John Curl's Blowtorch preamplifier part II

[pooge]

Hi Simon ! I got your resistors and they sound great. I do not want to spoil the discussion here, so read my MPP thread if you like to know how they performed subjectively ( my taste, others may hear no difference or prefer something else).

Please give link to thread.

 

[jan.didden]

John,
[snip]The error is the magazines and I have notified them.

FWIW, I don't see much substance in the whole article. It needs
to be done more scientifically with much better plot resolution.

One thing I did like was the NP interview.

Terry

Terry,

Glad you liked the NP interview.

Ed Dell confirmed to me that the captions were indeed switched.

jd

 

[Joachim Gerhard]

Simply go to "Analog Source". The thread is called "MPP".

 

[simon7000]

Simply go to "Analog Source". The thread is called "MPP".

http://www.diyaudio.com/forums/analogue-source/154210-mpp-119.html#post2157003 is found here.

Attached are some measurements of the Dale vs the Vishay. These are the "E" version, but the values requested were only available in the "C" version which has almost the same results as the "E", but I could not quickly find those.

Since these are just two sets of curves, I should mention these are very close, compare the pink curves. The dale has slightly more 2nd harmonic distortion. The 3rd harmonic tracks self heating due to signal level. At phono level I would expect this not be be an issue.

Of course "everyone" knows it is impossible to hear distortion at that level!

So this entire project really never happened!

 

[PMA]

Simon, you always have the same measurement configuration and setup (cables etc.), I assume. Only resistors changed, in the same fixture.

 

[simon7000]

Simon, you always have the same measurement configuration and setup (cables etc.), I assume. Only resistors changed, in the same fixture.

For the tests shown same fixture.

 

[john curl]

Are we through with resistors at this time?

 

[john curl]

I was hoping for added input on use of chokes for pi networks in power supplies. It might be that this is beyond, or at least outside the interest of people look in at this time. I do know that new government regulations will force audio manufacturers to either seriously compromise their power supplies or we will find adequate modifications or alternatives to the status quo, namely the single cap charge through a transformer.

 

[jan.didden]

I was hoping for added input on use of chokes for pi networks in power supplies. It might be that this is beyond, or at least outside the interest of people look in at this time. I do know that new government regulations will force audio manufacturers to either seriously compromise their power supplies or we will find adequate modifications or alternatives to the status quo, namely the single cap charge through a transformer.

John what kind of gov regulations are those? Is this US or Europe?

jd

 

[john curl]

Both.

 

[scott wurcer]

Of course "everyone" knows it is impossible to hear distortion at that level!

So this entire project really never happened!

Still wild speculation with no basis. Distortion at the < -130dB level (very low order for that matter) would be impossible to separate from any real world amplifier/transducer chain. So, it can't proven one way or the other.

 

[jan.didden]

Both.

Do you have any details of this regulations that will impact our power supply designs?

jd

 

[Nelson Pass]

It is my casual understanding that they want power factors of
0.8 or better. We get that number with a thermistor in series
with the line.

 

[john curl]

Hi Nelson, I am not being very specific here, as far as new laws, AND I don't like to use thermistors, except for initial turn on.

 

[Joachim Gerhard]

You can get information on new laws that limit especially stand by current in electrical aparatus from the German High End Society. Mr.Hecker the president is sitting in a gremium is Brussels. As i understand his Interview he did in several German magazines this laws will not come earliers then in three years but will make Class A amplifiers or tube amps imposible to sell. A pettition is going to avoid that situation and has the goal to leave out High End Audio. Is is already dicided that cars are taken out of the equation. Sofar about lobbyism.

 

[PHEONIX]

The Audio Beat and Constellation Audio

Hello John ,

Found some links about Constellation Audio that you might not know about , makes for interesting reading.

The Audio Beat - Constellation Audio Shoots for the Stars -- Part One - Michael Fremer interviews Murali Murugasu and David Payes


The Audio Beat - Constellation Audio Shoots for the Stars -- Part Two - Michael Fremer interviews Murali Murugasu and David Payes

 

[abraxalito]

Found some links about Constellation Audio that you might not know about , makes for interesting reading.

...

The Sirius built-from-the-ground-up DAC (no op-amps, no "off the shelf" chips)

This just has to be marketing fluff doesn't it? Otherwise, I can't wait to see SPDIF decoding done with discrete transistors.

 

[Trevor White]

This just has to be marketing fluff doesn't it? Otherwise, I can't wait to see SPDIF decoding done with discrete transistors.

Does this mean that all of the DSP is not done using off-the-shelf chips ??

And who is this mystical third person that doesn't want to be named ??

Why the secrecy ??

regards
Trev

 

[john curl]

Please have Demian Martin explain it to you. He does a lot of the digital design.

 

[Joachim Gerhard]

A new type of Fet .
The Nanowire Pinch Off Fet
Transistor ohne Sperrschicht - ELEKTOR.de | Elektronik: Analog Digital Embedded Mikrocontroller Audio Messtechnik