to my Pioneer in the midrange. The Goldmund seemed a touch bright, I added a 0.7 dB dip at 6 KHz, Q=1.
It's not the first time I've noticed how a small tweak can make a rather big sonic difference. I experienced a 'haze' on vocals, both in center and sides.
That little tweak got rid of it. My first gamble was 4 KHz, but 6 KHz nailed it for me. Silly huh?
Too small to tell right? Not for me . I feel like an audiophool
Help me out here...
I think if we knew where to look, we could actually measure it.
A little more information: the Goldmund is hooked up without a pré amp right now. In the above comparison all amps except the Pioneer were hooked up to a pré amp, the Neurochrome HP-1 headphone amplifier designed by forum member tomchr.
The tweak I did (at 6 KHz) was after I hooked the amp up to the DAC directly, increasing it's gain compared to how I had it setup with the Pioneer (the Pioneer started to clip with higher voltage input).
Overall the Goldmund still seems to have more control over the cones, both at high notes and definitely low ones.
A little more information: the Goldmund is hooked up without a pré amp right now. In the above comparison all amps except the Pioneer were hooked up to a pré amp, the Neurochrome HP-1 headphone amplifier designed by forum member tomchr.
The tweak I did (at 6 KHz) was after I hooked the amp up to the DAC directly, increasing it's gain compared to how I had it setup with the Pioneer (the Pioneer started to clip with higher voltage input).
Overall the Goldmund still seems to have more control over the cones, both at high notes and definitely low ones.
Its too late measure the other amps but Pioneer and Goldmond are still there : )
If remember correct stuff as Goldmond is 3mHz bandwidth and pioneer probably in 100-500kHz area, measurements would maybe show a difference when scales are zoomed in, also beside using the normal pure resistor load on output one could measure Pioneer verse Goldmond with their real load connected and maybe fire a complicated wave shape pattern to analyze on.
If remember correct stuff as Goldmond is 3mHz bandwidth and pioneer probably in 100-500kHz area, measurements would maybe show a difference when scales are zoomed in, also beside using the normal pure resistor load on output one could measure Pioneer verse Goldmond with their real load connected and maybe fire a complicated wave shape pattern to analyze on.
So do I, I think that's where the future's at, only according to those who know how to do the necessary tests, they are expensive and funding is an issue.
IMHO there would be a lot of differences (and are) if all amps are measured and analyzed thoroughly. THD , distribution of the harmonics, phase margin, how they act on real world loads, IMD , TIM aso. I have done some measurements on them (except the Pioneer) and I know there are differences.
Problem is to quantify these differences... Some years ago (actually many, come to think about it) I was convinced, that a lot of an amålifiers character came from the distribution of harmonics, but now I don´t believe in that anymore as I have listned to amps with the same distribution and they sounded different, and I have seen (and heard ) amplifiers with a distribution I would have deemed hard and uninvolving (second harmonic and even order suppressed in relation to third and odd harmonics) sounding absolutely lovely! Still IMHO, we are a far cry from being able to tell how an amp is sounding from just looking at a data sheet, even a very elaborate one. I , at a point, was constructing an amp, where I could change the harmonic contend with changing the bias point in the input. That taught me that the relationship I thought there were between the THD signature, was not correlated to the perceived sound, the way I thought it would be.
Even though I have given up on finding an exact correlation between amp data and sound, I encourage those who are younger and more persistent than I, to go on with the guest for the Holy Grail
Yes overall agree descriptions, with the add on than The My Ref Fremen had its own world of signature compared the others, not that it was bad at all and back home in koldby's system The My Ref Fremen is said to beat the others, but a worse direction than the others for this particular system situation.
A note is in lack of time those test runs was maybe a little short and also had we been neighbors then one would probably have a better reference how Pioneer on daily basis perform, yourself should have natural better grib on Pioneer's daily performance with closed eyes in sweet spot position
but we all three in the end did agree Goldmond won. From audio devices to room specs its a clever system setup so probably some very small tonality correction would help we could live with one or the other of those amps but as was that Goldmond shined.Reminds how i miss the sound of Roger Waters track in sweet spot, distance 686km in 6 hours and 24 minutes, see you later
and remember turn on coffee machine and feed little sweet kitty.
These are high end amplifiers. I have not heard them, but I would have expected them to have hit the point of diminishing returns (improvements).
Conventional speaker drivers should be considered a current controlled device. It is a form of electric motor (B field via current). However, they are designed to mimic voltage controlled devices because we use voltage amplifiers. The driver impedance increases with freq (inductance) and yet the SPL is mostly constant to make it "look" voltage controlled.
