John Curl's Blowtorch preamplifier part II - Page 8 - diyAudio
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Old 1st July 2009, 10:35 PM   #71
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John,
If it's of any help, I have a website where I can put anything you may wish.
Just email me.
However, I feel it isn't good idea to publish BlowTorch schematics. May be without part names and values would be better, so that the topology may be discussed. I believe no one here wants to see within few weeks on eBay some Hong Kong DIY merchants offering BT "copies" (as they do to other well known amps).
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Old 1st July 2009, 11:36 PM   #72
1audio is offline 1audio  United States
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If someone in Kong Kong wants to sell milled aluminum blocks at the cost of the raw aluminum I'm ready to send prints. If it has a bad kludge copy of a BT or a Ayre I'll toss the guts if I need to. I will know what I'm getting. (Recycled cylinder heads. . .)

The cost of getting metal machined in the US in small quantities is vastly higher than Asia usually.
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Old 2nd July 2009, 12:22 AM   #73
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Opps Ė Correction and sorry if I stepped on toes, the post by Justcallmedad was post 565 NOT Johnís 563 post. Very sorry for the mistake. The link that doesnít work is "LM317/337 datasheet example". There are a lot of specific references to the three examples in that post. Of course, who wouldnít love to examine Johnís work in detail, but Iím satisfied just to understand what is being shared as are many. Itís certainly more difficult without the once published picture to follow the logic. That's my error for not paying attention.

I currently donít have time to breadboard anything these days. The virtual breadboard looks interesting. Besides, my experience was with PSís and Digital Logic in the 70ís and 80ís, then it was OS software and applications, then Network design and now Iím in Network and Internet Security. I wish audio design was part of my repertoire, but not. Besides, to be really great at anything requires dedication, sweat and an enormous amount of time. Talent helps too! A number of those qualities are obvious in quite a few of those who post on this thread. Thanks for your patience, Iíll go back to lurking nowÖ
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Old 2nd July 2009, 12:32 AM   #74
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Oh, a voyeur!
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Old 2nd July 2009, 01:17 AM   #75
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"No, after! The great advantage of a shunt is that it lets you localize the return current, rather than running it back through the ground wire to the supply input, with the risk that it contaminates the signal ground. "

Good point. If you keep th e shunt localized (i.e. around th e imeadiate gain stage), th e great benefit of this is the reduction in ground line noise.

I think if you drive the shunts with a constant current source, rather than a voltage source and dropper resisters, you get further bennefits.
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Old 2nd July 2009, 01:25 AM   #76
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Quote:
Originally posted by john curl
Oh, a voyeur!
Me too for a while, in my own personal Texas. I apologize to all the members here and the mods for losing my temper last week.
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Old 2nd July 2009, 01:27 AM   #77
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Quote:
Originally posted by Bonsai


I think if you drive the shunts with a constant current source, rather than a voltage source and dropper resisters, you get further bennefits.
True, but the current source has to be as good (HF wise) as the regulator itself. Otherwise, stay with a resistor, it's better. A LM317 connected as current source is fair, but a LM337 on the negative side is a disaster.
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Old 2nd July 2009, 01:59 AM   #78
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Good to see you back, Scott. Dick Sequerra was just asking me about you. I said that you disappeared off the screen, but maybe you were on holiday. Just 10 minutes ago.
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Old 2nd July 2009, 03:05 AM   #79
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Maybe I can help
How about these
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File Type: jpg psu_study_1 blowtorch.jpg (37.6 KB, 1766 views)
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Old 2nd July 2009, 03:06 AM   #80
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And
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File Type: jpg psu_study_1more accurate ideas.jpg (37.6 KB, 1769 views)
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