I'd like to propose calling those that don't make a difference effect boxes as well. They allow listening experience of distortion and other irregular effects inherent to the transducers being used as pure as possible.
Certainly not more than the parts used do.
Anyone ever called a push pull EL34/300B with pio caps cold? Mushy, vague and constrained perhaps, but certainly not cold.
Same with SE. Replace all the coupling caps with wide-bandwidth iron on a fast core (amorph/nano), choose fixed bias and most of the warmth is gone.
A push-pull amplifier will tend to have less 2nd harmonic than 3rd harmonic (except for some few like the AKSAs). Going back to Hirage that evidence is that the ear/brain finds a monotonic decrease in the amounts of distortion products.
Now, the amplifier that has monotonic decrease in products will very often have higher measured, single number distortion. But that number has clearly been shown to be pretty irrelevant.
But this is not enuff, the amplifier has to be matched to the speaker. And this does not happen.
I see many, many recommends of Klipsch speakers for high output impedance amps because of the rated efficiency. But these speakers all have (at least the dozen i checked) with huge impedance rises at the XO that absolutely require a low output impedance amp unless one is lucky to have the native FR (as measured w a voltage amp) complemented by the change in the FR caused by the interaction of the amp’s output impedance & the speaker’s impedance (ie the situation in which an amplifier would be an effects box, really a refrencd to high output impedance amplifiers mated with the wrong speakers (most of them))..
In the end, the only tool that matters, are your ears/brain, those unfortunately have a large degree of deviation, hence many views on the subject dpending on the listeners natural hearing abilities and the real-world listening training they have had.
Use what makes it sound good. This AM i was thnking about the amps i have ended up keeping over the years. Three are Class A (one PP tubes, 2 SE SS), 1 Class AB (dual mono MOSFET AB), and one very close to Class B (the original AudioSector LM3875 chipamp). All based on how they sound, and how they drive the speakers that typically get used here.
dave
Actually, in today's workflow--- the studio is raw material. Maybe mixed-down. But the key step is a Mastering Room. A gold-ear tweaks EQ, compression, sometimes the mix, to produce a good sounding consistent product. The Final Balance is usually one guy in a very elaborate listening space.
And yes, he does not stir for his own enjoyment. Some of those mastering rigs are "harsh" to reveal flaws. He has to apply windage for what the distribution operation will do to the sound. And he is thinking of the wide range of consumer playback systems.
Why would anyone want a high impedance output amp? You dont seem to understand what effects box means. If it audibly changes the sound (most common would be freq response) its an effects box, dosnt matter if the effects change with speakers. And why would anyone want speakers that that change with amplifiers? You bring up examples that are 1% of whats out there to try to prove your point, I talk about the other 99%.
I'd like to propose calling those that don't make a difference effect boxes as well. They allow listening experience of distortion and other irregular effects inherent to the transducers being used as pure as possible.
You can propose what ever nonsense you like but an amp is supposed to only give you gain. These will all sound the same.( all will give exactly the same signal to the speaker). If you use your amp to change the sound of your speakers its an effects box.
The mastering engineer dosnt mix, never seen anyone send the full track layout to them. And if you think mastering makes more difference than mixing you need to spend some time in a mix session. Where they can pick the best guitar solo, eq, compress, add reverb, etc to just the vocal, kick drum etc, boost the guitar during the solo etc etc etc. Thats why the band and producer are usually there for the mix but not usually at the mastering session.
Only for voltage drive which leaves distortion of the transducer high. Your narrow definition falls apart for current drive that produces lower distortion. Not as simple to use as voltage drive, but you can not dismiss its virtue, works well on multi amp system.
up to now, all audio power amps are voltage sources, i.e. very low output impedance and so very high damping factor...
there are those who thinks that current sources are better for sound, although i have yet to see a lot of implementations..
the next battle ground after the VFA versus CFA amp wars...
it is like saying, a pentode works better than a triode....
i would like to learn more about this...
that is why there is no substitute for hearing the "real" thing, live performance...
A DIY'er picks a speaker in part because the Qts is "known good" for the particular cabinet style they wish to attempt. Investing time and $, they proceed with the construction and when finished, connect it to an amplifier with something other than a very low output impedance.
Lo and behold, the speaker Q has changed because it's now a different system than the one used to measure the parameter initially. So I would say ALL dynamic speakers will change their sound - particularly around Fs - depending on the design of the amplifier they are connect to. So yes, you can "roll through" amplifier designs to change the sound of your speakers, maybe even tune how the bass sounds to you that way.
The "effect" of the "box" is a particular amp designs output impedance. Gain aside. They used to provide a control for this, but I spose it's out of fashion these days - kind of like tone controls have been for a couple decades. Roll into a whole other amp design, versus turn a knob on the one you have at hand. That must keep amplifier manufacturers happy!
Who would want an amplifier with high output impedance? I spose no one who's trying to do a successful design based on measured driver parameters. On the Measuring Loudspeaker Driver Parameters site, Rod Elliott says under "Measuring Re, Fs, Qes, Qms and Qts" that one of the requirements is "A power amplifier ... (must have low output impedance <0.1 ohm)". I assume that's a standard.
Lo and behold, the speaker Q has changed because it's now a different system than the one used to measure the parameter initially. So I would say ALL dynamic speakers will change their sound - particularly around Fs - depending on the design of the amplifier they are connect to. So yes, you can "roll through" amplifier designs to change the sound of your speakers, maybe even tune how the bass sounds to you that way.
The "effect" of the "box" is a particular amp designs output impedance. Gain aside. They used to provide a control for this, but I spose it's out of fashion these days - kind of like tone controls have been for a couple decades. Roll into a whole other amp design, versus turn a knob on the one you have at hand. That must keep amplifier manufacturers happy!
Who would want an amplifier with high output impedance? I spose no one who's trying to do a successful design based on measured driver parameters. On the Measuring Loudspeaker Driver Parameters site, Rod Elliott says under "Measuring Re, Fs, Qes, Qms and Qts" that one of the requirements is "A power amplifier ... (must have low output impedance <0.1 ohm)". I assume that's a standard.
Last edited:
A more fundamental question is coming to the forefront, for me. What are you doing here in the tube-specific portion of the forums if you are immovably certain that tubes, and devices using tubes, are no good, and that anyone who sees things otherwise, you consider and excoriate as a fool. And why are the rest of us continuing to respond to you?
Don't like 'em? Don't use 'em. Go spend time engaging elsewhere about something that you do like and that you do use. I'm in "full ignore mode" for any more of the same insistently negativistic and condescending blather that you may wish to offer.
If you go back in history there was a much wider range of amplifier output impedances.
I started to realize that there wa smore to life than low output impedance amps when i talked with an old Western Elerctric engineer — he couldn’t understand why you would build anything but an amp where it amps R was really close to the speaker R.
Those with cbdb’s level of understanding tend to think of amps as amps and speakers as speakers. But that leaves a whole portion of the possible audio acousta-elecrik design space, but to venture into that (largly uncharted) space you need to pay way more attention to system matching.
With the advent of SS devices and (relatively) small speakers with a growing complexity of passive XOs, most of the entire industry took a right turn, leaving the path not followed largely ignored.
As diyers we should feel free to explore the great unknown and see if the assests it brings outweigh what is given up for their specific application.
dave
- Status
- Not open for further replies.