803S + HTM3S + SCMS - Need amp!

[RebelMan]

Chaterbot, it should be known that my casual trade show encounter suggests Accuphase gear is quality stuff which I am not challenging here. Nor am I challenging your opinion nor your decision for choosing. I am only contesting the methods used to collect the data.

I compared the integrated-amps at the dealer, where only an Accuphase-CDP was the source.
The more detail of music together with more precision in bass for my taste, if you
want, was with the Accu.

The results are the same. Using the same source player but different pre-amplifiers yields different results, similar to Case 3 above.

At the home-testing-session the Denon was the pre for both, and my understanding
for an external pre-input at an integrated power-amps back is,
that the internal amp leaves the pre-station alone and works as a pure power amp.
Again: the same results as written above.

I am afraid to tell you it's the wrong understanding. The volume knob on integrated amplifier is controlling the amplifier stage. You could use the "unity-gain" feature of the Classe' integrated and allow the Denon to control its amplifier stage but the line level voltages will still traverse the pre-amplifier circuits enroute to the amplifier stage of the CAP-2100. It's not a true by-pass.

Now, that I can switch my setup between the Accuphase being the integrated amp
or my Denon being the pre with the Accu used as power-amp, I can hear no
difference between
- the pre-section used in the Accuphase
and
- the pre-section used in the Denon AVR2805.

That, for my understanding, shows that the pre-section is not the reason for the
different soundings.

This in an incorrect interpretation. By definition an audio/video receiver (AVR) is an integrated amplifier with a built-in tuner. You have what is essentially two integrated amplifiers daisy chained together. When you connect your CD player (analog out) to the Denon and then to the Accuphase is there a difference? The Denon and the Accuphase will impose their own unique character to the signal so there should be a difference. I cannot fully explain why you do not detect any differences when the two are daisy chained together but could hypothesize a few possibilities.

I am not arguing that the amplifier stage is not contributing anything to what you hear only that it will be subtle in the vast majority of cases. The dominate sound character comes from the pre-amplifer which is found in separates, integrated's, processors and receivers.

Need more proof? I offer this challenge...

If someone, ANYONE, can find me one, just ONE, A/B/X test involving a constant system where only the pre-amplifier is changed with results that contradicts what I have said I'll publicly recant everything and offer my apologies. (Good luck finding an A/B/X case that just examines the pre-amplifier!)

Now try the same approach where only the power-amplifier is changed. (I think you find this to be no problem.)

I rest my case!

[Chatterbot]

@Rebelman:

This is a nice discussion, but it will go nowhere. I´ve seen this type of discussions
over and over in some German-speaking forums as well.
Cables, A/D-Converters, pre-, power-amps, *fill in any high-end-hifi-related subject*
;x(

I am afraid to tell you it's the wrong understanding. The volume knob on integrated amplifier is controlling the amplifier stage. You could use the "unity-gain" feature of the Classe' integrated and allow the Denon to control its amplifier stage but the line level voltages will still traverse the pre-amplifier circuits enroute to the amplifier stage of the CAP-2100. It's not a true by-pass.

You may be right in case of the CAP2100. There must be some kind of microprocessor
controlling the input-circuits and the pre-section might not be completely by-passed.
But in case of the Accuphase you´re not. There is a switch that controls a relais
which bypasses the pre-section.

So I might indeed have compared a pseudo-power-amp-circuit with a pure power-amp-circuit.
That either shows that the pre-section of the CAP2100 is not the best, or, if this
is not the case, that the Accuphase has got the better power-amp-circuits
(for my liking).

On a sidenote:
I did run the 803S on the Denon2805´s integrated power-amp-connection first.
Then i ran them on a Denon POA2800 power-amp driven by the 2805 being the pre.
After that, I exchanged the 2800 power-amp with the Rotel RMB1075 running by bi-amping.
Each step was an improvement to the former (I have to admit that the step "internal-final-stage
Denon2805 -> Denon 2800 power-amp" was bigger than the next step to the Rotel running bi-amped).

And, you´d not be surprised, I know my CDs very well. And I´ve never heard this precision
in bass as I have now with the Accu.

