Correct. Pot board missing. You erased the values, but I would ask John or Carl Thompson if it is good to publish even as blind.
BTW the values must have been lost in translation between PDF and JPEG, and maybe also because I had to re size the files.
Never mind, because the published values and transistor types are deliberately printed wrong anyway.
The rev. V was correct. I do not think it is very wise to publish drawings here without John's/Carl Thompson's and Parasound permission.
PMA said:
I agree, in principle, however, JC himself wanted to rather discuss JC-2 versus Blow Torch than whatever was discussed. So to have something to discuss it is better to have a basis. We could of course discuss how we thought the JC-2 is built, and how the BT is built, and how we thought two imaginary preamps would be different.
😎
So, as my principle is not to have principles, I simply published the JC-2 as I have it. As a kind of basis for the discussion. The BT as-is is never published, but some quite good guesswork is.
Values of components, JFET types etc etc is of no interest as I find the difference between the topologies of greater interest.
RK
My strongest comment would touch high-impedance pot board, sensitivity control and mainboard/potboard connections.
RK, I agree to have an actual topology to discuss as the discussions in general have mainly focussed around the BT and the JC2. Funny for so long a thread to discuss and rave about something most have not seen nor heard. It's like creating a myth around a preamp and keep that going.
As you stated earlier however, the topologies differ a great deal and without a stripped circuit one will never know what real differences are and discussions will again evolve around an enigma called the BT.
As you stated earlier however, the topologies differ a great deal and without a stripped circuit one will never know what real differences are and discussions will again evolve around an enigma called the BT.
PMA said:
Just having my own bad JPEGs on the forum handy, I should probably shut up, but it seems the volume control is realised with pots on both the "+" and "-" part of the balanced signal (?), and I do question the tracking of the wipers and if not all pros of balanced connections are lost - or to some degree lost.
We shall have to wait for "The New World" to wake up before we will learn.
RK
courage said:
That's exactly what this thread topic is all about. And about some people constantly attempting to monetize on the myth and it's creator.
Fortunately, off topic discussions are occasionally of great interest.
I would not say so. We also had a preamp based on NS opamps and TI PGA a week ago during our 2-days lasting high end fest. The reaction of 6O people in audience, who did not know circuit background has been quite spontaneous 😀, as are their posts after the fest.
courage said:
Reminds me of the correctly very cutting and humorous thread started on the AVSForum (by a barb who goes by the handle of QQQ) Called 'My Review of Five Projectors I've Never Seen". This was a deliberate attack on the babble and rabble characteristic of the forum members who attempt to articulate logical discourse -attached to nothing- by pulling it out of their butts.
However, here, we have both circuitry considerations mused upon and mulled over with the designer at hand and involved in the discourse.
One must remember, though, that the world/idea of human enrichment and advancement in (or via) science would not exist except for the idea and use of 'seasoned' guesswork. Guesswork, by it's very nature, comes from the non-vocalized areas of the mind, which are ruled by emotion and physical considerations. Thus the continual involvement of the monkey side of the self, on any given level as a baseline consideration.
PMA said:
Wow! You got 60 expert GEB members together! Or would this mean that almost anybody could hear the difference between a NS opamp vs. a discrete implementation?
And of course, the details about this test are unimportant as long as you got the desired result.
Courage, I don't know why you are allowed to say such rude and untrue things. The schematic posted is essentially the same schematic that I work from and we don't really hide anything at Parasound. Why bother changing the schematic?
PMA said:
I absolutely agree, l hope it’s possible to get the discussion back on track.
I think we should have some respect for people that has created a “legend”.
I haven’t seen or heard the BT, only a few have done that., but just to create a thing that are so much discussed and that probably will be for many years, we should have respect.
I don’t see the point in publishing the schematic or what kind of components that are used, it’s the idea and the thoughts behind the design that are interesting..
If the schematics are published it won’t be a “legend” anymore, and it will be copied by a lot of people and companies (from China).
By the way do you know what the Chinese think when they see “Copy Right” they think it is the same as “Right to Copy”.
Stinius
lineup said:
John.
you do not want to help or you missed my quest for your advice.
Anybody else that can better (than John Curl) give me some suggestion for a suitable JFET?
thanks for anything
R-K Rønningstad
thanks for your JC-2 schematic. As far as I know this has been public before.
So have no fear!
John.
At least give us a fair chance to compare, if this is what you really want 😉
So at least post a conceptual diagram of Blowtorch.
I suggested a blank, without any values or even transistors names.
If you can not even do this,
then post a block diagram with some of the transistors in
even without resistors
... so we can understand the currents flow and the voltage supply/references in your circuitry.
If you do not do this, then I have no other choice but to understand
you want to keep discussing a myth, a legend some sort of ghost.
A ghost that has its real value covered in a mist of subjective mind games.
How reluctant such a thought may be, to me, I cant help but thinking:
what has to be so very secret, so very hidden - does not stand the light of day.
Hope you can understand my thoughts.
If reading some other respectable members here .. I am not the only one.
Regards 🙂
Lineup - the unknown will give food for our imagination - our mythic mind ghosts
that does not really match reality - the things we can know exists, for real
I did not say that the schematic was different; only that values and transistor types are changed here and then.
As such I do not consider what I wrote as rude nor untrue.
However, I do find it rude to blame me for stupid behaviour if as if those who do, own this place.
Ironic to speak about a "legend" which has neither been seen or heard. But let's not spoil the upcoming discussions any further. I'll be behind the smoke curtain.
As such I do not consider what I wrote as rude nor untrue.
However, I do find it rude to blame me for stupid behaviour if as if those who do, own this place.
Ironic to speak about a "legend" which has neither been seen or heard. But let's not spoil the upcoming discussions any further. I'll be behind the smoke curtain.
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