What if we look at this a simplified 2-port network at the actual speaker driver. Looking into the driver is well known and has been well characterized. However if we "look" backwards to the amplifier (from the driver 2-port) we would see a complex impedance curve (surface?) including any compensation networks, crossovers, and the amplifier characteristics. It would an interesting experiment to measure that 2-port to compare the amplifiers. A surface plot (V-I-f) would do it. I have never seen one
Conventional speaker drivers should be considered a current controlled device. It is a form of electric motor (B field via current). However, they are designed to mimic voltage controlled devices because we use voltage amplifiers. The driver impedance increases with freq (inductance) and yet the SPL is mostly constant to make it "look" voltage controlled.
What if we look at this a simplified 2-port network at the actual speaker driver. Looking into the driver is well known and has been well characterized. However if we "look" backwards to the amplifier (from the driver 2-port) we would see a complex impedance curve (surface?) including any compensation networks, crossovers, and the amplifier characteristics. It would an interesting experiment to measure that 2-port to compare the amplifiers. A surface plot (V-I-f) would do it. I have never seen one
It is well beyond my scope and ability, so many ways to get to a faulty conclusion. However it is good to acknowledge differences do exist.
IMHO there would be a lot of differences (and are) if all amps are measured and analyzed thoroughly. THD , distribution of the harmonics, phase margin, how they act on real world loads, IMD , TIM aso. I have done some measurements on them (except the Pioneer) and I know there are differences.
Problem is to quantify these differences... Some years ago (actually many, come to think about it) I was convinced, that a lot of an amålifiers character came from the distribution of harmonics, but now I don´t believe in that anymore as I have listned to amps with the same distribution and they sounded different, and I have seen (and heard ) amplifiers with a distribution I would have deemed hard and uninvolving (second harmonic and even order suppressed in relation to third and odd harmonics) sounding absolutely lovely! Still IMHO, we are a far cry from being able to tell how an amp is sounding from just looking at a data sheet, even a very elaborate one. I , at a point, was constructing an amp, where I could change the harmonic contend with changing the bias point in the input. That taught me that the relationship I thought there were between the THD signature, was not correlated to the perceived sound, the way I thought it would be.
Even though I have given up on finding an exact correlation between amp data and sound, I encourage those who are younger and more persistent than I, to go on with the guest for the Holy Grail
I don't think it will become my journey, to find that specific Holy Grail, but this sure has opened up the discussion again. I had been curious about it for a long time.
I think what I enjoy most is a synergy of some sort.
That part was done best with the Goldmund coupled to the arrays. It just worked. Once again it proves that all details can and will matter.
My journey will continue, I'm sure... but I will stick to trying to improve balance, any way I can.
We may not be able to control everything, even when measuring. But for me it's clear we can improve our results over time. Just don't expect it to be easy and don't be in any hurry.
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Yes overall agree descriptions, with the add on than The My Ref Fremen had its own world of signature compared the others, not that it was bad at all and back home in koldby's system The My Ref Fremen is said to beat the others, but a worse direction than the others for this particular system situation.
A note is in lack of time those test runs was maybe a little short and also had we been neighbors then one would probably have a better reference how Pioneer on daily basis perform, yourself should have natural better grib on Pioneer's daily performance with closed eyes in sweet spot position
Reminds how i miss the sound of Roger Waters track in sweet spot, distance 686km in 6 hours and 24 minutes, see you later
I'd wish we were living closer too! Though I'm mighty glad to have found this Forum platform, where we actually share our journeys, for good and for bad.
So far it has brought a lot of joy and inspiration, speaking for myself. I sure am glad to have met you all! Be it in person or just from talking to each other from behind a screen.
These are high end amplifiers. I have not heard them, but I would have expected them to have hit the point of diminishing returns (improvements).
Conventional speaker drivers should be considered a current controlled device. It is a form of electric motor (B field via current). However, they are designed to mimic voltage controlled devices because we use voltage amplifiers. The driver impedance increases with freq (inductance) and yet the SPL is mostly constant to make it "look" voltage controlled.
What if we look at this a simplified 2-port network at the actual speaker driver. Looking into the driver is well known and has been well characterized. However if we "look" backwards to the amplifier (from the driver 2-port) we would see a complex impedance curve (surface?) including any compensation networks, crossovers, and the amplifier characteristics. It would an interesting experiment to measure that 2-port to compare the amplifiers. A surface plot (V-I-f) would do it. I have never seen one
I don't consider myself as a person with a lot of High End experience. Sure I've heard a few things I'll never forget again. This was really fun to be able to compare a variety of amp designs I would never get to hear otherwise.
I'm not up to the task to get to the bottom of this part of a system and what it does for perception.
My skills end with being a mechanical designer with a huge load of IT experience. So a PC driven DSP oriented setup was a given for me.
Electronics is just not my field at all. We all need each other at some point, right?
