John Curl's Blowtorch preamplifier

[lineup]

I agree with syn08, jam.
To sort this topic out would be a total nightmare for anyone.

This does not make it bad thread.
Many many interesting things has been focused on here.
And this is why so many do not want to miss these posts.

Just skip those posts that you do not like.
Or even put those 'crazy ones' on ignore.
You know where to find your button for this.
This is what I do, to save some time and try to find some things
that is of my own personal interest.

Regards to jam
from
/LineUp - hopes jam wont use the button on him

 

[john curl]

Please try to understand everyone. Also, Jam, you just caused more confusion, rather than helping, but I'm sure it wasn't on purpose, since we just talked on the phone.

 

[scott wurcer]

It's clear no circuit topologies less than 30yr. old are welcome or necessary. I think I'll go EnABL some Radio Shack computer speakers.

 

[john curl]

I hope to talk about more subtle aspects of audio design than mere topology, since our complementary differential folded cascode topologies seem to be quieter, (especially over a large resistance range), more open loop linear, higher voltage, etc., than any IC that I know that has ever been made or can be made. Going to a more recent topology seems pointless.

 

[Johnloudb]

John C,

Personally, I really do enjoy this thread and like to hear input from everyone on different subjects related to audio design. I don't see any reason to change the name of the thread, most people know what goes on here. Too bad some people can't disagree without attacking or throwing insults.

One question I have is about bypassing large coupling caps with smaller high quality ones. I haven't done any real comparisons myself, yet. But I have heard that this can be helpful especially in the high frequencies. For instance, bypassing a 10uF PolyP cap with say 0.1uF Polystyrene cap, or maybe a 0.1uF Teflon.

Have you found this beneficial? Any favorites? I plan on trying this on the 10uF output caps of my preamp.

 

[Variac]

I'm not suggesting changing the name of the thread, but to create a second thread that we can move the off topic posts to, instead of deleting them forever..

 

[john curl]

Bypassing is something that we take seriously. We have found that very high quality caps are better than paralleled caps of different values, in discrete analog audio.

 

[hitsware]

>We have found that very high quality caps
>are better than paralleled caps of different values,
>in discrete analog audio.

So if you wanted a 3300 uF cap to couple
a single supply SS power amp to a 8 Ohm
speaker ...... what cap would you choose ?

 

[john curl]

I would not use a cap.

 

[jam]

syn08 and lineup,

I will have to agree with you but I think we all can agree to disagree at times. I have some issues with design of the Blowtorch but I have to admit it is one of the best preamps designed....period.

I have learnt a huge amount from Mr.Curl and I have to respect his design choices even if I do not agree with all of them. A product like this takes years to develop and Mr.Curl has shared a fair amount of information with us.

.......I was hoping that the power supply of the design was to be examined and improvements suggested, since it is almost half of a good design.

Regards,
Jam

 

[john curl]

It has been, Jam. Do some research. I don't publish schematics.

 

[jam]

Mr.Curl,

Well, do you suggest any improvement ideas, without publishing schematics .................😉

I don't think that this area (power supply) has been studied in as much detail as the topology of the gain block (Which is pretty elegant and I can't see much to improve upon).

The power supply seems the logical place to look for improvements and I can see possibilities or are you trying to tell me that this is as good as it gets.🙂

Regards,

Jam

 

[john curl]

I can't think about what we have missed, except for common mode chokes, maybe. Some ideas I like to keep confidential. However, I am not NEARLY as 'trick' as Charles Hansen, and he won't even tell ME what he does, even though he knows that I would appreciate input and that I would not attack him for his new ideas.
I can't even recommend hi speed diodes, without everybody and his brother giving me 'guff' about it. I'm tired of repeating myself.

 

[PMA]

I would be happy to create a "Hanging with John" thread if you want one.. Like the "Pass Pub"

Well said. That's what this thread really is.

 

[john curl]

I don't understand why this thread cannot stay essentially the way it is. It does seem popular. Do you really want this 'focal point' to go away?

 

[h_a]

Dear Moderators, why are the posts just deleted and not - in good old fashion - moved to Texas?

Sometimes I look there for a good laugh and I have never been dissappointed. Could use some fresh material though.

Have fun, Hannes

 

[Variac]

We don't move stuff to Texas much anymore as it allows people to insult each other and then the insults are displayed in Texas so they the insult is effective. The main purpose of Texas was supposed to be to display offensive posts when people were sent to the Sinbin -to show why. But again , if we think insults are a bad thing, why should we display them?

 

[Variac]

I don't understand why this thread cannot stay essentially the way it is. It does seem popular. Do you really want this 'focal point' to go away?

Whenever this theread gets out of control and there are lots of people complaining, and we get this:

Hi everyone, this is John Curl, and I will be happy to contribute here if possible. However, you hurt my feelings when you attack me or my colleagues with hateful input. Please refrain from this, if possible, because when I am driven to respond in kind, (and I can) the moderators always take a dim view, and sometimes ban me for awhile.

Translation: "Please grant me, John Curl, and those who I appoint, the sole right to hurt your feelings when I attack you or your colleagues".

Two sides complaining, like children in a sandbox. "he started it" "No , he started it" To blame the other is silly this thread has hundreds of pages. NO one knows who is the instigator, or better said, both groups are instigators and both groups have gone to the bin more than once.


Then John suddenly is demanding that everyone stay on some topic and threatens to sic the moderators on the person if they don't. What is the topic ?cars?

In good faith I have suggested having two threads in the past - a chat thread and this thread for actual technical discussion, and you John always wring your hands and say "Don't shut down my thread" This is rather disingenuous as I have made it clear that I am not suggesting shutting down any thread, just starting a new one where you and others can ramble on about when you don't want to get technical, and save this thread for the technica l stuFf. What is the problem with this? You think that there isn't enough interest for two threads?

 

[jan.didden]

Maybe on the topic of optimum parts selection:

I just got this brochure about an improved fuse:

"This 'flat wire' fuse gives more 'openness' without skimping on 'naturalness'. The fuse also plays with more ease, more nuances and has more involved listening. The fuse tube is made from a special resonance-free material with a very fine-grain filling. The flat break-wire has a very efficient cooling due to the larger surface and has optimal conducting properties."

Yours for only $ 55 a piece.

Comments?

Jan didden

 

[PMA]

Don't forget directionality of the fuse, it makes a big sound difference if you insert it in reverse direction; and you need about 2 days of special burn-in before it catches the best sound.