John Curl's Blowtorch preamplifier part II

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#9,984
Hi Scott,

I can't disagree with you on that point but sometimes the noise and back stabbing become unbearable. This thread seems to polarize members for some reason.................surely the opposite of the goals of the forum.😕

Regards,

jam
 
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#9,985
simon7000 said:
Having briefly worked with a few of Nashville's top recording engineers I can tell you first hand they have the recording skills and hearing ability that is strikingly impressive. You may not like ballads about losing, your truck, job, wife or spending time in jail, but don't dismiss the skill!

As to wet cleaning records, let's take a brief look at how you stamp a record. After the original master is cut it is used to make a stamping master (or negative) by several different methods, most of which involve covering the surface with graphite or some other compound to make it conductive and then doing an electroplate to copy the grooves.

Even if that were perfect the master is now mounted on a heated platen, sprayed with a thin film of Polyvinyl Alcohol to keep the hopefully virgin (meaning containing all new material and no reground stuff or other filler) vinyl from sticking too hard to the master. This is pressed into the vinyl, where the vinyl gets the impression.

You take it home and wash of the Polyvinyl film that actually was in contact with the master stamper and wonder why the sound has changed?

Gee, no wonder once you play it wet you keep having to play it that way. So the issue is not how vinyl deforms under pressure but how the PVA coating does!

ES
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The first stamper (the mother) is usually used to make sons ( inverted ) and the many daughters to press the records, since tehy wear and after 5'000 pcs they shoud be replaced.

No chemicals are usually used to release the record from the stamper, the temperatur coefficient of metal is different than vinyl, so it shoud release by itself , since records have to be cooled down somewhat before release.
*pling*

Any chemical release stuff and that stuff would stick onto the diamond stylus, because the stylus gets hot while playing. So you have to clean styli permanent. Also do the record get hot, but its for extrem short time only on a specified point, the elasticity if vinyl will survive this without problems.

Wet playing modifies the elasticity module of vinyl. Be it pure water or alcohol or whatever. Furtermore any tube cantilever has a capillar effect, soaking up the liquid, cerating other problems.
 
#9,988
Bob Pease was told by someone else that Ron Quan was present at the meeting. This is when I heard Bob Pease say something strongly negative about my colleague of 33 years, Ron Quan, in reference to PIM, I'm pretty sure. This is when I stepped in, and gave him the challenge that since I GAVE Ron those awful ideas about TIM, (our TIM paper had just been given in NY, when he first came to work for me, and PIM came out of our subsequent conversations, that he should go after me, first. He backed off quickly, perhaps in politeness to avoid an incident. I don't know, nor care. He first insulted ME to my face 25 years ago, AND I never forgot it. However, that doesn't mean that I don't recommend his book: 'Troubleshooting Analog Circuits'. I have a copy, myself. I will learn from anyone who can teach me, and I will defend my colleagues who have been impugned by others, unfairly.
Where were you Scott? I was told you were coming.
 
#9,989
As far as Kirkwood Rough is concerned and his library: I pulled the 1941 edition of the 'Radiotron Designers Handbook' to page 43 or so, and showed Kirkwood that 7th harmonic distortion was taboo then, as it is today. They had a special statement about it is being completely unmusical and that it MUST be designed below audibility. Check it out, all!
 
#9,993
Yes, I'm fairly familiar with thermoplastics. 😀

Unless the liquid is very cold and it is applied with enough quantity to absorb the heat and is left long enough for the heat to conduct to it, I can see no reason why the vinyl would significantly change temperature. Remember, heating, cooling, and thermal flow are dynamic quantities- you can't just drop in static or equilibrium values and expect to get answers that are correct.
 
#9,994
john curl said:
I talked to Bob Pease, and I am reporting our 'conversation'.
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********. You didn't report any conversation. You were talking **** about him behind his back. What you wrote of your "conversation" had absolutely no substance whatsoever. It was just trash talk.

It was Bob Pease who was talking BEHIND Ron Quan's back.
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Then bad on Bob. But he's NOT doing it HERE.

And if you don't like Bob talking about Ron behind his back, then why do you feel it's ok for you to come here and talk about Bob behind his back?

se
 
#9,996
jam said:
Hi Scott,

I can't disagree with you on that point but sometimes the noise and back stabbing become unbearable. This thread seems to polarize members for some reason.................surely the opposite of the goals of the forum. 😉

I do though agree with your sentiments regarding the back-stabbing!

Regards,

jam
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Perhaps it attracts pre-polarised posters....after all they would be moderated off of most threads, yet there appears to be no moderation on this thread - except of Mr JC - whose product it is meant to be discussing.😉
 
#9,997
SY,

Well the noise theory I got seems to be pretty well shot down. So A quick test of yours, is the level of noise after wet playing the same on the outer grooves as the inner ones? Assuming damage is proportional to V squared there should be a 10-15 db difference.

ES
 
#9,998
john curl said:
As far as Kirkwood Rough is concerned and his library: I pulled the 1941 edition of the 'Radiotron Designers Handbook' to page 43 or so, and showed Kirkwood that 7th harmonic distortion was taboo then, as it is today. They had a special statement about it is being completely unmusical and that it MUST be designed below audibility. Check it out, all!
Click to expand...
Funny how old knowledge still applies....but gets forgotten...that's not so funny actually.
John, you have long advocated that the likes of 7th harmonic are the devil and I believe you without having substantiated your assertion - that said I will create a multitrack mix and hear for myself these nasties.
Also I have read differing opinions of the deleterious effects of 2nd harmonic VS 3rd harmonic production of amplification on the perception of music....what is your take on 2/3 harmonic and further what is your take on higher order harmonic production and sonic effects please.

Regards, Eric.
 
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