There seems to be many parameters, amplifier topology (Class A, AB, D, etc.), how much local, global feedback, THD spectra, damping factor, etc., including what Koldby said. If you read on Pass Lab's there are consistent remarks wrt each of Nelson's designs. e.g. F5 versus Aleph J for example have distinct, opposite sonic signatures.
It seems damping factor is one of those parameters that makes an audible difference, at least to my ears. Using a high damping factor amp, while most would agree of increased bass tightness, it has other sonic attributes as well. For example, the Crown Class D amp I have has a damping factor of 200, whereas the Nelson Pass ACA's have a DF of 7. Both sound different to my ears, aside from the topology and wattage, not only in the bass, but also the top end. Higher damping factor seems to have a sharper more analytical, dry sounding, sorry for the subjective words, whereas the Pass ACA has a smoother, more relaxed sound, even though both frequency responses measure the same...
As an objective measurement kind of guy, I am always intrigued by amps sounding different. I believe it is as a combination of several design parameters and implementation technologies. I have had several tube amps over the years and most simply do not have the low frequency control as compared to a high damping factor solid state design. Of course, this is anecdotal and generalization, but I do remember building Nelson's Class A-40 amp and listened to is daily for years. Then i decided to triple the power supply capacitance and was blown away on how much tighter the bass response was... go figure...
It seems damping factor is one of those parameters that makes an audible difference, at least to my ears. Using a high damping factor amp, while most would agree of increased bass tightness, it has other sonic attributes as well. For example, the Crown Class D amp I have has a damping factor of 200, whereas the Nelson Pass ACA's have a DF of 7. Both sound different to my ears, aside from the topology and wattage, not only in the bass, but also the top end. Higher damping factor seems to have a sharper more analytical, dry sounding, sorry for the subjective words, whereas the Pass ACA has a smoother, more relaxed sound, even though both frequency responses measure the same...
As an objective measurement kind of guy, I am always intrigued by amps sounding different. I believe it is as a combination of several design parameters and implementation technologies. I have had several tube amps over the years and most simply do not have the low frequency control as compared to a high damping factor solid state design. Of course, this is anecdotal and generalization, but I do remember building Nelson's Class A-40 amp and listened to is daily for years. Then i decided to triple the power supply capacitance and was blown away on how much tighter the bass response was... go figure...
Hypex was once on my wish list of things to try. Until I found reports on the First One amps beating it sonically. I think this is something that's never as clear cut as pointing to a single solution. I think going in koldby didn't expect the Goldmund clone to be the winner. Purely based on his own experience in his system. So is it that simple?
We had a Hypex UcD amp available but it would have required way more work to connect due to it being balanced only. Time was limited so we left it out. I do get the Ncore line is an evolution of that one and be considered a step up. Maybe one day I'll get to hear one.
Amps do indeed sound very different even if frequency response measures the same and they are the same power. Even amongst same Class AB, there are different input front topologies that subjectively (and measurement wise via harmonic profile) change the sound even for the same overall THD. And among Class A amps, the output stage topology, in addition to the front end topology changes everything. SE Class A vs push pull Class A vs SEPP Class A vs SE Class A with reactive inductor load is different than SE Class A with CCS load or resitive load. One thing that seems hard to quantify, yet in my experience impacts sound quality is how much global feedback is used. Some amps with little or no global feedback but local feedback on the VAS stage sound much more natural to my ears. Amps with a lot of global feedback may also be more susceptible to cable effects. I am one of the last people to think cables have an effect if I had not measured it myself.
Placing a dummy load resistor at the amp vs at the end of (7ft) of 16ga stranded copper wire had a large impact on the THD and harmonic profile of one of my best Class AB amps, I verfified by connecting 12ga solid copper Romex and got lower THD but then the 3rd order harmonic distortion went up.
So there is a fine line of secondary, sometimes primary effects on sound, when one changes the amp. The amp is a complex and sometimes reactive part of the system that should not be discounted as a crucial part of a system.
A system of source/DSP - preamp - amp - cables -speakers - room - room treatments, all have an impact, some more than others. Wesayso's system has been painstakingly improved and optimized and it sounds fantastic with the current Pioneer amp. I wonder how much more there is when a great/optimal amp us used?
Placing a dummy load resistor at the amp vs at the end of (7ft) of 16ga stranded copper wire had a large impact on the THD and harmonic profile of one of my best Class AB amps, I verfified by connecting 12ga solid copper Romex and got lower THD but then the 3rd order harmonic distortion went up.
So there is a fine line of secondary, sometimes primary effects on sound, when one changes the amp. The amp is a complex and sometimes reactive part of the system that should not be discounted as a crucial part of a system.
A system of source/DSP - preamp - amp - cables -speakers - room - room treatments, all have an impact, some more than others. Wesayso's system has been painstakingly improved and optimized and it sounds fantastic with the current Pioneer amp. I wonder how much more there is when a great/optimal amp us used?