This reminds me of some statements in hifi-magazines: the good ol´ German sounding and
the "warmer" English one. That was loudspeaker-related but fits my amp-impressions very well.

I am not arguing that the amplifier stage is not contributing anything to what you hear only that it will be subtle in the vast majority of cases. The dominate sound character comes from the pre-amplifer which is found in separates, integrated's, processors and receivers.

Can we arrange that there may be more than one piece of equipment, which
affects the final result (audiophile audio) at the end?
1. Room
2. Loudspeakers
3. Source-material (CD, SACD, mastering)
4. electronic (pre/power or integrated, DAC, CDP)
.
.
123: LS-cables :boozer:

If there only would be "the" amp, who fits everyones needs, hifi would be boring :T
...and active loudspeakers would increase quickly..


Greets,
Guenther

[RebelMan]

@Rebelman:

This is a nice discussion, but it will go nowhere. I´ve seen this type of discussions
over and over in some German-speaking forums as well.
Cables, A/D-Converters, pre-, power-amps, *fill in any high-end-hifi-related subject*
;x(

Perhaps my message is falling on deaf ears.

ABX testing was developed to dispel the belief that audible differences between certain “devices” could be detected with predictable regularity. It was not meant to prove that audible differences exist only that they didn’t. I am not making any claims for or against the audible credibility one has for a particular device. I am claiming that the extent or the magnitude of the audible differences occurs more frequently with some devices than it does others.

The challenge I put down has not been met by you. Why not? How hard could it be? You said you have read discussions like this over and over. Show me one case, just one case, of an ABX test that involves pre-amplifiers.

It is unlikely that you will be able to furnish an ABX test involving pre-amplifiers because the results would show that people have a propensity to detect changes between pre-amplifiers with predictable regularity. The results would contradict the intent of the test which is to prove that differences are inaudible, not audible. On the other hand ABX tests involving power amplifiers are plentiful and the results are overwhelmingly inconclusive.

The message, which up to now I have failed to get across, is not that differences don’t exist between devices. Rather it was to say that they exist in varying degrees. It’s an established and well known fact that the pre-amplifier stage of the electronics chain will have a profound effect on the system's overall performance. Your in home and at dealer demonstrations have shown this to be the case whether you choose to accept the notion or not.

You may be right in case of the CAP2100. There must be some kind of microprocessor
controlling the input-circuits and the pre-section might not be completely by-passed.
But in case of the Accuphase you´re not. There is a switch that controls a relais
which bypasses the pre-section.

So I might indeed have compared a pseudo-power-amp-circuit with a pure power-amp-circuit.
That either shows that the pre-section of the CAP2100 is not the best, or, if this
is not the case, that the Accuphase has got the better power-amp-circuits
(for my liking).

There is no microprocessor in the CAP-2100. I don’t think you understand what I meant by by-pass. By-pass on the CAP-2100 switches the pre-amplifier into a mode called “unity-gain” which means it doesn’t amplify the signal (pre-amplifiers amplify “low-voltage” signals not to be confused with power amplifiers that amplify “line-level” voltages). The E-208 should be no different unless it has a by-pass button that can switch the mode of the pre-amplifier stage from active to passive. I saw no such mechanism on the E-208 which could actually do more harm than good. Although if it includes one, as you say, then I wouldn’t be completely surprised given the inclusion of detrimental tonal and loudness compensation controls which I suspect much of the credit for liking belongs to.

[cug]

ABX testing was developed to dispel the belief that audible differences between certain “devices” could be detected with predictable regularity.

It was developed to find what can be heard (!), not what the brain of the tester makes from what he knows, hears, sees and feels.

Whether it shows a difference or not doesn't matter as long as it meets the requirements that a tester tests gear he doesn't know. Only with that can you "hear" the true difference - if there is one.

Example: I bought my first pair of speakers out of a setup of about ten different systems. I didn't know what speaker was playing, I wasn't told AND I had my eyes closed. I just listened, the sales rep switched speakers all the time (with a sophisticated switch board - yes, I didn't care about the minimal influence that thing might have had as long as ALL speakers got the same signal).

