John Curl's Blowtorch preamplifier part III

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..that is a theory, not a fact.

To say people missed the gorilla because they weren't expecting it is plain wrong. The people who saw the gorilla weren't expecting it either. It was a cognitive loading experiment, plain and simple. The difference between people who saw or didn't see the gorilla was highly correlated with whether or not they had been given the cognitive loading task to do during the game.
 
My main reason to mention the "Gorilla in our midst" experiment back then was that it illustrates why the argument "if not detected it can´t be of practical relevance" is incorrect.

Simon´s used the results of the cognitive task as exclusion/inclusion criterion; only if the result (number of passes in the game) was correct the participant got the questions for the gorilla detection.

It would be interesting to know the percentage of nondetectors among those with incorrect pass-number results.
 
I would like to have a sit down talk with him about his responses to questions at the end. First of all 'expectation' as shown in the slide is the wrong word, it should probably be 'primed.'
Are you an expert in human perceptions?
Second, people don't miss the gorilla in the movie 'because they weren't expecting it', they missed it because they had been given a cognitive loading task to do while watching the basketball game. That is to say, they missed the gorilla because of distraction caused by cognitive loading (same type of thing that makes ABX an insensitive test for showing detection of small differences, IMHO).
Your H.O. is the opposite of ABX intent. It's to eliminate the distractions caused by sight and expectation bias. It would be like removing those basketball players and focusing on gorilla alone when visual bias is removed in audio double blind test.

Despite missing the visual bias aspect, you did state essentially the same thing only couple months ago.
People can't see the gorilla because they are too busy counting up and trying to hold in memory how many passes of the ball one or both teams make during the game. Same type of thing can happen with listening: too much attention focused on the wrong things like frequency response or 'sound stage' (whatever that is), if trying to understand what different dacs, filters, jitter, etc., do to the sound.

To say people missed the gorilla because they weren't expecting it is plain wrong. The people who saw the gorilla weren't expecting it either. It was a cognitive loading experiment, plain and simple. The difference between people who saw or didn't see the gorilla was highly correlated with whether or not they had been given the cognitive loading task to do during the game.
In properly run audio electronics DBT, listeners are allowed to compare equipment any subjective way they want first. Then when they find it worthy to do more objective comparison, level matched DBT is performed. I'll bet you've never participated in audio electronics DBT.
 
Yes, no argument about the sound of early SS amps producing a lot of odd harmonics are NFG for accuracy. Just FETs are not the only one's any more. Fets are still doing a great job.

However, many newer designs do as well using bipolar. Esp some of the CMA circuits and also DIYAudio's DADod's circuit for example. All bipolar except OPS.



THx-RNMarsh

*gasp* No secret sauce? Be careful Richard, next you will be saying most competently designed and built amplifiers sound about the same!
 
Richard, in the spirit of new ideas, go for all bipolar designs. It is true that quality jfets are becoming more difficult to find, and are more expensive these days.
However, when it comes to just the transfer function, jfets are more 'linear' than bipolars, and tubes are more 'linear' than jfets. There are other advantages to jfets, including lower external RF sensitivity, low noise vs impedance, etc. and the ability to self bias.
 
You would lose.
I'm still betting that you've never participated in audio electronics DBT.
I am for blind testing, not against it. ABX is insensitive is all, so I prefer to use other blind and or double-blind protocols. In fact, I have described how one can usefully do one's own double blind testing of oneself. Nothing new here.
Do you have a proof that Jakob2 couldn't cite? A proof that DBT causes debilitating stress that reduces hearing sensitivity to a point of prohibiting the listener to hear difference that changed when the stress is lifted?
 
Long time ago, we used a tape recorder with a loop of tape, to make echos in studios.
The problem was the tape (and the heads) used up pretty quickly.

It seems that technology has made a lot of progress:
Sermonizers who want to impose their cheap audio religion* to the rest of the world always turn round and round and round. They seem insensitive to wear and tear. And it is our heads who tire.

There is a french proverb that says: "Culture is like Jam. The less we have the more we spread it."
And an other that says "Luckily, ridicule does not kill."

Frankly you do not have anything more intelligent to do?

* their holy book is "The hifi for dummies".
 
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......I am for blind testing, not against it. ABX is insensitive is all, so I prefer to use other blind and or double-blind protocols. In fact, I have described how one can usefully do one's own double blind testing of oneself. Nothing new here.
Hi Mark,

How is ABX insensitive ?.
How do you do DIY BT ?.
Sorry if I missed your previous info, could you please give a quick summary of what you find.

Dan.

True! Just checked.
So with tight temp control this is a useful single stage amp ?.

Dan.
 
Probably blind but levels unmatched.

Nope.

https://www.diyaudio.com/forums/the...owtorch-preamplifier-ii-9085.html#post4992367

have you or your coterie "of ears I trust" listened to the slow bridges with the snubbers vs exotic diodes? - Blind of course

john curl said:
Stick with mid-fi jcx, it is a better value for you. This is not an ABX sort of sound difference.

Blind does not mean only ABX, the circle goes unbroken. Peeking is required.

john curl said:
Peeking is indeed required, in order to hear small differences, like diode hash. Both the CTC Blowtorch AND the Vendetta Research have a similar problem with power supply rejection in order to use a resistively loaded complementary folded cascode. Charles Hansen has had a similar problem with his circuits.
 
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