John Curl's Blowtorch preamplifier - Page 18

john curl · 21st January 2006, 05:05 PM

JB, the use of V and GR components together is unfortunate, and not possible as a true match. This is a mistake of the preamp manufacturer, and not recommended.
How one makes the combination of series-shunt regulators is not well defined, and many approaches are potentially acceptable.

jbaudiophile · 21st January 2006, 05:37 PM

Hi, John

Thanks a lot for the input ! The Dennesen JC-80 is crowded (ahem... Just a few pairs...) with such strange things...I understand now that your own schematic didn't showed unprobable matches like these ones, and that only relies to Jim Dennesen... First, I thought that you had perhaps found that the P-channel high Idss class just matched the N-channel low end of the class...

Now, I understand what happened with your own designs a lot... And much more than audio specialized press related it, making your glory and then wiping you out of the market... They resulted from parts changes WITHOUT your own advice but on YOUR schematics, at an evidence to cut costs, by your employers at the time... A shame, as they knew little (or no? !) electronics at the time : Mark Levinson, a former musician, Jim Dennesen (I was heard he was first selling ice creams... Really ?).

But here in Europe as well as in most countries, employers HAVE THE INTELLECTUAL PROPERTY RIGHTS...

but if you have a registered patent... I am fighting against that and found some ways that seems valid (I am at first a lawyer, as I studied for but choosed another professional way). Anyone interested in full explanations of how itwould work, please drop me a line !

Jbaudiophile

Justcallmedad · 21st January 2006, 07:29 PM

Here is a first schematic for a global PSU to start learning with and to see progressively what’s important and of interest in audio power supplies, as well as what could be in the wrong way.
I didn’t represent the dual coil power transformer and the soft recovery diodes bridges.

I am not very experienced in shunt regs…

PSU - Global

pinkmouse · 21st January 2006, 08:04 PM

Just had to chip in - excellent contributions guys, I think I might actually be learning something!

jbaudiophile · 21st January 2006, 08:49 PM

Hi, Callmedad,

WOW ! A big effort indeed ... Close to my own thinking of the Blowtorch PSU... John said that the Xformer secondaries and rectyfying were taken apart from each other... And on the Blowtorch board, we can only see ONE CMC, not two... But perhaps you are not on the Blowtorch idea.. If such a case, I beg your pardon....

John didn't say that the 3 terminals stage was only made with ONE LM317... Two, IMO... But I already posted a thread about it... To be discussed !

Your proposed shunt regulation is interesting, as the first stage is a current source as I guess it (but I think that it would be far more manageable to do that with a single LM317... Just see my previous post in answer to Darry's proposal).

Also, the last stage is VERY interesreting to me, and I will study this one a lot (after some sleeping time !). But IMO, this one woud be much more at ease on the Blowtorch Line amplifier, in lieu of a local regulatiion (when John Curl speaks, I just listen... then wonder why he said so... NO parables from him... But to be thought of several times !).

Seems that the Jfet constant current trick I suggested to you is now in all of your designs... A good thing, really !

I am not sure, but on the Blowtorch PSUs, all Mosfets seem to be driven from an op-amp, and NOT through a Jfet... To be discussed further... But wait a minute.. I notice now that you are also in France... Could drop me a message through the "Direct line" (out of the forum)... Perhap that we can cross some guess and data to share with other guys... But anyway, just an interesting last stage for me...

All the best, Callmedad

Jbaudiophile

Algar_emi · 21st January 2006, 10:24 PM

I speak french too. You may include me in your offline discussions if you like. I would like to learn more about open loop shunt regulator. Can we make them using a 3-pins reg as J. Curl suggested (2 3-pins reg into the power supply)?

john curl · 21st January 2006, 11:05 PM

Richard, pretty darn good shunt regulator. I learned a trick or two from this schematic. I also like your CM choke. I use one in exactly the same place.

Upupa Epops · 21st January 2006, 11:39 PM

John, only a little question : which is your personnal signal source ? Have it all sense ? Aren't other things in construction much more significant ? For example RF rejection, rejection of ground loops, full disconecting of inputs, which aren't in function etc....

carlosfm · 22nd January 2006, 12:00 AM

Quote:

Originally posted by Upupa Epops
...full disconecting of inputs, which aren't in function etc....

You make a good point.
IMO a really serious preamp (either commercial or DIY) should switch signal and ground on each input.

Algar_emi · 22nd January 2006, 12:26 AM

The ML38 Preamp is doing just that switching the signal and ground at the same time, for example.

