John Curl's Blowtorch preamplifier

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Hello,

I present you, for opinions and critics, a simplified schematic only of the positive rail, of my project of power supply.

I tried to take into account your observations with regard to the precedent schematic appeared in the post #191.

Darry
 

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Hi, John Curl, Elso Kwak,

Push-pull regulation :
this has been done with power IC's with a zener at the input. If the output is not at the middle of the IC power supply, one limb only is delivering current.
If a push-pull supply regulator is working in class A, it should be faster and have a lower impedance than either a series or a shunt regulator.
I thought of it rather as an academic speculation than for a practical implementation.

~~~~~ Forr

§§§
 
Sorry a very big error, an horrible mistake !!! In the 3 term regs adjust pins circuit, !
Not time now, I will fix this ! This circuit is more a “schematic" representation of some ideas…

Thanks Mrupp for the shunt regulation links.

John: About my first schematic (PSU1)
“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.”

It was just a first attempt for a shunt regulator, with some logical considerations. What did you especially like in it ? In this design load regulation is not very good, but if the audio circuit current suck is constant, it could be o.k.

PSU1

John: About Darry's first circuit.
“I read these latest inputs with some confusion. I think that Darry's circuit is pretty darn good, and very close to what I do. In fact, the left half is almost exactly what my schematic looks like, including the input power cap configuration.”


You mean until the LM317/337 in CCS config included ? In this case why did you choose an LM317/337 as CCS over a BJT or even a mosfet? For a more stable current ? Simplified design with good results?

Darry's 1st circuit

Darry what are the benefits of your second design over the first one?

What are we trying to achieve with this first PSU? (I mean before the local ones)

For me the purpose is to “isolate” the audio circuits from AC line, filtering it as well as we can, with low noise and get a good, but no more, DC regulation. Right?
 
Hello,

I am very amazed that this thread does not fascinate many members of DiyAudio, set apart, apparently, some French, while I think that there is no Blowtorch preamplifier in France, nor in Europe. Surprising.

Richard,

My first circuit (post #189) allows an good insulation of the AC line at the same moment positive rail and negative rail with LM317 and LM337. Furthermore, every LM share the tension to the pins of the CMC (in - out divided by two, thus power divided by two).

But John Curl, my boss, says: The first regulator is feedback and zener controlled.

My second circuit (post #230) uses two LM317 in parallel (to divide the power by two) in a configuration high stability of tension with LM329 before shunt resistor (or CCS LM317) and shunt regulator.

Darry
 
DARRY
--I am very amazed that this thread does not fascinate many members of DiyAudio, set apart, apparently, some French, while I think that there is no Blowtorch preamplifier in France, nor in Europe. Surprising.--

17000 views in less than three weeks is quite a good score.
Christer's LED noise measurements thread, with its fundamental circuit preoccupations, scores about 5000 views only in three monthes.

~~~~~~~ Forr

§§§
 
You can see some parts on: www.tgaudio.com
Pictures: P6220008
Or see some Dutch B... at the drivingtest !

But why not look at a picture of Mr. Bob Crump instead >
 

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Hi,

Another configuration for the first regulator which uses a tracking pre-regulator, circuit recommended by Walt Jung for this power supplies.

The addition of a tracking pre-regulator brings safety features.The whole is then well protected against short-circuits, thermal overload. The tracking pre-regulator permits to choose a input - output differential for voltage regulator. This minimises power dissipation and voltage variations, and enhances performance, lowering noise, improving line rejection.
 

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  • psu-2.pdf
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Darry said:
Hello,

I am very amazed that this thread does not fascinate many members of DiyAudio, set apart, apparently, some French, while I think that there is no Blowtorch preamplifier in France, nor in Europe. Surprising.

Darry


It has fascinated me and I guess many others members are also quite interested, I have been following this thread since the start.

I really appreciate that Master John has been so open and has given many of his secrets (to us DIY’s mortals that have never seen, will be seeing or less hearing a Blowtorch).

Also, Darry and Callmedad contribution have been outstanding regarding proposals schematics for regulators. Get this thread going, you are great guys… I would like to see one of these regs with values and test it. I’m very much interested on finding an outstanding reg (shunt type) for the Threshold NS10 preamp since this circuit needs and deserves one.

I have copied most all post from Master John and intend to study them and learn something with my humble understanding on electronics. Thank you John for your great contribution.:cool: :cool: :cool:
 
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