In the end I decided, that two speakers were my absolute favourites - I liked one more than the other, but the sales rep told me that one was a bit above my budget. There was A LOT OF AUDIBLE DIFFERENCE and it was the sole purpose to find that difference and to tell whether I like it or not.

Surprise: In this test in 1988 I chose from the whole bunch of speakers a Bowers & Wilkins Matrix III as my favourite and a Matrix II as my second. I bought the Matrix II as I didn't have the money for the other.

And this is how you should buy audio gear: listen to stuff you don't know. Do blind testing, select the gear you like most by LISTENING and after that take a look what it is ... you can discard the ugly NAD receiver then ... :B

[RebelMan]

It was developed to find what can be heard (!), not what the brain of the tester makes from what he knows, hears, sees and feels.

Whether it shows a difference or not doesn't matter as long as it meets the requirements that a tester tests gear he doesn't know. Only with that can you "hear" the true difference - if there is one.

Isn't that what I said? No one doubts what they can hear only what they can't but think they should. To be convinced they ABX not the other way around as there's really no need to. The formal test settings to which you are referring was designed to prove that differences don't exist or are inconclusive. It's guised up and sold differently but the intent is the same.

Have you got the ABX lowdown on pre-amplifiers? I'd like to see them if you do.

[bigburner]

RebelMan,

The ABX test is a method of comparing two kinds of sensory stimuli to identify detectable differences. This is an important distinction from what you have stated because it is impossible to prove that something does not exist. The burden of the proof is on the person claiming that a difference can be heard.

In the absence of an ABX test involving preamplifiers, what proof can you provide to support your claims that "people have a propensity to detect changes between pre-amplifiers with predictable regularity" and "it’s an established and well known fact that the pre-amplifier stage of the electronics chain will have a profound effect on the system's overall performance"? Surely the only proof is an ABX test?

Nigel.

[RebelMan]

The ABX test is a method of comparing two kinds of sensory stimuli to identify detectable differences. This is an important distinction from what you have stated because it is impossible to prove that something does not exist. The burden of the proof is on the person claiming that a difference can be heard.

The burden of proof that the listener bears implies that differences are hard to detect or cannot be distinguished with absolute certainty. An absence of change that becomes a guessing game to resolve. The only distinction is in the semantics.

In the absence of an ABX test involving preamplifiers, what proof can you provide to support your claims that "people have a propensity to detect changes between pre-amplifiers with predictable regularity" and "it’s an established and well known fact that the pre-amplifier stage of the electronics chain will have a profound effect on the system's overall performance"? Surely the only proof is an ABX test?

No one questions it on an empirical basis. Do you have proof to the contrary?

[bigburner]

The burden of proof that the listener bears implies that differences are hard to detect or cannot be distinguished with absolute certainty. An absence of change that becomes a guessing game to resolve. The only distinction is in the semantics.
No one questions it on an empirical basis. Do you have proof to the contrary?

Empirical means that it is capable of being verified or disproved by observation or experiment. What is the experiment and where is the data from that experiment? What valid experiment is there other than an ABX test?

You have made a factual claim in your post and I have asked you to provide some proof to support your claim. If you can't provide that proof then it's an opinion, albeit supported by anecdotal evidence, but it's not a fact.

You are a knowledgeable contributor to this forum and sound logic is usually a feature of your posts. On this occasion I think that your logic is flawed.

Anyway, that's all I have to say on the matter so feel free to get the last shot in.

Nigel.

[Minardi2]

Lock it up

It's time for the mods to shut this one down. It's no longer about what the original poster was asking, which is unusual for this forum. I feel like I'm reading the high-end forum on AVS where this stuff happens all the time.

[cug]

Isn't that what I said? No one doubts what they can hear only what they can't but think they should. To be convinced they ABX not the other way around as there's really no need to. The formal test settings to which you are referring was designed to prove that differences don't exist or are inconclusive. It's guised up and sold differently but the intent is the same.

Have you got the ABX lowdown on pre-amplifiers? I'd like to see them if you do.

We are doing word play here. I think blind tests are for those wanting to prove that there is a difference AND those wanting to prove there is no difference.

