But you never listen in isolation to an instrument with only 5kHz fundamental. You listen to a full spectrum of music. And if both amps have 0.1% at 10kHz, both will reproduce the 5kHz instrument equally well. But the 0.001% at 100Hz (which probably has 0.01 at 1kHz) reproduces the lower fundamental instruments better, more uncolored.
Anyway, I note that you say 'I would like to think' which is of course your personal prerogative.
jd
Fully agreed.
Partly agreed, what about higher harmonics?
I have designed amplifiers with no global feedback and amplifiers with global feedback with an open loop bandwidth greater than 20 kHz (Class A all over).
To me, these amplifiers have a similar way of reproducing music. I also must add: THD is quite low also for the amplifiers with no global feedback. But as everybody(?) know, all amplifiers sound different. It is all about design philosophy and personal preferences, I am afraid.
It was your argument that amps with the same hf distortion reproduce the hf signals (exacmple 5kHz fundamental) equally well, in this context, so I don't understand your question.
It's what everybody BELIEVES. The repeatable, reliable and well controlled tests that have been done about this fail to uncover this difference.
But as you say, it's all about personal preference and as anyone knows, personal preference has an overwhelming impact on what you perceive.
jd
Hi,
just a bit of conjecture on my part.
THD has few uses beyond proving that what one has just tested is not working to specification. Repair it.
Then start listening.
just a bit of conjecture on my part.
THD has few uses beyond proving that what one has just tested is not working to specification. Repair it.
Then start listening.
why oh why do we have to accept posts134 & 135 with a 3.5Mb pic.
The system should reject this size of attachment/download.
The system should reject this size of attachment/download.
OPamp stages can be made nearly distortion free so the sound they produce is what i call
"transparent". This not always gives the best subjective sound. I developped a series of buffers that can insert for example an amount of second harmonic. That put behind a CD player can increase the subjective enyoyment.
"transparent". This not always gives the best subjective sound. I developped a series of buffers that can insert for example an amount of second harmonic. That put behind a CD player can increase the subjective enyoyment.
If it is a non-commercial design then consider starting a thread about it!
I can't speak for anyone else here, so I won't - just for myself. This statement is not true. I have no beliefs in regard to amplifier sound - but I do hear differences between differently wired amplifiers. A well grounded amp (star earthing) sounds more transparent, more 'musical' than one with poor grounding.
Look at my MPP thread, there i posted several buffer designs with different types of distortion profiles. Unfortunately that thread got rather long and complex but i could post 3 types with different profiles that where measured and auditioned. I found like others before me that a small amout of low order harmonics can be benefical for subjective sound quality. The intesting thing is that for example 0.1% second harmonic does not sound distorted but full and dynamic. I usually design for lowest distortion posible and add distortion ( if i want ) in that buffer stage. So i can keep the amplification chain clean and modify the signal at only one place in the topology. I thought for a long time to develop a modern version of a tone control that is able to add "designed" amounts of distortion, has a parametric equalizer to tame problems in the recording and loudspeaker - room interface and is of cause a total seperate module that can be bypassed.
OP-Amp
- we can not generalize, as there are 1.000 of different op-amps
with their very own mix of different transistors inside
One op-amp can be almost as different to another
as one Tube can be different to one Silicon Transistor
When we tell one op-amp 'sounds' like this or that compared to something
we should always tell WHAT op-amp we refere to.
My opinion
is that for a gain of 4 (+12dB) at very high performance
there are at least a handful 5-10 'audio op-amps'
that would do as good a job so no discrete circuit
could make you noticable improvement soundwise.
Several such op-amps has already been mentioned.
Finally.
op-amp vs. (discrete) transistors circuit for same use
There should not be much difference, basically.
- An op-amp is a bunch of fet/silicon transistors attached as a circuit.
- The discrete transistor circuit will be a bunch of fet/silicon transistor
attached in another way as a circuit.
- we can not generalize, as there are 1.000 of different op-amps
with their very own mix of different transistors inside
One op-amp can be almost as different to another
as one Tube can be different to one Silicon Transistor
When we tell one op-amp 'sounds' like this or that compared to something
we should always tell WHAT op-amp we refere to.
My opinion
is that for a gain of 4 (+12dB) at very high performance
there are at least a handful 5-10 'audio op-amps'
that would do as good a job so no discrete circuit
could make you noticable improvement soundwise.
Several such op-amps has already been mentioned.
Finally.
op-amp vs. (discrete) transistors circuit for same use
There should not be much difference, basically.
- An op-amp is a bunch of fet/silicon transistors attached as a circuit.
- The discrete transistor circuit will be a bunch of fet/silicon transistor
attached in another way as a circuit.
I take your point AndrewT, I don't intend to make a habit of it.
w
Exactly why it was necessary to quote it I don't know...
I agree with your post, but the thing you don't agree with is not what I meant - it was taken out of context.
The poster said: "everybody KNOWS that etc..." to which I said: "everybody BELIEVES that etc.".
But we agree basically I BELIEVE 😉
jd
Good points. Badly wired amps will introduce distortion problems. Similarly, amplifiers with bad compensation design also introduce sonic problems. These two issues I believe, are very key factors in why amplifers sound different.
"I thought for a long time to develop a modern version of a tone control that is able to add "designed" amounts of distortion,"
Hello Joachim, That would be very interesting.
Hello Joachim, That would be very interesting.
Very Truth.
I think one can truly have much more influence in sound with proper PCB design and very good grounding, rather then picking components. Components are just Tool's (like paint for a painter) the designer is the Artis, and the end product will be as good as the tools are used. I think people focus way to much on components alone.
With kind regards.
Bas
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