Simulating Reactive Loads

[Melon Head]

I am having trouble reproducing the same results of impedance and phase vs frequency that stereophile have published for the dummy speaker load.
Here is the link
Stereophile: Real-Life Measurements

See the attachments for my results

If anyone else is familiar with LTSPICE that can check this out to let me know if I or stereophile have made a mistake, I would be greatful.

 

[Melon Head]

Sorry everyone I found my stupid mistake

 

[wahab]

generator output impedance is about 0.006R for the phase
response being the one displayed at stereophile..
That makes an amp with more than 1000 damping factor
at 8R load....
Did they test some SET with such "speaker equivalent load" ?...
The result should be intringuing...

 

[ecir38]

thanh, did you ever build this?

I only seen one in the archieves by EUVL here
http://www.diyaudio.com/forums/solid-state/91479-what-do-you-use-simple-cheap-load.html#post1073195

reference
Stereophile: Real-Life Measurements

Brad

 

[Melon Head]

I have not built it yet.
At the moment I use it for a few simulation tests.

 

[ecir38]

Hi thanks for the reply. Would you or EUVL care to comment on wattage of resistors or heat sink size?

R1 5 ohm
R2 4 ohm
R3 5.6 ohm
R4 0.7 ohm
R5 100 ohm
R6 39 ohm
R7 0.6 ohm
R8 0.9 ohm

From EUVL's pic it looks like 63v electrolyptics are fine.

C1 4.7 uF
C2 3.3 uF
C3 500 uF

Wouldn't think gauge or esr would matter on the inductors.

L1 0.3 mH
L2 0.5 mH
L3 10 mH
L4 1 mH

Regards,
Brad

 

[Melon Head]

How many volts are you intending to put through it?

 

[ecir38]

New to solid state, would want something to handle any diy amp in the forums.

If am going to build it wouldn't you want it to handle most if not all amplifiers with no sweat.

ie. My Citation II would smoke a 25 watt resistor in less than a minute when checking ac balance for the driver pentodes with a 1K signal.

Brad