John Curl's Blowtorch preamplifier part II

[miklos]

Budapest 1969 we're in mono and collecting red Soviet metal film resistors, they were amazingly small. I was just replacing my 8W 2xEL84 circlotron amp with a newly built 2x20W solid state one with 2N3055's. I was very proud of it, until one of my friends told me it didn't sounded to hot.

[hitsware]

Originally Posted by RNMarsh

Tiz true. I live about 20 minutes from where gold was discovered in the state of california. So many people came here to dig up gold that there was enough of them to vote for state-hood. There is still gold in these hills around me. But now everywhere is private property.
[My Apache women friend (lisa) who lives with me panned for gold with her two young boys all summer up in canada for a living and took out a lot of gold. Just lived in a tent until winter and then migrated south. Its what she did when she needed money. She's 71 now. Tough lady -- made it to the base camp of Mt Everest on her 60th with no gear nor training nor oxygen tanks.... 17,600ft - 1/2 oxygen] She says there's still gold near by in the streams and will teach me how to find it and pan it.. after each heavy rain. At current gold prices, i might take her up on it. -RNM

My Grandparents (with attendant Great Uncle
(and me when I could arrange it)) lived near
Applegate. ~ June each year my Grandpa and me
would drive Uncle Charlie up (and then down
(into the canyon)) near Forest Hill. He would
spend the summer with a pan, and at times a
sluice box.
@ $35 / ounce (the standard for years)
He did OK .........

[RNMarsh]

Originally Posted by hitsware

My Grandparents (with attendant Great Uncle
(and me when I could arrange it)) lived near
Applegate. ~ June each year my Grandpa and me
would drive Uncle Charlie up (and then down
(into the canyon)) near Forest Hill. He would
spend the summer with a pan, and at times a
sluice box.
@ $35 / ounce (the standard for years)
He did OK .........

Both places are near by... just up the hill. In Auburn there is still a store that will sell you gold panning supplies. many people supplimented their income by gold panning.... now its growing pot. Where are you now?

[1audio]

When you are enjoying your new found wealth remember us. .

[Esperado]

Originally Posted by 1audio

When you are enjoying your new found wealth remember us. .

Mr Goldman ? or Sach ?

[john curl]

Speaking of gold, my friend Jack Bybee is now putting several hundred dollars of gold into each set of a new product he is making. Gold is still useful for something! '-)

[john curl]

On another subject, today is the big day! When my colleague gives his summary of the 30 page paper he wrote on FM distortion etc. called: 'Further Testing and Newer Method of Evaluating Amplifiers for Induced Phase and Frequency Modulation vas Tones, Amplitude Modulated Signals and Pulsed Waveforms' at the AES Convention today. We should have something up for discussion, soon.

[Bob Cordell]

Originally Posted by john curl

On another subject, today is the big day! When my colleague gives his summary of the 30 page paper he wrote on FM distortion etc. called: 'Further Testing and Newer Method of Evaluating Amplifiers for Induced Phase and Frequency Modulation vas Tones, Amplitude Modulated Signals and Pulsed Waveforms' at the AES Convention today. We should have something up for discussion, soon.

Hi John,

I'll look forward to Ron Quan's paper, even though I will not be at AES. He's a smart guy and a nice guy.

Let's all just remember that no-one is saying that PIM does not exist. Its more a matter of how it must be measured (including what stimulous is used) and to what extent, and in what way the amount of negative feedback and open-loop bandwidth affect it. It is also important to bear in mind that PIM can be created in the complete absence of negative feedback. Finally, its nothing more than a new name for differential gain and phase that the color TV guys worried about 60 years ago.

Cheers,
Bob

[jan.didden]

Originally Posted by john curl

On another subject, today is the big day! When my colleague gives his summary of the 30 page paper he wrote on FM distortion etc. called: 'Further Testing and Newer Method of Evaluating Amplifiers for Induced Phase and Frequency Modulation vas Tones, Amplitude Modulated Signals and Pulsed Waveforms' at the AES Convention today. We should have something up for discussion, soon.

Hi John,

Just went to see this, had a great chat with Ron.
He does a LOT of interesting things, and it will take some time for someone with a feeble brain like me to digest it all.
What did surprise me from a quick read was that the usual opamp suspects did quite well in his test, basically showing his test residual at medium gains, while some well regarded (for sound quality) power amps, even class A, did not do so well.
His measurements are pretty sensitive judging from the waveform curves he has in his paper.
If you are interested his paper is # 8722, available from the AES.

Edit: You probably have this paper already...

jan

[hitsware]

Originally Posted by RNMarsh

Where are you now?

Sacramento .......