There are another requirements to "control" the interconnect cable?
Because if it's only impedance, I don't see any issue connecting a dac with a 600 Ohm output impedance to a power amp with 49k or more (even less than that, but I aim for 1:100 ratio).
As i said in my first post, when there are issues, the issues are in the source (in the D/A conversion).
A transformer will filter the RFI (which is a VERY good thing), and the HF (also good, if not done too early like most transformer which rolloff at 30khz or such), And it will also introduce ringing (which is VERY bad and the main reason that i dont use transformers).
But a transformer cannot fix the intrinsically flawed d/a conversion done by a delta-sigma dac. For that you need to ADD the lost and mutated harmonics, which is masterfully done by vacuum tubes.
Just shortly I realized that Linn was right when they created the "source first" motto.
You cannot correct what is wrong from the beginning. You can improve it, make more pleasant, but it will never be 100% right.
That's half the story- output impedance is a small signal measurement, necessary but not sufficient. The other half is having enough current to charge and discharge the cable capacitance at the highest frequency of interest at the highest voltage needed without distortion and the ability to reject noise pickup from whatever length interconnect is needed.
"But a transformer cannot fix the intrinsically flawed d/a conversion done by a delta-sigma dac. For that you need to ADD the lost and mutated harmonics, which is masterfully done by vacuum tubes."
Where do you get this from?
Where do you get this from?
Are the concerns of cabling, in reference to separate pre and power boxes,
less of an issue in an integrated unit?
If an integrated can be designed to the highest performance, would it not be the method of choice?
less of an issue in an integrated unit?
If an integrated can be designed to the highest performance, would it not be the method of choice?
If the output impedance is 600 ohms, its unlikely that you will be able to *drive* 600 ohms. For that you need something closer to 60 ohms, the usual rule being that the source should have 1/10th the output impedance of the load that it is driving. Imagine that the amp has an input impedance of 600 ohms, in fact take a 600 ohm resistor and put it at the input of the amp and see if you still get the same levels, and the same bass. If you do, then I would expect that you won't hear differences between interconnect cables (or their length) as well.
The replies regarding I/O conditions, cabling between I/O, etc. are interesting.
Even though they have not addressed my original post directly, they are a necessary consideration to the original question.
So, again, I'll ask the same question, as quoted above, but a little differently.
Regarding an Integrated, I assume the following:
Distance from pre amp to power amp sections is much shorter, or can be.
Signals from pre-to-power are board traces or other, but are not cables-as defined for interconnects.
So, how much do these factors give advantage concerning cables, Imp, I/O electrical conditions?
Back to original post question- SS versus tubes:
I did not receive certain replies that I had hoped to, for example.
There must exist an empirical difference as measured and additionally to a musically trained ear.
If I am wrong, I still have not heard the two sound the same when examining subtleties.
I assume that when wide-ranging, meaningful and exhaustive measurements are compared, knowledgeable people (without knowing the device under test) would be able to distinguish tube from ss designs just by the examination of those measurements without seeing the schematics... is this true?
Perhaps the two can be made to sound indistinguishable, but I have not presently seen this.
If the highest level of non-deviation from source to power amp is the subject here, and the interface device between the two shall be called a "pre amp' by common convention, whether it be located in the output stage of a CD player, etc or as a dedicated box, then in the strictest sense regarding almost perfect transfer, I would be surprised that both types could accord the same result in an exact manner, especially as measured diligently.
It doesn't seem possible that both can perform electrically to produce the exact same output analysis.
The real reason you'd want to boxes pre-amp and power-amp is a practical one. You can only build, test and debug one item at a time. That and later you might want to upgrade.
But if you know well in advance that the ONLY source is an iPod then the preamp is so simple as to disapear. (It is actually inside the iPod.) It you do need to select and control the sound then you might want a pre-amp init's own chassis
Cables? If you are building both boxes you get to define the type of cables used so there can be near zero loss. You might even go with RF type coax and use BNC connectors or XML type pro-audo interconnects. No reason to use consumer style RCA.
I think the desiion is practical more then audio.