For me: it's often enough a cost saver as I compare the sound, and nothing else in the beginning. After that I start with the rest and see, whether it's worth spending more for getting more features, nicer look, better name, longer guarantee or whatever.

[cug]

The burden of proof that the listener bears implies that differences are hard to detect or cannot be distinguished with absolute certainty.

Nope. It implies that you concentrate on the one thing you WANT to concentrate on: sound.

[Chatterbot]

@Minardy:
I´m feeling sorry that this thread dissapoints you, that surely wasn´t my intention. But oh well...

Perhaps my message is falling on deaf ears.

I can show you my last audiometry

There is no microprocessor in the CAP-2100. I don’t think you understand what I meant by by-pass. By-pass on the CAP-2100 switches the pre-amplifier into a mode called “unity-gain” which means it doesn’t amplify the signal (pre-amplifiers amplify “low-voltage” signals not to be confused with power amplifiers that amplify “line-level” voltages). The E-208 should be no different unless it has a by-pass button that can switch the mode of the pre-amplifier stage from active to passive. I saw no such mechanism on the E-208 which could actually do more harm than good. Although if it includes one, as you say, then I wouldn’t be completely surprised given the inclusion of detrimental tonal and loudness compensation controls which I suspect much of the credit for liking belongs to.

I surely know how to bypass something. 8)
The "little" Accuphase-amps do not have the bypass-switch.
The older bigger models, like the E305, do indeed have the bypass-switch at the
back of the case
(for your information: the tone-control also can be fully bypassed).

The E308 has got the switch on the front (which I prefer, ´cause I often have to switch
between "stereo-mode" (integrated) and "5.1-Surround-mode (power-amp).
The switch accesses a relais which deactivates
- Volume-knob
- Loudness/Tone/all other "features"

See for yourself:

http://www.accuphase.com/historys/cate/e-308_ef.pdf

EXT-PRE-button and dedicated inputs/outputs enable independent use of pre-amplifier and power-amplifier sections

And for the microprocessor:
maybe the words I´ve choosen were not the best, but show me how to access
a touch-panel-display without any kind of processor, that´s what I meant.


@threadstarter
However, I say it again:
Do yourself a favour and listen to your selection of amps at the shop and important: at home.

If you don´t hear any differences, then select the one with the most features or
the best look or that one that costs the least.
If you do hear differences, please let us know, I´m really curious.
:T

Cheers
Guenther

[scanido]

FWIW, To maintain a constant state of affairs I am actively involved in all my critical evaluations. I check connections on both sides, connection types (RCA vs XLR) (gotta be the same) I level out the volume to a comfortable 76dB SPL at the listening spot and I use the same set of discs all in the same room date and time when comparing component pieces. Finally and most importantly I spend hours and hours demoing.
.

When i demoed the MC207 and RB_1072, the only variable was the amp. Same pre-amp, interconnects, volume at the same level, and source material the same as well. I didn't feel i needed more than an hour to decide which was superior. The superior one made itself apparent after the first song. Maybe If I changed the players to say an MC207 vs an CA-5200 then I'm sure I'd be harder pressed to discern the differences.

[scanido]

It's time for the mods to shut this one down. It's no longer about what the original poster was asking, which is unusual for this forum. I feel like I'm reading the high-end forum on AVS where this stuff happens all the time.

I would say it's in the same general context. No need to shut this one down.

[scanido]

@threadstarter
However, I say it again:
Do yourself a favour and listen to your selection of amps at the shop and important: at home.

If you don´t hear any differences, then select the one with the most features or
the best look or that one that costs the least.
If you do hear differences, please let us know, I´m really curious.
:T

Cheers
Guenther

I would agree that demoeing at home and spending a few days with the equipment would be best, but lugging around 100lb amps would just not be practical for me at least. If the demo environment at the dealer can accommodate your speakers (or close enough to it), and only one variable changes in the buying decision (in my case the amp), then one can get a very good idea of the differences between the items.

