I have posted the following question, in multiple forums, without really getting a clear answer. So, I hope the knowledgeable people here can answer…
what about the design, of a tube amp, makes it sound more syrupy than analytical?
somewhere around the year 2000, tube amps started getting more analytical. They still sound good; however, they became more analytical, clean, solid state sounding (I know they still have the holographic airy sound). I don’t think parts just got better; rather something in the design must have changed to create this change.
personally, I like the old sound better and would like to figure out of to get an amp done, with the old characteristics….
what about the design, of a tube amp, makes it sound more syrupy than analytical?
somewhere around the year 2000, tube amps started getting more analytical. They still sound good; however, they became more analytical, clean, solid state sounding (I know they still have the holographic airy sound). I don’t think parts just got better; rather something in the design must have changed to create this change.
personally, I like the old sound better and would like to figure out of to get an amp done, with the old characteristics….
Why do you assume its only one thing? The sound of an old tube amp is dependent on pretty much everything about its design, including the components used in it. For one thing, a lot of old style components are no longer made. Manufacturing processes for making components have changed, and so on.
Regarding design, power supply design affects the sound, transformer design affects the sound, etc.
Regarding circuit design, there may be use of more feedback, there may be MOSFETs intermixed with tubes, etc., which also can have some effect on the sound. There is also layout and the use of printed circuit boards.
Yet another thing is that in the old days a commercially successful amplifier may have been designed to some extent by ear and by trial and error to produce a nice, holographic sound. Today amplifiers tend to be optimized by FFT measurements for low harmonic distortion and noise. The FFT analysis equipment doesn't have a measurement for holographic, nor for syrupy. Now amplifiers are designed according to what can be practically measured.
What you hear is the totality of all that stuff, its not just one simple difference.
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Guys, this is a general question being asked. I do want to get into specifics; however, I think it’s clear that most people will recognize that the sound of tubes amps have gotten more detailed, than the past.
Example:
Cary Audio early stuff was old sound. inspire, by Dennis Had has new sound. Same designer.
Conrad Johnson old sound (MVA-45) vs new sound (any new amp in their offering)
Example:
Cary Audio early stuff was old sound. inspire, by Dennis Had has new sound. Same designer.
Conrad Johnson old sound (MVA-45) vs new sound (any new amp in their offering)
Also, I wonder if this is the use of more distortion in the old amps…. I’m sure someone has tested these old amps to understand what they didn’t know when designing the old amps…
Syrupy - odd choice of word. Analytical - blameless understand. If you mean lower distortion, high slew rate, good intermod performance, flat frequency response, good speaker damping, no hum then that's analytical.
There's a concept of blameless. That's an amp which does not add coloration of its own to the sound. Modern amps are designed that way. The ear is actually quite a imperfect thing - sensitive to some things and not others - that why audio compression these days works so well. Older amps never reached blameless levels. The designers had to make to with the best technology of the day - it not they wanted to design imperfection in.
I think Mark sums it up pretty well. Modern passive components are made with better materials and tighter tolerances. Regulators, current sources, autobias circuits etc. are added to take the "guesswork" out of owning tube equipment, and to allow for more elaborate tube swapping. (In the old days, you would never drop a 6550 into a 6L6 amp unless you wanted to put some serious strain on the power supply, much up the feedback, etc.) I recently heard an Elekit 300B amp and to me it sounded sterile, nothing like the warm and bouncy 300B amps I used to build.
OTOH, a lot of people first experience the "tube" sound through vintage equipment that has not been properly restored or optimized. For example, a Heathkit W4 or Scott receiver in mediocre shape sounds pretty "tubey"--loose bass, rolled top end, poor articulation. Properly refurbished, these pieces sound much better and more "modern." ;-)
OTOH, a lot of people first experience the "tube" sound through vintage equipment that has not been properly restored or optimized. For example, a Heathkit W4 or Scott receiver in mediocre shape sounds pretty "tubey"--loose bass, rolled top end, poor articulation. Properly refurbished, these pieces sound much better and more "modern." ;-)
I don't think there's an actual set of numbers. It was a concept that Douglas Self came up with to describe modules of of amplifier so that each module did not add is own colour to an amp's sound.
Conceptually its possible to have the idea of a blameless amplifier. Regarding the first amplifier Self dubbed as blameless, some people didn't feel the goal was entirely met. Its that there is more than is usually measured with an FFT analyzer that can affect the sound of an amp. There are difficult loads, there are oscilloscope tests, there are distortion residuals, there can be nonstationary noise problems that don't show up as noise floor nor as distortion, there can be sensitivity to conducted and or radiated EMI/RFI, etc.
THD for example would be a poor measure. Some types of distortion such as crossover distortion are much more objectionable than say 2nd harmonic found in SE valve amps. If you designed your valve amp to be indistinguishable from a good quality modern transistor amp on a blind test then yes that is blameless. Analytical it would be. however.
Some people can't distinguish 128kbps mp3 from CD. Does that make for former blameless? IOW it matters how you define and measure "indistinguishable."
You can have an two amps that measure well in typical tests into a resistive load in lab setting. Take them into the real world and work into a difficult load and they may be clearly distinguishable.
Yes we did some tests at work comparing MP3, AAC and uncompressed wav file from a CD of their choice. Most could not tell the difference, some could tell the MP3. Nobody could tell the AAC, So yes I would say blameless to the ear, but not the spectrogram where you could see differences. However the original concept was for an amp rather than audio compression.
I can tell AAC from CD. Easily. If you test people on a system that is full of problems like ground loops, implicit resampling by an OS, and nonstationary noise then of course you will get skewed results. So, how did you qualify the test apparatus?
Syrupy sound is usually related to large amount of 2nd order harmonic distortion.
OK if you can sometimes this can be an issue with a codec. Try the latest and best from the web. Lame for MP3, you can also try opus too. We used a modern DAC with headphones.