Tube vs. SS? There are things you can measure. Tubes have a different sound. It's not magic. It is caused by things you can measure. The basic difference is the kind of distortion products each type of amp makes. ALL amps will distort even if only at the 0.001% level. But for the most part the distortion products from a tube sounds good to the ear. We tend to like second harmonics. Musicians use the term "octave". So a tube amp with THD = 1% can sound good but when transistors clip or distort the sound is so ugly that SS amps need to have specs like THD = 0.01% to be even acceptable. The sound of a SS amp clipping is so bad (and destructive to speakers) that you need a 100+ WPC amp. But tubes don't really clip, they compress so a 10W tube amp can sound good.
The idea is that when tubes get pushed out of their comfortable zone by loud dynamics or whatever they fail on a "musically correct" way. But SS fails in a very ugly, hard on the eras way so much so that SS designed have t make 100% sure this never happens. Guitar player take advantage of this and purposfuly cause their amps to distort past all reason into the THD=200% and it sounds musical Even jazz guitarists are running amps at maybe 10% THD and the tubes are making a cool/soft kind of sound.
There s much more to this, and not everyone agrees but that is the basics of tube vs. SS.
The amount of this aeefect depends on how much of the TOTAL gain is done with tubes or SS. With a preamp running near unity gain, the effect is not much You need some golden ears to pick out a SS from a tube line level preamp.
OK finally one last difference. Yuo are going to build this? Which kind of construction do yu like. SS mostly uses PCBs and tubes use wire and when you are done will have that 1950's "look".
Integrateds are great in concept but often lacking in implementation. I would not consider seriously building one mostly due to weight issues. A well built preamp (IME) weighs on average slighly more than 10kg and the idea of adding the weight of two power amps to this makes my lower back cringe. Sure, they can share power cords, but that's as far as i would compromise.
Then again, the longest interconnect i drive is under 1m. Someone with monoblocks or a large room may hold a very different view.
This may be true in extreme cases or in the absence of NFB. High NFB designs may produce very similar measurements. Whether orthodox engineers like it or not, there is a substantial gap between what is audible and what is measurable.
First let's examine the integrated vs separates approach. There are two problems with integrated amps: noise and cables.
The noise issue has mostly to do with power supplies. You could build an integrated with separate power supplies and a layout that keeps the noise of the power amp section well clear of the preamp, and then design the grounds well enough that there is no additional noise introduced in the grounds. Could do it- but no-one in the last 60 years has, and this suggests that maybe its either never going to happen or else you will have to do it.
The 2nd issue is cables- specifically the speaker cables. An integrated has to sit between the speakers or have very long speaker cables. Long speaker cables are an easy way to loose definition. Its much easier to run long (balanced) interconnects than it is to run long speaker cables: try running 100 feet of speaker cable and see what it sounds like at the other end! OTOH 100 feet of balanced line will loose nothing in bandwidth or resolution.
As far as the SS/tubes thing, you can measure and identify the tube unit as opposed to the SS unit, without knowing which is which, merely by examining the odd-ordered harmonic distortion. You can't do it by looking at the 2nd, as a fully-differential balanced tube preamp won't have any and so will not be given away that easily. So you look at the odds. You will need a good deal of resolution in your equipment, as the difference between the two will be small, and we are talking about a very small amount of distortion to begin with, but the SS unit will have more odd orders. The other, very simple way is to clip the circuits and examine the overload behavior, but that would be cheating 🙂
Since the human ear uses these harmonics to gauge the volume of a sound, we are actually more sensitive than our test equipment tends to be in this regard (some odd ordered distortion levels in preamps may only be few 1/1000ths of a percent- this is often buried in noise), so this is why we can often hear this phenomena easier than it will show up in the specs.
Thank you all for the thoughtful responses.
Actually, I was aware of everything said in the last two responses.
I was trying to get into it on a more microscopic level because someone had posted that the possibility existed where both the tube and ss pre could be designed to where the sonic evaluations were virtually indistinguishable.
So, you see why I kept on that theme.
I've been in music a long time from classical to contemporary, as a performing electronic violinist, recording, production, designing reverberation and other audio modulation algorithms for DSP based audio processors, and yes around many electric guitarists.
