John Curl's Blowtorch preamplifier part II - Page 3680

simon7000 · 17th March 2013, 07:43 PM

Quote:

Originally Posted by gpapag

Ed
Check which harmonics are these.
Odd harmonics (3rd to 11th) on mains change with time not only in amplitude but in phase as well. This is due to unequal loading of the phases on utility local distribution.

George
PS. I don’t see the glass on your hand.

I was looking at the results from the clean AC source.

It is still a bit early here.

gorgon53 · 17th March 2013, 07:54 PM

May I ask, is Rdc and Rac of the measured transformers made to be equivalent?

gorgon53 · 17th March 2013, 08:02 PM

Quote:

Originally Posted by jacco vermeulen

Stupid question 1 : How many (serial) preamp models, with cases out of a solid chunk of easy to machine aluminum, were there at the time of BT No2 ('97)?

Stupid question 2 : How many now (+ power amps/phono stages/DAC's) ?

(aviation/military not acceptable)

No idea jacco

RNMarsh · 17th March 2013, 11:09 PM

Quote:

Originally Posted by simon7000

I was looking at the results from the clean AC source.

It is still a bit early here.

here are some harmonics on an otherwise clean ac line... only a lamp dimmer on the light (turned on).

-RNM

Dimmer current on ac line.jpg

Kindhornman · 17th March 2013, 11:18 PM

RNM,
Why is that meter optimized for 50hz electrical service? Why not 60hz and is that something that matters or does it just extend the range of the meter? That is a 43B meter right? Just wondering what difference that makes to the test results.

Steve Eddy · 18th March 2013, 01:58 AM

Quote:

Originally Posted by Kindhornman

RNM,
Why is that meter optimized for 50hz electrical service? Why not 60hz and is that something that matters or does it just extend the range of the meter? That is a 43B meter right? Just wondering what difference that makes to the test results.

The meter says 59.97Hz. Might as well be 60Hz.

se

Kindhornman · 18th March 2013, 02:13 AM

Steve E,
I was looking at the Fluke website and it listed the meter as a 50hz meter and that is why I asked that question. I guess you are saying that it is something you can chose for the test point. Perhaps it is auto-setting and picks up the power line frequency? For some reason my internet connection is so poor that many times I don't get the complete image when I try to zoom in on the image on the page so it is hard to see some of the details on the scope screen.

Steve Eddy · 18th March 2013, 02:19 AM

Ah, ok. Thought perhaps you saw the "5" and overlooked the rest and thought it was running around 50 Hz.

Sorry.

se

elektroj · 18th March 2013, 06:45 AM

John's Blowtorch wasn't the only product with machined aluminium enclosure on the market, by the way. Wadia did the same with their "flagship" DAC.
Anyone want to give Wadia a call and offer them assistance in enclosure design? I'd love to hear Wadia's response

PMA · 18th March 2013, 09:17 AM

Ayre KX-R.
D'Agostino Momentum
Dan D'Agostino Momentum Monoblock Power Amp | Home Theater

18th March 2013, 02:19 AM	#36798
Steve Eddy diyAudio Member Join Date: Sep 2002 Location: Sacramento, CA	Ah, ok. Thought perhaps you saw the "5" and overlooked the rest and thought it was running around 50 Hz. Sorry. se __________________ The Audio Guild

18th March 2013, 09:17 AM	#36800
PMA diyAudio Member Join Date: Apr 2002 Location: Prague, Kitakyushu, Fukuoka	Ayre KX-R. D'Agostino Momentum Dan D'Agostino Momentum Monoblock Power Amp \| Home Theater __________________ Pavel Macura http://www.linkedin.com/pub/pavel-macura/4/783/637 http://web.telecom.cz/macura/audiopage.html

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17th March 2013, 07:54 PM	#36792
gorgon53 diyAudio Member Join Date: Nov 2006	May I ask, is Rdc and Rac of the measured transformers made to be equivalent?

17th March 2013, 11:18 PM	#36795
Kindhornman diyAudio Member Join Date: Aug 2012 Location: Los Angeles, California	RNM, Why is that meter optimized for 50hz electrical service? Why not 60hz and is that something that matters or does it just extend the range of the meter? That is a 43B meter right? Just wondering what difference that makes to the test results.

18th March 2013, 02:13 AM	#36797
Kindhornman diyAudio Member Join Date: Aug 2012 Location: Los Angeles, California	Steve E, I was looking at the Fluke website and it listed the meter as a 50hz meter and that is why I asked that question. I guess you are saying that it is something you can chose for the test point. Perhaps it is auto-setting and picks up the power line frequency? For some reason my internet connection is so poor that many times I don't get the complete image when I try to zoom in on the image on the page so it is hard to see some of the details on the scope screen.