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Old 3rd December 2008, 01:37 AM   #1
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Default LU1014 differential amplifier

I'm playing with something simple; sim says it works. Looking for advice.
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Old 3rd December 2008, 07:15 AM   #2
Tyimo is offline Tyimo  Hungary
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How did you set the bias ?

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Old 3rd December 2008, 07:38 AM   #3
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It runs full out but doesn't seem to get enough current to blow it up... the resistance of the choke is 0.4 ohms.

Oddest thing I've ever played around with.
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Old 3rd December 2008, 12:12 PM   #4
flg is offline flg  United States
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Hi John, Happy Holiday's
I've been thinking about a LU1014 diff version lately too
My ideas are more like a SOZJ with lower CCs and 7000W water heater elements(8 ohm) for a Resistive load. Playing with the "1 ohm" cross coupling resister gives interesting results. Havent totally figured out the details yet...
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Old 3rd December 2008, 02:50 PM   #5
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Very cool. Convenient that the coils have that 0.4 ohms...

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Old 3rd December 2008, 02:53 PM   #6
Magura is offline Magura  Denmark
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Quote:
Originally posted by Nelson Pass
Convenient that the coils have that 0.4 ohms...

I've been thinking along those lines as well, just have to figure how to work around the voltage limitation.

0R4 for 200mH, is that something you just found in spice, or are they for real?


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Old 3rd December 2008, 03:26 PM   #7
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Quote:
Originally posted by Nelson Pass
Very cool. Convenient that the coils have that 0.4 ohms...

Thanks, Nelson. It's my trusty Plitron 1000V/A power transformer to the rescue. I'd better double check those values, aye?


Quote:
Originally posted by Magura


I've been thinking along those lines as well, just have to figure how to work around the voltage limitation.

0R4 for 200mH, is that something you just found in spice, or are they for real?


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Hi Magura (love your new avatar).

Hi flg.

The voltmeter wanders (kinda like my brain) between 0.3 through 0.6. ohms. So, I'm in the ballpark. Also, I was thinking that a slightly smaller transformer will probably yield a stronger output since it has less resistance.

What a blast. I can order a regulated 6 volt power supply for somewhere in the neighborhood of 55 bucks. This little fellow has no tolerance for voltage variation. Regulated 5 volt units are plentiful as well--the amp delivers less wattage, but gets the diff voltage between the legs of the jfet closer to the desired triode state.

It's interesting to note that other members ride the same wavelength at the same time... Universal consciousness?
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Old 3rd December 2008, 03:30 PM   #8
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Quote:
Originally posted by Magura


.... just have to figure how to work around the voltage limitation.


is that just fact that English is not my native language , or I simply don't understand that sentence ...
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Old 3rd December 2008, 03:42 PM   #9
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The way this amp is laid out, the LU1014 runs more voltage than current compared against the triode curve on the LU1014 VDS graph: the sim states 5.4 volt diff with 1.6 amps--the graph curves asks for 8 or 9 amps at this voltage diff. My question to anyone who has an understanding of triode characteristics is this: will the amp sound sweeter, or simply more distorted when running less current than the curve requires?
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Old 3rd December 2008, 03:44 PM   #10
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Quote:
Originally posted by Zen Mod



is that just fact that English is not my native language , or I simply don't understand that sentence ...
Hi Choky,


Magura likes to warm his house in class A mode.
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