My original post was actually started due to a friend who said that the only proper pre is SS, so hence the post.
Of course guitarist especially are aware of the differences between SS/tube and in those cases the differences are more exaggerated than in in normal audio reproduce systems.
I thank everyone for participating.
I still will continue to explore in-depth, theories regarding audio in general, what hasn't been done and what may be possible.
I believe that some of the smartest people in audio design converse here.
So, I am especially glad to be able to come here for conversation.
Thanks and I'll be back.
Actually, I was aware of everything said in the last two responses.
I was trying to get into it on a more microscopic level because someone had posted that the possibility existed where both the tube and ss pre could be designed to where the sonic evaluations were virtually indistinguishable.
So, you see why I kept on that theme.
I've been in music a long time from classical to contemporary, as a performing electronic violinist, recording, production, designing reverberation and other audio modulation algorithms for DSP based audio processors, and yes around many electric guitarists.
My original post was actually started due to a friend who said that the only proper pre is SS, so hence the post.
Of course guitarist especially are aware of the differences between SS/tube and in those cases the differences are more exaggerated than in in normal audio reproduce systems.
I thank everyone for participating.
I still will continue to explore in-depth, theories regarding audio in general, what hasn't been done and what may be possible.
I believe that some of the smartest people in audio design converse here.
So, I am especially glad to be able to come here for conversation.
Thanks and I'll be back.
My preamp has an active phono stage and both active and passive line stages. So, does that make it a 2/3 preamp - 1/3 passive line stage?
And if they are competently designed, they indeed will be indistinguishable in any sonic evaluation where you can't peek.
Treble rolloff and distortion.
Correction.
When I said that I understood everything in the last two posts, I meant to say posts #89 ChrisA and #90 analog_sa., but should also have said-almost everything🙂
As the replies continued, I realized that build considerations for an integrated are a big deal, so actually this thread is becomming much more to the point than earlier. A lot of very useful replies!
Hello atmasphere:
You said regarding a proper built integrated... " no-one in the last 60 years has,"
Could you explain who and what please?
When I said that I understood everything in the last two posts, I meant to say posts #89 ChrisA and #90 analog_sa., but should also have said-almost everything🙂
As the replies continued, I realized that build considerations for an integrated are a big deal, so actually this thread is becomming much more to the point than earlier. A lot of very useful replies!
Hello atmasphere:
You said regarding a proper built integrated... " no-one in the last 60 years has,"
Could you explain who and what please?
No-one in the last 60 years has done an integrated that lacks compromise; all of them I have seen have power supply problems, ground problems and in some cases extra noise due to layout.
Although I design amps and preamps for a living doing an uncompromised integrated is the same to me as military intelligence, honest government, Microsoft Works and host of similar 🙂
How are you defining "integrated"? Is it an "integrated" only if it has a distinct line preamplifier and/or phono preamplifier circuit in it?
se
Integrated means speaker cables plugged in, dedicated power supply was the point in the case. Separating pre-stage from power stage more practical due to differences in power supply requirements: transformers size, current that goes through voltage regulators.
Old days commercially available pre-amps provide phono-stage. Today vinyl considered to be exotic or hi-end so phono is expense to cut🙂
Pre-amp (or control-amp to be more precise) + power mono-blocks by speakers work the best imho. Good tube preamp sounds very appealing and transperent exactly to my taste despite the fact that Wadia, for example, do not recommend using any extra with Wadia decoding computers.
Suntechnik got it; an integrated refers to amp and preamp in one box.
A preamp with a phono section is generally called 'full function' as opposed to a 'line stage'.
With regards to the phono in the same box with the line section- I think this is a good idea as otherwise you have to provide the phono section with cable driving ability (otherwise the cable will be part of the sound), which means some of the line stage circuitry will be duplicated. I prefer a simple approach- so far its always worked better.
A preamp with a phono section is generally called 'full function' as opposed to a 'line stage'.
With regards to the phono in the same box with the line section- I think this is a good idea as otherwise you have to provide the phono section with cable driving ability (otherwise the cable will be part of the sound), which means some of the line stage circuitry will be duplicated. I prefer a simple approach- so far its always worked better.
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