In the case of the MC207/RB-1072 the differences I heard at moderate levels were a more open sound, notes sounded very fluid and smooth (perfect for the S tweeter), and the base sounded authoritative and natural. More importantly for me, when i cranked the MC207 it delivered!!! The sound was crystal clear and the highs were not harsh and the bass was not compressed.

[Chatterbot]

In the case of the MC207/RB-1072 the differences I heard at moderate levels were a more open sound, notes sounded very fluid and smooth (perfect for the S tweeter), and the base sounded authoritative and natural. More importantly for me, when i cranked the MC207 it delivered!!! The sound was crystal clear and the highs were not harsh and the bass was not compressed.

Hi scanido,

well, you´ve made your decision. The MCs are damn good looking amps. Unfortunately
I´ve never had the privilege to hear one.


(not the same model, but still...)
seen here


;x(

I wish you a wonderful time with your new equipment 8)

Greets,
Guenther

[george_k]

You can probably save a couple of bucks by buying the Mac piece used. Audioclassics is a great resource for used Mac stuff and the staff is very knowledgeable and supportive. They have a unit for sale at $4499 at the moment.

[RebelMan]

Empirical means that it is capable of being verified or disproved by observation or experiment. What is the experiment and where is the data from that experiment? What valid experiment is there other than an ABX test?

You have made a factual claim in your post and I have asked you to provide some proof to support your claim. If you can't provide that proof then it's an opinion, albeit supported by anecdotal evidence, but it's not a fact.

You are a knowledgeable contributor to this forum and sound logic is usually a feature of your posts. On this occasion I think that your logic is flawed.

Anyway, that's all I have to say on the matter so feel free to get the last shot in.

Nigel.

Your inquisition is valid and it deserves an equally valid response. Before I proceed I would like to reiterate that my position on component roles and their importance should not be misconstrued. Every item in the reproduction chain has its place and purpose. The intent as I see it has been to demonstrate that some devices play a bigger role in the process of recreating quality sound.

I don’t think anyone would disagree that the source recording plays a big role or that the room or the speakers play a big role. Nor do I think people should question the role that the pre-amplifier plays which is also significant. It will take some convincing but it is my hope that any one reading this with an open mind would consider what is said, attempt a fair analysis on their own and formulate their own conclusions… not beliefs. You can believe whatever you want but the facts should not be ignored or you’ll be doing yourself a disservice. If you are genuine about this hobby you’ll follow through.

My message couldn’t be more applicable to the situation we have here. First we have a comparison between two power amplifiers then we have a comparison between two integrated amplifiers. In the end each contributor posted the results of their respective evaluations and the choices they exercised in conclusion, for which I have no objection. The problem that I saw with some of the results involves the manner in which the evaluation was performed. In one of the cases the pre-amplifier was not taken out of the equation. The information and the choices that followed were not based on the proper set of variables. While the choices made are irrelevant the conclusions they were based on are not.

Empirical studies is observable evidence of the situation. Formalities are not required. To illustrate I am going to use a simplified analogy. Suppose you have a room that has windows. When you enter the room when the sun is shinning the room will be bright and when the sun isn’t shinning the room will be dark. No quantifiable measurement was taken or necessary to prove the empirical fact.

Now suppose you have another room that has no windows. What proof is necessary to satisfy the claim that the room is bright? When you enter the room with a candle is the room bright? How about when you enter the room with a flashlight or a lamp, is the room bright? The answer would depend on a number of variables which would include the room’s size and the luminous intensity of the object and how one would define “bright” but it doesn’t require measurable data to formulate the conclusions. We only need to quantify our claims if the arguments are made with measurable certainty. No one can say the lamp was in fact ten times brighter than the candle without qualifying the remarks. However, it could be said as a matter of fact that the lamp was significantly brighter.

The logic that exists in the example I provided above is equally relevant in cases involving pre-amplifiers and the claim that I have made about their significance in a system. Unfortunately, I cannot furnish the quantifiable proof that an ABX test could provide. I can, however, prove that the scarcity of the data implies it’s irrelevance. I’ve made no claim that scrutinizes a pre-amplifier’s degree of importance only the existence of it and that it is significant. To say that a pre-amplifier’s role in a system is twice that of a power amplifier would be misleading without supporting data. To say that it is more significant is not. The proof comes from the information I have read from others, from the systems that I have heard and from the experiences that I have been engaged in. If you read about fast cars, see fast cars and drive fast cars then you’ll know when you’ve got a fast car, that’s a fact. How fast a car is another matter! The fact that no quantifiable data exists to refute my claims serves to support my argument not contest it.

