John Curl's Blowtorch preamplifier part II

[john curl]

Many here could learn just about everything about the BLOWTORCH circuitry, just by going through pages 20-30, of part one of the BLOWTORCH thread.

[PMA]

Really?

[Variac]

I think the page number varies. The post number is more reliable.

This is my page 20:
John Curl's Blowtorch preamplifier

[Audioford]

Can anyone post the three schematics that Richard Perez posted way back on the original thread, post 563. There is a lot of reference to them in the following posts and the conversations are obscured without them. Please excuse my ignorance if there is another post that contains them - I hate to intrude, but I’m really impelled to. Sorry to say I just stumbled onto the original thread last week. I didn’t even notice how big it was until it closed and I had to remove my jaw off of my keyboard and put it back in my head. Truly phenomenal, must be a record of some kind. (801 pages-yikes!) Thanks.

P.s. In the mid 80’s John Curl helped me fix my Symmetry ACS-1 crossover with a phone call and a Xeroxed copy of the Repair Manual for the ACS-2. I was amazed and thankful at the time that the crossover’s designer would actually help a customer at that level. It’s still operating and is still my Audio system’s centerpiece. Thanks again!

Pps. I tried to email Richard (Justcallmedad) but I couldn’t – system said I had to post a few times first. I guess that ends my career as a lurker!

[john curl]

Unfortunately, the review of pages 20-30 or so will be difficult for many, because many schematics are not available. Still, most is there, enough for anyone, but 'lurkers, voyeurs, and cloners'. Amateurs, you can't reproduce this design properly, anymore than you can make a hi end sports car, just don't bother.

[anatech]

Hi John,
Rather than trying to copy your work, I'm sure most people simply want a reference so they can understand better what you refer to.

Is it at all possible to scratch out something "not as good", post the diagram and talk about your concepts that way? Your interests then remain protected.

-Chris

[john curl]

I have no way of posting a schematic, my only way over the years, was SY, and he appears to be unavailable to me. Not for lack of trying.

[Audioford]

Anateck – exactly.

I certainly respect your opinion Mr. Curl. Actually I thought the schematics were posted and created by Richard Perez (Justcallmedad). Sorry. You said back in post 245 and more or less repeated at least once since:

“…The JC-80 would be a good candidate, but the output fets are not available to anyone, anymore. In fact, most of my best designs use difficult to find or obsolete fet's. It seems that only Erno Borbely and I have any stock of these fets and Erno sells them to audiophiles at a high price. I would too, if I were to sell any.

This poses a bit of a dilemma. If I publish specific circuits, then I will be asked by audiophiles around the world to 'help' them find parts, etc. This creates an almost impossible situation, so I would prefer not to do it. I hope that this explains my reluctance to publish my circuits, especially on a DIY website.”

Perfectly reasonable and understandable point of view and that is easy for me to accept. However it is hard to follow the logic when the words reference a picture that is no longer there. Too bad, great discussion, very valuable to understand with more insight than I can acquire on my own.. Oh well…

[SY]

John, if you email me something, I could put it up later tonight- I'm back home in Texas.

[anatech]

Hi John,
I don't mind helping you with that, if possible. I'm sure there are no shortage of people you trust to assist as well.

Send to bhome at sympatico dot ca and I'll resize it if required. I don't have a hosting site though. I don't even really know how that works.

Hi Audioford,
If you post a project, you are in no way responsible to guide people in part selection. As long as you try to use common parts, I can't see any problems. Besides, there are many members who can help. I would suggest "Google" first, or the manufacturer's web site.

There is a big difference between a basic amp, an amp from a data sheet and a device that was developed with such high participation such as the Symasym. (use the search feature). All you are expected to do is list the parts you did use. If you designed a PCB, post that also, or link to a place where the image is hosted.

-Chris

Edit:
Hi SY, the site was unresponsive for a bit before you posted. Either way, problem solved.