21st January 2006, 07:29 PM	#173
Justcallmedad diyAudio Member Join Date: Jun 2004 Location: Paris	Here is a first schematic for a global PSU to start learning with and to see progressively what’s important and of interest in audio power supplies, as well as what could be in the wrong way. I didn’t represent the dual coil power transformer and the soft recovery diodes bridges. I am not very experienced in shunt regs… PSU - Global __________________ Richard Perez

21st January 2006, 08:04 PM	#174
pinkmouse diyAudio Moderator Join Date: Apr 2002 Location: Chatham, England	Just had to chip in - excellent contributions guys, I think I might actually be learning something! __________________ Al I conceive of nothing, in religion, science or philosophy, that is more than the proper thing to wear, for a while. Charles Fort

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21st January 2006, 05:05 PM	#171
john curl diyAudio Member Join Date: Jul 2003 Location: berkeley ca	JB, the use of V and GR components together is unfortunate, and not possible as a true match. This is a mistake of the preamp manufacturer, and not recommended. How one makes the combination of series-shunt regulators is not well defined, and many approaches are potentially acceptable.

21st January 2006, 05:37 PM	#172
jbaudiophile Account Disabled Join Date: Apr 2004 Location: Cysoing, near Lille	Hi, John Thanks a lot for the input ! The Dennesen JC-80 is crowded (ahem... Just a few pairs...) with such strange things...I understand now that your own schematic didn't showed unprobable matches like these ones, and that only relies to Jim Dennesen... First, I thought that you had perhaps found that the P-channel high Idss class just matched the N-channel low end of the class... Now, I understand what happened with your own designs a lot... And much more than audio specialized press related it, making your glory and then wiping you out of the market... They resulted from parts changes WITHOUT your own advice but on YOUR schematics, at an evidence to cut costs, by your employers at the time... A shame, as they knew little (or no? !) electronics at the time : Mark Levinson, a former musician, Jim Dennesen (I was heard he was first selling ice creams... Really ?). But here in Europe as well as in most countries, employers HAVE THE INTELLECTUAL PROPERTY RIGHTS... but if you have a registered patent... I am fighting against that and found some ways that seems valid (I am at first a lawyer, as I studied for but choosed another professional way). Anyone interested in full explanations of how itwould work, please drop me a line ! Jbaudiophile

21st January 2006, 08:49 PM	#175
jbaudiophile Account Disabled Join Date: Apr 2004 Location: Cysoing, near Lille	Hi, Callmedad, WOW ! A big effort indeed ... Close to my own thinking of the Blowtorch PSU... John said that the Xformer secondaries and rectyfying were taken apart from each other... And on the Blowtorch board, we can only see ONE CMC, not two... But perhaps you are not on the Blowtorch idea.. If such a case, I beg your pardon.... John didn't say that the 3 terminals stage was only made with ONE LM317... Two, IMO... But I already posted a thread about it... To be discussed ! Your proposed shunt regulation is interesting, as the first stage is a current source as I guess it (but I think that it would be far more manageable to do that with a single LM317... Just see my previous post in answer to Darry's proposal). Also, the last stage is VERY interesreting to me, and I will study this one a lot (after some sleeping time !). But IMO, this one woud be much more at ease on the Blowtorch Line amplifier, in lieu of a local regulatiion (when John Curl speaks, I just listen... then wonder why he said so... NO parables from him... But to be thought of several times !). Seems that the Jfet constant current trick I suggested to you is now in all of your designs... A good thing, really ! I am not sure, but on the Blowtorch PSUs, all Mosfets seem to be driven from an op-amp, and NOT through a Jfet... To be discussed further... But wait a minute.. I notice now that you are also in France... Could drop me a message through the "Direct line" (out of the forum)... Perhap that we can cross some guess and data to share with other guys... But anyway, just an interesting last stage for me... All the best, Callmedad Jbaudiophile

21st January 2006, 10:24 PM	#176
Algar_emi diyAudio Member Join Date: Oct 2002 Location: Canada, Qc	I speak french too. You may include me in your offline discussions if you like. I would like to learn more about open loop shunt regulator. Can we make them using a 3-pins reg as J. Curl suggested (2 3-pins reg into the power supply)?

21st January 2006, 11:05 PM	#177
john curl diyAudio Member Join Date: Jul 2003 Location: berkeley ca	Richard, pretty darn good shunt regulator. I learned a trick or two from this schematic. I also like your CM choke. I use one in exactly the same place.

21st January 2006, 11:39 PM	#178
Upupa Epops diyAudio Member Join Date: Aug 2003 Location: Prague,Czech Republic	John, only a little question : which is your personnal signal source ? Have it all sense ? Aren't other things in construction much more significant ? For example RF rejection, rejection of ground loops, full disconecting of inputs, which aren't in function etc....

22nd January 2006, 12:26 AM	#180
Algar_emi diyAudio Member Join Date: Oct 2002 Location: Canada, Qc	The ML38 Preamp is doing just that switching the signal and ground at the same time, for example.

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