The pre-amplifer/processor is in fact the most important part of the electronics chain. How much importance is another matter not to be confused.

[RebelMan]

When i demoed the MC207 and RB_1072, the only variable was the amp. Same pre-amp, interconnects, volume at the same level, and source material the same as well. I didn't feel i needed more than an hour to decide which was superior. The superior one made itself apparent after the first song. Maybe If I changed the players to say an MC207 vs an CA-5200 then I'm sure I'd be harder pressed to discern the differences.

Hey scanido,

I don't doubt that you found the MC207 more to your liking than the RB-1072. But in all fairness to both brands do you believe that due diligence was fully exercised in the audition? You found an immediate distinction between the two amplifiers but did you consider the possibilities as to why? My encounters with power amplifiers have usually required a little more time to ensure that psycho-acoustics were not impairing my judgement. I see two possible influences that may have been overlooked that warrant further clarification.

1.) Were single-ended RCA connections used between both amplifiers or was the MC207 running balanced XLR connections? Balanced connections will incur a 6dB boost that cannot be measured with the volume control. It's is a well know fact that people miss-associate loudness with quality. A review of equal loudness curves can explain this.

2.) Was the MC207 running on the 8 ohm tap and do you know the difference in voltage gain between both amplifiers? If there are any discrepancies between amplifier gain, say the McIntosh is higher or lower than the Rotel, it will again manifest itself as sounding better or worse respectively. Again a specific setting on the volume control that is shared by both amplifiers will be insufficient evidence. An SPL meter of some kind is always required to fairly level the playing field. Can you say in all honest that this was done?

Please understand these questions are not meant to measure ones integrity but rather gauge the accuracy and prudence in evaluating the information.

[scanido]

You can probably save a couple of bucks by buying the Mac piece used. Audioclassics is a great resource for used Mac stuff and the staff is very knowledgeable and supportive. They have a unit for sale at $4499 at the moment.

I looked into the same one prior to my purchase and although I heard great feedback on Audioclassics, the warranty is only for 1 year.

I couldn't resist the discount my local dealer gave me when I told them i was dead serious on buying now!

[scanido]

Hey scanido,
I don't doubt that you found the MC207 more to your liking than the RB-1072. But in all fairness to both brands do you believe that due diligence was fully exercised in the audition? You found an immediate distinction between the two amplifiers but did you consider the possibilities as to why?
...

In terms of the MC205/MC207, I would say yes. I must have read every article and post on this amp. I could say almost the same for the Rotel RB-1092. It's too bad no-one had this amp for demo. I'm sure on pure SPL it wouldn't disappoint! As to why? I can only speculate. Maybe the main reason being the Rotel was a Class D amp.

1.) Were single-ended RCA connections used between both amplifiers or was the MC207 running balanced XLR connections? Balanced connections will incur a 6dB boost that cannot be measured with the volume control. It's is a well know fact that people miss-associate loudness with quality. A review of equal loudness curves can explain this.

Yes, both used RCA.

2.) Was the MC207 running on the 8 ohm tap and do you know the difference in voltage gain between both amplifiers? If there are any discrepancies between amplifier gain, say the McIntosh is higher or lower than the Rotel, it will again manifest itself as sounding better or worse respectively. Again a specific setting on the volume control that is shared by both amplifiers will be insufficient evidence. An SPL meter of some kind is always required to fairly level the playing field. Can you say in all honest that this was done?

Not sure the difference in voltage nor what setting the taps were on. I should have brought my SPL meter, so i had to gauge everything by ear and volume setting. Not that scientific, but it would be close enough.

Thanks for this informative discussion Guys!!! :T

[ninja12]

Connecting to the Rotel amp's XLR is not necessary because Rotel does not produce an amp that is truly balanced all the way through it circuity.