John Curl's Blowtorch preamplifier

[albin]

Joshua I'm sorrry

I spent the last 10 minutes trying to reply,& hit a button & it all
disapeared.
regards
Max

 

[bear]

minor correction that didn't post:

the headphones ought to sound no different than any other reasonably good electromechanical interface to the ear, certainly not "bad"!!

would best read:

the headphones ought to sound no better or worse than any other reasonably good electromechanical interface to the ear, certainly not "bad"!!

dunno why the edit didn't post...

_-_-bear

 

[albin]

Okay i'll try & precis what I lost

John, this is to Joshua.
Speakers & headsets are affected by 1st order effects, classic newtonian physics,Electronics uses these things multiplied by each other,how does a feedback resistor alter whats already happened,& all that.
look I wish I could type faster.

Max

 

[cliffforrest]

Re: Okay i'll try & precis what I lost

John, this is to Joshua.
Speakers & headsets are affected by 1st order effects, classic newtonian physics,Electronics uses these things multiplied by each other,how does a feedback resistor alter whats already happened,& all that.
look I wish I could type faster.

Max

Others are maybe more charitable.

i think you are simply pissed.

 

[albin]

I value your contribution

And you're correct in your thinking.
regards
Max

 

[john curl]

Sophomore alert!

 

[john curl]

Now that I clearly know what the question is, let me try to address it.
Back in 1971 or so, three audio designers got together and asked the same question. We did not have the answer ourselves, but we thought that the great Richard Heyser could answer it for us. So we went to see him, personally, and asked him this question. He didn't have a direct answer either, BUT he pointed out the limitations of our measurements, the problems with ANYTHING with global negative feedback, an how he was developing a different measurement process that might resolve at least some questions.
We went away, not completely satisfied, but hopeful. The rest is history.

 

[PMA]

Caps can sing. Just not very well,

Exactly. Not only caps, but also power transistors and power resistors.

 

[Sigurd Ruschkow]

If you find them too revealing, the HD650:s might suit you better. They sound very good and are more made to enjoy music than being a tool for studio musicians.






Sigurd

I forgot to mention that I have Sennheiser HD-600 head phones and a pure class A driver for them. Isn't that OK for hearing small things? Frankly they are too revealing and I find something wrong with just about everything through them.

 

[PMA]

The headamp may make a huge difference, regardless how low is THD. Again, it is about circuit topology, power supplies, PCB layout, signal filtration, and wiring (and probably passive components - still a niche to explore for me )

 

[Cauhtemoc]

Re: can anyone tell me

What the black dot on the new post old post things means,my head's full of propellers interacting with each other.
regards
Max

Very off topic, but the black dot means you have posted in that thread.

 

[albin]

thanks

for the reply
Max

 

[john curl]

Sigurd, unfortunately you miss the point. IF the headphones ARE revealing, then Scott might be able to hear differences. If not, he won't.

 

[Terry Demol]

NOTHING is benign. However, we seem to be able to tolerate a fair amount of distortion from speakers or headsets that we usually would condemn in electronics. Why?

45/2A3/300B type SET amps produce distortion levels not dissimilar to
speakers. They are not only tolerated but revered, and I hate to admit
it - but they can sound very very good!

T

 

[FrankWW]

However, we seem to be able to tolerate a fair amount of distortion from speakers or headsets that we usually would condemn in electronics. Why?

Partial answer:

Most speakers are symmetrical mechanical devices and good speakers - used within their design limits - therefore produce mostly even order distortion which we can tolerate easily. It's subjectively sort of like tape hiss or groove noise, only less obtrusive.

We don't easily tolerate odd order distortions, especially higher order, and they are produced more easily by electronic devices and reproduced faithfully by good speakers.

Also, since a good transducer will consistently produce the same errors at any given input level, we become acclimated to it's sound and thus an aberrant signal produced by electronics has novelty which we may notice in some fashion. So in the end, even even order distortion from electronics may get noticed - folk will say an amp sounds "warm", for instance, compared to another played on the same speakers.

 

[PHEONIX]

45/2A3/300B type SET amps produce distortion levels not dissimilar to
speakers. They are not only tolerated but revered, and I hate to admit
it - but they can sound very very good!

T

T
Not everybody reveres SET power amps.

A

 

[Edmond Stuart]

Partial answer:

Most speakers are symmetrical mechanical devices and good speakers - used within their design limits - therefore produce mostly even order distortion which we can tolerate easily.
[snip]

Hi Frank,

Apart from the question whether speakers produce more even harmonics than odd, any symmetrical system produces odd harmonics.

Regards,
Edmond.

 

[jan.didden]

I find it amusing how lesser ones feel the need to put down greater ones on order to feel good about themselves.

I tend not to think in terms of lesser and greater, I assume everybody is equal amongst equals. Which means all would be treated equal as well. Which means that when I ask for engineering info from those that profess to be engineers, I'm not treated as the village idiot by so-called 'greaters'.

But it's a temporary problem anyway. Those so-called 'greaters' do a great job to cut themselves down to size with almost every post here.

Jan Didden

 

[Joshua_G]

Max and Frank,

I sense you are right.

 

[Joshua_G]

Those so-called 'greaters' do a great job to cut themselves down to size with almost every post here.

Jan Didden

By what criteria they "cut themselves down to size"?